[PATCH v7 02/31] dyndbg: add stub macro for DECLARE_DYNDBG_CLASSMAP

[PATCH v7 02/31] dyndbg: add stub macro for DECLARE_DYNDBG_CLASSMAP

[Jim Cromie]

Add the stub macro for !DYNAMIC_DEBUG builds, after moving the
original macro-defn down under the big ifdef.  Do it now so future
changes have a cleaner starting point.

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 include/linux/dynamic_debug.h | 43 ++++++++++++++++++-----------------
 1 file changed, 22 insertions(+), 21 deletions(-)

diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index ff44ec346162..98a36e2f94b6 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -92,27 +92,6 @@ struct ddebug_class_map {
 	enum class_map_type map_type;
 };
 
-/**
- * DECLARE_DYNDBG_CLASSMAP - declare classnames known by a module
- * @_var:   a struct ddebug_class_map, passed to module_param_cb
- * @_type:  enum class_map_type, chooses bits/verbose, numeric/symbolic
- * @_base:  offset of 1st class-name. splits .class_id space
- * @classes: class-names used to control class'd prdbgs
- */
-#define DECLARE_DYNDBG_CLASSMAP(_var, _maptype, _base, ...)		\
-	static const char *_var##_classnames[] = { __VA_ARGS__ };	\
-	static struct ddebug_class_map __aligned(8) __used		\
-		__section("__dyndbg_classes") _var = {			\
-		.mod = THIS_MODULE,					\
-		.mod_name = KBUILD_MODNAME,				\
-		.base = _base,						\
-		.map_type = _maptype,					\
-		.length = NUM_TYPE_ARGS(char*, __VA_ARGS__),		\
-		.class_names = _var##_classnames,			\
-	}
-#define NUM_TYPE_ARGS(eltype, ...)				\
-        (sizeof((eltype[]){__VA_ARGS__}) / sizeof(eltype))
-
 /* encapsulate linker provided built-in (or module) dyndbg data */
 struct _ddebug_info {
 	struct _ddebug *descs;
@@ -137,6 +116,27 @@ struct ddebug_class_param {
 #if defined(CONFIG_DYNAMIC_DEBUG) || \
 	(defined(CONFIG_DYNAMIC_DEBUG_CORE) && defined(DYNAMIC_DEBUG_MODULE))
 
+/**
+ * DECLARE_DYNDBG_CLASSMAP - declare classnames known by a module
+ * @_var:   a struct ddebug_class_map, passed to module_param_cb
+ * @_type:  enum class_map_type, chooses bits/verbose, numeric/symbolic
+ * @_base:  offset of 1st class-name. splits .class_id space
+ * @classes: class-names used to control class'd prdbgs
+ */
+#define DECLARE_DYNDBG_CLASSMAP(_var, _maptype, _base, ...)		\
+	static const char *_var##_classnames[] = { __VA_ARGS__ };	\
+	static struct ddebug_class_map __aligned(8) __used		\
+		__section("__dyndbg_classes") _var = {			\
+		.mod = THIS_MODULE,					\
+		.mod_name = KBUILD_MODNAME,				\
+		.base = _base,						\
+		.map_type = _maptype,					\
+		.length = NUM_TYPE_ARGS(char*, __VA_ARGS__),		\
+		.class_names = _var##_classnames,			\
+	}
+#define NUM_TYPE_ARGS(eltype, ...)				\
+	(sizeof((eltype[]) {__VA_ARGS__}) / sizeof(eltype))
+
 extern __printf(2, 3)
 void __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...);
 
@@ -303,6 +303,7 @@ void __dynamic_ibdev_dbg(struct _ddebug *descriptor,
 
 #define DEFINE_DYNAMIC_DEBUG_METADATA(name, fmt)
 #define DYNAMIC_DEBUG_BRANCH(descriptor) false
+#define DECLARE_DYNDBG_CLASSMAP(...)
 
 #define dynamic_pr_debug(fmt, ...)					\
 	no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
-- 
2.52.0

[PATCH v7 03/31] docs/dyndbg: update examples \012 to \n

[Jim Cromie]

commit 47ea6f99d06e ("dyndbg: use ESCAPE_SPACE for cat control")
changed the control-file to display format strings with "\n" rather
than "\012".  Update the docs to match the new reality.

Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
Tested-by: Louis Chauvet <louis.chauvet@bootlin.com>
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 .../admin-guide/dynamic-debug-howto.rst       | 20 +++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/Documentation/admin-guide/dynamic-debug-howto.rst b/Documentation/admin-guide/dynamic-debug-howto.rst
index 7c036590cd07..4ac18c0a1d95 100644
--- a/Documentation/admin-guide/dynamic-debug-howto.rst
+++ b/Documentation/admin-guide/dynamic-debug-howto.rst
@@ -38,12 +38,12 @@ You can view the currently configured behaviour in the *prdbg* catalog::
 
   :#> head -n7 /proc/dynamic_debug/control
   # filename:lineno [module]function flags format
-  init/main.c:1179 [main]initcall_blacklist =_ "blacklisting initcall %s\012
-  init/main.c:1218 [main]initcall_blacklisted =_ "initcall %s blacklisted\012"
-  init/main.c:1424 [main]run_init_process =_ "  with arguments:\012"
-  init/main.c:1426 [main]run_init_process =_ "    %s\012"
-  init/main.c:1427 [main]run_init_process =_ "  with environment:\012"
-  init/main.c:1429 [main]run_init_process =_ "    %s\012"
+  init/main.c:1179 [main]initcall_blacklist =_ "blacklisting initcall %s\n"
+  init/main.c:1218 [main]initcall_blacklisted =_ "initcall %s blacklisted\n"
+  init/main.c:1424 [main]run_init_process =_ "  with arguments:\n"
+  init/main.c:1426 [main]run_init_process =_ "    %s\n"
+  init/main.c:1427 [main]run_init_process =_ "  with environment:\n"
+  init/main.c:1429 [main]run_init_process =_ "    %s\n"
 
 The 3rd space-delimited column shows the current flags, preceded by
 a ``=`` for easy use with grep/cut. ``=p`` shows enabled callsites.
@@ -59,10 +59,10 @@ query/commands to the control file.  Example::
 
   :#> ddcmd '-p; module main func run* +p'
   :#> grep =p /proc/dynamic_debug/control
-  init/main.c:1424 [main]run_init_process =p "  with arguments:\012"
-  init/main.c:1426 [main]run_init_process =p "    %s\012"
-  init/main.c:1427 [main]run_init_process =p "  with environment:\012"
-  init/main.c:1429 [main]run_init_process =p "    %s\012"
+  init/main.c:1424 [main]run_init_process =p "  with arguments:\n"
+  init/main.c:1426 [main]run_init_process =p "    %s\n"
+  init/main.c:1427 [main]run_init_process =p "  with environment:\n"
+  init/main.c:1429 [main]run_init_process =p "    %s\n"
 
 Error messages go to console/syslog::
 
-- 
2.52.0

[PATCH v7 04/31] docs/dyndbg: explain flags parse 1st

[Jim Cromie]

When writing queries to >control, flags are parsed 1st, since they are
the only required field, and they require specific compositions.  So
if the flags draw an error (on those specifics), then keyword errors
aren't reported.  This can be mildly confusing/annoying, so explain it
instead.

cc: linux-doc@vger.kernel.org
Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 .../admin-guide/dynamic-debug-howto.rst         | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/Documentation/admin-guide/dynamic-debug-howto.rst b/Documentation/admin-guide/dynamic-debug-howto.rst
index 4ac18c0a1d95..e76ccd987704 100644
--- a/Documentation/admin-guide/dynamic-debug-howto.rst
+++ b/Documentation/admin-guide/dynamic-debug-howto.rst
@@ -109,10 +109,19 @@ The match-spec's select *prdbgs* from the catalog, upon which to apply
 the flags-spec, all constraints are ANDed together.  An absent keyword
 is the same as keyword "*".
 
-
-A match specification is a keyword, which selects the attribute of
-the callsite to be compared, and a value to compare against.  Possible
-keywords are:::
+Note that since the match-spec can be empty, the flags are checked 1st,
+then the pairs of keyword and value.  Flag errs will hide keyword errs::
+
+  bash-5.2# ddcmd mod bar +foo
+  dyndbg: read 13 bytes from userspace
+  dyndbg: query 0: "mod bar +foo" mod:*
+  dyndbg: unknown flag 'o'
+  dyndbg: flags parse failed
+  dyndbg: processed 1 queries, with 0 matches, 1 errs
+
+So a match-spec is a keyword, which selects the attribute of the
+callsite to be compared, and a value to compare against.  Possible
+keywords are::
 
   match-spec ::= 'func' string |
 		 'file' string |
-- 
2.52.0

[PATCH v7 05/31] test-dyndbg: fixup CLASSMAP usage error

[Jim Cromie]

commit 6ea3bf466ac6 ("dyndbg: test DECLARE_DYNDBG_CLASSMAP, sysfs nodes")

A closer look at test_dynamic_debug.ko logging output reveals a macro
usage error:

lib/test_dynamic_debug.c:105 [test_dynamic_debug]do_cats =p "LOW msg\n" class:MID
lib/test_dynamic_debug.c:106 [test_dynamic_debug]do_cats =p "MID msg\n" class:HI
lib/test_dynamic_debug.c:107 [test_dynamic_debug]do_cats =_ "HI msg\n" class unknown, _id:13

107 says: HI is unknown, and 105,106 have a LOW/MID and MID/HI skew.

DECLARE_DYNDBG_CLASSMAP() _base arg must equal the enum's 1st value,
in this case it was _base + 1.  This leaves HI class un-selectable.

NB: the macro could better validate its arguments.

Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
Tested-by: Louis Chauvet <louis.chauvet@bootlin.com>
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 lib/test_dynamic_debug.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/test_dynamic_debug.c b/lib/test_dynamic_debug.c
index 77c2a669b6af..396144cf351b 100644
--- a/lib/test_dynamic_debug.c
+++ b/lib/test_dynamic_debug.c
@@ -75,7 +75,7 @@ DD_SYS_WRAP(disjoint_bits, p);
 DD_SYS_WRAP(disjoint_bits, T);
 
 /* symbolic input, independent bits */
-enum cat_disjoint_names { LOW = 11, MID, HI };
+enum cat_disjoint_names { LOW = 10, MID, HI };
 DECLARE_DYNDBG_CLASSMAP(map_disjoint_names, DD_CLASS_TYPE_DISJOINT_NAMES, 10,
 			"LOW", "MID", "HI");
 DD_SYS_WRAP(disjoint_names, p);
-- 
2.52.0

[PATCH v7 06/31] dyndbg: reword "class unknown, " to "class:_UNKNOWN_"

[Jim Cromie]

When a dyndbg classname is unknown to a kernel module (as before
previous patch), the callsite is un-addressable via >control queries.

The control-file displays this condition as "class unknown,"
currently.  That spelling is sub-optimal/too-generic, so change it to
"class:_UNKNOWN_" to loudly announce the erroneous situation, and to
make it uniquely greppable.

Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 lib/dynamic_debug.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index eb5146bcfaca..cb171088850c 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -1165,7 +1165,7 @@ static int ddebug_proc_show(struct seq_file *m, void *p)
 		if (class)
 			seq_printf(m, " class:%s", class);
 		else
-			seq_printf(m, " class unknown, _id:%d", dp->class_id);
+			seq_printf(m, " class:_UNKNOWN_ _id:%d", dp->class_id);
 	}
 	seq_putc(m, '\n');
 
-- 
2.52.0

[PATCH v7 07/31] dyndbg: make ddebug_class_param union members same size

[Jim Cromie]

struct ddebug_class_param keeps a ref to the state-storage of the
param; make both class-types use the same unsigned long storage type.

ISTM this is simpler and safer; it avoids an irrelevant difference,
and if 2 users somehow get class-type mixed up (or refer to the wrong
union member), at least they will both see the same value.

Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 include/linux/dynamic_debug.h | 2 +-
 lib/dynamic_debug.c           | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index 98a36e2f94b6..4b7c3b997657 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -103,7 +103,7 @@ struct _ddebug_info {
 struct ddebug_class_param {
 	union {
 		unsigned long *bits;
-		unsigned int *lvl;
+		unsigned long *lvl;
 	};
 	char flags[8];
 	const struct ddebug_class_map *map;
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index cb171088850c..d2ff203d0873 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -810,7 +810,7 @@ int param_get_dyndbg_classes(char *buffer, const struct kernel_param *kp)
 
 	case DD_CLASS_TYPE_LEVEL_NAMES:
 	case DD_CLASS_TYPE_LEVEL_NUM:
-		return scnprintf(buffer, PAGE_SIZE, "%d\n", *dcp->lvl);
+		return scnprintf(buffer, PAGE_SIZE, "%ld\n", *dcp->lvl);
 	default:
 		return -1;
 	}
-- 
2.52.0

[PATCH v7 08/31] dyndbg: drop NUM_TYPE_ARRAY

[Jim Cromie]

ARRAY_SIZE works here, since array decl is complete.

no functional change

Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 include/linux/dynamic_debug.h | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index 4b7c3b997657..c4ae79f934d9 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -131,11 +131,9 @@ struct ddebug_class_param {
 		.mod_name = KBUILD_MODNAME,				\
 		.base = _base,						\
 		.map_type = _maptype,					\
-		.length = NUM_TYPE_ARGS(char*, __VA_ARGS__),		\
+		.length = ARRAY_SIZE(_var##_classnames),		\
 		.class_names = _var##_classnames,			\
 	}
-#define NUM_TYPE_ARGS(eltype, ...)				\
-	(sizeof((eltype[]) {__VA_ARGS__}) / sizeof(eltype))
 
 extern __printf(2, 3)
 void __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...);
-- 
2.52.0

[PATCH v7 09/31] dyndbg: tweak pr_fmt to avoid expansion conflicts

[Jim Cromie]

Disambiguate pr_fmt(fmt) arg, by changing it to _FMT_, to avoid naming
confusion with many later macros also using that argname.

no functional change

Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 lib/dynamic_debug.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index d2ff203d0873..21c1db7e8705 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -11,7 +11,7 @@
  * Copyright (C) 2013 Du, Changbin <changbin.du@gmail.com>
  */
 
-#define pr_fmt(fmt) "dyndbg: " fmt
+#define pr_fmt(_FMT_) "dyndbg: " _FMT_
 
 #include <linux/kernel.h>
 #include <linux/module.h>
-- 
2.52.0

[PATCH v7 10/31] dyndbg: reduce verbose/debug clutter

[Jim Cromie]

currently, for verbose=3, these are logged (blank lines for clarity):

 dyndbg: query 0: "class DRM_UT_CORE +p" mod:*
 dyndbg: split into words: "class" "DRM_UT_CORE" "+p"

 dyndbg: op='+'
 dyndbg: flags=0x1
 dyndbg: *flagsp=0x1 *maskp=0xffffffff

 dyndbg: parsed: func="" file="" module="" format="" lineno=0-0 class=...
 dyndbg: no matches for query
 dyndbg: no-match: func="" file="" module="" format="" lineno=0-0 class=...
 dyndbg: processed 1 queries, with 0 matches, 0 errs

That is excessive, so this patch:
 - shrinks 3 lines of 2nd stanza to single line
 - drops 1st 2 lines of 3rd stanza
   3rd line is like 1st, with result, not procedure.
   2nd line is just status, retold in 4th, with more info.

New output:

 dyndbg: query 0: "class DRM_UT_CORE +p" mod:*
 dyndbg: split into words: "class" "DRM_UT_CORE" "+p"
 dyndbg: op='+' flags=0x1 *flagsp=0x1 *maskp=0xffffffff
 dyndbg: no-match: func="" file="" module="" format="" lineno=0-0 class=...
 dyndbg: processed 1 queries, with 0 matches, 0 errs

Also reduce verbose=3 messages in ddebug_add_module

When modprobing a module, dyndbg currently logs/says "add-module", and
then "skipping" if the module has no prdbgs.  Instead just check 1st
and return quietly.

no functional change

Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 lib/dynamic_debug.c | 21 ++++++---------------
 1 file changed, 6 insertions(+), 15 deletions(-)

diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 21c1db7e8705..1db2f627237a 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -275,9 +275,6 @@ static int ddebug_change(const struct ddebug_query *query,
 	}
 	mutex_unlock(&ddebug_lock);
 
-	if (!nfound && verbose)
-		pr_info("no matches for query\n");
-
 	return nfound;
 }
 
@@ -510,7 +507,6 @@ static int ddebug_parse_flags(const char *str, struct flag_settings *modifiers)
 		pr_err("bad flag-op %c, at start of %s\n", *str, str);
 		return -EINVAL;
 	}
-	v3pr_info("op='%c'\n", op);
 
 	for (; *str ; ++str) {
 		for (i = ARRAY_SIZE(opt_array) - 1; i >= 0; i--) {
@@ -524,7 +520,6 @@ static int ddebug_parse_flags(const char *str, struct flag_settings *modifiers)
 			return -EINVAL;
 		}
 	}
-	v3pr_info("flags=0x%x\n", modifiers->flags);
 
 	/* calculate final flags, mask based upon op */
 	switch (op) {
@@ -540,7 +535,7 @@ static int ddebug_parse_flags(const char *str, struct flag_settings *modifiers)
 		modifiers->flags = 0;
 		break;
 	}
-	v3pr_info("*flagsp=0x%x *maskp=0x%x\n", modifiers->flags, modifiers->mask);
+	v3pr_info("op='%c' flags=0x%x maskp=0x%x\n", op, modifiers->flags, modifiers->mask);
 
 	return 0;
 }
@@ -550,7 +545,7 @@ static int ddebug_exec_query(char *query_string, const char *modname)
 	struct flag_settings modifiers = {};
 	struct ddebug_query query = {};
 #define MAXWORDS 9
-	int nwords, nfound;
+	int nwords;
 	char *words[MAXWORDS];
 
 	nwords = ddebug_tokenize(query_string, words, MAXWORDS);
@@ -568,10 +563,7 @@ static int ddebug_exec_query(char *query_string, const char *modname)
 		return -EINVAL;
 	}
 	/* actually go and implement the change */
-	nfound = ddebug_change(&query, &modifiers);
-	vpr_info_dq(&query, nfound ? "applied" : "no-match");
-
-	return nfound;
+	return ddebug_change(&query, &modifiers);
 }
 
 /* handle multiple queries in query string, continue on error, return
@@ -1245,11 +1237,10 @@ static int ddebug_add_module(struct _ddebug_info *di, const char *modname)
 {
 	struct ddebug_table *dt;
 
-	v3pr_info("add-module: %s.%d sites\n", modname, di->num_descs);
-	if (!di->num_descs) {
-		v3pr_info(" skip %s\n", modname);
+	if (!di->num_descs)
 		return 0;
-	}
+
+	v3pr_info("add-module: %s %d sites\n", modname, di->num_descs);
 
 	dt = kzalloc(sizeof(*dt), GFP_KERNEL);
 	if (dt == NULL) {
-- 
2.52.0

[PATCH v7 11/31] dyndbg: refactor param_set_dyndbg_classes and below

[Jim Cromie]

Refactor callchain below param_set_dyndbg_classes(1) to allow mod-name
specific settings.  Split (1) into upper/lower fns, adding modname
param to lower, and passing NULL in from upper.  Below that, add the
same param to ddebug_apply_class_bitmap(), and pass it thru to
_ddebug_queries(), replacing NULL with the param.

This allows the callchain to update the classmap in just one module,
vs just all as currently done.  While the sysfs param is unlikely to
ever update just one module, the callchain will be used for modprobe
handling, which should update only that just-probed module.

In ddebug_apply_class_bitmap(), also check for actual changes to the
bits before announcing them, to declutter logs.

No functional change.

Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 lib/dynamic_debug.c | 65 ++++++++++++++++++++++++++++-----------------
 1 file changed, 40 insertions(+), 25 deletions(-)

diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 1db2f627237a..64d69f5cba1b 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -604,9 +604,10 @@ static int ddebug_exec_queries(char *query, const char *modname)
 	return nfound;
 }
 
-/* apply a new bitmap to the sys-knob's current bit-state */
+/* apply a new class-param setting */
 static int ddebug_apply_class_bitmap(const struct ddebug_class_param *dcp,
-				     unsigned long *new_bits, unsigned long *old_bits)
+				     unsigned long *new_bits, unsigned long *old_bits,
+				     const char *query_modname)
 {
 #define QUERY_SIZE 128
 	char query[QUERY_SIZE];
@@ -614,7 +615,9 @@ static int ddebug_apply_class_bitmap(const struct ddebug_class_param *dcp,
 	int matches = 0;
 	int bi, ct;
 
-	v2pr_info("apply: 0x%lx to: 0x%lx\n", *new_bits, *old_bits);
+	if (*new_bits != *old_bits)
+		v2pr_info("apply bitmap: 0x%lx to: 0x%lx for %s\n", *new_bits,
+			  *old_bits, query_modname ?: "'*'");
 
 	for (bi = 0; bi < map->length; bi++) {
 		if (test_bit(bi, new_bits) == test_bit(bi, old_bits))
@@ -623,12 +626,16 @@ static int ddebug_apply_class_bitmap(const struct ddebug_class_param *dcp,
 		snprintf(query, QUERY_SIZE, "class %s %c%s", map->class_names[bi],
 			 test_bit(bi, new_bits) ? '+' : '-', dcp->flags);
 
-		ct = ddebug_exec_queries(query, NULL);
+		ct = ddebug_exec_queries(query, query_modname);
 		matches += ct;
 
 		v2pr_info("bit_%d: %d matches on class: %s -> 0x%lx\n", bi,
 			  ct, map->class_names[bi], *new_bits);
 	}
+	if (*new_bits != *old_bits)
+		v2pr_info("applied bitmap: 0x%lx to: 0x%lx for %s\n", *new_bits,
+			  *old_bits, query_modname ?: "'*'");
+
 	return matches;
 }
 
@@ -683,7 +690,7 @@ static int param_set_dyndbg_classnames(const char *instr, const struct kernel_pa
 				continue;
 			}
 			curr_bits ^= BIT(cls_id);
-			totct += ddebug_apply_class_bitmap(dcp, &curr_bits, dcp->bits);
+			totct += ddebug_apply_class_bitmap(dcp, &curr_bits, dcp->bits, NULL);
 			*dcp->bits = curr_bits;
 			v2pr_info("%s: changed bit %d:%s\n", KP_NAME(kp), cls_id,
 				  map->class_names[cls_id]);
@@ -693,7 +700,7 @@ static int param_set_dyndbg_classnames(const char *instr, const struct kernel_pa
 			old_bits = CLASSMAP_BITMASK(*dcp->lvl);
 			curr_bits = CLASSMAP_BITMASK(cls_id + (wanted ? 1 : 0 ));
 
-			totct += ddebug_apply_class_bitmap(dcp, &curr_bits, &old_bits);
+			totct += ddebug_apply_class_bitmap(dcp, &curr_bits, &old_bits, NULL);
 			*dcp->lvl = (cls_id + (wanted ? 1 : 0));
 			v2pr_info("%s: changed bit-%d: \"%s\" %lx->%lx\n", KP_NAME(kp), cls_id,
 				  map->class_names[cls_id], old_bits, curr_bits);
@@ -707,18 +714,9 @@ static int param_set_dyndbg_classnames(const char *instr, const struct kernel_pa
 	return 0;
 }
 
-/**
- * param_set_dyndbg_classes - class FOO >control
- * @instr: string echo>d to sysfs, input depends on map_type
- * @kp:    kp->arg has state: bits/lvl, map, map_type
- *
- * Enable/disable prdbgs by their class, as given in the arguments to
- * DECLARE_DYNDBG_CLASSMAP.  For LEVEL map-types, enforce relative
- * levels by bitpos.
- *
- * Returns: 0 or <0 if error.
- */
-int param_set_dyndbg_classes(const char *instr, const struct kernel_param *kp)
+static int param_set_dyndbg_module_classes(const char *instr,
+					   const struct kernel_param *kp,
+					   const char *mod_name)
 {
 	const struct ddebug_class_param *dcp = kp->arg;
 	const struct ddebug_class_map *map = dcp->map;
@@ -755,8 +753,8 @@ int param_set_dyndbg_classes(const char *instr, const struct kernel_param *kp)
 				KP_NAME(kp), inrep, CLASSMAP_BITMASK(map->length));
 			inrep &= CLASSMAP_BITMASK(map->length);
 		}
-		v2pr_info("bits:%lx > %s\n", inrep, KP_NAME(kp));
-		totct += ddebug_apply_class_bitmap(dcp, &inrep, dcp->bits);
+		v2pr_info("bits:0x%lx > %s.%s\n", inrep, mod_name ?: "*", KP_NAME(kp));
+		totct += ddebug_apply_class_bitmap(dcp, &inrep, dcp->bits, mod_name);
 		*dcp->bits = inrep;
 		break;
 	case DD_CLASS_TYPE_LEVEL_NUM:
@@ -769,7 +767,7 @@ int param_set_dyndbg_classes(const char *instr, const struct kernel_param *kp)
 		old_bits = CLASSMAP_BITMASK(*dcp->lvl);
 		new_bits = CLASSMAP_BITMASK(inrep);
 		v2pr_info("lvl:%ld bits:0x%lx > %s\n", inrep, new_bits, KP_NAME(kp));
-		totct += ddebug_apply_class_bitmap(dcp, &new_bits, &old_bits);
+		totct += ddebug_apply_class_bitmap(dcp, &new_bits, &old_bits, mod_name);
 		*dcp->lvl = inrep;
 		break;
 	default:
@@ -778,16 +776,33 @@ int param_set_dyndbg_classes(const char *instr, const struct kernel_param *kp)
 	vpr_info("%s: total matches: %d\n", KP_NAME(kp), totct);
 	return 0;
 }
+
+/**
+ * param_set_dyndbg_classes - classmap kparam setter
+ * @instr: string echo>d to sysfs, input depends on map_type
+ * @kp:    kp->arg has state: bits/lvl, map, map_type
+ *
+ * enable/disable all class'd pr_debugs in the classmap. For LEVEL
+ * map-types, enforce * relative levels by bitpos.
+ *
+ * Returns: 0 or <0 if error.
+ */
+int param_set_dyndbg_classes(const char *instr, const struct kernel_param *kp)
+{
+	return param_set_dyndbg_module_classes(instr, kp, NULL);
+}
 EXPORT_SYMBOL(param_set_dyndbg_classes);
 
 /**
- * param_get_dyndbg_classes - classes reader
+ * param_get_dyndbg_classes - classmap kparam getter
  * @buffer: string description of controlled bits -> classes
  * @kp:     kp->arg has state: bits, map
  *
- * Reads last written state, underlying prdbg state may have been
- * altered by direct >control.  Displays 0x for DISJOINT, 0-N for
- * LEVEL Returns: #chars written or <0 on error
+ * Reads last written state, underlying pr_debug states may have been
+ * altered by direct >control.  Displays 0x for DISJOINT classmap
+ * types, 0-N for LEVEL types.
+ *
+ * Returns: ct of chars written or <0 on error
  */
 int param_get_dyndbg_classes(char *buffer, const struct kernel_param *kp)
 {
-- 
2.52.0

[PATCH v7 12/31] dyndbg: tighten fn-sig of ddebug_apply_class_bitmap

[Jim Cromie]

old_bits arg is currently a pointer to the input bits, but this could
allow inadvertent changes to the input by the fn.  Disallow this.
And constify new_bits while here.

Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 lib/dynamic_debug.c | 21 +++++++++++----------
 1 file changed, 11 insertions(+), 10 deletions(-)

diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 64d69f5cba1b..db0559763e60 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -606,7 +606,8 @@ static int ddebug_exec_queries(char *query, const char *modname)
 
 /* apply a new class-param setting */
 static int ddebug_apply_class_bitmap(const struct ddebug_class_param *dcp,
-				     unsigned long *new_bits, unsigned long *old_bits,
+				     const unsigned long *new_bits,
+				     const unsigned long old_bits,
 				     const char *query_modname)
 {
 #define QUERY_SIZE 128
@@ -615,12 +616,12 @@ static int ddebug_apply_class_bitmap(const struct ddebug_class_param *dcp,
 	int matches = 0;
 	int bi, ct;
 
-	if (*new_bits != *old_bits)
+	if (*new_bits != old_bits)
 		v2pr_info("apply bitmap: 0x%lx to: 0x%lx for %s\n", *new_bits,
-			  *old_bits, query_modname ?: "'*'");
+			  old_bits, query_modname ?: "'*'");
 
 	for (bi = 0; bi < map->length; bi++) {
-		if (test_bit(bi, new_bits) == test_bit(bi, old_bits))
+		if (test_bit(bi, new_bits) == test_bit(bi, &old_bits))
 			continue;
 
 		snprintf(query, QUERY_SIZE, "class %s %c%s", map->class_names[bi],
@@ -632,9 +633,9 @@ static int ddebug_apply_class_bitmap(const struct ddebug_class_param *dcp,
 		v2pr_info("bit_%d: %d matches on class: %s -> 0x%lx\n", bi,
 			  ct, map->class_names[bi], *new_bits);
 	}
-	if (*new_bits != *old_bits)
+	if (*new_bits != old_bits)
 		v2pr_info("applied bitmap: 0x%lx to: 0x%lx for %s\n", *new_bits,
-			  *old_bits, query_modname ?: "'*'");
+			  old_bits, query_modname ?: "'*'");
 
 	return matches;
 }
@@ -690,7 +691,7 @@ static int param_set_dyndbg_classnames(const char *instr, const struct kernel_pa
 				continue;
 			}
 			curr_bits ^= BIT(cls_id);
-			totct += ddebug_apply_class_bitmap(dcp, &curr_bits, dcp->bits, NULL);
+			totct += ddebug_apply_class_bitmap(dcp, &curr_bits, *dcp->bits, NULL);
 			*dcp->bits = curr_bits;
 			v2pr_info("%s: changed bit %d:%s\n", KP_NAME(kp), cls_id,
 				  map->class_names[cls_id]);
@@ -700,7 +701,7 @@ static int param_set_dyndbg_classnames(const char *instr, const struct kernel_pa
 			old_bits = CLASSMAP_BITMASK(*dcp->lvl);
 			curr_bits = CLASSMAP_BITMASK(cls_id + (wanted ? 1 : 0 ));
 
-			totct += ddebug_apply_class_bitmap(dcp, &curr_bits, &old_bits, NULL);
+			totct += ddebug_apply_class_bitmap(dcp, &curr_bits, old_bits, NULL);
 			*dcp->lvl = (cls_id + (wanted ? 1 : 0));
 			v2pr_info("%s: changed bit-%d: \"%s\" %lx->%lx\n", KP_NAME(kp), cls_id,
 				  map->class_names[cls_id], old_bits, curr_bits);
@@ -754,7 +755,7 @@ static int param_set_dyndbg_module_classes(const char *instr,
 			inrep &= CLASSMAP_BITMASK(map->length);
 		}
 		v2pr_info("bits:0x%lx > %s.%s\n", inrep, mod_name ?: "*", KP_NAME(kp));
-		totct += ddebug_apply_class_bitmap(dcp, &inrep, dcp->bits, mod_name);
+		totct += ddebug_apply_class_bitmap(dcp, &inrep, *dcp->bits, mod_name);
 		*dcp->bits = inrep;
 		break;
 	case DD_CLASS_TYPE_LEVEL_NUM:
@@ -767,7 +768,7 @@ static int param_set_dyndbg_module_classes(const char *instr,
 		old_bits = CLASSMAP_BITMASK(*dcp->lvl);
 		new_bits = CLASSMAP_BITMASK(inrep);
 		v2pr_info("lvl:%ld bits:0x%lx > %s\n", inrep, new_bits, KP_NAME(kp));
-		totct += ddebug_apply_class_bitmap(dcp, &new_bits, &old_bits, mod_name);
+		totct += ddebug_apply_class_bitmap(dcp, &new_bits, old_bits, mod_name);
 		*dcp->lvl = inrep;
 		break;
 	default:
-- 
2.52.0

[PATCH v7 13/31] dyndbg: replace classmap list with a vector

[Jim Cromie]

Classmaps are stored in an elf section/array, but currently are
individually list-linked onto dyndbg's per-module ddebug_table for
operation. This is unnecessary.

Just like dyndbg's descriptors, classes are packed in compile order;
so even with many builtin modules employing multiple classmaps, each
modules' maps are packed contiguously, and can be treated as a
array-start-address & array-length.

So this drops the whole list building operation done in
ddebug_attach_module_classes(), and removes the list-head members.
The "select-by-modname" condition is reused to find the start,end of
the subrange.

NOTE: This "filter-by-modname" on classmaps should really be done in
ddebug_add_module(1); ie at least one step closer to ddebug_init(2),
which already splits up pr-debug descriptors into subranges by
modname, then calls (1) on each.  (2) knows nothing of classmaps
currently, and doesn't need to.  For now, just add comment.

Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 include/linux/dynamic_debug.h |  1 -
 lib/dynamic_debug.c           | 62 ++++++++++++++++++-----------------
 2 files changed, 32 insertions(+), 31 deletions(-)

diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index c4ae79f934d9..51ed26e42032 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -83,7 +83,6 @@ enum class_map_type {
 };
 
 struct ddebug_class_map {
-	struct list_head link;
 	struct module *mod;
 	const char *mod_name;	/* needed for builtins */
 	const char **class_names;
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index db0559763e60..e882e951d585 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -45,10 +45,11 @@ extern struct ddebug_class_map __start___dyndbg_classes[];
 extern struct ddebug_class_map __stop___dyndbg_classes[];
 
 struct ddebug_table {
-	struct list_head link, maps;
+	struct list_head link;
 	const char *mod_name;
-	unsigned int num_ddebugs;
 	struct _ddebug *ddebugs;
+	struct ddebug_class_map *classes;
+	unsigned int num_ddebugs, num_classes;
 };
 
 struct ddebug_query {
@@ -148,12 +149,13 @@ static void vpr_info_dq(const struct ddebug_query *query, const char *msg)
 }
 
 static struct ddebug_class_map *ddebug_find_valid_class(struct ddebug_table const *dt,
-							  const char *class_string, int *class_id)
+							const char *class_string,
+							int *class_id)
 {
 	struct ddebug_class_map *map;
-	int idx;
+	int i, idx;
 
-	list_for_each_entry(map, &dt->maps, link) {
+	for (map = dt->classes, i = 0; i < dt->num_classes; i++, map++) {
 		idx = match_string(map->class_names, map->length, class_string);
 		if (idx >= 0) {
 			*class_id = idx + map->base;
@@ -164,7 +166,6 @@ static struct ddebug_class_map *ddebug_find_valid_class(struct ddebug_table cons
 	return NULL;
 }
 
-#define __outvar /* filled by callee */
 /*
  * Search the tables for _ddebug's which match the given `query' and
  * apply the `flags' and `mask' to them.  Returns number of matching
@@ -226,7 +227,7 @@ static int ddebug_change(const struct ddebug_query *query,
 	unsigned int nfound = 0;
 	struct flagsbuf fbuf, nbuf;
 	struct ddebug_class_map *map = NULL;
-	int __outvar valid_class;
+	int valid_class;
 
 	/* search for matching ddebugs */
 	mutex_lock(&ddebug_lock);
@@ -1133,9 +1134,10 @@ static void *ddebug_proc_next(struct seq_file *m, void *p, loff_t *pos)
 
 static const char *ddebug_class_name(struct ddebug_iter *iter, struct _ddebug *dp)
 {
-	struct ddebug_class_map *map;
+	struct ddebug_class_map *map = iter->table->classes;
+	int i, nc = iter->table->num_classes;
 
-	list_for_each_entry(map, &iter->table->maps, link)
+	for (i = 0; i < nc; i++, map++)
 		if (class_in_range(dp->class_id, map))
 			return map->class_names[dp->class_id - map->base];
 
@@ -1219,30 +1221,31 @@ static const struct proc_ops proc_fops = {
 	.proc_write = ddebug_proc_write
 };
 
-static void ddebug_attach_module_classes(struct ddebug_table *dt,
-					 struct ddebug_class_map *classes,
-					 int num_classes)
+static void ddebug_attach_module_classes(struct ddebug_table *dt, struct _ddebug_info *di)
 {
 	struct ddebug_class_map *cm;
-	int i, j, ct = 0;
+	int i, nc = 0;
 
-	for (cm = classes, i = 0; i < num_classes; i++, cm++) {
+	/*
+	 * Find this module's classmaps in a subrange/wholerange of
+	 * the builtin/modular classmap vector/section.  Save the start
+	 * and length of the subrange at its edges.
+	 */
+	for (cm = di->classes, i = 0; i < di->num_classes; i++, cm++) {
 
 		if (!strcmp(cm->mod_name, dt->mod_name)) {
-
-			v2pr_info("class[%d]: module:%s base:%d len:%d ty:%d\n", i,
-				  cm->mod_name, cm->base, cm->length, cm->map_type);
-
-			for (j = 0; j < cm->length; j++)
-				v3pr_info(" %d: %d %s\n", j + cm->base, j,
-					  cm->class_names[j]);
-
-			list_add(&cm->link, &dt->maps);
-			ct++;
+			if (!nc) {
+				v2pr_info("start subrange, class[%d]: module:%s base:%d len:%d ty:%d\n",
+					  i, cm->mod_name, cm->base, cm->length, cm->map_type);
+				dt->classes = cm;
+			}
+			nc++;
 		}
 	}
-	if (ct)
-		vpr_info("module:%s attached %d classes\n", dt->mod_name, ct);
+	if (nc) {
+		dt->num_classes = nc;
+		vpr_info("module:%s attached %d classes\n", dt->mod_name, nc);
+	}
 }
 
 /*
@@ -1274,10 +1277,9 @@ static int ddebug_add_module(struct _ddebug_info *di, const char *modname)
 	dt->num_ddebugs = di->num_descs;
 
 	INIT_LIST_HEAD(&dt->link);
-	INIT_LIST_HEAD(&dt->maps);
 
 	if (di->classes && di->num_classes)
-		ddebug_attach_module_classes(dt, di->classes, di->num_classes);
+		ddebug_attach_module_classes(dt, di);
 
 	mutex_lock(&ddebug_lock);
 	list_add_tail(&dt->link, &ddebug_tables);
@@ -1390,8 +1392,8 @@ static void ddebug_remove_all_tables(void)
 	mutex_lock(&ddebug_lock);
 	while (!list_empty(&ddebug_tables)) {
 		struct ddebug_table *dt = list_entry(ddebug_tables.next,
-						      struct ddebug_table,
-						      link);
+						     struct ddebug_table,
+						     link);
 		ddebug_table_free(dt);
 	}
 	mutex_unlock(&ddebug_lock);
-- 
2.52.0

[PATCH v7 14/31] dyndbg: macrofy a 2-index for-loop pattern

[Jim Cromie]

dynamic-debug currently has 2 __sections (__dyndbg, __dyndb_classes),
struct _ddebug_info keeps track of them both, with 2 members each:
_vec and _vec#_len.

We need to loop over these sections, with index and record pointer,
making ref to both _vec and _vec_len.  This is already fiddly and
error-prone, and will get worse as we add a 3rd section.

Lets instead embed/abstract the fiddly-ness in the `for_subvec()`
macro, and avoid repeating it going forward.

This is a for-loop macro expander, so it syntactically expects to
precede either a single statement or a { block } of them, and the
usual typeof or do-while-0 tricks are unavailable to fix the
multiple-expansion warning.

The macro needs a lot from its caller: it needs 2 local vars, 1 of
which is a ref to a contained struct with named members.  To support
these requirements, add:

1. __ASSERT_IS_LVALUE(_X):
   ie: ((void)sizeof((void)0, &(x)))

2. __ASSERT_HAS_VEC_MEMBERS(_X, _Y):
   compile-time check that the _Y "vector" exists
   ie: _X->_Y and _X->num##_Y are lvalues.

The for_subvec() macro then invokes these before the for-loop itself;
they disappear at runtime.  They do cause a "complex macro" CHECK from
checkpatch --strict.

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 lib/dynamic_debug.c | 27 ++++++++++++++++++++++++---
 1 file changed, 24 insertions(+), 3 deletions(-)

diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index e882e951d585..94d05d09a128 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -128,6 +128,28 @@ do {								\
 #define v3pr_info(fmt, ...)	vnpr_info(3, fmt, ##__VA_ARGS__)
 #define v4pr_info(fmt, ...)	vnpr_info(4, fmt, ##__VA_ARGS__)
 
+/*
+ * simplify a repeated for-loop pattern walking N steps in a T _vec
+ * member inside a struct _box.  It expects int i and T *_sp to be
+ * declared in the caller.
+ * @_i:  caller provided counter.
+ * @_sp: cursor into _vec, to examine each item.
+ * @_box: ptr to a struct containing @_vec member
+ * @_vec: name of a member in @_box
+ */
+#define __ASSERT_IS_LVALUE(x) ((void)sizeof((void)0, &(x)))
+#define __ASSERT_HAS_VEC_MEMBER(_box, _vec) ({	\
+	(void)sizeof((_box)->_vec);		\
+	(void)sizeof((_box)->num_##_vec);	\
+})
+#define for_subvec(_i, _sp, _box, _vec)			\
+	__ASSERT_IS_LVALUE(_i);				\
+	__ASSERT_IS_LVALUE(_sp);			\
+	__ASSERT_HAS_VEC_MEMBER(_box, _vec);		\
+	for ((_i) = 0, (_sp) = (_box)->_vec;		\
+	     (_i) < (_box)->num_##_vec;			\
+	     (_i)++, (_sp)++)
+
 static void vpr_info_dq(const struct ddebug_query *query, const char *msg)
 {
 	/* trim any trailing newlines */
@@ -155,7 +177,7 @@ static struct ddebug_class_map *ddebug_find_valid_class(struct ddebug_table cons
 	struct ddebug_class_map *map;
 	int i, idx;
 
-	for (map = dt->classes, i = 0; i < dt->num_classes; i++, map++) {
+	for_subvec(i, map, dt, classes) {
 		idx = match_string(map->class_names, map->length, class_string);
 		if (idx >= 0) {
 			*class_id = idx + map->base;
@@ -1231,8 +1253,7 @@ static void ddebug_attach_module_classes(struct ddebug_table *dt, struct _ddebug
 	 * the builtin/modular classmap vector/section.  Save the start
 	 * and length of the subrange at its edges.
 	 */
-	for (cm = di->classes, i = 0; i < di->num_classes; i++, cm++) {
-
+	for_subvec(i, cm, di, classes) {
 		if (!strcmp(cm->mod_name, dt->mod_name)) {
 			if (!nc) {
 				v2pr_info("start subrange, class[%d]: module:%s base:%d len:%d ty:%d\n",
-- 
2.52.0

[PATCH v7 15/31] dyndbg, module: make proper substructs in _ddebug_info

[Jim Cromie]

recompose struct _ddebug_info, inserting proper sub-structs.

The struct _ddebug_info has 2 pairs of _vec, num##_vec fields, for
descs and classes respectively.  for_subvec() makes walking these
vectors less cumbersome, now lets move those field pairs into their
own "vec" structs: _ddebug_descs & _ddebug_class_maps, and re-compose
struct _ddebug_info to contain them cleanly.  This also lets us rid
for_subvec() of its num##_vec paste-up.

Also recompose struct ddebug_table to contain a _ddebug_info.  This
reinforces its use as a cursor into relevant data for a builtin
module, and access to the full _ddebug state for modules.

NOTES:

Invariant: These vectors ref a contiguous subrange of __section memory
in builtin/DATA or in loadable modules via mod->dyndbg_info; with
guaranteed life-time for us.

Fixup names: Normalize all struct names to "struct _ddebug_*"
eliminating the minor/stupid variations created in classmaps-v1.
Also normalize the __section names to "__dyndbg_*".

struct module contains a _ddebug_info field and module/main.c sets it
up, so that gets adjusted rather obviously.

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 include/asm-generic/vmlinux.lds.h |   4 +-
 include/linux/dynamic_debug.h     |  42 ++++++----
 kernel/module/main.c              |  12 +--
 lib/dynamic_debug.c               | 127 +++++++++++++++---------------
 lib/test_dynamic_debug.c          |   2 +-
 5 files changed, 100 insertions(+), 87 deletions(-)

diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index e04d56a5332e..da15cf0c16d0 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -366,8 +366,8 @@ defined(CONFIG_AUTOFDO_CLANG) || defined(CONFIG_PROPELLER_CLANG)
 	*(__tracepoints)						\
 	/* implement dynamic printk debug */				\
 	. = ALIGN(8);							\
-	BOUNDED_SECTION_BY(__dyndbg_classes, ___dyndbg_classes)		\
-	BOUNDED_SECTION_BY(__dyndbg, ___dyndbg)				\
+	BOUNDED_SECTION_BY(__dyndbg_class_maps, ___dyndbg_class_maps)	\
+	BOUNDED_SECTION_BY(__dyndbg_descriptors, ___dyndbg_descs)	\
 	CODETAG_SECTIONS()						\
 	LIKELY_PROFILE()		       				\
 	BRANCH_PROFILE()						\
diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index 51ed26e42032..4775f66e96dd 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -82,30 +82,42 @@ enum class_map_type {
 	 */
 };
 
-struct ddebug_class_map {
-	struct module *mod;
-	const char *mod_name;	/* needed for builtins */
+struct _ddebug_class_map {
+	struct module *mod;	/* NULL for builtins */
+	const char *mod_name;
 	const char **class_names;
 	const int length;
 	const int base;		/* index of 1st .class_id, allows split/shared space */
 	enum class_map_type map_type;
 };
 
-/* encapsulate linker provided built-in (or module) dyndbg data */
+/*
+ * @_ddebug_info: gathers module/builtin dyndbg_* __sections together.
+ * For builtins, it is used as a cursor, with the inner structs
+ * marking sub-vectors of the builtin __sections in DATA.
+ */
+struct _ddebug_descs {
+	struct _ddebug *start;
+	int len;
+};
+
+struct _ddebug_class_maps {
+	struct _ddebug_class_map *start;
+	int len;
+};
+
 struct _ddebug_info {
-	struct _ddebug *descs;
-	struct ddebug_class_map *classes;
-	unsigned int num_descs;
-	unsigned int num_classes;
+	struct _ddebug_descs descs;
+	struct _ddebug_class_maps maps;
 };
 
-struct ddebug_class_param {
+struct _ddebug_class_param {
 	union {
 		unsigned long *bits;
 		unsigned long *lvl;
 	};
 	char flags[8];
-	const struct ddebug_class_map *map;
+	const struct _ddebug_class_map *map;
 };
 
 /*
@@ -124,8 +136,8 @@ struct ddebug_class_param {
  */
 #define DECLARE_DYNDBG_CLASSMAP(_var, _maptype, _base, ...)		\
 	static const char *_var##_classnames[] = { __VA_ARGS__ };	\
-	static struct ddebug_class_map __aligned(8) __used		\
-		__section("__dyndbg_classes") _var = {			\
+	static struct _ddebug_class_map __aligned(8) __used		\
+		__section("__dyndbg_class_maps") _var = {		\
 		.mod = THIS_MODULE,					\
 		.mod_name = KBUILD_MODNAME,				\
 		.base = _base,						\
@@ -159,7 +171,7 @@ void __dynamic_ibdev_dbg(struct _ddebug *descriptor,
 
 #define DEFINE_DYNAMIC_DEBUG_METADATA_CLS(name, cls, fmt)	\
 	static struct _ddebug  __aligned(8)			\
-	__section("__dyndbg") name = {				\
+	__section("__dyndbg_descriptors") name = {		\
 		.modname = KBUILD_MODNAME,			\
 		.function = __func__,				\
 		.filename = __FILE__,				\
@@ -242,7 +254,7 @@ void __dynamic_ibdev_dbg(struct _ddebug *descriptor,
  * macro.
  */
 #define _dynamic_func_call_cls(cls, fmt, func, ...)			\
-	__dynamic_func_call_cls(__UNIQUE_ID(ddebug), cls, fmt, func, ##__VA_ARGS__)
+	__dynamic_func_call_cls(__UNIQUE_ID(_ddebug), cls, fmt, func, ##__VA_ARGS__)
 #define _dynamic_func_call(fmt, func, ...)				\
 	_dynamic_func_call_cls(_DPRINTK_CLASS_DFLT, fmt, func, ##__VA_ARGS__)
 
@@ -252,7 +264,7 @@ void __dynamic_ibdev_dbg(struct _ddebug *descriptor,
  * with precisely the macro's varargs.
  */
 #define _dynamic_func_call_cls_no_desc(cls, fmt, func, ...)		\
-	__dynamic_func_call_cls_no_desc(__UNIQUE_ID(ddebug), cls, fmt,	\
+	__dynamic_func_call_cls_no_desc(__UNIQUE_ID(_ddebug), cls, fmt,	\
 					func, ##__VA_ARGS__)
 #define _dynamic_func_call_no_desc(fmt, func, ...)			\
 	_dynamic_func_call_cls_no_desc(_DPRINTK_CLASS_DFLT, fmt,	\
diff --git a/kernel/module/main.c b/kernel/module/main.c
index c66b26184936..1ccc5d4399c3 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -2710,12 +2710,12 @@ static int find_module_sections(struct module *mod, struct load_info *info)
 		pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
 
 #ifdef CONFIG_DYNAMIC_DEBUG_CORE
-	mod->dyndbg_info.descs = section_objs(info, "__dyndbg",
-					      sizeof(*mod->dyndbg_info.descs),
-					      &mod->dyndbg_info.num_descs);
-	mod->dyndbg_info.classes = section_objs(info, "__dyndbg_classes",
-						sizeof(*mod->dyndbg_info.classes),
-						&mod->dyndbg_info.num_classes);
+	mod->dyndbg_info.descs.start = section_objs(info, "__dyndbg_descriptors",
+						    sizeof(*mod->dyndbg_info.descs.start),
+						    &mod->dyndbg_info.descs.len);
+	mod->dyndbg_info.maps.start = section_objs(info, "__dyndbg_class_maps",
+						   sizeof(*mod->dyndbg_info.maps.start),
+						   &mod->dyndbg_info.maps.len);
 #endif
 
 	return 0;
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 94d05d09a128..c9377a444fc8 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -39,17 +39,15 @@
 
 #include <rdma/ib_verbs.h>
 
-extern struct _ddebug __start___dyndbg[];
-extern struct _ddebug __stop___dyndbg[];
-extern struct ddebug_class_map __start___dyndbg_classes[];
-extern struct ddebug_class_map __stop___dyndbg_classes[];
+extern struct _ddebug __start___dyndbg_descs[];
+extern struct _ddebug __stop___dyndbg_descs[];
+extern struct _ddebug_class_map __start___dyndbg_class_maps[];
+extern struct _ddebug_class_map __stop___dyndbg_class_maps[];
 
 struct ddebug_table {
 	struct list_head link;
 	const char *mod_name;
-	struct _ddebug *ddebugs;
-	struct ddebug_class_map *classes;
-	unsigned int num_ddebugs, num_classes;
+	struct _ddebug_info info;
 };
 
 struct ddebug_query {
@@ -135,20 +133,21 @@ do {								\
  * @_i:  caller provided counter.
  * @_sp: cursor into _vec, to examine each item.
  * @_box: ptr to a struct containing @_vec member
- * @_vec: name of a member in @_box
+ * @_vec: name of a a vector member in @_box
  */
+
 #define __ASSERT_IS_LVALUE(x) ((void)sizeof((void)0, &(x)))
-#define __ASSERT_HAS_VEC_MEMBER(_box, _vec) ({	\
-	(void)sizeof((_box)->_vec);		\
-	(void)sizeof((_box)->num_##_vec);	\
+#define __ASSERT_HAS_VEC_MEMBER(_box, _vec) ({		\
+	(void)sizeof((_box)->_vec.start);		\
+	(void)sizeof((_box)->_vec.len);			\
 })
 #define for_subvec(_i, _sp, _box, _vec)			\
 	__ASSERT_IS_LVALUE(_i);				\
 	__ASSERT_IS_LVALUE(_sp);			\
 	__ASSERT_HAS_VEC_MEMBER(_box, _vec);		\
-	for ((_i) = 0, (_sp) = (_box)->_vec;		\
-	     (_i) < (_box)->num_##_vec;			\
-	     (_i)++, (_sp)++)
+	for ((_i) = 0, (_sp) = (_box)->_vec.start;	\
+	     (_i) < (_box)->_vec.len;			\
+	     (_i)++, (_sp)++)		/* { block } */
 
 static void vpr_info_dq(const struct ddebug_query *query, const char *msg)
 {
@@ -170,14 +169,14 @@ static void vpr_info_dq(const struct ddebug_query *query, const char *msg)
 		  query->first_lineno, query->last_lineno, query->class_string);
 }
 
-static struct ddebug_class_map *ddebug_find_valid_class(struct ddebug_table const *dt,
+static struct _ddebug_class_map *ddebug_find_valid_class(struct ddebug_table const *dt,
 							const char *class_string,
 							int *class_id)
 {
-	struct ddebug_class_map *map;
+	struct _ddebug_class_map *map;
 	int i, idx;
 
-	for_subvec(i, map, dt, classes) {
+	for_subvec(i, map, &dt->info, maps) {
 		idx = match_string(map->class_names, map->length, class_string);
 		if (idx >= 0) {
 			*class_id = idx + map->base;
@@ -248,7 +247,7 @@ static int ddebug_change(const struct ddebug_query *query,
 	unsigned int newflags;
 	unsigned int nfound = 0;
 	struct flagsbuf fbuf, nbuf;
-	struct ddebug_class_map *map = NULL;
+	struct _ddebug_class_map *map = NULL;
 	int valid_class;
 
 	/* search for matching ddebugs */
@@ -269,8 +268,8 @@ static int ddebug_change(const struct ddebug_query *query,
 			valid_class = _DPRINTK_CLASS_DFLT;
 		}
 
-		for (i = 0; i < dt->num_ddebugs; i++) {
-			struct _ddebug *dp = &dt->ddebugs[i];
+		for (i = 0; i < dt->info.descs.len; i++) {
+			struct _ddebug *dp = &dt->info.descs.start[i];
 
 			if (!ddebug_match_desc(query, dp, valid_class))
 				continue;
@@ -628,14 +627,14 @@ static int ddebug_exec_queries(char *query, const char *modname)
 }
 
 /* apply a new class-param setting */
-static int ddebug_apply_class_bitmap(const struct ddebug_class_param *dcp,
+static int ddebug_apply_class_bitmap(const struct _ddebug_class_param *dcp,
 				     const unsigned long *new_bits,
 				     const unsigned long old_bits,
 				     const char *query_modname)
 {
 #define QUERY_SIZE 128
 	char query[QUERY_SIZE];
-	const struct ddebug_class_map *map = dcp->map;
+	const struct _ddebug_class_map *map = dcp->map;
 	int matches = 0;
 	int bi, ct;
 
@@ -671,8 +670,8 @@ static int ddebug_apply_class_bitmap(const struct ddebug_class_param *dcp,
 /* accept comma-separated-list of [+-] classnames */
 static int param_set_dyndbg_classnames(const char *instr, const struct kernel_param *kp)
 {
-	const struct ddebug_class_param *dcp = kp->arg;
-	const struct ddebug_class_map *map = dcp->map;
+	const struct _ddebug_class_param *dcp = kp->arg;
+	const struct _ddebug_class_map *map = dcp->map;
 	unsigned long curr_bits, old_bits;
 	char *cl_str, *p, *tmp;
 	int cls_id, totct = 0;
@@ -742,8 +741,8 @@ static int param_set_dyndbg_module_classes(const char *instr,
 					   const struct kernel_param *kp,
 					   const char *mod_name)
 {
-	const struct ddebug_class_param *dcp = kp->arg;
-	const struct ddebug_class_map *map = dcp->map;
+	const struct _ddebug_class_param *dcp = kp->arg;
+	const struct _ddebug_class_map *map = dcp->map;
 	unsigned long inrep, new_bits, old_bits;
 	int rc, totct = 0;
 
@@ -830,8 +829,8 @@ EXPORT_SYMBOL(param_set_dyndbg_classes);
  */
 int param_get_dyndbg_classes(char *buffer, const struct kernel_param *kp)
 {
-	const struct ddebug_class_param *dcp = kp->arg;
-	const struct ddebug_class_map *map = dcp->map;
+	const struct _ddebug_class_param *dcp = kp->arg;
+	const struct _ddebug_class_map *map = dcp->map;
 
 	switch (map->map_type) {
 
@@ -1082,8 +1081,8 @@ static struct _ddebug *ddebug_iter_first(struct ddebug_iter *iter)
 	}
 	iter->table = list_entry(ddebug_tables.next,
 				 struct ddebug_table, link);
-	iter->idx = iter->table->num_ddebugs;
-	return &iter->table->ddebugs[--iter->idx];
+	iter->idx = iter->table->info.descs.len;
+	return &iter->table->info.descs.start[--iter->idx];
 }
 
 /*
@@ -1104,10 +1103,10 @@ static struct _ddebug *ddebug_iter_next(struct ddebug_iter *iter)
 		}
 		iter->table = list_entry(iter->table->link.next,
 					 struct ddebug_table, link);
-		iter->idx = iter->table->num_ddebugs;
+		iter->idx = iter->table->info.descs.len;
 		--iter->idx;
 	}
-	return &iter->table->ddebugs[iter->idx];
+	return &iter->table->info.descs.start[iter->idx];
 }
 
 /*
@@ -1151,16 +1150,19 @@ static void *ddebug_proc_next(struct seq_file *m, void *p, loff_t *pos)
 	return dp;
 }
 
-#define class_in_range(class_id, map)					\
-	(class_id >= map->base && class_id < map->base + map->length)
+static bool ddebug_class_in_range(const int class_id, const struct _ddebug_class_map *map)
+{
+	return (class_id >= map->base &&
+		class_id < map->base + map->length);
+}
 
-static const char *ddebug_class_name(struct ddebug_iter *iter, struct _ddebug *dp)
+static const char *ddebug_class_name(struct ddebug_table *dt, struct _ddebug *dp)
 {
-	struct ddebug_class_map *map = iter->table->classes;
-	int i, nc = iter->table->num_classes;
+	struct _ddebug_class_map *map;
+	int i;
 
-	for (i = 0; i < nc; i++, map++)
-		if (class_in_range(dp->class_id, map))
+	for_subvec(i, map, &dt->info, maps)
+		if (ddebug_class_in_range(dp->class_id, map))
 			return map->class_names[dp->class_id - map->base];
 
 	return NULL;
@@ -1193,7 +1195,7 @@ static int ddebug_proc_show(struct seq_file *m, void *p)
 	seq_putc(m, '"');
 
 	if (dp->class_id != _DPRINTK_CLASS_DFLT) {
-		class = ddebug_class_name(iter, dp);
+		class = ddebug_class_name(iter->table, dp);
 		if (class)
 			seq_printf(m, " class:%s", class);
 		else
@@ -1245,7 +1247,7 @@ static const struct proc_ops proc_fops = {
 
 static void ddebug_attach_module_classes(struct ddebug_table *dt, struct _ddebug_info *di)
 {
-	struct ddebug_class_map *cm;
+	struct _ddebug_class_map *cm;
 	int i, nc = 0;
 
 	/*
@@ -1253,18 +1255,18 @@ static void ddebug_attach_module_classes(struct ddebug_table *dt, struct _ddebug
 	 * the builtin/modular classmap vector/section.  Save the start
 	 * and length of the subrange at its edges.
 	 */
-	for_subvec(i, cm, di, classes) {
+	for_subvec(i, cm, di, maps) {
 		if (!strcmp(cm->mod_name, dt->mod_name)) {
 			if (!nc) {
 				v2pr_info("start subrange, class[%d]: module:%s base:%d len:%d ty:%d\n",
 					  i, cm->mod_name, cm->base, cm->length, cm->map_type);
-				dt->classes = cm;
+				dt->info.maps.start = cm;
 			}
 			nc++;
 		}
 	}
 	if (nc) {
-		dt->num_classes = nc;
+		dt->info.maps.len = nc;
 		vpr_info("module:%s attached %d classes\n", dt->mod_name, nc);
 	}
 }
@@ -1277,10 +1279,10 @@ static int ddebug_add_module(struct _ddebug_info *di, const char *modname)
 {
 	struct ddebug_table *dt;
 
-	if (!di->num_descs)
+	if (!di->descs.len)
 		return 0;
 
-	v3pr_info("add-module: %s %d sites\n", modname, di->num_descs);
+	v3pr_info("add-module: %s %d sites\n", modname, di->descs.len);
 
 	dt = kzalloc(sizeof(*dt), GFP_KERNEL);
 	if (dt == NULL) {
@@ -1294,19 +1296,18 @@ static int ddebug_add_module(struct _ddebug_info *di, const char *modname)
 	 * this struct ddebug_table.
 	 */
 	dt->mod_name = modname;
-	dt->ddebugs = di->descs;
-	dt->num_ddebugs = di->num_descs;
+	dt->info = *di;
 
 	INIT_LIST_HEAD(&dt->link);
 
-	if (di->classes && di->num_classes)
+	if (di->maps.len)
 		ddebug_attach_module_classes(dt, di);
 
 	mutex_lock(&ddebug_lock);
 	list_add_tail(&dt->link, &ddebug_tables);
 	mutex_unlock(&ddebug_lock);
 
-	vpr_info("%3u debug prints in module %s\n", di->num_descs, modname);
+	vpr_info("%3u debug prints in module %s\n", di->descs.len, modname);
 	return 0;
 }
 
@@ -1453,10 +1454,10 @@ static int __init dynamic_debug_init(void)
 	char *cmdline;
 
 	struct _ddebug_info di = {
-		.descs = __start___dyndbg,
-		.classes = __start___dyndbg_classes,
-		.num_descs = __stop___dyndbg - __start___dyndbg,
-		.num_classes = __stop___dyndbg_classes - __start___dyndbg_classes,
+		.descs.start = __start___dyndbg_descs,
+		.maps.start  = __start___dyndbg_class_maps,
+		.descs.len = __stop___dyndbg_descs - __start___dyndbg_descs,
+		.maps.len  = __stop___dyndbg_class_maps - __start___dyndbg_class_maps,
 	};
 
 #ifdef CONFIG_MODULES
@@ -1467,7 +1468,7 @@ static int __init dynamic_debug_init(void)
 	}
 #endif /* CONFIG_MODULES */
 
-	if (&__start___dyndbg == &__stop___dyndbg) {
+	if (&__start___dyndbg_descs == &__stop___dyndbg_descs) {
 		if (IS_ENABLED(CONFIG_DYNAMIC_DEBUG)) {
 			pr_warn("_ddebug table is empty in a CONFIG_DYNAMIC_DEBUG build\n");
 			return 1;
@@ -1477,16 +1478,16 @@ static int __init dynamic_debug_init(void)
 		return 0;
 	}
 
-	iter = iter_mod_start = __start___dyndbg;
+	iter = iter_mod_start = __start___dyndbg_descs;
 	modname = iter->modname;
 	i = mod_sites = mod_ct = 0;
 
-	for (; iter < __stop___dyndbg; iter++, i++, mod_sites++) {
+	for (; iter < __stop___dyndbg_descs; iter++, i++, mod_sites++) {
 
 		if (strcmp(modname, iter->modname)) {
 			mod_ct++;
-			di.num_descs = mod_sites;
-			di.descs = iter_mod_start;
+			di.descs.len = mod_sites;
+			di.descs.start = iter_mod_start;
 			ret = ddebug_add_module(&di, modname);
 			if (ret)
 				goto out_err;
@@ -1496,8 +1497,8 @@ static int __init dynamic_debug_init(void)
 			iter_mod_start = iter;
 		}
 	}
-	di.num_descs = mod_sites;
-	di.descs = iter_mod_start;
+	di.descs.len = mod_sites;
+	di.descs.start = iter_mod_start;
 	ret = ddebug_add_module(&di, modname);
 	if (ret)
 		goto out_err;
@@ -1507,8 +1508,8 @@ static int __init dynamic_debug_init(void)
 		 i, mod_ct, (int)((mod_ct * sizeof(struct ddebug_table)) >> 10),
 		 (int)((i * sizeof(struct _ddebug)) >> 10));
 
-	if (di.num_classes)
-		v2pr_info("  %d builtin ddebug class-maps\n", di.num_classes);
+	if (di.maps.len)
+		v2pr_info("  %d builtin ddebug class-maps\n", di.maps.len);
 
 	/* now that ddebug tables are loaded, process all boot args
 	 * again to find and activate queries given in dyndbg params.
diff --git a/lib/test_dynamic_debug.c b/lib/test_dynamic_debug.c
index 396144cf351b..8434f70b51bb 100644
--- a/lib/test_dynamic_debug.c
+++ b/lib/test_dynamic_debug.c
@@ -41,7 +41,7 @@ module_param_cb(do_prints, &param_ops_do_prints, NULL, 0600);
  */
 #define DD_SYS_WRAP(_model, _flags)					\
 	static unsigned long bits_##_model;				\
-	static struct ddebug_class_param _flags##_model = {		\
+	static struct _ddebug_class_param _flags##_model = {		\
 		.bits = &bits_##_model,					\
 		.flags = #_flags,					\
 		.map = &map_##_model,					\
-- 
2.52.0

[PATCH v7 16/31] dyndbg: hoist classmap-filter-by-modname up to ddebug_add_module

[Jim Cromie]

The body of ddebug_attach_module_classes() is dominated by a
code-block that finds the contiguous subrange of classmaps matching on
modname, and saves it into the ddebug_table's info record.

Implement this block in a macro to accommodate different component
vectors in the "box" (as named in the for_subvec macro).  We will
reuse this macro shortly.

And hoist its invocation out of ddebug_attach_module_classes() up into
ddebug_add_module().  This moves the filtering step up closer to
dynamic_debug_init(), which already segments the builtin pr_debug
descriptors on their mod_name boundaries.

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
reordered params to match kdoc
---
 lib/dynamic_debug.c | 57 ++++++++++++++++++++++++++-------------------
 1 file changed, 33 insertions(+), 24 deletions(-)

diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index c9377a444fc8..d668140794ac 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -170,8 +170,8 @@ static void vpr_info_dq(const struct ddebug_query *query, const char *msg)
 }
 
 static struct _ddebug_class_map *ddebug_find_valid_class(struct ddebug_table const *dt,
-							const char *class_string,
-							int *class_id)
+							 const char *class_string,
+							 int *class_id)
 {
 	struct _ddebug_class_map *map;
 	int i, idx;
@@ -1247,30 +1247,35 @@ static const struct proc_ops proc_fops = {
 
 static void ddebug_attach_module_classes(struct ddebug_table *dt, struct _ddebug_info *di)
 {
-	struct _ddebug_class_map *cm;
-	int i, nc = 0;
-
-	/*
-	 * Find this module's classmaps in a subrange/wholerange of
-	 * the builtin/modular classmap vector/section.  Save the start
-	 * and length of the subrange at its edges.
-	 */
-	for_subvec(i, cm, di, maps) {
-		if (!strcmp(cm->mod_name, dt->mod_name)) {
-			if (!nc) {
-				v2pr_info("start subrange, class[%d]: module:%s base:%d len:%d ty:%d\n",
-					  i, cm->mod_name, cm->base, cm->length, cm->map_type);
-				dt->info.maps.start = cm;
-			}
-			nc++;
-		}
-	}
-	if (nc) {
-		dt->info.maps.len = nc;
-		vpr_info("module:%s attached %d classes\n", dt->mod_name, nc);
-	}
+	vpr_info("module:%s attached %d classes\n", dt->mod_name, dt->info.maps.len);
 }
 
+/*
+ * Walk the @_box->@_vec member, over @_vec.start[0..len], and find
+ * the contiguous subrange of elements matching on ->mod_name.  Copy
+ * the subrange into @_dst.  This depends on vars defd by caller.
+ *
+ * @_i:   caller provided counter var, init'd by macro
+ * @_sp:  cursor into @_vec.
+ * @_box: contains member named @_vec
+ * @_vec: member-name of a type with: .start .len fields.
+ * @_dst: an array-ref: to remember the module's subrange
+ */
+#define dd_mark_vector_subrange(_i, _sp, _box, _vec, _dst) ({		\
+	typeof(_dst) __dst = (_dst);					\
+	int __nc = 0;							\
+	for_subvec(_i, _sp, _box, _vec) {				\
+		if (!strcmp((_sp)->mod_name, (_dst)->mod_name)) {	\
+			if (!__nc++)					\
+				(__dst)->info._vec.start = (_sp);	\
+		} else {						\
+			if (__nc)					\
+				break; /* end of consecutive matches */ \
+		}							\
+	}								\
+	(__dst)->info._vec.len = __nc;					\
+})
+
 /*
  * Allocate a new ddebug_table for the given module
  * and add it to the global list.
@@ -1278,6 +1283,8 @@ static void ddebug_attach_module_classes(struct ddebug_table *dt, struct _ddebug
 static int ddebug_add_module(struct _ddebug_info *di, const char *modname)
 {
 	struct ddebug_table *dt;
+	struct _ddebug_class_map *cm;
+	int i;
 
 	if (!di->descs.len)
 		return 0;
@@ -1300,6 +1307,8 @@ static int ddebug_add_module(struct _ddebug_info *di, const char *modname)
 
 	INIT_LIST_HEAD(&dt->link);
 
+	dd_mark_vector_subrange(i, cm, di, maps, dt);
+
 	if (di->maps.len)
 		ddebug_attach_module_classes(dt, di);
 
-- 
2.52.0

[PATCH v7 17/31] dyndbg: move mod_name down from struct ddebug_table to _ddebug_info

[Jim Cromie]

struct _ddebug_info already has most of dyndbg's info for a module;
push debug_table.mod_name down into it, finishing the encapsulation.

This allows refactoring several callchains, passing &_ddebug_info
instead of &ddebug_table, and hoisting the "&dt->info" deref up
instead of repeating it thru the callchans

ddebug_table contains a _ddebug_info member, so its users keep access
to mod_name, just now with "->info." added in.

In static ddebug_add_module(&di), reinforce the cursor-model by
dropping the modname arg, and setting di->mod_name at each caller.

Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 include/linux/dynamic_debug.h |  1 +
 lib/dynamic_debug.c           | 50 ++++++++++++++++++-----------------
 2 files changed, 27 insertions(+), 24 deletions(-)

diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index 4775f66e96dd..10f1a2a1bee4 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -107,6 +107,7 @@ struct _ddebug_class_maps {
 };
 
 struct _ddebug_info {
+	const char *mod_name;
 	struct _ddebug_descs descs;
 	struct _ddebug_class_maps maps;
 };
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index d668140794ac..77972da271ee 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -46,7 +46,6 @@ extern struct _ddebug_class_map __stop___dyndbg_class_maps[];
 
 struct ddebug_table {
 	struct list_head link;
-	const char *mod_name;
 	struct _ddebug_info info;
 };
 
@@ -253,10 +252,11 @@ static int ddebug_change(const struct ddebug_query *query,
 	/* search for matching ddebugs */
 	mutex_lock(&ddebug_lock);
 	list_for_each_entry(dt, &ddebug_tables, link) {
+		struct _ddebug_info *di = &dt->info;
 
 		/* match against the module name */
 		if (query->module &&
-		    !match_wildcard(query->module, dt->mod_name))
+		    !match_wildcard(query->module, di->mod_name))
 			continue;
 
 		if (query->class_string) {
@@ -268,8 +268,8 @@ static int ddebug_change(const struct ddebug_query *query,
 			valid_class = _DPRINTK_CLASS_DFLT;
 		}
 
-		for (i = 0; i < dt->info.descs.len; i++) {
-			struct _ddebug *dp = &dt->info.descs.start[i];
+		for (i = 0; i < di->descs.len; i++) {
+			struct _ddebug *dp = &di->descs.start[i];
 
 			if (!ddebug_match_desc(query, dp, valid_class))
 				continue;
@@ -289,7 +289,7 @@ static int ddebug_change(const struct ddebug_query *query,
 #endif
 			v4pr_info("changed %s:%d [%s]%s %s => %s\n",
 				  trim_prefix(dp->filename), dp->lineno,
-				  dt->mod_name, dp->function,
+				  di->mod_name, dp->function,
 				  ddebug_describe_flags(dp->flags, &fbuf),
 				  ddebug_describe_flags(newflags, &nbuf));
 			dp->flags = newflags;
@@ -1156,12 +1156,12 @@ static bool ddebug_class_in_range(const int class_id, const struct _ddebug_class
 		class_id < map->base + map->length);
 }
 
-static const char *ddebug_class_name(struct ddebug_table *dt, struct _ddebug *dp)
+static const char *ddebug_class_name(struct _ddebug_info *di, struct _ddebug *dp)
 {
 	struct _ddebug_class_map *map;
 	int i;
 
-	for_subvec(i, map, &dt->info, maps)
+	for_subvec(i, map, di, maps)
 		if (ddebug_class_in_range(dp->class_id, map))
 			return map->class_names[dp->class_id - map->base];
 
@@ -1189,13 +1189,13 @@ static int ddebug_proc_show(struct seq_file *m, void *p)
 
 	seq_printf(m, "%s:%u [%s]%s =%s \"",
 		   trim_prefix(dp->filename), dp->lineno,
-		   iter->table->mod_name, dp->function,
+		   iter->table->info.mod_name, dp->function,
 		   ddebug_describe_flags(dp->flags, &flags));
 	seq_escape_str(m, dp->format, ESCAPE_SPACE, "\t\r\n\"");
 	seq_putc(m, '"');
 
 	if (dp->class_id != _DPRINTK_CLASS_DFLT) {
-		class = ddebug_class_name(iter->table, dp);
+		class = ddebug_class_name(&iter->table->info, dp);
 		if (class)
 			seq_printf(m, " class:%s", class);
 		else
@@ -1247,7 +1247,7 @@ static const struct proc_ops proc_fops = {
 
 static void ddebug_attach_module_classes(struct ddebug_table *dt, struct _ddebug_info *di)
 {
-	vpr_info("module:%s attached %d classes\n", dt->mod_name, dt->info.maps.len);
+	vpr_info("module:%s attached %d classes\n", dt->info.mod_name, dt->info.maps.len);
 }
 
 /*
@@ -1265,7 +1265,7 @@ static void ddebug_attach_module_classes(struct ddebug_table *dt, struct _ddebug
 	typeof(_dst) __dst = (_dst);					\
 	int __nc = 0;							\
 	for_subvec(_i, _sp, _box, _vec) {				\
-		if (!strcmp((_sp)->mod_name, (_dst)->mod_name)) {	\
+		if (!strcmp((_sp)->mod_name, (__dst)->info.mod_name)) {	\
 			if (!__nc++)					\
 				(__dst)->info._vec.start = (_sp);	\
 		} else {						\
@@ -1280,7 +1280,7 @@ static void ddebug_attach_module_classes(struct ddebug_table *dt, struct _ddebug
  * Allocate a new ddebug_table for the given module
  * and add it to the global list.
  */
-static int ddebug_add_module(struct _ddebug_info *di, const char *modname)
+static int ddebug_add_module(struct _ddebug_info *di)
 {
 	struct ddebug_table *dt;
 	struct _ddebug_class_map *cm;
@@ -1289,20 +1289,19 @@ static int ddebug_add_module(struct _ddebug_info *di, const char *modname)
 	if (!di->descs.len)
 		return 0;
 
-	v3pr_info("add-module: %s %d sites\n", modname, di->descs.len);
+	v3pr_info("add-module: %s %d sites\n", di->mod_name, di->descs.len);
 
 	dt = kzalloc(sizeof(*dt), GFP_KERNEL);
 	if (dt == NULL) {
-		pr_err("error adding module: %s\n", modname);
+		pr_err("error adding module: %s\n", di->mod_name);
 		return -ENOMEM;
 	}
 	/*
-	 * For built-in modules, name lives in .rodata and is
-	 * immortal. For loaded modules, name points at the name[]
-	 * member of struct module, which lives at least as long as
-	 * this struct ddebug_table.
+	 * For built-in modules, name (as supplied in di by its
+	 * callers) lives in .rodata and is immortal. For loaded
+	 * modules, name points at the name[] member of struct module,
+	 * which lives at least as long as this struct ddebug_table.
 	 */
-	dt->mod_name = modname;
 	dt->info = *di;
 
 	INIT_LIST_HEAD(&dt->link);
@@ -1316,7 +1315,7 @@ static int ddebug_add_module(struct _ddebug_info *di, const char *modname)
 	list_add_tail(&dt->link, &ddebug_tables);
 	mutex_unlock(&ddebug_lock);
 
-	vpr_info("%3u debug prints in module %s\n", di->descs.len, modname);
+	vpr_info("%3u debug prints in module %s\n", di->descs.len, di->mod_name);
 	return 0;
 }
 
@@ -1379,7 +1378,7 @@ static int ddebug_remove_module(const char *mod_name)
 
 	mutex_lock(&ddebug_lock);
 	list_for_each_entry_safe(dt, nextdt, &ddebug_tables, link) {
-		if (dt->mod_name == mod_name) {
+		if (dt->info.mod_name == mod_name) {
 			ddebug_table_free(dt);
 			ret = 0;
 			break;
@@ -1399,7 +1398,8 @@ static int ddebug_module_notify(struct notifier_block *self, unsigned long val,
 
 	switch (val) {
 	case MODULE_STATE_COMING:
-		ret = ddebug_add_module(&mod->dyndbg_info, mod->name);
+		mod->dyndbg_info.mod_name = mod->name;
+		ret = ddebug_add_module(&mod->dyndbg_info);
 		if (ret)
 			WARN(1, "Failed to allocate memory: dyndbg may not work properly.\n");
 		break;
@@ -1497,7 +1497,8 @@ static int __init dynamic_debug_init(void)
 			mod_ct++;
 			di.descs.len = mod_sites;
 			di.descs.start = iter_mod_start;
-			ret = ddebug_add_module(&di, modname);
+			di.mod_name = modname;
+			ret = ddebug_add_module(&di);
 			if (ret)
 				goto out_err;
 
@@ -1508,7 +1509,8 @@ static int __init dynamic_debug_init(void)
 	}
 	di.descs.len = mod_sites;
 	di.descs.start = iter_mod_start;
-	ret = ddebug_add_module(&di, modname);
+	di.mod_name = modname;
+	ret = ddebug_add_module(&di);
 	if (ret)
 		goto out_err;
 
-- 
2.52.0

[PATCH v7 18/31] dyndbg-API: remove DD_CLASS_TYPE_(DISJOINT|LEVEL)_NAMES and code

[Jim Cromie]

Remove the DD_CLASS_TYPE_*_NAMES classmap types and code.

These 2 classmap types accept class names at the PARAM interface, for
example:

  echo +DRM_UT_CORE,-DRM_UT_KMS > /sys/module/drm/parameters/debug_names

The code works, but its only used by test-dynamic-debug, and wasn't
asked for by anyone else, so reduce LOC & test-surface; simplify things.

Also rename enum class_map_type to enum ddebug_class_map_type.

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 include/linux/dynamic_debug.h |  23 ++------
 lib/dynamic_debug.c           | 102 +++-------------------------------
 lib/test_dynamic_debug.c      |  26 ---------
 3 files changed, 14 insertions(+), 137 deletions(-)

diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index 10f1a2a1bee4..d543b84d447e 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -58,27 +58,16 @@ struct _ddebug {
 #endif
 } __attribute__((aligned(8)));
 
-enum class_map_type {
+enum ddebug_class_map_type {
 	DD_CLASS_TYPE_DISJOINT_BITS,
 	/**
-	 * DD_CLASS_TYPE_DISJOINT_BITS: classes are independent, one per bit.
-	 * expecting hex input. Built for drm.debug, basis for other types.
+	 * DD_CLASS_TYPE_DISJOINT_BITS: classes are independent, mapped to bits[0..N].
+	 * Expects hex input. Built for drm.debug, basis for other types.
 	 */
 	DD_CLASS_TYPE_LEVEL_NUM,
 	/**
-	 * DD_CLASS_TYPE_LEVEL_NUM: input is numeric level, 0-N.
-	 * N turns on just bits N-1 .. 0, so N=0 turns all bits off.
-	 */
-	DD_CLASS_TYPE_DISJOINT_NAMES,
-	/**
-	 * DD_CLASS_TYPE_DISJOINT_NAMES: input is a CSV of [+-]CLASS_NAMES,
-	 * classes are independent, like _DISJOINT_BITS.
-	 */
-	DD_CLASS_TYPE_LEVEL_NAMES,
-	/**
-	 * DD_CLASS_TYPE_LEVEL_NAMES: input is a CSV of [+-]CLASS_NAMES,
-	 * intended for names like: INFO,DEBUG,TRACE, with a module prefix
-	 * avoid EMERG,ALERT,CRIT,ERR,WARNING: they're not debug
+	 * DD_CLASS_TYPE_LEVEL_NUM: input is numeric level, 0..N.
+	 * Input N turns on bits 0..N-1
 	 */
 };
 
@@ -88,7 +77,7 @@ struct _ddebug_class_map {
 	const char **class_names;
 	const int length;
 	const int base;		/* index of 1st .class_id, allows split/shared space */
-	enum class_map_type map_type;
+	enum ddebug_class_map_type map_type;
 };
 
 /*
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 77972da271ee..63bfe1891a9e 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -667,76 +667,6 @@ static int ddebug_apply_class_bitmap(const struct _ddebug_class_param *dcp,
 
 #define CLASSMAP_BITMASK(width) ((1UL << (width)) - 1)
 
-/* accept comma-separated-list of [+-] classnames */
-static int param_set_dyndbg_classnames(const char *instr, const struct kernel_param *kp)
-{
-	const struct _ddebug_class_param *dcp = kp->arg;
-	const struct _ddebug_class_map *map = dcp->map;
-	unsigned long curr_bits, old_bits;
-	char *cl_str, *p, *tmp;
-	int cls_id, totct = 0;
-	bool wanted;
-
-	cl_str = tmp = kstrdup_and_replace(instr, '\n', '\0', GFP_KERNEL);
-	if (!tmp)
-		return -ENOMEM;
-
-	/* start with previously set state-bits, then modify */
-	curr_bits = old_bits = *dcp->bits;
-	vpr_info("\"%s\" > %s:0x%lx\n", cl_str, KP_NAME(kp), curr_bits);
-
-	for (; cl_str; cl_str = p) {
-		p = strchr(cl_str, ',');
-		if (p)
-			*p++ = '\0';
-
-		if (*cl_str == '-') {
-			wanted = false;
-			cl_str++;
-		} else {
-			wanted = true;
-			if (*cl_str == '+')
-				cl_str++;
-		}
-		cls_id = match_string(map->class_names, map->length, cl_str);
-		if (cls_id < 0) {
-			pr_err("%s unknown to %s\n", cl_str, KP_NAME(kp));
-			continue;
-		}
-
-		/* have one or more valid class_ids of one *_NAMES type */
-		switch (map->map_type) {
-		case DD_CLASS_TYPE_DISJOINT_NAMES:
-			/* the +/- pertains to a single bit */
-			if (test_bit(cls_id, &curr_bits) == wanted) {
-				v3pr_info("no change on %s\n", cl_str);
-				continue;
-			}
-			curr_bits ^= BIT(cls_id);
-			totct += ddebug_apply_class_bitmap(dcp, &curr_bits, *dcp->bits, NULL);
-			*dcp->bits = curr_bits;
-			v2pr_info("%s: changed bit %d:%s\n", KP_NAME(kp), cls_id,
-				  map->class_names[cls_id]);
-			break;
-		case DD_CLASS_TYPE_LEVEL_NAMES:
-			/* cls_id = N in 0..max. wanted +/- determines N or N-1 */
-			old_bits = CLASSMAP_BITMASK(*dcp->lvl);
-			curr_bits = CLASSMAP_BITMASK(cls_id + (wanted ? 1 : 0 ));
-
-			totct += ddebug_apply_class_bitmap(dcp, &curr_bits, old_bits, NULL);
-			*dcp->lvl = (cls_id + (wanted ? 1 : 0));
-			v2pr_info("%s: changed bit-%d: \"%s\" %lx->%lx\n", KP_NAME(kp), cls_id,
-				  map->class_names[cls_id], old_bits, curr_bits);
-			break;
-		default:
-			pr_err("illegal map-type value %d\n", map->map_type);
-		}
-	}
-	kfree(tmp);
-	vpr_info("total matches: %d\n", totct);
-	return 0;
-}
-
 static int param_set_dyndbg_module_classes(const char *instr,
 					   const struct kernel_param *kp,
 					   const char *mod_name)
@@ -745,29 +675,17 @@ static int param_set_dyndbg_module_classes(const char *instr,
 	const struct _ddebug_class_map *map = dcp->map;
 	unsigned long inrep, new_bits, old_bits;
 	int rc, totct = 0;
-
-	switch (map->map_type) {
-
-	case DD_CLASS_TYPE_DISJOINT_NAMES:
-	case DD_CLASS_TYPE_LEVEL_NAMES:
-		/* handle [+-]classnames list separately, we are done here */
-		return param_set_dyndbg_classnames(instr, kp);
-
-	case DD_CLASS_TYPE_DISJOINT_BITS:
-	case DD_CLASS_TYPE_LEVEL_NUM:
-		/* numeric input, accept and fall-thru */
-		rc = kstrtoul(instr, 0, &inrep);
-		if (rc) {
-			pr_err("expecting numeric input: %s > %s\n", instr, KP_NAME(kp));
-			return -EINVAL;
-		}
-		break;
-	default:
-		pr_err("%s: bad map type: %d\n", KP_NAME(kp), map->map_type);
+	char *nl;
+
+	rc = kstrtoul(instr, 0, &inrep);
+	if (rc) {
+		nl = strchr(instr, '\n');
+		if (nl)
+			*nl = '\0';
+		pr_err("expecting numeric input, not: %s > %s\n", instr, KP_NAME(kp));
 		return -EINVAL;
 	}
 
-	/* only _BITS,_NUM (numeric) map-types get here */
 	switch (map->map_type) {
 	case DD_CLASS_TYPE_DISJOINT_BITS:
 		/* expect bits. mask and warn if too many */
@@ -833,12 +751,8 @@ int param_get_dyndbg_classes(char *buffer, const struct kernel_param *kp)
 	const struct _ddebug_class_map *map = dcp->map;
 
 	switch (map->map_type) {
-
-	case DD_CLASS_TYPE_DISJOINT_NAMES:
 	case DD_CLASS_TYPE_DISJOINT_BITS:
 		return scnprintf(buffer, PAGE_SIZE, "0x%lx\n", *dcp->bits);
-
-	case DD_CLASS_TYPE_LEVEL_NAMES:
 	case DD_CLASS_TYPE_LEVEL_NUM:
 		return scnprintf(buffer, PAGE_SIZE, "%ld\n", *dcp->lvl);
 	default:
diff --git a/lib/test_dynamic_debug.c b/lib/test_dynamic_debug.c
index 8434f70b51bb..9c3e53cd26bd 100644
--- a/lib/test_dynamic_debug.c
+++ b/lib/test_dynamic_debug.c
@@ -74,13 +74,6 @@ DECLARE_DYNDBG_CLASSMAP(map_disjoint_bits, DD_CLASS_TYPE_DISJOINT_BITS, 0,
 DD_SYS_WRAP(disjoint_bits, p);
 DD_SYS_WRAP(disjoint_bits, T);
 
-/* symbolic input, independent bits */
-enum cat_disjoint_names { LOW = 10, MID, HI };
-DECLARE_DYNDBG_CLASSMAP(map_disjoint_names, DD_CLASS_TYPE_DISJOINT_NAMES, 10,
-			"LOW", "MID", "HI");
-DD_SYS_WRAP(disjoint_names, p);
-DD_SYS_WRAP(disjoint_names, T);
-
 /* numeric verbosity, V2 > V1 related */
 enum cat_level_num { V0 = 14, V1, V2, V3, V4, V5, V6, V7 };
 DECLARE_DYNDBG_CLASSMAP(map_level_num, DD_CLASS_TYPE_LEVEL_NUM, 14,
@@ -88,13 +81,6 @@ DECLARE_DYNDBG_CLASSMAP(map_level_num, DD_CLASS_TYPE_LEVEL_NUM, 14,
 DD_SYS_WRAP(level_num, p);
 DD_SYS_WRAP(level_num, T);
 
-/* symbolic verbosity */
-enum cat_level_names { L0 = 22, L1, L2, L3, L4, L5, L6, L7 };
-DECLARE_DYNDBG_CLASSMAP(map_level_names, DD_CLASS_TYPE_LEVEL_NAMES, 22,
-			"L0", "L1", "L2", "L3", "L4", "L5", "L6", "L7");
-DD_SYS_WRAP(level_names, p);
-DD_SYS_WRAP(level_names, T);
-
 /* stand-in for all pr_debug etc */
 #define prdbg(SYM) __pr_debug_cls(SYM, #SYM " msg\n")
 
@@ -102,10 +88,6 @@ static void do_cats(void)
 {
 	pr_debug("doing categories\n");
 
-	prdbg(LOW);
-	prdbg(MID);
-	prdbg(HI);
-
 	prdbg(D2_CORE);
 	prdbg(D2_DRIVER);
 	prdbg(D2_KMS);
@@ -129,14 +111,6 @@ static void do_levels(void)
 	prdbg(V5);
 	prdbg(V6);
 	prdbg(V7);
-
-	prdbg(L1);
-	prdbg(L2);
-	prdbg(L3);
-	prdbg(L4);
-	prdbg(L5);
-	prdbg(L6);
-	prdbg(L7);
 }
 
 static void do_prints(void)
-- 
2.52.0

[PATCH v7 19/31] selftests-dyndbg: add a dynamic_debug run_tests target

[Jim Cromie]

Add a selftest script for dynamic-debug.  The config requires
CONFIG_TEST_DYNAMIC_DEBUG=m and CONFIG_TEST_DYNAMIC_DEBUG_SUBMOD=m,
which tacitly requires either CONFIG_DYNAMIC_DEBUG=y or
CONFIG_DYNAMIC_DEBUG_CORE=y

ATM this has just basic_tests(), which modify pr_debug() flags in the
builtin params module.  This means they're available to manipulate and
observe the effects in "cat control".

This is backported from another feature branch; the support-fns (thx
Lukas) have unused features at the moment, they'll get used shortly.

The script enables simple virtme-ng testing:

   [jimc@gandalf b0-ftrace]$ vrun_t
   virtme-ng 1.32+115.g07b109d
   doing: vng --name v6.14-rc4-60-gd5f48427de0c \
	  --user root -v -p 4 -a dynamic_debug.verbose=3 V=1 \
	  -- ../tools/testing/selftests/dynamic_debug/dyndbg_selftest.sh
   virtme: waiting for virtiofsd to start
   ..

And add dynamic_debug to TARGETS, so `make run_tests` sees it properly
For the impatient, set TARGETS explicitly:

  [root@v6 selftests]# make TARGETS=dynamic_debug run_tests
  make[1]: Nothing to be done for 'all'.
  TAP version 13
  1..1
  # timeout set to 45
  # selftests: dynamic_debug: dyndbg_selftest.sh
  # # BASIC_TESTS    95.422122] dyndbg: query 0: 0"=_" mod:*
  ...

NOTES

check KCONFIG_CONFIG to avoid silly fails

Several tests are dependent upon config choices. Lets avoid failing
where that is noise.

The KCONFIG_CONFIG var exists to convey the config-file around.  If
the var names a file, read it and extract the relevant CONFIG items,
and use them to skip the dependent tests, thus avoiding the fails that
would follow, and the disruption to whatever CI is running these
selftests.

If the envar doesn't name a config-file, ".config" is assumed.

CONFIG_DYNAMIC_DEBUG=y:

basic-tests() and comma-terminator-tests() test for the presence of
the builtin pr_debugs in module/main.c, which I deemed stable and
therefore safe to count.  That said, the test fails if only
CONFIG_DYNAMIC_DEBUG_CORE=y is set.  It could be rewritten to test
against test-dynamic-debug.ko, but that just trades one config
dependence for another.

CONFIG_TEST_DYNAMIC_DEBUG=m

As written, test_percent_splitting() modprobes test_dynamic_debug,
enables several classes, and counts them.  It could be re-written to
work for the builtin module also, but builtin test modules are not a
common or desirable build/config.

Co-developed-by: Łukasz Bartosik <ukaszb@chromium.org>
Signed-off-by: Łukasz Bartosik <ukaszb@chromium.org>
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 MAINTAINERS                                   |   1 +
 tools/testing/selftests/Makefile              |   1 +
 .../testing/selftests/dynamic_debug/Makefile  |   9 +
 tools/testing/selftests/dynamic_debug/config  |   7 +
 .../dynamic_debug/dyndbg_selftest.sh          | 257 ++++++++++++++++++
 5 files changed, 275 insertions(+)
 create mode 100644 tools/testing/selftests/dynamic_debug/Makefile
 create mode 100644 tools/testing/selftests/dynamic_debug/config
 create mode 100755 tools/testing/selftests/dynamic_debug/dyndbg_selftest.sh

diff --git a/MAINTAINERS b/MAINTAINERS
index e8f06145fb54..b9d38a5b4f12 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -8772,6 +8772,7 @@ S:	Maintained
 F:	include/linux/dynamic_debug.h
 F:	lib/dynamic_debug.c
 F:	lib/test_dynamic_debug.c
+F:	tools/testing/selftests/dynamic_debug/*
 
 DYNAMIC INTERRUPT MODERATION
 M:	Tal Gilboa <talgi@nvidia.com>
diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile
index c46ebdb9b8ef..8a2542006e23 100644
--- a/tools/testing/selftests/Makefile
+++ b/tools/testing/selftests/Makefile
@@ -26,6 +26,7 @@ TARGETS += drivers/net/team
 TARGETS += drivers/net/virtio_net
 TARGETS += drivers/platform/x86/intel/ifs
 TARGETS += dt
+TARGETS += dynamic_debug
 TARGETS += efivarfs
 TARGETS += exec
 TARGETS += fchmodat2
diff --git a/tools/testing/selftests/dynamic_debug/Makefile b/tools/testing/selftests/dynamic_debug/Makefile
new file mode 100644
index 000000000000..6d06fa7f1040
--- /dev/null
+++ b/tools/testing/selftests/dynamic_debug/Makefile
@@ -0,0 +1,9 @@
+# SPDX-License-Identifier: GPL-2.0-only
+# borrowed from Makefile for user memory selftests
+
+# No binaries, but make sure arg-less "make" doesn't trigger "run_tests"
+all:
+
+TEST_PROGS := dyndbg_selftest.sh
+
+include ../lib.mk
diff --git a/tools/testing/selftests/dynamic_debug/config b/tools/testing/selftests/dynamic_debug/config
new file mode 100644
index 000000000000..0f906ff53908
--- /dev/null
+++ b/tools/testing/selftests/dynamic_debug/config
@@ -0,0 +1,7 @@
+
+# basic tests ref the builtin params module
+CONFIG_DYNAMIC_DEBUG=m
+
+# more testing is possible with these
+# CONFIG_TEST_DYNAMIC_DEBUG=m
+# CONFIG_TEST_DYNAMIC_DEBUG_SUBMOD=m
diff --git a/tools/testing/selftests/dynamic_debug/dyndbg_selftest.sh b/tools/testing/selftests/dynamic_debug/dyndbg_selftest.sh
new file mode 100755
index 000000000000..465fad3f392c
--- /dev/null
+++ b/tools/testing/selftests/dynamic_debug/dyndbg_selftest.sh
@@ -0,0 +1,257 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0-only
+
+V=${V:=0}  # invoke as V=1 $0  for global verbose
+RED="\033[0;31m"
+GREEN="\033[0;32m"
+YELLOW="\033[0;33m"
+BLUE="\033[0;34m"
+MAGENTA="\033[0;35m"
+CYAN="\033[0;36m"
+NC="\033[0;0m"
+error_msg=""
+
+[ -e /proc/dynamic_debug/control ] || {
+    echo -e "${RED}: this test requires CONFIG_DYNAMIC_DEBUG=y ${NC}"
+    exit 0 # nothing to test here, no good reason to fail.
+}
+
+# need info to avoid failures due to untestable configs
+
+[ -f "$KCONFIG_CONFIG" ] || KCONFIG_CONFIG=".config"
+if [ -f "$KCONFIG_CONFIG" ]; then
+    echo "# consulting KCONFIG_CONFIG: $KCONFIG_CONFIG"
+    grep -q "CONFIG_DYNAMIC_DEBUG=y" $KCONFIG_CONFIG ; LACK_DD_BUILTIN=$?
+    grep -q "CONFIG_TEST_DYNAMIC_DEBUG=m" $KCONFIG_CONFIG ; LACK_TMOD=$?
+    grep -q "CONFIG_TEST_DYNAMIC_DEBUG_SUBMOD=m" $KCONFIG_CONFIG ; LACK_TMOD_SUBMOD=$?
+    if [ $V -eq 1 ]; then
+	echo LACK_DD_BUILTIN: $LACK_DD_BUILTIN
+	echo LACK_TMOD: $LACK_TMOD
+	echo LACK_TMOD_SUBMOD: $LACK_TMOD_SUBMOD
+    fi
+else
+    LACK_DD_BUILTIN=0
+    LACK_TMOD=0
+    LACK_TMOD_SUBMOD=0
+fi
+
+function vx () {
+    echo $1 > /sys/module/dynamic_debug/parameters/verbose
+}
+
+function ddgrep () {
+    grep $1 /proc/dynamic_debug/control
+}
+
+function doprints () {
+    cat /sys/module/test_dynamic_debug/parameters/do_prints
+}
+
+function ddcmd () {
+    exp_exit_code=0
+    num_args=$#
+    if [ "${@:$#}" = "pass" ]; then
+	num_args=$#-1
+    elif [ "${@:$#}" = "fail" ]; then
+        num_args=$#-1
+	exp_exit_code=1
+    fi
+    args=${@:1:$num_args}
+    output=$((echo "$args" > /proc/dynamic_debug/control) 2>&1)
+    exit_code=$?
+    error_msg=$(echo $output | cut -d ":" -f 5 | sed -e 's/^[[:space:]]*//')
+    handle_exit_code $BASH_LINENO $FUNCNAME $exit_code $exp_exit_code
+}
+
+function handle_exit_code() {
+    local exp_exit_code=0
+    [ $# == 4 ] && exp_exit_code=$4
+    if [ $3 -ne $exp_exit_code ]; then
+        echo -e "${RED}: $BASH_SOURCE:$1 $2() expected to exit with code $exp_exit_code"
+	[ $3 == 1 ] && echo "Error: '$error_msg'"
+        exit
+    fi
+}
+
+# $1 - pattern to match, pattern in $1 is enclosed by spaces for a match ""\s$1\s"
+# $2 - number of times the pattern passed in $1 is expected to match
+# $3 - optional can be set either to "-r" or "-v"
+#       "-r" means relaxed matching in this case pattern provided in $1 is passed
+#       as is without enclosing it with spaces
+#       "-v" prints matching lines
+# $4 - optional when $3 is set to "-r" then $4 can be used to pass "-v"
+function check_match_ct {
+    pattern="\s$1\s"
+    exp_cnt=0
+
+    [ "$3" == "-r" ] && pattern="$1"
+    let cnt=$(ddgrep "$pattern" | wc -l)
+    if [ $V -eq 1 ] || [ "$3" == "-v" ] || [ "$4" == "-v" ]; then
+        echo -ne "${BLUE}" && ddgrep $pattern && echo -ne "${NC}"
+    fi
+    [ $# -gt 1 ] && exp_cnt=$2
+    if [ $cnt -ne $exp_cnt ]; then
+        echo -e "${RED}: $BASH_SOURCE:$BASH_LINENO check failed expected $exp_cnt on $1, got $cnt"
+        exit
+    else
+        echo ": $cnt matches on $1"
+    fi
+}
+
+# $1 - trace instance name
+# #2 - if > 0 then directory is expected to exist, if <= 0 then otherwise
+# $3 - "-v" for verbose
+function check_trace_instance_dir {
+    if [ -e /sys/kernel/tracing/instances/$1 ]; then
+        if [ "$3" == "-v" ] ; then
+            echo "ls -l /sys/kernel/tracing/instances/$1: "
+            ls -l /sys/kernel/tracing/instances/$1
+        fi
+	if [ $2 -le 0 ]; then
+            echo -e "${RED}: $BASH_SOURCE:$BASH_LINENO error trace instance \
+		    '/sys/kernel/tracing/instances/$1' does exist"
+	    exit
+	fi
+    else
+	if [ $2 -gt 0 ]; then
+            echo -e "${RED}: $BASH_SOURCE:$BASH_LINENO error trace instance \
+		    '/sys/kernel/tracing/instances/$1' does not exist"
+	    exit
+        fi
+    fi
+}
+
+function tmark {
+    echo $* > /sys/kernel/tracing/trace_marker
+}
+
+# $1 - trace instance name
+# $2 - line number
+# $3 - if > 0 then the instance is expected to be opened, otherwise
+# the instance is expected to be closed
+function check_trace_instance {
+    output=$(tail -n9 /proc/dynamic_debug/control | grep ": Opened trace instances" \
+	    | xargs -n1 | grep $1)
+    if [ "$output" != $1 ] && [ $3 -gt 0 ]; then
+        echo -e "${RED}: $BASH_SOURCE:$2 trace instance $1 is not opened"
+        exit
+    fi
+    if [ "$output" == $1 ] && [ $3 -le 0 ]; then
+        echo -e "${RED}: $BASH_SOURCE:$2 trace instance $1 is not closed"
+        exit
+    fi
+}
+
+function is_trace_instance_opened {
+    check_trace_instance $1 $BASH_LINENO 1
+}
+
+function is_trace_instance_closed {
+    check_trace_instance $1 $BASH_LINENO 0
+}
+
+# $1 - trace instance directory to delete
+# $2 - if > 0 then directory is expected to be deleted successfully, if <= 0 then otherwise
+function del_trace_instance_dir() {
+    exp_exit_code=1
+    [ $2 -gt 0 ] && exp_exit_code=0
+    output=$((rmdir /sys/kernel/debug/tracing/instances/$1) 2>&1)
+    exit_code=$?
+    error_msg=$(echo $output | cut -d ":" -f 3 | sed -e 's/^[[:space:]]*//')
+    handle_exit_code $BASH_LINENO $FUNCNAME $exit_code $exp_exit_code
+}
+
+function error_log_ref {
+    # to show what I got
+    : echo "# error-log-ref: $1"
+    : echo cat \$2
+}
+
+function ifrmmod {
+    lsmod | grep $1 2>&1>/dev/null && rmmod $1
+}
+
+# $1 - text to search for
+function search_trace() {
+    search_trace_name 0 1 $1
+}
+
+# $1 - trace instance name, 0 for global event trace
+# $2 - line number counting from the bottom
+# $3 - text to search for
+function search_trace_name() {
+	if [ "$1" = "0" ]; then
+	    buf=$(cat /sys/kernel/debug/tracing/trace)
+	    line=$(tail -$2 /sys/kernel/debug/tracing/trace | head -1 | sed -e 's/^[[:space:]]*//')
+	else
+	    buf=$(cat /sys/kernel/debug/tracing/instances/$1/trace)
+	    line=$(tail -$2 /sys/kernel/debug/tracing/instances/$1/trace | head -1 | \
+		   sed -e 's/^[[:space:]]*//')
+	fi
+	if [ $2 = 0 ]; then
+	    # whole-buf check
+	    output=$(echo $buf | grep "$3")
+	else
+	    output=$(echo $line | grep "$3")
+	fi
+	if [ "$output" = "" ]; then
+            echo -e "${RED}: $BASH_SOURCE:$BASH_LINENO search for '$3' failed \
+		    in line '$line' or '$buf'"
+	    exit
+	fi
+	if [ $V = 1 ]; then
+	    echo -e "${MAGENTA}: search_trace_name in $1 found: \n$output \nin:${BLUE} $buf ${NC}"
+        fi
+}
+
+# $1 - error message to check
+function check_err_msg() {
+    if [ "$error_msg" != "$1" ]; then
+        echo -e "${RED}: $BASH_SOURCE:$BASH_LINENO error message '$error_msg' \
+		does not match with '$1'"
+        exit
+    fi
+}
+
+function basic_tests {
+    echo -e "${GREEN}# BASIC_TESTS ${NC}"
+    if [ $LACK_DD_BUILTIN -eq 1 ]; then
+	echo "SKIP"
+	return
+    fi
+    ddcmd =_ # zero everything
+    check_match_ct =p 0
+
+    # module params are builtin to handle boot args
+    check_match_ct '\[params\]' 4 -r
+    ddcmd module params +mpf
+    check_match_ct =pmf 4
+
+    # multi-cmd input, newline separated, with embedded comments
+    cat <<"EOF" > /proc/dynamic_debug/control
+      module params =_				# clear params
+      module params +mf				# set flags
+      module params func parse_args +sl		# other flags
+EOF
+    check_match_ct =mf 3
+    check_match_ct =mfsl 1
+    ddcmd =_
+}
+
+tests_list=(
+    basic_tests
+)
+
+# Run tests
+
+ifrmmod test_dynamic_debug_submod
+ifrmmod test_dynamic_debug
+
+for test in "${tests_list[@]}"
+do
+    $test
+    echo ""
+done
+echo -en "${GREEN}# Done on: "
+date
+echo -en "${NC}"
-- 
2.52.0

[PATCH v7 20/31] dyndbg: change __dynamic_func_call_cls* macros into expressions

[Jim Cromie]

The Xe driver's XE_IOCTL_DBG macro calls drm_dbg() from inside an if
(expression).  This breaks when CONFIG_DRM_USE_DYNAMIC_DEBUG=y because
the invoked macro has a do-while-0 wrapper, and is not an expression.

   if (cond && (drm_dbg("expr-form"),1)) {
      ... do some more stuff
   }

Fix for this usage by changing __dynamic_func_call_cls{,_no_desc}
macros into expressions, by replacing the do-while-0s with a ({ })
wrapper.  In the common usage, the trailing ';' converts the
expression into a statement.

   drm_dbg("statement form");

Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 include/linux/dynamic_debug.h | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index d543b84d447e..c4ebbccca5d1 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -217,20 +217,20 @@ void __dynamic_ibdev_dbg(struct _ddebug *descriptor,
  * (|_cls):	adds in _DPRINT_CLASS_DFLT as needed
  * (|_no_desc):	former gets callsite descriptor as 1st arg (for prdbgs)
  */
-#define __dynamic_func_call_cls(id, cls, fmt, func, ...) do {	\
+#define __dynamic_func_call_cls(id, cls, fmt, func, ...) ({	\
 	DEFINE_DYNAMIC_DEBUG_METADATA_CLS(id, cls, fmt);	\
 	if (DYNAMIC_DEBUG_BRANCH(id))				\
 		func(&id, ##__VA_ARGS__);			\
-} while (0)
+})
 #define __dynamic_func_call(id, fmt, func, ...)				\
 	__dynamic_func_call_cls(id, _DPRINTK_CLASS_DFLT, fmt,		\
 				func, ##__VA_ARGS__)
 
-#define __dynamic_func_call_cls_no_desc(id, cls, fmt, func, ...) do {	\
+#define __dynamic_func_call_cls_no_desc(id, cls, fmt, func, ...) ({	\
 	DEFINE_DYNAMIC_DEBUG_METADATA_CLS(id, cls, fmt);		\
 	if (DYNAMIC_DEBUG_BRANCH(id))					\
 		func(__VA_ARGS__);					\
-} while (0)
+})
 #define __dynamic_func_call_no_desc(id, fmt, func, ...)			\
 	__dynamic_func_call_cls_no_desc(id, _DPRINTK_CLASS_DFLT,	\
 					fmt, func, ##__VA_ARGS__)
-- 
2.52.0

[PATCH v7 21/31] dyndbg-API: replace DECLARE_DYNDBG_CLASSMAP

[Jim Cromie]

commit aad0214f3026 ("dyndbg: add DECLARE_DYNDBG_CLASSMAP macro")

DECLARE_DYNDBG_CLASSMAP() has a design error; its usage fails a
basic K&R rule: "define once, refer many times".

When CONFIG_DRM_USE_DYNAMIC_DEBUG=y, it is used across DRM core &
drivers; each invocation allocates/inits the classmap understood by
that module.  They *all* must match for the DRM modules to respond
consistently when drm.debug categories are enabled.  This is at least
a maintenance hassle.

Worse, its the root-cause of the CONFIG_DRM_USE_DYNAMIC_DEBUG=Y
regression; its use in both core & drivers obfuscates the 2 roles,
muddling the design, yielding an incomplete initialization when
modprobing drivers:

1st drm.ko loads, and dyndbg initializes its drm.debug callsites, then
a drm-driver loads, but too late for the drm.debug enablement.

And that gave us:
commit bb2ff6c27bc9 ("drm: Disable dynamic debug as broken")

So retire it, replace with 2 macros:
  DYNAMIC_DEBUG_CLASSMAP_DEFINE - invoked once from core - drm.ko
  DYNAMIC_DEBUG_CLASSMAP_USE    - from all drm drivers and helpers.
  NB: name-space de-noise

DYNAMIC_DEBUG_CLASSMAP_DEFINE: this reworks DECLARE_DYNDBG_CLASSMAP,
basically by dropping the static qualifier on the classmap, and
exporting it instead.

DYNAMIC_DEBUG_CLASSMAP_USE: then refers to the exported var by name:
  used from drivers, helper-mods
  lets us drop the repetitive "classname" declarations
  fixes 2nd-defn problem
  creates a ddebug_class_user record in new __dyndbg_class_users section
  new section is scanned "differently"

DECLARE_DYNDBG_CLASSMAP is preserved temporarily, to decouple DRM
adaptation work and avoid compile-errs before its done.

The DEFINE,USE distinction, and the separate classmap-use record,
allows dyndbg to initialize the driver's & helper's drm.debug
callsites separately after each is modprobed.

Basically, the classmap initial scan is repeated for classmap-users.

dyndbg's existing __dyndbg_classes[] section does:

. catalogs the module's classmaps
. tells dyndbg about them, allowing >control
. DYNAMIC_DEBUG_CLASSMAP_DEFINE creates section records.
. we rename it to: __dyndbg_class_maps[]

this patch adds __dyndbg_class_users[] section:

. catalogs users of classmap definitions from elsewhere
. authorizes dyndbg to >control user's class'd prdbgs
. DYNAMIC_DEBUG_CLASSMAP_USE() creates section records.

Now ddebug_add_module(etal) can handle classmap-uses similar to (and
after) classmaps; when a dependent module is loaded, if it has
classmap-uses (to a classmap-def in another module), that module's
kernel params are scanned to find if it has a kparam that is wired to
dyndbg's param-ops, and whose classmap is the one being ref'd.

To support this, theres a few data/header changes:

new struct ddebug_class_user
  contains: user-module-name, &classmap-defn
  it records drm-driver's use of a classmap in the section, allowing lookup

struct ddebug_info gets 2 new fields for the new sections:
  class_users, num_class_users.
  set by dynamic_debug_init() for builtins.
  or by kernel/module/main:load_info() for loadable modules.

vmlinux.lds.h: new BOUNDED_SECTION for __dyndbg_class_users.
this creates start,len C symbol-names for the section.

TLDR ?

dynamic_debug.c: 2 changes from ddebug_add_module() & ddebug_change():

ddebug_add_module():

ddebug_attach_module_classes() is reworked/renamed/split into
debug_apply_class_maps(), ddebug_apply_class_users(), which both call
ddebug_apply_params().

ddebug_apply_params(new fn):

It scans module's/builtin kernel-params, calls ddebug_match_apply_kparam
for each to find any params/sysfs-nodes which may be wired to a classmap.

ddebug_match_apply_kparam(new fn):

1st, it tests the kernel-param.ops is dyndbg's; this guarantees that
the attached arg is a struct ddebug_class_param, which has a ref to
the param's state, and to the classmap defining the param's handling.

2nd, it requires that the classmap ref'd by the kparam is the one
we've been called for; modules can use many separate classmaps (as
test_dynamic_debug does).

Then apply the "parent" kparam's setting to the dependent module,
using ddebug_apply_class_bitmap().

ddebug_change(and callees) also gets adjustments:

ddebug_find_valid_class(): This does a search over the module's
classmaps, looking for the class FOO echo'd to >control.  So now it
searches over __dyndbg_class_users[] after __dyndbg_classes[].

ddebug_class_name(): return class-names for defined OR used classes.

test_dynamic_debug.c, test_dynamic_debug_submod.c:

This demonstrates the 2 types of classmaps & sysfs-params, following
the 4-part recipe:

0. define an enum for the classmap's class_ids
   drm.debug gives us DRM_UT_<*> (aka <T>)
   multiple classmaps in a module(s) must share 0-62 classid space.

1. DYNAMIC_DEBUG_CLASSMAP_DEFINE(classmap_name, .. "<T>")
   names the classes, maps them to consecutive class-ids.
   convention here is stringified ENUM_SYMBOLS
   these become API/ABI if 2 is done.

2. DYNAMIC_DEBUG_CLASSMAP_PARAM* (classmap_name)
   adds a controlling kparam to the class

3. DYNAMIC_DEBUG_CLASSMAP_USE(classmap_name)
   for subsystem/group/drivers to use extern created by 1.

Move all the enum declarations together, to better explain how they
share the 0..62 class-id space available to a module (non-overlapping
subranges).

reorg macros 2,3 by name.  This gives a tabular format, making it easy
to see the pattern of repetition, and the points of change.

And extend the test to replicate the 2-module (parent & dependent)
scenario which caused the CONFIG_DRM_USE_DYNAMIC_DEBUG=y regression
seen in drm & drivers.

The _submod.c is a 2-line file: #define _SUBMOD, #include parent.

This gives identical complements of prdbgs in parent & _submod, and
thus identical print behavior when all of: >control, >params, and
parent->_submod propagation are working correctly.

It also puts all the parent/_submod declarations together in the same
source; the new ifdef _SUBMOD block invokes DYNAMIC_DEBUG_CLASSMAP_USE
for the 2 test-interfaces.  I think this is clearer.

These 2 modules are both tristate, allowing 3 super/sub combos: Y/Y,
Y/M, M/M (not N/Y, since this is disallowed by dependence).

Y/Y, Y/M testing once exposed a missing __align(8) in the _METADATA
macro, which M/M didn't see, probably because the module-loader memory
placement constrained it from misalignment.

Fixes: aad0214f3026 ("dyndbg: add DECLARE_DYNDBG_CLASSMAP macro")
cc: linux-doc@vger.kernel.org
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
replace di with &dt->info, since its stale
fix dd_mark_vector_subrange macro param ordering to match kdoc
---
 MAINTAINERS                       |   2 +-
 include/asm-generic/vmlinux.lds.h |   1 +
 include/linux/dynamic_debug.h     | 139 +++++++++++++++++++++---
 kernel/module/main.c              |   3 +
 lib/Kconfig.debug                 |  24 ++++-
 lib/Makefile                      |   5 +
 lib/dynamic_debug.c               | 172 +++++++++++++++++++++++++-----
 lib/test_dynamic_debug.c          | 132 ++++++++++++++++-------
 lib/test_dynamic_debug_submod.c   |  14 +++
 9 files changed, 413 insertions(+), 79 deletions(-)
 create mode 100644 lib/test_dynamic_debug_submod.c

diff --git a/MAINTAINERS b/MAINTAINERS
index b9d38a5b4f12..b6c549cc27e6 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -8771,7 +8771,7 @@ M:	Jim Cromie <jim.cromie@gmail.com>
 S:	Maintained
 F:	include/linux/dynamic_debug.h
 F:	lib/dynamic_debug.c
-F:	lib/test_dynamic_debug.c
+F:	lib/test_dynamic_debug*.c
 F:	tools/testing/selftests/dynamic_debug/*
 
 DYNAMIC INTERRUPT MODERATION
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index da15cf0c16d0..c7d85b857997 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -367,6 +367,7 @@ defined(CONFIG_AUTOFDO_CLANG) || defined(CONFIG_PROPELLER_CLANG)
 	/* implement dynamic printk debug */				\
 	. = ALIGN(8);							\
 	BOUNDED_SECTION_BY(__dyndbg_class_maps, ___dyndbg_class_maps)	\
+	BOUNDED_SECTION_BY(__dyndbg_class_users, ___dyndbg_class_users)	\
 	BOUNDED_SECTION_BY(__dyndbg_descriptors, ___dyndbg_descs)	\
 	CODETAG_SECTIONS()						\
 	LIKELY_PROFILE()		       				\
diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index c4ebbccca5d1..905db0b49104 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -71,8 +71,11 @@ enum ddebug_class_map_type {
 	 */
 };
 
+/*
+ * map @class_names 0..N to consecutive constants starting at @base.
+ */
 struct _ddebug_class_map {
-	struct module *mod;	/* NULL for builtins */
+	const struct module *mod;	/* NULL for builtins */
 	const char *mod_name;
 	const char **class_names;
 	const int length;
@@ -80,10 +83,18 @@ struct _ddebug_class_map {
 	enum ddebug_class_map_type map_type;
 };
 
+struct _ddebug_class_user {
+	char *mod_name;
+	struct _ddebug_class_map *map;
+	const int base;		/* user offset to re-number the used map */
+};
+
 /*
- * @_ddebug_info: gathers module/builtin dyndbg_* __sections together.
+ * @_ddebug_info: gathers module/builtin __dyndbg_<T> __sections
+ * together, each is a vec_<T>: a struct { struct T start[], int len }.
+ *
  * For builtins, it is used as a cursor, with the inner structs
- * marking sub-vectors of the builtin __sections in DATA.
+ * marking sub-vectors of the builtin __sections in DATA_DATA
  */
 struct _ddebug_descs {
 	struct _ddebug *start;
@@ -95,10 +106,16 @@ struct _ddebug_class_maps {
 	int len;
 };
 
+struct _ddebug_class_users {
+	struct _ddebug_class_user *start;
+	int len;
+};
+
 struct _ddebug_info {
 	const char *mod_name;
 	struct _ddebug_descs descs;
 	struct _ddebug_class_maps maps;
+	struct _ddebug_class_users users;
 };
 
 struct _ddebug_class_param {
@@ -117,12 +134,81 @@ struct _ddebug_class_param {
 #if defined(CONFIG_DYNAMIC_DEBUG) || \
 	(defined(CONFIG_DYNAMIC_DEBUG_CORE) && defined(DYNAMIC_DEBUG_MODULE))
 
+/*
+ * dyndbg classmaps is modelled closely upon drm.debug:
+ *
+ *  1. run-time control via sysfs node (api/abi)
+ *  2. each bit 0..N controls a single "category"
+ *  3. a pr_debug can have only 1 category, not several.
+ *  4. "kind" is a compile-time constant: 0..N or BIT() thereof
+ *  5. macro impls - give compile-time resolution or fail.
+ *
+ * dyndbg classmaps design axioms/constraints:
+ *
+ *  . optimizing compilers use 1-5 above, so preserve them.
+ *  . classmaps.class_id *is* the category.
+ *  . classmap definers/users are modules.
+ *  . every user wants 0..N
+ *  . 0..N exposes as ABI
+ *  . no 1 use-case wants N > 32, 16 is more usable
+ *  . N <= 64 in *all* cases
+ *  . modules/subsystems make category/classmap decisions
+ *  . ie an enum: DRM has DRM_UT_CORE..DRM_UT_DRMRES
+ *  . some categories are exposed to user: ABI
+ *  . making modules change their numbering is bogus, avoid if possible
+ *
+ * We can solve for all these at once:
+ *  A: map class-names to a .class_id range at compile-time
+ *  B: allow only "class NAME" changes to class'd callsites at run-time
+ *  C: users/modules must manage 0..62 hardcoded .class_id range limit.
+ *  D: existing pr_debugs get CLASS_DFLT=63
+ *
+ * By mapping class-names at >control to class-ids underneath, and
+ * responding only to class-names DEFINEd or USEd by the module, we
+ * can private-ize the class-id, and adjust class'd pr_debugs only by
+ * their names.
+ *
+ * This give us:
+ *  E: class_ids without classnames are unreachable
+ *  F: user modules opt-in by DEFINEing a classmap and/or USEing another
+ *
+ * Multi-classmap modules/groups are supported, if the classmaps share
+ * the class_id space [0..62] without overlap/conflict.
+ *
+ * NOTE: Due to the integer class_id, this api cannot disallow these:
+ * __pr_debug_cls(0, "fake CORE msg");  works only if a classmap maps 0.
+ * __pr_debug_cls(22, "no such class"); compiles but is not reachable
+ */
+
 /**
- * DECLARE_DYNDBG_CLASSMAP - declare classnames known by a module
- * @_var:   a struct ddebug_class_map, passed to module_param_cb
- * @_type:  enum class_map_type, chooses bits/verbose, numeric/symbolic
- * @_base:  offset of 1st class-name. splits .class_id space
- * @classes: class-names used to control class'd prdbgs
+ * DYNAMIC_DEBUG_CLASSMAP_DEFINE - define debug classes used by a module.
+ * @_var:   name of the classmap, exported for other modules coordinated use.
+ * @_mapty: enum ddebug_class_map_type: 0:DISJOINT - independent, 1:LEVEL - v2>v1
+ * @_base:  reserve N classids starting at _base, to split 0..62 classid space
+ * @classes: names of the N classes.
+ *
+ * This tells dyndbg what class_ids the module is using: _base..+N, by
+ * mapping names onto them.  This qualifies "class NAME" >controls on
+ * the defining module, ignoring unknown names.
+ */
+#define DYNAMIC_DEBUG_CLASSMAP_DEFINE(_var, _mapty, _base, ...)		\
+	static const char *_var##_classnames[] = { __VA_ARGS__ };	\
+	extern struct _ddebug_class_map _var;				\
+	struct _ddebug_class_map __aligned(8) __used			\
+		__section("__dyndbg_class_maps") _var = {		\
+		.mod = THIS_MODULE,					\
+		.mod_name = KBUILD_MODNAME,				\
+		.base = (_base),					\
+		.map_type = (_mapty),					\
+		.length = ARRAY_SIZE(_var##_classnames),		\
+		.class_names = _var##_classnames,			\
+	};								\
+	EXPORT_SYMBOL(_var)
+
+/*
+ * XXX: keep this until DRM adapts to use the DEFINE/USE api, it
+ * differs from DYNAMIC_DEBUG_CLASSMAP_DEFINE by the lack of the
+ * extern/EXPORT on the struct init, and cascading thinkos.
  */
 #define DECLARE_DYNDBG_CLASSMAP(_var, _maptype, _base, ...)		\
 	static const char *_var##_classnames[] = { __VA_ARGS__ };	\
@@ -136,6 +222,26 @@ struct _ddebug_class_param {
 		.class_names = _var##_classnames,			\
 	}
 
+/**
+ * DYNAMIC_DEBUG_CLASSMAP_USE - refer to a classmap, DEFINEd elsewhere.
+ * @_var: name of the exported classmap var
+ * @_not_yet: _base-like, but applies only to this USEr. (if needed)
+ *
+ * This tells dyndbg that the module has prdbgs with classids defined
+ * in the named classmap.  This qualifies "class NAME" >controls on
+ * the user module, and ignores unknown names.
+ */
+#define DYNAMIC_DEBUG_CLASSMAP_USE(_var)				\
+	DYNAMIC_DEBUG_CLASSMAP_USE_(_var, 0, __UNIQUE_ID(_ddebug_class_user))
+#define DYNAMIC_DEBUG_CLASSMAP_USE_(_var, _base, _uname)		\
+	extern struct _ddebug_class_map _var;				\
+	static struct _ddebug_class_user __aligned(8) __used		\
+	__section("__dyndbg_class_users") _uname = {			\
+		.mod_name = KBUILD_MODNAME,				\
+		.map = &(_var),						\
+		.base = _base						\
+	}
+
 extern __printf(2, 3)
 void __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...);
 
@@ -287,12 +393,18 @@ void __dynamic_ibdev_dbg(struct _ddebug *descriptor,
 				   KERN_DEBUG, prefix_str, prefix_type,	\
 				   rowsize, groupsize, buf, len, ascii)
 
-/* for test only, generally expect drm.debug style macro wrappers */
-#define __pr_debug_cls(cls, fmt, ...) do {			\
+/*
+ * This is the "model" class variant of pr_debug.  It is not really
+ * intended for direct use; I'd encourage DRM-style drm_dbg_<T>
+ * macros for the interface, along with an enum for the <T>
+ *
+ * __printf(2, 3) would apply.
+ */
+#define __pr_debug_cls(cls, fmt, ...) ({			\
 	BUILD_BUG_ON_MSG(!__builtin_constant_p(cls),		\
 			 "expecting constant class int/enum");	\
 	dynamic_pr_debug_cls(cls, fmt, ##__VA_ARGS__);		\
-	} while (0)
+})
 
 #else /* !(CONFIG_DYNAMIC_DEBUG || (CONFIG_DYNAMIC_DEBUG_CORE && DYNAMIC_DEBUG_MODULE)) */
 
@@ -300,6 +412,8 @@ void __dynamic_ibdev_dbg(struct _ddebug *descriptor,
 #include <linux/errno.h>
 #include <linux/printk.h>
 
+#define DYNAMIC_DEBUG_CLASSMAP_DEFINE(_var, _mapty, _base, ...)
+#define DYNAMIC_DEBUG_CLASSMAP_USE(_var)
 #define DEFINE_DYNAMIC_DEBUG_METADATA(name, fmt)
 #define DYNAMIC_DEBUG_BRANCH(descriptor) false
 #define DECLARE_DYNDBG_CLASSMAP(...)
@@ -346,8 +460,7 @@ static inline int param_set_dyndbg_classes(const char *instr, const struct kerne
 static inline int param_get_dyndbg_classes(char *buffer, const struct kernel_param *kp)
 { return 0; }
 
-#endif
-
+#endif /* !CONFIG_DYNAMIC_DEBUG_CORE */
 
 extern const struct kernel_param_ops param_ops_dyndbg_classes;
 
diff --git a/kernel/module/main.c b/kernel/module/main.c
index 1ccc5d4399c3..ee35238d2d0a 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -2716,6 +2716,9 @@ static int find_module_sections(struct module *mod, struct load_info *info)
 	mod->dyndbg_info.maps.start = section_objs(info, "__dyndbg_class_maps",
 						   sizeof(*mod->dyndbg_info.maps.start),
 						   &mod->dyndbg_info.maps.len);
+	mod->dyndbg_info.users.start = section_objs(info, "__dyndbg_class_users",
+						   sizeof(*mod->dyndbg_info.users.start),
+						   &mod->dyndbg_info.users.len);
 #endif
 
 	return 0;
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 713cc94caa02..9bc6f76830a6 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -2979,12 +2979,26 @@ config TEST_STATIC_KEYS
 	  If unsure, say N.
 
 config TEST_DYNAMIC_DEBUG
-	tristate "Test DYNAMIC_DEBUG"
-	depends on DYNAMIC_DEBUG
+	tristate "Build test-dynamic-debug module"
+	depends on DYNAMIC_DEBUG || DYNAMIC_DEBUG_CORE
 	help
-	  This module registers a tracer callback to count enabled
-	  pr_debugs in a 'do_debugging' function, then alters their
-	  enablements, calls the function, and compares counts.
+	  This module exercises/demonstrates dyndbg's classmap API, by
+	  creating 2 classes: a DISJOINT classmap (supporting DRM.debug)
+	  and a LEVELS/VERBOSE classmap (like verbose2 > verbose1).
+
+	  If unsure, say N.
+
+config TEST_DYNAMIC_DEBUG_SUBMOD
+	tristate "Build test-dynamic-debug submodule"
+	default m
+	depends on DYNAMIC_DEBUG || DYNAMIC_DEBUG_CORE
+	depends on TEST_DYNAMIC_DEBUG
+	help
+	  This sub-module uses a classmap defined and exported by the
+	  parent module, recapitulating drm & driver's shared use of
+	  drm.debug to control enabled debug-categories.
+	  It is tristate, independent of parent, to allow testing all
+	  proper combinations of parent=y/m submod=y/m.
 
 	  If unsure, say N.
 
diff --git a/lib/Makefile b/lib/Makefile
index 1ab2c4be3b66..63ed5fabada2 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -82,6 +82,9 @@ obj-$(CONFIG_TEST_RHASHTABLE) += test_rhashtable.o
 obj-$(CONFIG_TEST_STATIC_KEYS) += test_static_keys.o
 obj-$(CONFIG_TEST_STATIC_KEYS) += test_static_key_base.o
 obj-$(CONFIG_TEST_DYNAMIC_DEBUG) += test_dynamic_debug.o
+obj-$(CONFIG_TEST_DYNAMIC_DEBUG_SUBMOD) += test_dynamic_debug_submod.o
+obj-$(CONFIG_TEST_PRINTF) += test_printf.o
+obj-$(CONFIG_TEST_SCANF) += test_scanf.o
 
 obj-$(CONFIG_TEST_BITMAP) += test_bitmap.o
 ifeq ($(CONFIG_CC_IS_CLANG)$(CONFIG_KASAN),yy)
@@ -204,6 +207,8 @@ obj-$(CONFIG_ARCH_NEED_CMPXCHG_1_EMU) += cmpxchg-emu.o
 obj-$(CONFIG_DYNAMIC_DEBUG_CORE) += dynamic_debug.o
 #ensure exported functions have prototypes
 CFLAGS_dynamic_debug.o := -DDYNAMIC_DEBUG_MODULE
+CFLAGS_test_dynamic_debug.o := -DDYNAMIC_DEBUG_MODULE
+CFLAGS_test_dynamic_debug_submod.o := -DDYNAMIC_DEBUG_MODULE
 
 obj-$(CONFIG_SYMBOLIC_ERRNAME) += errname.o
 
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 63bfe1891a9e..c60c2142f8ac 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -29,6 +29,7 @@
 #include <linux/string_helpers.h>
 #include <linux/uaccess.h>
 #include <linux/dynamic_debug.h>
+
 #include <linux/debugfs.h>
 #include <linux/slab.h>
 #include <linux/jump_label.h>
@@ -43,6 +44,8 @@ extern struct _ddebug __start___dyndbg_descs[];
 extern struct _ddebug __stop___dyndbg_descs[];
 extern struct _ddebug_class_map __start___dyndbg_class_maps[];
 extern struct _ddebug_class_map __stop___dyndbg_class_maps[];
+extern struct _ddebug_class_user __start___dyndbg_class_users[];
+extern struct _ddebug_class_user __stop___dyndbg_class_users[];
 
 struct ddebug_table {
 	struct list_head link;
@@ -168,20 +171,37 @@ static void vpr_info_dq(const struct ddebug_query *query, const char *msg)
 		  query->first_lineno, query->last_lineno, query->class_string);
 }
 
-static struct _ddebug_class_map *ddebug_find_valid_class(struct ddebug_table const *dt,
-							 const char *class_string,
-							 int *class_id)
+#define vpr_di_info(di_p, msg_p, ...) ({				\
+	struct _ddebug_info const *_di = di_p;				\
+	v2pr_info(msg_p "module:%s nd:%d nc:%d nu:%d\n", ##__VA_ARGS__, \
+		  _di->mod_name, _di->descs.len, _di->maps.len,		\
+		  _di->users.len);					\
+	})
+
+static struct _ddebug_class_map *
+ddebug_find_valid_class(struct _ddebug_info const *di, const char *query_class, int *class_id)
 {
 	struct _ddebug_class_map *map;
+	struct _ddebug_class_user *cli;
 	int i, idx;
 
-	for_subvec(i, map, &dt->info, maps) {
-		idx = match_string(map->class_names, map->length, class_string);
+	for_subvec(i, map, di, maps) {
+		idx = match_string(map->class_names, map->length, query_class);
 		if (idx >= 0) {
+			vpr_di_info(di, "good-class: %s.%s ", map->mod_name, query_class);
 			*class_id = idx + map->base;
 			return map;
 		}
 	}
+	for_subvec(i, cli, di, users) {
+		idx = match_string(cli->map->class_names, cli->map->length, query_class);
+		if (idx >= 0) {
+			vpr_di_info(di, "class-ref: %s -> %s.%s ",
+				    cli->mod_name, cli->map->mod_name, query_class);
+			*class_id = idx + cli->map->base;
+			return cli->map;
+		}
+	}
 	*class_id = -ENOENT;
 	return NULL;
 }
@@ -238,8 +258,7 @@ static bool ddebug_match_desc(const struct ddebug_query *query,
 	return true;
 }
 
-static int ddebug_change(const struct ddebug_query *query,
-			 struct flag_settings *modifiers)
+static int ddebug_change(const struct ddebug_query *query, struct flag_settings *modifiers)
 {
 	int i;
 	struct ddebug_table *dt;
@@ -260,7 +279,8 @@ static int ddebug_change(const struct ddebug_query *query,
 			continue;
 
 		if (query->class_string) {
-			map = ddebug_find_valid_class(dt, query->class_string, &valid_class);
+			map = ddebug_find_valid_class(&dt->info, query->class_string,
+						      &valid_class);
 			if (!map)
 				continue;
 		} else {
@@ -590,7 +610,7 @@ static int ddebug_exec_query(char *query_string, const char *modname)
 
 /* handle multiple queries in query string, continue on error, return
    last error or number of matching callsites.  Module name is either
-   in param (for boot arg) or perhaps in query string.
+   in the modname arg (for boot args) or perhaps in query string.
 */
 static int ddebug_exec_queries(char *query, const char *modname)
 {
@@ -721,7 +741,7 @@ static int param_set_dyndbg_module_classes(const char *instr,
 /**
  * param_set_dyndbg_classes - classmap kparam setter
  * @instr: string echo>d to sysfs, input depends on map_type
- * @kp:    kp->arg has state: bits/lvl, map, map_type
+ * @kp:    kp->arg has state: bits/lvl, classmap, map_type
  *
  * enable/disable all class'd pr_debugs in the classmap. For LEVEL
  * map-types, enforce * relative levels by bitpos.
@@ -758,6 +778,7 @@ int param_get_dyndbg_classes(char *buffer, const struct kernel_param *kp)
 	default:
 		return -1;
 	}
+	return 0;
 }
 EXPORT_SYMBOL(param_get_dyndbg_classes);
 
@@ -1073,12 +1094,17 @@ static bool ddebug_class_in_range(const int class_id, const struct _ddebug_class
 static const char *ddebug_class_name(struct _ddebug_info *di, struct _ddebug *dp)
 {
 	struct _ddebug_class_map *map;
+	struct _ddebug_class_user *cli;
 	int i;
 
 	for_subvec(i, map, di, maps)
 		if (ddebug_class_in_range(dp->class_id, map))
 			return map->class_names[dp->class_id - map->base];
 
+	for_subvec(i, cli, di, users)
+		if (ddebug_class_in_range(dp->class_id, cli->map))
+			return cli->map->class_names[dp->class_id - cli->map->base];
+
 	return NULL;
 }
 
@@ -1159,9 +1185,85 @@ static const struct proc_ops proc_fops = {
 	.proc_write = ddebug_proc_write
 };
 
-static void ddebug_attach_module_classes(struct ddebug_table *dt, struct _ddebug_info *di)
+#define vpr_cm_info(cm_p, msg_fmt, ...) ({				\
+	struct _ddebug_class_map const *_cm = cm_p;			\
+	v2pr_info(msg_fmt "%s [%d..%d] %s..%s\n", ##__VA_ARGS__,	\
+		  _cm->mod_name, _cm->base, _cm->base + _cm->length,	\
+		  _cm->class_names[0], _cm->class_names[_cm->length - 1]); \
+	})
+
+static void ddebug_sync_classbits(const struct kernel_param *kp, const char *modname)
+{
+	const struct _ddebug_class_param *dcp = kp->arg;
+
+	/* clamp initial bitvec, mask off hi-bits */
+	if (*dcp->bits & ~CLASSMAP_BITMASK(dcp->map->length)) {
+		*dcp->bits &= CLASSMAP_BITMASK(dcp->map->length);
+		v2pr_info("preset classbits: %lx\n", *dcp->bits);
+	}
+	/* force class'd prdbgs (in USEr module) to match (DEFINEr module) class-param */
+	ddebug_apply_class_bitmap(dcp, dcp->bits, ~0, modname);
+	ddebug_apply_class_bitmap(dcp, dcp->bits, 0, modname);
+}
+
+static void ddebug_match_apply_kparam(const struct kernel_param *kp,
+				      const struct _ddebug_class_map *map,
+				      const char *mod_name)
+{
+	struct _ddebug_class_param *dcp;
+
+	if (kp->ops != &param_ops_dyndbg_classes)
+		return;
+
+	dcp = (struct _ddebug_class_param *)kp->arg;
+
+	if (map == dcp->map) {
+		v2pr_info(" kp:%s.%s =0x%lx", mod_name, kp->name, *dcp->bits);
+		vpr_cm_info(map, " %s maps ", mod_name);
+		ddebug_sync_classbits(kp, mod_name);
+	}
+}
+
+static void ddebug_apply_params(const struct _ddebug_class_map *cm, const char *mod_name)
+{
+	const struct kernel_param *kp;
+#if IS_ENABLED(CONFIG_MODULES)
+	int i;
+
+	if (cm->mod) {
+		vpr_cm_info(cm, "loaded classmap: %s ", mod_name);
+		/* ifdef protects the cm->mod->kp deref */
+		for (i = 0, kp = cm->mod->kp; i < cm->mod->num_kp; i++, kp++)
+			ddebug_match_apply_kparam(kp, cm, mod_name);
+	}
+#endif
+	if (!cm->mod) {
+		vpr_cm_info(cm, "builtin classmap: %s ", mod_name);
+		for (kp = __start___param; kp < __stop___param; kp++)
+			ddebug_match_apply_kparam(kp, cm, mod_name);
+	}
+}
+
+static void ddebug_apply_class_maps(const struct _ddebug_info *di)
 {
-	vpr_info("module:%s attached %d classes\n", dt->info.mod_name, dt->info.maps.len);
+	struct _ddebug_class_map *cm;
+	int i;
+
+	for_subvec(i, cm, di, maps)
+		ddebug_apply_params(cm, cm->mod_name);
+
+	vpr_di_info(di, "attached %d class-maps to ", i);
+}
+
+static void ddebug_apply_class_users(const struct _ddebug_info *di)
+{
+	struct _ddebug_class_user *cli;
+	int i;
+
+	for_subvec(i, cli, di, users)
+		ddebug_apply_params(cli->map, cli->mod_name);
+
+	vpr_di_info(di, "attached %d class-users to ", i);
 }
 
 /*
@@ -1190,6 +1292,22 @@ static void ddebug_attach_module_classes(struct ddebug_table *dt, struct _ddebug
 	(__dst)->info._vec.len = __nc;					\
 })
 
+static int __maybe_unused
+ddebug_class_range_overlap(struct _ddebug_class_map *cm,
+			   u64 *reserved_ids)
+{
+	u64 range = (((1ULL << cm->length) - 1) << cm->base);
+
+	if (range & *reserved_ids) {
+		pr_err("[%d..%d] on %s conflicts with %llx\n", cm->base,
+		       cm->base + cm->length - 1, cm->class_names[0],
+		       *reserved_ids);
+		return -EINVAL;
+	}
+	*reserved_ids |= range;
+	return 0;
+}
+
 /*
  * Allocate a new ddebug_table for the given module
  * and add it to the global list.
@@ -1198,6 +1316,7 @@ static int ddebug_add_module(struct _ddebug_info *di)
 {
 	struct ddebug_table *dt;
 	struct _ddebug_class_map *cm;
+	struct _ddebug_class_user *cli;
 	int i;
 
 	if (!di->descs.len)
@@ -1210,26 +1329,29 @@ static int ddebug_add_module(struct _ddebug_info *di)
 		pr_err("error adding module: %s\n", di->mod_name);
 		return -ENOMEM;
 	}
+	INIT_LIST_HEAD(&dt->link);
 	/*
-	 * For built-in modules, name (as supplied in di by its
-	 * callers) lives in .rodata and is immortal. For loaded
-	 * modules, name points at the name[] member of struct module,
-	 * which lives at least as long as this struct ddebug_table.
+	 * For built-in modules, di-> referents live in .*data and are
+	 * immortal. For loaded modules, di points at the dyndbg_info
+	 * member of its struct module, which lives at least as
+	 * long as this struct ddebug_table.
 	 */
 	dt->info = *di;
-
-	INIT_LIST_HEAD(&dt->link);
-
-	dd_mark_vector_subrange(i, cm, di, maps, dt);
-
-	if (di->maps.len)
-		ddebug_attach_module_classes(dt, di);
+	dd_mark_vector_subrange(i, cm, &dt->info, maps, dt);
+	dd_mark_vector_subrange(i, cli, &dt->info, users, dt);
+	/* now di is stale */
 
 	mutex_lock(&ddebug_lock);
 	list_add_tail(&dt->link, &ddebug_tables);
 	mutex_unlock(&ddebug_lock);
 
-	vpr_info("%3u debug prints in module %s\n", di->descs.len, di->mod_name);
+	if (dt->info.maps.len)
+		ddebug_apply_class_maps(&dt->info);
+	if (dt->info.users.len)
+		ddebug_apply_class_users(&dt->info);
+
+	vpr_info("%3u debug prints in module %s\n",
+		 dt->info.descs.len, dt->info.mod_name);
 	return 0;
 }
 
@@ -1379,8 +1501,10 @@ static int __init dynamic_debug_init(void)
 	struct _ddebug_info di = {
 		.descs.start = __start___dyndbg_descs,
 		.maps.start  = __start___dyndbg_class_maps,
+		.users.start = __start___dyndbg_class_users,
 		.descs.len = __stop___dyndbg_descs - __start___dyndbg_descs,
 		.maps.len  = __stop___dyndbg_class_maps - __start___dyndbg_class_maps,
+		.users.len = __stop___dyndbg_class_users - __start___dyndbg_class_users,
 	};
 
 #ifdef CONFIG_MODULES
diff --git a/lib/test_dynamic_debug.c b/lib/test_dynamic_debug.c
index 9c3e53cd26bd..6c4548f63512 100644
--- a/lib/test_dynamic_debug.c
+++ b/lib/test_dynamic_debug.c
@@ -6,11 +6,30 @@
  *      Jim Cromie	<jim.cromie@gmail.com>
  */
 
-#define pr_fmt(fmt) "test_dd: " fmt
+/*
+ * This file is built 2x, also making test_dynamic_debug_submod.ko,
+ * whose 2-line src file #includes this file.  This gives us a _submod
+ * clone with identical pr_debugs, without further maintenance.
+ *
+ * If things are working properly, they should operate identically
+ * when printed or adjusted by >control.  This eases visual perusal of
+ * the logs, and simplifies testing, by easing the proper accounting
+ * of expectations.
+ *
+ * It also puts both halves of the subsystem _DEFINE & _USE use case
+ * together, and integrates the common ENUM providing both class_ids
+ * and class-names to both _DEFINErs and _USERs.  I think this makes
+ * the usage clearer.
+ */
+#if defined(TEST_DYNAMIC_DEBUG_SUBMOD)
+  #define pr_fmt(fmt) "test_dd_submod: " fmt
+#else
+  #define pr_fmt(fmt) "test_dd: " fmt
+#endif
 
 #include <linux/module.h>
 
-/* run tests by reading or writing sysfs node: do_prints */
+/* re-gen output by reading or writing sysfs node: do_prints */
 
 static void do_prints(void); /* device under test */
 static int param_set_do_prints(const char *instr, const struct kernel_param *kp)
@@ -29,24 +48,39 @@ static const struct kernel_param_ops param_ops_do_prints = {
 };
 module_param_cb(do_prints, &param_ops_do_prints, NULL, 0600);
 
-/*
- * Using the CLASSMAP api:
- * - classmaps must have corresponding enum
- * - enum symbols must match/correlate with class-name strings in the map.
- * - base must equal enum's 1st value
- * - multiple maps must set their base to share the 0-30 class_id space !!
- *   (build-bug-on tips welcome)
- * Additionally, here:
- * - tie together sysname, mapname, bitsname, flagsname
- */
-#define DD_SYS_WRAP(_model, _flags)					\
-	static unsigned long bits_##_model;				\
-	static struct _ddebug_class_param _flags##_model = {		\
+#define CLASSMAP_BITMASK(width, base) (((1UL << (width)) - 1) << (base))
+
+/* sysfs param wrapper, proto-API */
+#define DYNAMIC_DEBUG_CLASSMAP_PARAM_(_model, _flags, _init)		\
+	static unsigned long bits_##_model = _init;			\
+	static struct _ddebug_class_param _flags##_##_model = {		\
 		.bits = &bits_##_model,					\
 		.flags = #_flags,					\
 		.map = &map_##_model,					\
 	};								\
-	module_param_cb(_flags##_##_model, &param_ops_dyndbg_classes, &_flags##_model, 0600)
+	module_param_cb(_flags##_##_model, &param_ops_dyndbg_classes,	\
+			&_flags##_##_model, 0600)
+#ifdef DEBUG
+#define DYNAMIC_DEBUG_CLASSMAP_PARAM(_model, _flags)		\
+	DYNAMIC_DEBUG_CLASSMAP_PARAM_(_model, _flags, ~0)
+#else
+#define DYNAMIC_DEBUG_CLASSMAP_PARAM(_model, _flags)		\
+	DYNAMIC_DEBUG_CLASSMAP_PARAM_(_model, _flags, 0)
+#endif
+
+/*
+ * Demonstrate/test DISJOINT & LEVEL typed classmaps with a sys-param.
+ *
+ * To comport with DRM debug-category (an int), classmaps map names to
+ * ids (also an int).  So a classmap starts with an enum; DRM has enum
+ * debug_category: with DRM_UT_<CORE,DRIVER,KMS,etc>.  We use the enum
+ * values as class-ids, and stringified enum-symbols as classnames.
+ *
+ * Modules with multiple CLASSMAPS must have enums with distinct
+ * value-ranges, as arranged below with explicit enum_sym = X inits.
+ * To clarify this sharing, declare the 2 enums now, for the 2
+ * different classmap types
+ */
 
 /* numeric input, independent bits */
 enum cat_disjoint_bits {
@@ -60,26 +94,51 @@ enum cat_disjoint_bits {
 	D2_LEASE,
 	D2_DP,
 	D2_DRMRES };
-DECLARE_DYNDBG_CLASSMAP(map_disjoint_bits, DD_CLASS_TYPE_DISJOINT_BITS, 0,
-			"D2_CORE",
-			"D2_DRIVER",
-			"D2_KMS",
-			"D2_PRIME",
-			"D2_ATOMIC",
-			"D2_VBL",
-			"D2_STATE",
-			"D2_LEASE",
-			"D2_DP",
-			"D2_DRMRES");
-DD_SYS_WRAP(disjoint_bits, p);
-DD_SYS_WRAP(disjoint_bits, T);
-
-/* numeric verbosity, V2 > V1 related */
-enum cat_level_num { V0 = 14, V1, V2, V3, V4, V5, V6, V7 };
-DECLARE_DYNDBG_CLASSMAP(map_level_num, DD_CLASS_TYPE_LEVEL_NUM, 14,
-		       "V0", "V1", "V2", "V3", "V4", "V5", "V6", "V7");
-DD_SYS_WRAP(level_num, p);
-DD_SYS_WRAP(level_num, T);
+
+/* numeric verbosity, V2 > V1 related.  V0 is > D2_DRMRES */
+enum cat_level_num { V0 = 16, V1, V2, V3, V4, V5, V6, V7 };
+
+/* recapitulate DRM's multi-classmap setup */
+#if !defined(TEST_DYNAMIC_DEBUG_SUBMOD)
+/*
+ * In single user, or parent / coordinator (drm.ko) modules, define
+ * classmaps on the client enums above, and then declares the PARAMS
+ * ref'g the classmaps.  Each is exported.
+ */
+DYNAMIC_DEBUG_CLASSMAP_DEFINE(map_disjoint_bits, DD_CLASS_TYPE_DISJOINT_BITS,
+			      D2_CORE,
+			      "D2_CORE",
+			      "D2_DRIVER",
+			      "D2_KMS",
+			      "D2_PRIME",
+			      "D2_ATOMIC",
+			      "D2_VBL",
+			      "D2_STATE",
+			      "D2_LEASE",
+			      "D2_DP",
+			      "D2_DRMRES");
+
+DYNAMIC_DEBUG_CLASSMAP_DEFINE(map_level_num, DD_CLASS_TYPE_LEVEL_NUM,
+			      V0, "V0", "V1", "V2", "V3", "V4", "V5", "V6", "V7");
+
+/*
+ * now add the sysfs-params
+ */
+
+DYNAMIC_DEBUG_CLASSMAP_PARAM(disjoint_bits, p);
+DYNAMIC_DEBUG_CLASSMAP_PARAM(level_num, p);
+
+#else /* TEST_DYNAMIC_DEBUG_SUBMOD */
+
+/*
+ * in submod/drm-drivers, use the classmaps defined in top/parent
+ * module above.
+ */
+
+DYNAMIC_DEBUG_CLASSMAP_USE(map_disjoint_bits);
+DYNAMIC_DEBUG_CLASSMAP_USE(map_level_num);
+
+#endif
 
 /* stand-in for all pr_debug etc */
 #define prdbg(SYM) __pr_debug_cls(SYM, #SYM " msg\n")
@@ -115,6 +174,7 @@ static void do_levels(void)
 
 static void do_prints(void)
 {
+	pr_debug("do_prints:\n");
 	do_cats();
 	do_levels();
 }
diff --git a/lib/test_dynamic_debug_submod.c b/lib/test_dynamic_debug_submod.c
new file mode 100644
index 000000000000..672aabf40160
--- /dev/null
+++ b/lib/test_dynamic_debug_submod.c
@@ -0,0 +1,14 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Kernel module for testing dynamic_debug
+ *
+ * Authors:
+ *      Jim Cromie	<jim.cromie@gmail.com>
+ */
+
+/*
+ * clone the parent, inherit all the properties, for consistency and
+ * simpler accounting in test expectations.
+ */
+#define TEST_DYNAMIC_DEBUG_SUBMOD
+#include "test_dynamic_debug.c"
-- 
2.52.0

[PATCH v7 22/31] dyndbg: detect class_id reservation conflicts

[Jim Cromie]

If a module _DEFINEs 2 or more classmaps, it must devise them to share
the per-module 0..62 class-id space; ie their respective base,+length
reservations cannot overlap.

To detect conflicts at modprobe, add ddebug_class_range_overlap(),
call it from ddebug_add_module(), and WARN and return -EINVAL when
they're detected.

This insures that class_id -> classname lookup has just 1 answer, so
the 1st-found search in find-class-name works properly.

test_dynamic_debug.c:

If built with -DFORCE_CLASSID_CONFLICT, the test-modules invoke 2
conflicting DYNAMIC_DEBUG_CLASSMAP_DEFINE() declarations, into parent
and the _submod.  These conflict with one of the good ones in the
parent (D2_CORE..etc), causing the modprobe(s) to warn

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 lib/dynamic_debug.c      | 10 ++++++++++
 lib/test_dynamic_debug.c |  8 ++++++++
 2 files changed, 18 insertions(+)

diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index c60c2142f8ac..e5a18a7d3780 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -1317,6 +1317,7 @@ static int ddebug_add_module(struct _ddebug_info *di)
 	struct ddebug_table *dt;
 	struct _ddebug_class_map *cm;
 	struct _ddebug_class_user *cli;
+	u64 reserved_ids = 0;
 	int i;
 
 	if (!di->descs.len)
@@ -1341,6 +1342,11 @@ static int ddebug_add_module(struct _ddebug_info *di)
 	dd_mark_vector_subrange(i, cli, &dt->info, users, dt);
 	/* now di is stale */
 
+	/* insure 2+ classmaps share the per-module 0..62 class_id space */
+	for_subvec(i, cm, &dt->info, maps)
+		if (ddebug_class_range_overlap(cm, &reserved_ids))
+			goto cleanup;
+
 	mutex_lock(&ddebug_lock);
 	list_add_tail(&dt->link, &ddebug_tables);
 	mutex_unlock(&ddebug_lock);
@@ -1353,6 +1359,10 @@ static int ddebug_add_module(struct _ddebug_info *di)
 	vpr_info("%3u debug prints in module %s\n",
 		 dt->info.descs.len, dt->info.mod_name);
 	return 0;
+cleanup:
+	WARN_ONCE("dyndbg multi-classmap conflict in %s\n", di->mod_name);
+	kfree(dt);
+	return -EINVAL;
 }
 
 /* helper for ddebug_dyndbg_(boot|module)_param_cb */
diff --git a/lib/test_dynamic_debug.c b/lib/test_dynamic_debug.c
index 6c4548f63512..1ba4be9a403a 100644
--- a/lib/test_dynamic_debug.c
+++ b/lib/test_dynamic_debug.c
@@ -128,6 +128,14 @@ DYNAMIC_DEBUG_CLASSMAP_DEFINE(map_level_num, DD_CLASS_TYPE_LEVEL_NUM,
 DYNAMIC_DEBUG_CLASSMAP_PARAM(disjoint_bits, p);
 DYNAMIC_DEBUG_CLASSMAP_PARAM(level_num, p);
 
+#ifdef FORCE_CLASSID_CONFLICT
+/*
+ * Enable with -Dflag on compile to test overlapping class-id range
+ * detection.  This should warn on modprobes.
+ */
+DYNDBG_CLASSMAP_DEFINE(classid_range_conflict, 0, D2_CORE + 1, "D3_CORE");
+#endif
+
 #else /* TEST_DYNAMIC_DEBUG_SUBMOD */
 
 /*
-- 
2.52.0

[PATCH v7 23/31] dyndbg: check DYNAMIC_DEBUG_CLASSMAP_DEFINE args at compile-time

[Jim Cromie]

Add __DYNAMIC_DEBUG_CLASSMAP_CHECK to implement the following
arg-checks at compile-time:

	0 <= _base < 63
	class_names is not empty
	class_names[0] is a string
	(class_names.length + _base) < 63

These compile-time checks will prevent several simple misuses, and
will issue obvious errors if violated.

4 such examples are added to test_dynamic_debug_submod.ko, and will
fail compilation if -DDD_MACRO_ARGCHECK is added to cflags.  This
wouldn't be a useful CONFIG_ item, since it breaks the build.

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 include/linux/dynamic_debug.h |  9 +++++++++
 lib/test_dynamic_debug.c      | 13 ++++++++++++-
 2 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index 905db0b49104..b19c9b1d53b6 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -180,6 +180,14 @@ struct _ddebug_class_param {
  * __pr_debug_cls(22, "no such class"); compiles but is not reachable
  */
 
+#define __DYNAMIC_DEBUG_CLASSMAP_CHECK(_clnames, _base)			\
+	static_assert(((_base) >= 0 && (_base) < _DPRINTK_CLASS_DFLT),	\
+		      "_base must be in 0..62");			\
+	static_assert(ARRAY_SIZE(_clnames) > 0,				\
+		      "classnames array size must be > 0");		\
+	static_assert((ARRAY_SIZE(_clnames) + (_base)) < _DPRINTK_CLASS_DFLT, \
+		      "_base + classnames.length exceeds range")
+
 /**
  * DYNAMIC_DEBUG_CLASSMAP_DEFINE - define debug classes used by a module.
  * @_var:   name of the classmap, exported for other modules coordinated use.
@@ -193,6 +201,7 @@ struct _ddebug_class_param {
  */
 #define DYNAMIC_DEBUG_CLASSMAP_DEFINE(_var, _mapty, _base, ...)		\
 	static const char *_var##_classnames[] = { __VA_ARGS__ };	\
+	__DYNAMIC_DEBUG_CLASSMAP_CHECK(_var##_classnames, (_base));	\
 	extern struct _ddebug_class_map _var;				\
 	struct _ddebug_class_map __aligned(8) __used			\
 		__section("__dyndbg_class_maps") _var = {		\
diff --git a/lib/test_dynamic_debug.c b/lib/test_dynamic_debug.c
index 1ba4be9a403a..b2bdfdfb6ba1 100644
--- a/lib/test_dynamic_debug.c
+++ b/lib/test_dynamic_debug.c
@@ -133,7 +133,7 @@ DYNAMIC_DEBUG_CLASSMAP_PARAM(level_num, p);
  * Enable with -Dflag on compile to test overlapping class-id range
  * detection.  This should warn on modprobes.
  */
-DYNDBG_CLASSMAP_DEFINE(classid_range_conflict, 0, D2_CORE + 1, "D3_CORE");
+DYNAMIC_DEBUG_CLASSMAP_DEFINE(classid_range_conflict, 0, D2_CORE + 1, "D3_CORE");
 #endif
 
 #else /* TEST_DYNAMIC_DEBUG_SUBMOD */
@@ -146,8 +146,19 @@ DYNDBG_CLASSMAP_DEFINE(classid_range_conflict, 0, D2_CORE + 1, "D3_CORE");
 DYNAMIC_DEBUG_CLASSMAP_USE(map_disjoint_bits);
 DYNAMIC_DEBUG_CLASSMAP_USE(map_level_num);
 
+#if defined(DD_MACRO_ARGCHECK)
+/*
+ * Exersize compile-time arg-checks in DYNAMIC_DEBUG_CLASSMAP_DEFINE.
+ * These will break compilation.
+ */
+DYNAMIC_DEBUG_CLASSMAP_DEFINE(fail_base_neg, 0, -1, "NEGATIVE_BASE_ARG");
+DYNAMIC_DEBUG_CLASSMAP_DEFINE(fail_base_big, 0, 100, "TOOBIG_BASE_ARG");
+DYNAMIC_DEBUG_CLASSMAP_DEFINE(fail_str_type, 0, 0, 1 /* not a string */);
+DYNAMIC_DEBUG_CLASSMAP_DEFINE(fail_emptyclass, 0, 0 /* ,empty */);
 #endif
 
+#endif /* TEST_DYNAMIC_DEBUG_SUBMOD */
+
 /* stand-in for all pr_debug etc */
 #define prdbg(SYM) __pr_debug_cls(SYM, #SYM " msg\n")
 
-- 
2.52.0

[PATCH v7 24/31] dyndbg-test: change do_prints testpoint to accept a loopct

[Jim Cromie]

echo 1000 > /sys/module/test_dynamic_debug/parameters/do_prints

This allows its use as a scriptable load generator, to generate
dynamic-prefix-emits for flag combinations vs undecorated messages.
This will make it easy to assess the cost of the prefixing.

Reading the ./do_prints node also prints messages (once) to the-log.

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 lib/test_dynamic_debug.c | 32 +++++++++++++++++++++-----------
 1 file changed, 21 insertions(+), 11 deletions(-)

diff --git a/lib/test_dynamic_debug.c b/lib/test_dynamic_debug.c
index b2bdfdfb6ba1..fa81177e8089 100644
--- a/lib/test_dynamic_debug.c
+++ b/lib/test_dynamic_debug.c
@@ -29,18 +29,25 @@
 
 #include <linux/module.h>
 
-/* re-gen output by reading or writing sysfs node: do_prints */
-
-static void do_prints(void); /* device under test */
+/* re-trigger debug output by reading or writing sysfs node: do_prints */
+static void do_prints(unsigned int); /* device under test */
 static int param_set_do_prints(const char *instr, const struct kernel_param *kp)
 {
-	do_prints();
+	int rc;
+	unsigned int ct;
+
+	rc = kstrtouint(instr, 0, &ct);
+	if (rc) {
+		pr_err("expecting numeric input, using 1 instead\n");
+		ct = 1;
+	}
+	do_prints(ct);
 	return 0;
 }
 static int param_get_do_prints(char *buffer, const struct kernel_param *kp)
 {
-	do_prints();
-	return scnprintf(buffer, PAGE_SIZE, "did do_prints\n");
+	do_prints(1);
+	return scnprintf(buffer, PAGE_SIZE, "did 1 do_prints\n");
 }
 static const struct kernel_param_ops param_ops_do_prints = {
 	.set = param_set_do_prints,
@@ -191,17 +198,20 @@ static void do_levels(void)
 	prdbg(V7);
 }
 
-static void do_prints(void)
+static void do_prints(unsigned int ct)
 {
-	pr_debug("do_prints:\n");
-	do_cats();
-	do_levels();
+	/* maybe clamp this */
+	pr_debug("do-prints %d times:\n", ct);
+	for (; ct; ct--) {
+		do_cats();
+		do_levels();
+	}
 }
 
 static int __init test_dynamic_debug_init(void)
 {
 	pr_debug("init start\n");
-	do_prints();
+	do_prints(1);
 	pr_debug("init done\n");
 	return 0;
 }
-- 
2.52.0

[PATCH v7 25/31] dyndbg-API: promote DYNAMIC_DEBUG_CLASSMAP_PARAM to API

[Jim Cromie]

move the DYNAMIC_DEBUG_CLASSMAP_PARAM macro from test-dynamic-debug.c into
the header, and refine it, by distinguishing the 2 use cases:

1.DYNAMIC_DEBUG_CLASSMAP_PARAM_REF
    for DRM, to pass in extern __drm_debug by name.
    dyndbg keeps bits in it, so drm can still use it as before

2.DYNAMIC_DEBUG_CLASSMAP_PARAM
    new user (test_dynamic_debug) doesn't need to share state,
    decls a static long unsigned int to store the bitvec.

__DYNAMIC_DEBUG_CLASSMAP_PARAM
   bottom layer - allocate,init a ddebug-class-param, module-param-cb.

Modify ddebug_sync_classbits() argtype deref inside the fn, to give
access to all kp members.

Also add stub macros, clean up and improve comments in test-code, and
add MODULE_DESCRIPTIONs.

cc: linux-doc@vger.kernel.org
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 include/linux/dynamic_debug.h   | 40 ++++++++++++++++++++++
 lib/dynamic_debug.c             | 60 ++++++++++++++++++++++-----------
 lib/test_dynamic_debug.c        | 47 ++++++++++----------------
 lib/test_dynamic_debug_submod.c |  9 ++++-
 4 files changed, 106 insertions(+), 50 deletions(-)

diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index b19c9b1d53b6..b1d11d946780 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -251,6 +251,44 @@ struct _ddebug_class_param {
 		.base = _base						\
 	}
 
+/**
+ * DYNAMIC_DEBUG_CLASSMAP_PARAM - control a ddebug-classmap from a sys-param
+ * @_name:  sysfs node name
+ * @_var:   name of the classmap var defining the controlled classes/bits
+ * @_flags: flags to be toggled, typically just 'p'
+ *
+ * Creates a sysfs-param to control the classes defined by the
+ * exported classmap, with bits 0..N-1 mapped to the classes named.
+ * This version keeps class-state in a private long int.
+ */
+#define DYNAMIC_DEBUG_CLASSMAP_PARAM(_name, _var, _flags)		\
+	static unsigned long _name##_bvec;				\
+	__DYNAMIC_DEBUG_CLASSMAP_PARAM(_name, _name##_bvec, _var, _flags)
+
+/**
+ * DYNAMIC_DEBUG_CLASSMAP_PARAM_REF - wrap a classmap with a controlling sys-param
+ * @_name:  sysfs node name
+ * @_bits:  name of the module's unsigned long bit-vector, ex: __drm_debug
+ * @_var:   name of the (exported) classmap var defining the classes/bits
+ * @_flags: flags to be toggled, typically just 'p'
+ *
+ * Creates a sysfs-param to control the classes defined by the
+ * exported clasmap, with bits 0..N-1 mapped to the classes named.
+ * This version keeps class-state in user @_bits.  This lets drm check
+ * __drm_debug elsewhere too.
+ */
+#define DYNAMIC_DEBUG_CLASSMAP_PARAM_REF(_name, _bits, _var, _flags)	\
+	__DYNAMIC_DEBUG_CLASSMAP_PARAM(_name, _bits, _var, _flags)
+
+#define __DYNAMIC_DEBUG_CLASSMAP_PARAM(_name, _bits, _var, _flags)	\
+	static struct _ddebug_class_param _name##_##_flags = {		\
+		.bits = &(_bits),					\
+		.flags = #_flags,					\
+		.map = &(_var),						\
+	};								\
+	module_param_cb(_name, &param_ops_dyndbg_classes,		\
+			&_name##_##_flags, 0600)
+
 extern __printf(2, 3)
 void __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...);
 
@@ -423,6 +461,8 @@ void __dynamic_ibdev_dbg(struct _ddebug *descriptor,
 
 #define DYNAMIC_DEBUG_CLASSMAP_DEFINE(_var, _mapty, _base, ...)
 #define DYNAMIC_DEBUG_CLASSMAP_USE(_var)
+#define DYNAMIC_DEBUG_CLASSMAP_PARAM(_name, _var, _flags)
+#define DYNAMIC_DEBUG_CLASSMAP_PARAM_REF(_name, _var, _flags)
 #define DEFINE_DYNAMIC_DEBUG_METADATA(name, fmt)
 #define DYNAMIC_DEBUG_BRANCH(descriptor) false
 #define DECLARE_DYNDBG_CLASSMAP(...)
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index e5a18a7d3780..1da2de7b1769 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -687,6 +687,30 @@ static int ddebug_apply_class_bitmap(const struct _ddebug_class_param *dcp,
 
 #define CLASSMAP_BITMASK(width) ((1UL << (width)) - 1)
 
+static void ddebug_class_param_clamp_input(unsigned long *inrep, const struct kernel_param *kp)
+{
+	const struct _ddebug_class_param *dcp = kp->arg;
+	const struct _ddebug_class_map *map = dcp->map;
+
+	switch (map->map_type) {
+	case DD_CLASS_TYPE_DISJOINT_BITS:
+		/* expect bits. mask and warn if too many */
+		if (*inrep & ~CLASSMAP_BITMASK(map->length)) {
+			pr_warn("%s: input: 0x%lx exceeds mask: 0x%lx, masking\n",
+				KP_NAME(kp), *inrep, CLASSMAP_BITMASK(map->length));
+			*inrep &= CLASSMAP_BITMASK(map->length);
+		}
+		break;
+	case DD_CLASS_TYPE_LEVEL_NUM:
+		/* input is bitpos, of highest verbosity to be enabled */
+		if (*inrep > map->length) {
+			pr_warn("%s: level:%ld exceeds max:%d, clamping\n",
+				KP_NAME(kp), *inrep, map->length);
+			*inrep = map->length;
+		}
+		break;
+	}
+}
 static int param_set_dyndbg_module_classes(const char *instr,
 					   const struct kernel_param *kp,
 					   const char *mod_name)
@@ -705,26 +729,15 @@ static int param_set_dyndbg_module_classes(const char *instr,
 		pr_err("expecting numeric input, not: %s > %s\n", instr, KP_NAME(kp));
 		return -EINVAL;
 	}
+	ddebug_class_param_clamp_input(&inrep, kp);
 
 	switch (map->map_type) {
 	case DD_CLASS_TYPE_DISJOINT_BITS:
-		/* expect bits. mask and warn if too many */
-		if (inrep & ~CLASSMAP_BITMASK(map->length)) {
-			pr_warn("%s: input: 0x%lx exceeds mask: 0x%lx, masking\n",
-				KP_NAME(kp), inrep, CLASSMAP_BITMASK(map->length));
-			inrep &= CLASSMAP_BITMASK(map->length);
-		}
 		v2pr_info("bits:0x%lx > %s.%s\n", inrep, mod_name ?: "*", KP_NAME(kp));
 		totct += ddebug_apply_class_bitmap(dcp, &inrep, *dcp->bits, mod_name);
 		*dcp->bits = inrep;
 		break;
 	case DD_CLASS_TYPE_LEVEL_NUM:
-		/* input is bitpos, of highest verbosity to be enabled */
-		if (inrep > map->length) {
-			pr_warn("%s: level:%ld exceeds max:%d, clamping\n",
-				KP_NAME(kp), inrep, map->length);
-			inrep = map->length;
-		}
 		old_bits = CLASSMAP_BITMASK(*dcp->lvl);
 		new_bits = CLASSMAP_BITMASK(inrep);
 		v2pr_info("lvl:%ld bits:0x%lx > %s\n", inrep, new_bits, KP_NAME(kp));
@@ -1195,15 +1208,24 @@ static const struct proc_ops proc_fops = {
 static void ddebug_sync_classbits(const struct kernel_param *kp, const char *modname)
 {
 	const struct _ddebug_class_param *dcp = kp->arg;
+	unsigned long new_bits;
 
-	/* clamp initial bitvec, mask off hi-bits */
-	if (*dcp->bits & ~CLASSMAP_BITMASK(dcp->map->length)) {
-		*dcp->bits &= CLASSMAP_BITMASK(dcp->map->length);
-		v2pr_info("preset classbits: %lx\n", *dcp->bits);
+	ddebug_class_param_clamp_input(dcp->bits, kp);
+
+	switch (dcp->map->map_type) {
+	case DD_CLASS_TYPE_DISJOINT_BITS:
+		v2pr_info("  %s: classbits: 0x%lx\n", KP_NAME(kp), *dcp->bits);
+		ddebug_apply_class_bitmap(dcp, dcp->bits, 0UL, modname);
+		break;
+	case DD_CLASS_TYPE_LEVEL_NUM:
+		new_bits = CLASSMAP_BITMASK(*dcp->lvl);
+		v2pr_info("  %s: lvl:%ld bits:0x%lx\n", KP_NAME(kp), *dcp->lvl, new_bits);
+		ddebug_apply_class_bitmap(dcp, &new_bits, 0UL, modname);
+		break;
+	default:
+		pr_err("bad map type %d\n", dcp->map->map_type);
+		return;
 	}
-	/* force class'd prdbgs (in USEr module) to match (DEFINEr module) class-param */
-	ddebug_apply_class_bitmap(dcp, dcp->bits, ~0, modname);
-	ddebug_apply_class_bitmap(dcp, dcp->bits, 0, modname);
 }
 
 static void ddebug_match_apply_kparam(const struct kernel_param *kp,
diff --git a/lib/test_dynamic_debug.c b/lib/test_dynamic_debug.c
index fa81177e8089..83c4d571a8c9 100644
--- a/lib/test_dynamic_debug.c
+++ b/lib/test_dynamic_debug.c
@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0-only
 /*
- * Kernel module for testing dynamic_debug
+ * Kernel module to test/demonstrate dynamic_debug features,
+ * particularly classmaps and their support for subsystems like DRM.
  *
  * Authors:
  *      Jim Cromie	<jim.cromie@gmail.com>
@@ -57,24 +58,6 @@ module_param_cb(do_prints, &param_ops_do_prints, NULL, 0600);
 
 #define CLASSMAP_BITMASK(width, base) (((1UL << (width)) - 1) << (base))
 
-/* sysfs param wrapper, proto-API */
-#define DYNAMIC_DEBUG_CLASSMAP_PARAM_(_model, _flags, _init)		\
-	static unsigned long bits_##_model = _init;			\
-	static struct _ddebug_class_param _flags##_##_model = {		\
-		.bits = &bits_##_model,					\
-		.flags = #_flags,					\
-		.map = &map_##_model,					\
-	};								\
-	module_param_cb(_flags##_##_model, &param_ops_dyndbg_classes,	\
-			&_flags##_##_model, 0600)
-#ifdef DEBUG
-#define DYNAMIC_DEBUG_CLASSMAP_PARAM(_model, _flags)		\
-	DYNAMIC_DEBUG_CLASSMAP_PARAM_(_model, _flags, ~0)
-#else
-#define DYNAMIC_DEBUG_CLASSMAP_PARAM(_model, _flags)		\
-	DYNAMIC_DEBUG_CLASSMAP_PARAM_(_model, _flags, 0)
-#endif
-
 /*
  * Demonstrate/test DISJOINT & LEVEL typed classmaps with a sys-param.
  *
@@ -105,12 +88,15 @@ enum cat_disjoint_bits {
 /* numeric verbosity, V2 > V1 related.  V0 is > D2_DRMRES */
 enum cat_level_num { V0 = 16, V1, V2, V3, V4, V5, V6, V7 };
 
-/* recapitulate DRM's multi-classmap setup */
+/*
+ * use/demonstrate multi-module-group classmaps, as for DRM
+ */
 #if !defined(TEST_DYNAMIC_DEBUG_SUBMOD)
 /*
- * In single user, or parent / coordinator (drm.ko) modules, define
- * classmaps on the client enums above, and then declares the PARAMS
- * ref'g the classmaps.  Each is exported.
+ * For module-groups of 1+, define classmaps with names (stringified
+ * enum-symbols) copied from above. 1-to-1 mapping is recommended.
+ * The classmap is exported, so that other modules in the group can
+ * link to it and control their prdbgs.
  */
 DYNAMIC_DEBUG_CLASSMAP_DEFINE(map_disjoint_bits, DD_CLASS_TYPE_DISJOINT_BITS,
 			      D2_CORE,
@@ -129,11 +115,13 @@ DYNAMIC_DEBUG_CLASSMAP_DEFINE(map_level_num, DD_CLASS_TYPE_LEVEL_NUM,
 			      V0, "V0", "V1", "V2", "V3", "V4", "V5", "V6", "V7");
 
 /*
- * now add the sysfs-params
+ * for use-cases that want it, provide a sysfs-param to set the
+ * classes in the classmap.  It is at this interface where the
+ * "v3>v2" property is applied to DD_CLASS_TYPE_LEVEL_NUM inputs.
  */
 
-DYNAMIC_DEBUG_CLASSMAP_PARAM(disjoint_bits, p);
-DYNAMIC_DEBUG_CLASSMAP_PARAM(level_num, p);
+DYNAMIC_DEBUG_CLASSMAP_PARAM(p_disjoint_bits,	map_disjoint_bits, p);
+DYNAMIC_DEBUG_CLASSMAP_PARAM(p_level_num,	map_level_num, p);
 
 #ifdef FORCE_CLASSID_CONFLICT
 /*
@@ -144,12 +132,10 @@ DYNAMIC_DEBUG_CLASSMAP_DEFINE(classid_range_conflict, 0, D2_CORE + 1, "D3_CORE")
 #endif
 
 #else /* TEST_DYNAMIC_DEBUG_SUBMOD */
-
 /*
- * in submod/drm-drivers, use the classmaps defined in top/parent
- * module above.
+ * the +1 members of a multi-module group refer to the classmap
+ * DEFINEd (and exported) above.
  */
-
 DYNAMIC_DEBUG_CLASSMAP_USE(map_disjoint_bits);
 DYNAMIC_DEBUG_CLASSMAP_USE(map_level_num);
 
@@ -224,6 +210,7 @@ static void __exit test_dynamic_debug_exit(void)
 module_init(test_dynamic_debug_init);
 module_exit(test_dynamic_debug_exit);
 
+MODULE_DESCRIPTION("test/demonstrate dynamic-debug features");
 MODULE_AUTHOR("Jim Cromie <jim.cromie@gmail.com>");
 MODULE_DESCRIPTION("Kernel module for testing dynamic_debug");
 MODULE_LICENSE("GPL");
diff --git a/lib/test_dynamic_debug_submod.c b/lib/test_dynamic_debug_submod.c
index 672aabf40160..3adf3925fb86 100644
--- a/lib/test_dynamic_debug_submod.c
+++ b/lib/test_dynamic_debug_submod.c
@@ -1,6 +1,9 @@
 // SPDX-License-Identifier: GPL-2.0
 /*
- * Kernel module for testing dynamic_debug
+ * Kernel module to test/demonstrate dynamic_debug features,
+ * particularly classmaps and their support for subsystems, like DRM,
+ * which defines its drm_debug classmap in drm module, and uses it in
+ * helpers & drivers.
  *
  * Authors:
  *      Jim Cromie	<jim.cromie@gmail.com>
@@ -12,3 +15,7 @@
  */
 #define TEST_DYNAMIC_DEBUG_SUBMOD
 #include "test_dynamic_debug.c"
+
+MODULE_DESCRIPTION("test/demonstrate dynamic-debug subsystem support");
+MODULE_AUTHOR("Jim Cromie <jim.cromie@gmail.com>");
+MODULE_LICENSE("GPL");
-- 
2.52.0

[PATCH v7 26/31] dyndbg: treat comma as a token separator

[Jim Cromie]

Treat comma as a token terminator, just like a space.  This allows a
user to avoid quoting hassles when spaces are otherwise needed:

 :#> modprobe drm dyndbg=class,DRM_UT_CORE,+p\;class,DRM_UT_KMS,+p

or as a boot arg:

 drm.dyndbg=class,DRM_UT_CORE,+p  # todo: support multi-query here

Given the many ways a boot-line +args can be assembled and then passed
in/down/around shell based tools, this may allow side-stepping all
sorts of quoting hassles thru those layers.

existing query format:

 modprobe test_dynamic_debug dyndbg="class D2_CORE +p"

new format:

 modprobe test_dynamic_debug dyndbg=class,D2_CORE,+p

ALSO

selftests-dyndbg: add comma_terminator_tests

New fn validates parsing and effect of queries using combinations of
commas and spaces to delimit the tokens.

It manipulates pr-debugs in builtin module/params, so might have deps
I havent foreseen on odd configurations.

Co-developed-by: Łukasz Bartosik <ukaszb@chromium.org>
Signed-off-by: Łukasz Bartosik <ukaszb@chromium.org>
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 .../admin-guide/dynamic-debug-howto.rst       |  9 +++++---
 lib/dynamic_debug.c                           | 17 +++++++++++----
 .../dynamic_debug/dyndbg_selftest.sh          | 21 ++++++++++++++++++-
 3 files changed, 39 insertions(+), 8 deletions(-)

diff --git a/Documentation/admin-guide/dynamic-debug-howto.rst b/Documentation/admin-guide/dynamic-debug-howto.rst
index e76ccd987704..350d93834e19 100644
--- a/Documentation/admin-guide/dynamic-debug-howto.rst
+++ b/Documentation/admin-guide/dynamic-debug-howto.rst
@@ -78,11 +78,12 @@ Command Language Reference
 ==========================
 
 At the basic lexical level, a command is a sequence of words separated
-by spaces or tabs.  So these are all equivalent::
+by spaces, tabs, or commas.  So these are all equivalent::
 
   :#> ddcmd file svcsock.c line 1603 +p
   :#> ddcmd "file svcsock.c line 1603 +p"
   :#> ddcmd '  file   svcsock.c     line  1603 +p  '
+  :#> ddcmd file,svcsock.c,line,1603,+p
 
 Command submissions are bounded by a write() system call.
 Multiple commands can be written together, separated by ``;`` or ``\n``::
@@ -167,9 +168,11 @@ module
     The given string is compared against the module name
     of each callsite.  The module name is the string as
     seen in ``lsmod``, i.e. without the directory or the ``.ko``
-    suffix and with ``-`` changed to ``_``.  Examples::
+    suffix and with ``-`` changed to ``_``.
 
-	module sunrpc
+    Examples::
+
+	module,sunrpc	# with ',' as token separator
 	module nfsd
 	module drm*	# both drm, drm_kms_helper
 
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 1da2de7b1769..5ac7248d51bb 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -320,6 +320,14 @@ static int ddebug_change(const struct ddebug_query *query, struct flag_settings
 	return nfound;
 }
 
+static char *skip_spaces_and_commas(const char *str)
+{
+	str = skip_spaces(str);
+	while (*str == ',')
+		str = skip_spaces(++str);
+	return (char *)str;
+}
+
 /*
  * Split the buffer `buf' into space-separated words.
  * Handles simple " and ' quoting, i.e. without nested,
@@ -333,8 +341,8 @@ static int ddebug_tokenize(char *buf, char *words[], int maxwords)
 	while (*buf) {
 		char *end;
 
-		/* Skip leading whitespace */
-		buf = skip_spaces(buf);
+		/* Skip leading whitespace and comma */
+		buf = skip_spaces_and_commas(buf);
 		if (!*buf)
 			break;	/* oh, it was trailing whitespace */
 		if (*buf == '#')
@@ -350,7 +358,7 @@ static int ddebug_tokenize(char *buf, char *words[], int maxwords)
 				return -EINVAL;	/* unclosed quote */
 			}
 		} else {
-			for (end = buf; *end && !isspace(*end); end++)
+			for (end = buf; *end && !isspace(*end) && *end != ','; end++)
 				;
 			if (end == buf) {
 				pr_err("parse err after word:%d=%s\n", nwords,
@@ -622,7 +630,8 @@ static int ddebug_exec_queries(char *query, const char *modname)
 		if (split)
 			*split++ = '\0';
 
-		query = skip_spaces(query);
+		query = skip_spaces_and_commas(query);
+
 		if (!query || !*query || *query == '#')
 			continue;
 
diff --git a/tools/testing/selftests/dynamic_debug/dyndbg_selftest.sh b/tools/testing/selftests/dynamic_debug/dyndbg_selftest.sh
index 465fad3f392c..c7bf521f36ee 100755
--- a/tools/testing/selftests/dynamic_debug/dyndbg_selftest.sh
+++ b/tools/testing/selftests/dynamic_debug/dyndbg_selftest.sh
@@ -216,7 +216,7 @@ function check_err_msg() {
 function basic_tests {
     echo -e "${GREEN}# BASIC_TESTS ${NC}"
     if [ $LACK_DD_BUILTIN -eq 1 ]; then
-	echo "SKIP"
+	echo "SKIP - test requires params, which is a builtin module"
 	return
     fi
     ddcmd =_ # zero everything
@@ -238,8 +238,27 @@ EOF
     ddcmd =_
 }
 
+function comma_terminator_tests {
+    echo -e "${GREEN}# COMMA_TERMINATOR_TESTS ${NC}"
+    if [ $LACK_DD_BUILTIN -eq 1 ]; then
+	echo "SKIP - test requires params, which is a builtin module"
+	return
+    fi
+    # try combos of spaces & commas
+    check_match_ct '\[params\]' 4 -r
+    ddcmd module,params,=_		# commas as spaces
+    ddcmd module,params,+mpf		# turn on module's pr-debugs
+    check_match_ct =pmf 4
+    ddcmd ,module ,, ,  params, -p
+    check_match_ct =mf 4
+    ddcmd " , module ,,, ,  params, -m"	#
+    check_match_ct =f 4
+    ddcmd =_
+}
+
 tests_list=(
     basic_tests
+    comma_terminator_tests
 )
 
 # Run tests
-- 
2.52.0

[PATCH v7 27/31] dyndbg: split multi-query strings with %

[Jim Cromie]

Since commit
85f7f6c0edb8 ("dynamic_debug: process multiple debug-queries on a line")

Multi-query commands have been allowed:

  modprobe drm dyndbg="class DRM_UT_CORE +p; class DRM_UT_KMS +p"
  modprobe drm dyndbg=<<EOX
     class DRM_UT_CORE +p
     class DRM_UT_KMS +p
  EOX

More recently, the need for quoting was avoided by treating a comma
like a space/token-terminator:

  modprobe drm dyndbg=class,DRM_UT_CORE,+p\;class,DRM_UT_KMS,+p

That works, but it needs the escaped semicolon, which is a shell
special-char (one of the bash control operators), so it is brittle
when passed in/down/around scripts.  In particular, it fails when
passed to vng (virtme-ng).

So this patch adds '%' to the existing ';' and '\n' multi-command
separators, which is more shell-friendly, so you can more fully avoid
quoting and escaping hassles.

NOTE: it does break format matching on '%' patterns:

bash-5.2# ddcmd 'format "find-me: %foo" +p'
[  203.900581] dyndbg: read 26 bytes from userspace
[  203.900883] dyndbg: query 0: "format "find-me: " mod:*
[  203.901118] dyndbg: unclosed quote: find-me:
[  203.901355] dyndbg: tokenize failed
[  203.901529] dyndbg: query 1: "foo" +p" mod:*
[  203.901957] dyndbg: split into words: "foo"" "+p"
[  203.902243] dyndbg: op='+' flags=0x1 maskp=0xffffffff
[  203.902458] dyndbg: expecting pairs of match-spec <value>
[  203.902703] dyndbg: query parse failed
[  203.902871] dyndbg: processed 2 queries, with 0 matches, 2 errs
bash: echo: write error: Invalid argument

The '%' splits the input into 2 queries, and both fail.  Given the
limited utility of matching against the working parts of a format
string "foo: %d bar %s", nothing is actually lost here.

selftests-dyndbg: test_percent_splitting

This does basic testing of classmaps using '%' separated
multi-queries.  It modprobes test_dynamic_debug with several classes
enabled, and counts to verify that the expected sites show the
enablement in the control file.

Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 .../admin-guide/dynamic-debug-howto.rst       |  8 ++++---
 lib/dynamic_debug.c                           |  2 +-
 .../dynamic_debug/dyndbg_selftest.sh          | 24 +++++++++++++++++++
 3 files changed, 30 insertions(+), 4 deletions(-)

diff --git a/Documentation/admin-guide/dynamic-debug-howto.rst b/Documentation/admin-guide/dynamic-debug-howto.rst
index 350d93834e19..89ee15d7ae58 100644
--- a/Documentation/admin-guide/dynamic-debug-howto.rst
+++ b/Documentation/admin-guide/dynamic-debug-howto.rst
@@ -85,10 +85,12 @@ by spaces, tabs, or commas.  So these are all equivalent::
   :#> ddcmd '  file   svcsock.c     line  1603 +p  '
   :#> ddcmd file,svcsock.c,line,1603,+p
 
-Command submissions are bounded by a write() system call.
-Multiple commands can be written together, separated by ``;`` or ``\n``::
+Command submissions are bounded by a write() system call.  Multiple
+commands can be written together, separated by ``%``, ``;`` or ``\n``::
 
-  :#> ddcmd "func pnpacpi_get_resources +p; func pnp_assign_mem +p"
+  :#> ddcmd func foo +p % func bar +p
+  :#> ddcmd func foo +p \; func bar +p
+  :#> ddcmd "func foo +p ; func bar +p"
   :#> ddcmd <<"EOC"
   func pnpacpi_get_resources +p
   func pnp_assign_mem +p
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 5ac7248d51bb..c50836c262b4 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -626,7 +626,7 @@ static int ddebug_exec_queries(char *query, const char *modname)
 	int i, errs = 0, exitcode = 0, rc, nfound = 0;
 
 	for (i = 0; query; query = split) {
-		split = strpbrk(query, ";\n");
+		split = strpbrk(query, "%;\n");
 		if (split)
 			*split++ = '\0';
 
diff --git a/tools/testing/selftests/dynamic_debug/dyndbg_selftest.sh b/tools/testing/selftests/dynamic_debug/dyndbg_selftest.sh
index c7bf521f36ee..513f6cb1db1d 100755
--- a/tools/testing/selftests/dynamic_debug/dyndbg_selftest.sh
+++ b/tools/testing/selftests/dynamic_debug/dyndbg_selftest.sh
@@ -256,9 +256,33 @@ function comma_terminator_tests {
     ddcmd =_
 }
 
+function test_percent_splitting {
+    echo -e "${GREEN}# TEST_PERCENT_SPLITTING - multi-command splitting on % ${NC}"
+    if [ $LACK_TMOD -eq 1 ]; then
+	echo "SKIP - test requires test-dynamic-debug.ko"
+	return
+    fi
+    ifrmmod test_dynamic_debug_submod
+    ifrmmod test_dynamic_debug
+    ddcmd =_
+    modprobe test_dynamic_debug dyndbg=class,D2_CORE,+pf%class,D2_KMS,+pt%class,D2_ATOMIC,+pm
+    check_match_ct =pf 1
+    check_match_ct =pt 1
+    check_match_ct =pm 1
+    check_match_ct test_dynamic_debug 23 -r
+    # add flags to those callsites
+    ddcmd class,D2_CORE,+mf%class,D2_KMS,+lt%class,D2_ATOMIC,+ml
+    check_match_ct =pmf 1
+    check_match_ct =plt 1
+    check_match_ct =pml 1
+    check_match_ct test_dynamic_debug 23 -r
+    ifrmmod test_dynamic_debug
+}
+
 tests_list=(
     basic_tests
     comma_terminator_tests
+    test_percent_splitting
 )
 
 # Run tests
-- 
2.52.0

[PATCH v7 28/31] selftests-dyndbg: add test_mod_submod

[Jim Cromie]

This new test-fn runs 3 module/submodule modprobe scenarios, variously
using both the generic dyndbg=<queries> modprobe arg, and the
test-module's classmap-params to manipulate the test-mod*'s pr_debugs.
In all cases, the current flag-settings are counted and tested vs
expectations.

The 3rd scenario recapitulates the DRM_USE_DYNAMIC_DEBUG=y failure.

1. 2 modprobes (super then sub), with separate dyndbg=class-settings
   check module specific flag settings

2. modprobe submod, supermod is auto-loaded
   set supermod class-params
   check expected enablements in super & submod

3. modprobe super, with param=setting (like drm.debug=0x1ef)
   modprobe submod
   validate submod's class'd pr_debugs get properly enabled

The test uses multi-queries, with both commas and percents (to avoid
spaces and quoting).  This is the main reason the test wasn't earlier
in the patchset, closer to the classmap patches its validating.

With some tedium, the tests could be refactored to split out early
tests which avoid multi-cmds, and test only the class-params.

Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com>
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 .../dynamic_debug/dyndbg_selftest.sh          | 73 +++++++++++++++++++
 1 file changed, 73 insertions(+)

diff --git a/tools/testing/selftests/dynamic_debug/dyndbg_selftest.sh b/tools/testing/selftests/dynamic_debug/dyndbg_selftest.sh
index 513f6cb1db1d..09937dca3056 100755
--- a/tools/testing/selftests/dynamic_debug/dyndbg_selftest.sh
+++ b/tools/testing/selftests/dynamic_debug/dyndbg_selftest.sh
@@ -279,10 +279,83 @@ function test_percent_splitting {
     ifrmmod test_dynamic_debug
 }
 
+function test_mod_submod {
+    echo -e "${GREEN}# TEST_MOD_SUBMOD ${NC}"
+    if [ $LACK_TMOD -eq 1 ]; then
+	echo "SKIP - test requires test-dynamic-debug.ko"
+	return
+    fi
+    ifrmmod test_dynamic_debug_submod
+    ifrmmod test_dynamic_debug
+    ddcmd =_
+
+    # modprobe with class enablements
+    modprobe test_dynamic_debug \
+	dyndbg=class,D2_CORE,+pf%class,D2_KMS,+pt%class,D2_ATOMIC,+pm
+
+    check_match_ct '\[test_dynamic_debug\]' 23 -r
+    check_match_ct =pf 1
+    check_match_ct =pt 1
+    check_match_ct =pm 1
+
+    modprobe test_dynamic_debug_submod
+    check_match_ct test_dynamic_debug_submod 23 -r
+    check_match_ct '\[test_dynamic_debug\]' 23 -r
+    check_match_ct test_dynamic_debug 46 -r
+
+    # no enablements propagate here
+    check_match_ct =pf 1
+    check_match_ct =pt 1
+    check_match_ct =pm 1
+
+    # change classes again, this time submod too
+    ddcmd class,D2_CORE,+mf%class,D2_KMS,+lt%class,D2_ATOMIC,+ml "# add some prefixes"
+    check_match_ct =pmf 1
+    check_match_ct =plt 1
+    check_match_ct =pml 1
+    #  submod changed too
+    check_match_ct =mf 1
+    check_match_ct =lt 1
+    check_match_ct =ml 1
+
+    # now work the classmap-params
+    # fresh start, to clear all above flags (test-fn limits)
+    ifrmmod test_dynamic_debug_submod
+    ifrmmod test_dynamic_debug
+    modprobe test_dynamic_debug_submod # get supermod too
+
+    echo 1 > /sys/module/test_dynamic_debug/parameters/p_disjoint_bits
+    echo 4 > /sys/module/test_dynamic_debug/parameters/p_level_num
+    # 2 mods * ( V1-3 + D2_CORE )
+    check_match_ct =p 8
+    echo 3 > /sys/module/test_dynamic_debug/parameters/p_disjoint_bits
+    echo 0 > /sys/module/test_dynamic_debug/parameters/p_level_num
+    # 2 mods * ( D2_CORE, D2_DRIVER )
+    check_match_ct =p 4
+    echo 0x16 > /sys/module/test_dynamic_debug/parameters/p_disjoint_bits
+    echo 0 > /sys/module/test_dynamic_debug/parameters/p_level_num
+    # 2 mods * ( D2_DRIVER, D2_KMS, D2_ATOMIC )
+    check_match_ct =p 6
+
+    # recap DRM_USE_DYNAMIC_DEBUG regression
+    ifrmmod test_dynamic_debug_submod
+    ifrmmod test_dynamic_debug
+    # set super-mod params
+    modprobe test_dynamic_debug p_disjoint_bits=0x16 p_level_num=5
+    check_match_ct =p 7
+    modprobe test_dynamic_debug_submod
+    # see them picked up by submod
+    check_match_ct =p 14
+    ifrmmod test_dynamic_debug_submod
+    ifrmmod test_dynamic_debug
+}
+
 tests_list=(
     basic_tests
+    # these require test_dynamic_debug*.ko
     comma_terminator_tests
     test_percent_splitting
+    test_mod_submod
 )
 
 # Run tests
-- 
2.52.0

[PATCH v7 29/31] dyndbg: resolve "protection" of class'd pr_debug

[Jim Cromie]

classmap-v1 code protected class'd pr_debugs from unintended
changes by unclassed/_DFLT queries:

  # - to declutter examples:
  alias ddcmd='echo $* > /proc/dynamic_debug/control'

  # IOW, this should NOT alter drm.debug settings
  ddcmd -p

  # Instead, you must name the class to change it.
  # Protective but tedious
  ddcmd class DRM_UT_CORE +p

  # Or do it the (old school) subsystem way
  # This is ABI !!
  echo 1 > /sys/module/drm/parameters/debug

Since the debug sysfs-node is ABI, if dyndbg is going to implement it,
it must also honor its settings; it must at least protect against
accidental changes to its classes from legacy queries.

The protection allows all previously conceived queries to work the way
they always have; ie select the same set of pr_debugs, despite the
inclusion of whole new classes of pr_debugs.

But that choice has 2 downsides:

1. "name the class to change it" makes a tedious long-winded
interface, needing many commands to set DRM_UT_* one at a time.

2. It makes the class keyword special in some sense; the other
keywords skip only on query mismatch, otherwise the code falls thru to
adjust the pr-debug site.

 Jason Baron	didn't like v1 on point 2.
 Louis Chauvet	didn't like recent rev on point 1 tedium.

But that said: /sys/ is ABI, so this must be reliable:

  #> echo 0x1f > /sys/module/drm/parameters/debug

It 'just works' without dyndbg underneath; we must deliver that same
stability.  Convenience is secondary.

The new resolution:

If ABI is the blocking issue, then no ABI means no blocking issue.
IOW, if the classmap has no presence under /sys/*, ie no PARAM, there
is no ABI to guard, and no reason to enforce a tedious interface.

In the future, if DRM wants to alter this protection, that is
practical, but I think default-on is the correct mode.

So atm classes without a PARAM are unprotected at >control, allowing
admins their shortcuts.  I think this could satisfy all viewpoints.

That said, theres also a possibility of wildcard classes:

   #> ddcmd class '*' +p

Currently, the query-class is exact-matched against each module's
classmaps.names.  This gives precise behavior, a good basis.

But class wildcards are possible, they just did'nt appear useful for
DRM, whose classmap names are a flat DRM_UT_* namespace.

IOW, theres no useful selectivity there:

   #> ddcmd class "DRM_*" +p		# these enable every DRM_* class
   #> ddcmd class "DRM_UT_*" +p

   #> ddcmd class "DRM_UT_V*" +p	# finally select just 1: DRM_UT_VBL
   #> ddcmd class "DRM_UT_D*" +p	# but this gets 3

   #> ddcmd class "D*V*" +p		# here be dragons

But there is debatable utility in the feature.

   #> ddcmd class __DEFAULT__ -p	# what about this ?
   #> ddcmd -p				# thats what this does. automatically

Anyway, this patch does:

1. adds link field from _ddebug_class_map to the .controlling_param

2. sets it in ddebug_match_apply_kparam(), during modprobe/init,
   when options like drm.debug=VAL are handled.

3. ddebug_class_has_param() now checks .controlling_param

4. ddebug_class_wants_protection() macro renames 3.
   this frames it as a separable policy decision

5. ddebug_match_desc() gets the most attention:

a. move classmap consideration to the bottom
   this insures all other constraints act 1st.
   allows simpler 'final' decisions.

b. split class choices cleanly on query:
   class FOO vs none, and class'd vs _DPRINTK_CLASS_DFLT site.

c. calls 4 when applying a class-less query to a class'd pr_debug
   here we need a new fn to find the classmap with this .class_id

d. calls new ddebug_find_classmap_by_class_id().
   when class-less query looks at a class'd pr_debug.
   finds classmap, which can then decide, currently by PARAM existence.

NOTES:

protection is only against class-less queries, explicit "class FOO"
adjustments are allowed (that is the mechanism).

The drm.debug sysfs-node heavily under-specifies the class'd pr_debugs
it controls; none of the +mfls prefixing flags have any effect, and
each callsite remains individually controllable. drm.debug just
toggles the +p flag for all the modules' class'd pr_debugs.

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 include/linux/dynamic_debug.h |  14 ++--
 lib/dynamic_debug.c           | 127 +++++++++++++++++++++++++++-------
 2 files changed, 110 insertions(+), 31 deletions(-)

diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index b1d11d946780..b22da40e2583 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -75,6 +75,7 @@ enum ddebug_class_map_type {
  * map @class_names 0..N to consecutive constants starting at @base.
  */
 struct _ddebug_class_map {
+	struct _ddebug_class_param *controlling_param;
 	const struct module *mod;	/* NULL for builtins */
 	const char *mod_name;
 	const char **class_names;
@@ -259,7 +260,12 @@ struct _ddebug_class_param {
  *
  * Creates a sysfs-param to control the classes defined by the
  * exported classmap, with bits 0..N-1 mapped to the classes named.
- * This version keeps class-state in a private long int.
+ *
+ * Since sysfs-params are ABI, this also protects the classmap'd
+ * pr_debugs from un-class'd `echo -p > /proc/dynamic_debug/control`
+ * changes.
+ *
+ * This keeps class-state in a private long int.
  */
 #define DYNAMIC_DEBUG_CLASSMAP_PARAM(_name, _var, _flags)		\
 	static unsigned long _name##_bvec;				\
@@ -272,10 +278,8 @@ struct _ddebug_class_param {
  * @_var:   name of the (exported) classmap var defining the classes/bits
  * @_flags: flags to be toggled, typically just 'p'
  *
- * Creates a sysfs-param to control the classes defined by the
- * exported clasmap, with bits 0..N-1 mapped to the classes named.
- * This version keeps class-state in user @_bits.  This lets drm check
- * __drm_debug elsewhere too.
+ * Like DYNAMIC_DEBUG_CLASSMAP_PARAM, but maintains param-state in
+ * extern @_bits.  This lets DRM check __drm_debug elsewhere too.
  */
 #define DYNAMIC_DEBUG_CLASSMAP_PARAM_REF(_name, _bits, _var, _flags)	\
 	__DYNAMIC_DEBUG_CLASSMAP_PARAM(_name, _bits, _var, _flags)
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index c50836c262b4..f60a723a441b 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -206,6 +206,50 @@ ddebug_find_valid_class(struct _ddebug_info const *di, const char *query_class,
 	return NULL;
 }
 
+static bool ddebug_class_in_range(const int class_id, const struct _ddebug_class_map *map)
+{
+	return (class_id >= map->base &&
+		class_id < map->base + map->length);
+}
+
+static struct _ddebug_class_map *
+ddebug_find_map_by_class_id(struct _ddebug_info *di, int class_id)
+{
+	struct _ddebug_class_map *map;
+	struct _ddebug_class_user *cli;
+	int i;
+
+	for_subvec(i, map, di, maps)
+		if (ddebug_class_in_range(class_id, map))
+			return map;
+
+	for_subvec(i, cli, di, users)
+		if (ddebug_class_in_range(class_id, cli->map))
+			return cli->map;
+
+	return NULL;
+}
+
+/*
+ * classmaps-V1 protected classes from changes by legacy commands
+ * (those selecting _DPRINTK_CLASS_DFLT by omission).  This had the
+ * downside that saying "class FOO" for every change can get tedious.
+ *
+ * V2 is smarter, it protects class-maps if the defining module also
+ * calls DYNAMIC_DEBUG_CLASSMAP_PARAM to create a sysfs parameter.
+ * Since the author wants the knob, we should assume they intend to
+ * use it (in preference to "class FOO +p" >control), and want to
+ * trust its settings.  This gives protection when its useful, and not
+ * when its just tedious.
+ */
+static inline bool ddebug_class_has_param(const struct _ddebug_class_map *map)
+{
+	return !!(map->controlling_param);
+}
+
+/* re-framed as a policy choice */
+#define ddebug_class_wants_protection(map) (ddebug_class_has_param(map))
+
 /*
  * Search the tables for _ddebug's which match the given `query' and
  * apply the `flags' and `mask' to them.  Returns number of matching
@@ -214,11 +258,10 @@ ddebug_find_valid_class(struct _ddebug_info const *di, const char *query_class,
  */
 static bool ddebug_match_desc(const struct ddebug_query *query,
 			      struct _ddebug *dp,
-			      int valid_class)
+			      struct _ddebug_info *di,
+			      int selected_class)
 {
-	/* match site against query-class */
-	if (dp->class_id != valid_class)
-		return false;
+	struct _ddebug_class_map *site_map;
 
 	/* match against the source filename */
 	if (query->filename &&
@@ -255,7 +298,28 @@ static bool ddebug_match_desc(const struct ddebug_query *query,
 	    dp->lineno > query->last_lineno)
 		return false;
 
-	return true;
+	/*
+	 * above are all satisfied, so we can make final decisions:
+	 * 1- class FOO or implied class __DEFAULT__
+	 * 2- site.is_classed or not
+	 */
+	if (query->class_string) {
+		/* class FOO given, exact match required */
+		return (dp->class_id == selected_class);
+	}
+	/* query class __DEFAULT__ by omission. */
+	if (dp->class_id == _DPRINTK_CLASS_DFLT) {
+		/* un-classed site */
+		return true;
+	}
+	/* site is class'd */
+	site_map = ddebug_find_map_by_class_id(di, dp->class_id);
+	if (!site_map) {
+		WARN_ONCE(1, "unknown class_id %d, check %s's CLASSMAP definitions", dp->class_id, di->mod_name);
+		return false;
+	}
+	/* module(-param) decides protection */
+	return !ddebug_class_wants_protection(site_map);
 }
 
 static int ddebug_change(const struct ddebug_query *query, struct flag_settings *modifiers)
@@ -265,33 +329,31 @@ static int ddebug_change(const struct ddebug_query *query, struct flag_settings
 	unsigned int newflags;
 	unsigned int nfound = 0;
 	struct flagsbuf fbuf, nbuf;
-	struct _ddebug_class_map *map = NULL;
-	int valid_class;
+	int selected_class;
 
 	/* search for matching ddebugs */
 	mutex_lock(&ddebug_lock);
 	list_for_each_entry(dt, &ddebug_tables, link) {
 		struct _ddebug_info *di = &dt->info;
+		struct _ddebug_class_map *mods_map;
 
 		/* match against the module name */
 		if (query->module &&
 		    !match_wildcard(query->module, di->mod_name))
 			continue;
 
+		selected_class = _DPRINTK_CLASS_DFLT;
 		if (query->class_string) {
-			map = ddebug_find_valid_class(&dt->info, query->class_string,
-						      &valid_class);
-			if (!map)
+			mods_map = ddebug_find_valid_class(di, query->class_string,
+							   &selected_class);
+			if (!mods_map)
 				continue;
-		} else {
-			/* constrain query, do not touch class'd callsites */
-			valid_class = _DPRINTK_CLASS_DFLT;
 		}
 
 		for (i = 0; i < di->descs.len; i++) {
 			struct _ddebug *dp = &di->descs.start[i];
 
-			if (!ddebug_match_desc(query, dp, valid_class))
+			if (!ddebug_match_desc(query, dp, di, selected_class))
 				continue;
 
 			nfound++;
@@ -656,6 +718,7 @@ static int ddebug_exec_queries(char *query, const char *modname)
 }
 
 /* apply a new class-param setting */
+
 static int ddebug_apply_class_bitmap(const struct _ddebug_class_param *dcp,
 				     const unsigned long *new_bits,
 				     const unsigned long old_bits,
@@ -1107,12 +1170,6 @@ static void *ddebug_proc_next(struct seq_file *m, void *p, loff_t *pos)
 	return dp;
 }
 
-static bool ddebug_class_in_range(const int class_id, const struct _ddebug_class_map *map)
-{
-	return (class_id >= map->base &&
-		class_id < map->base + map->length);
-}
-
 static const char *ddebug_class_name(struct _ddebug_info *di, struct _ddebug *dp)
 {
 	struct _ddebug_class_map *map;
@@ -1237,25 +1294,36 @@ static void ddebug_sync_classbits(const struct kernel_param *kp, const char *mod
 	}
 }
 
-static void ddebug_match_apply_kparam(const struct kernel_param *kp,
-				      const struct _ddebug_class_map *map,
-				      const char *mod_name)
+static struct _ddebug_class_param *
+ddebug_get_classmap_kparam(const struct kernel_param *kp,
+			   const struct _ddebug_class_map *map)
 {
 	struct _ddebug_class_param *dcp;
 
 	if (kp->ops != &param_ops_dyndbg_classes)
-		return;
+		return false;
 
 	dcp = (struct _ddebug_class_param *)kp->arg;
 
-	if (map == dcp->map) {
+	return (map == dcp->map)
+		? dcp : (struct _ddebug_class_param *)NULL;
+}
+
+static void ddebug_match_apply_kparam(const struct kernel_param *kp,
+				      struct _ddebug_class_map *map,
+				      const char *mod_name)
+{
+	struct _ddebug_class_param *dcp = ddebug_get_classmap_kparam(kp, map);
+
+	if (dcp) {
+		map->controlling_param = dcp;
 		v2pr_info(" kp:%s.%s =0x%lx", mod_name, kp->name, *dcp->bits);
 		vpr_cm_info(map, " %s maps ", mod_name);
 		ddebug_sync_classbits(kp, mod_name);
 	}
 }
 
-static void ddebug_apply_params(const struct _ddebug_class_map *cm, const char *mod_name)
+static void ddebug_apply_params(struct _ddebug_class_map *cm, const char *mod_name)
 {
 	const struct kernel_param *kp;
 #if IS_ENABLED(CONFIG_MODULES)
@@ -1275,6 +1343,13 @@ static void ddebug_apply_params(const struct _ddebug_class_map *cm, const char *
 	}
 }
 
+/*
+ * called from add_module, ie early. it can find controlling kparams,
+ * which can/does? enable protection of this classmap from class-less
+ * queries, on the grounds that the user created the kparam, means to
+ * use it, and expects it to reflect reality.  We should oblige him,
+ * and protect those classmaps from classless "-p" changes.
+ */
 static void ddebug_apply_class_maps(const struct _ddebug_info *di)
 {
 	struct _ddebug_class_map *cm;
-- 
2.52.0

[PATCH v7 30/31] dyndbg: add DYNAMIC_DEBUG_CLASSMAP_USE_(dd_class_name, offset)

[Jim Cromie]

Allow a module to use 2 classmaps together that would otherwise have a
class_id range conflict.

Suppose drm-driver does:

  DYNAMIC_DEBUG_CLASSMAP_USE(drm_debug_classes);
  DYNAMIC_DEBUG_CLASSMAP_USE(drm_accel_xfer_debug);

And (for some reason) drm-accel will not define their constants to
avoid DRM's 0..10 reservations (seems a long stretch).

So I dont think this potential conflict would become an issue until we
have at least a 3-X-3 of classmap-defns X classmap-users

So drop this if its too speculative, knowing theres at least a
notional solution should the situation arise.

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 include/linux/dynamic_debug.h | 30 +++++++++++++++++++++++-------
 lib/dynamic_debug.c           | 19 ++++++++++++-------
 2 files changed, 35 insertions(+), 14 deletions(-)

diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index b22da40e2583..5307be8da5c1 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -87,7 +87,7 @@ struct _ddebug_class_map {
 struct _ddebug_class_user {
 	char *mod_name;
 	struct _ddebug_class_map *map;
-	const int base;		/* user offset to re-number the used map */
+	const int offset;	/* offset from map->base */
 };
 
 /*
@@ -235,21 +235,37 @@ struct _ddebug_class_param {
 /**
  * DYNAMIC_DEBUG_CLASSMAP_USE - refer to a classmap, DEFINEd elsewhere.
  * @_var: name of the exported classmap var
- * @_not_yet: _base-like, but applies only to this USEr. (if needed)
  *
  * This tells dyndbg that the module has prdbgs with classids defined
  * in the named classmap.  This qualifies "class NAME" >controls on
- * the user module, and ignores unknown names.
+ * the user module, and ignores unknown names. This is a wrapper for
+ * DYNAMIC_DEBUG_CLASSMAP_USE_() with a base offset of 0.
  */
-#define DYNAMIC_DEBUG_CLASSMAP_USE(_var)				\
-	DYNAMIC_DEBUG_CLASSMAP_USE_(_var, 0, __UNIQUE_ID(_ddebug_class_user))
-#define DYNAMIC_DEBUG_CLASSMAP_USE_(_var, _base, _uname)		\
+#define DYNAMIC_DEBUG_CLASSMAP_USE(_var) \
+	DYNAMIC_DEBUG_CLASSMAP_USE_(_var, 0)
+
+/**
+ * DYNAMIC_DEBUG_CLASSMAP_USE_ - refer to a classmap with a manual offset.
+ * @_var:   name of the exported classmap var to use.
+ * @_offset:  an integer offset to add to the class IDs of the used map.
+ *
+ * This is an extended version of DYNAMIC_DEBUG_CLASSMAP_USE(). It should
+ * only be used to resolve class ID conflicts when a module uses multiple
+ * classmaps that have overlapping ID ranges.
+ *
+ * The final class IDs for the used map will be calculated as:
+ * original_map_base + class_index + @_base.
+ */
+#define DYNAMIC_DEBUG_CLASSMAP_USE_(_var, _offset)			\
+	__DYNAMIC_DEBUG_CLASSMAP_USE(_var, _offset, __UNIQUE_ID(_ddebug_class_user))
+
+#define __DYNAMIC_DEBUG_CLASSMAP_USE(_var, _offset, _uname)		\
 	extern struct _ddebug_class_map _var;				\
 	static struct _ddebug_class_user __aligned(8) __used		\
 	__section("__dyndbg_class_users") _uname = {			\
 		.mod_name = KBUILD_MODNAME,				\
 		.map = &(_var),						\
-		.base = _base						\
+		.offset = _offset						\
 	}
 
 /**
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index f60a723a441b..b0da3dd4ac44 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -198,7 +198,7 @@ ddebug_find_valid_class(struct _ddebug_info const *di, const char *query_class,
 		if (idx >= 0) {
 			vpr_di_info(di, "class-ref: %s -> %s.%s ",
 				    cli->mod_name, cli->map->mod_name, query_class);
-			*class_id = idx + cli->map->base;
+			*class_id = idx + cli->map->base - cli->offset;
 			return cli->map;
 		}
 	}
@@ -206,12 +206,17 @@ ddebug_find_valid_class(struct _ddebug_info const *di, const char *query_class,
 	return NULL;
 }
 
-static bool ddebug_class_in_range(const int class_id, const struct _ddebug_class_map *map)
+static bool ddebug_class_map_in_range(const int class_id, const struct _ddebug_class_map *map)
 {
 	return (class_id >= map->base &&
 		class_id < map->base + map->length);
 }
 
+static bool ddebug_class_user_in_range(const int class_id, const struct _ddebug_class_user *user)
+{
+	return ddebug_class_map_in_range(class_id - user->offset, user->map);
+}
+
 static struct _ddebug_class_map *
 ddebug_find_map_by_class_id(struct _ddebug_info *di, int class_id)
 {
@@ -220,11 +225,11 @@ ddebug_find_map_by_class_id(struct _ddebug_info *di, int class_id)
 	int i;
 
 	for_subvec(i, map, di, maps)
-		if (ddebug_class_in_range(class_id, map))
+		if (ddebug_class_map_in_range(class_id, map))
 			return map;
 
 	for_subvec(i, cli, di, users)
-		if (ddebug_class_in_range(class_id, cli->map))
+		if (ddebug_class_user_in_range(class_id, cli))
 			return cli->map;
 
 	return NULL;
@@ -1177,12 +1182,12 @@ static const char *ddebug_class_name(struct _ddebug_info *di, struct _ddebug *dp
 	int i;
 
 	for_subvec(i, map, di, maps)
-		if (ddebug_class_in_range(dp->class_id, map))
+		if (ddebug_class_map_in_range(dp->class_id, map))
 			return map->class_names[dp->class_id - map->base];
 
 	for_subvec(i, cli, di, users)
-		if (ddebug_class_in_range(dp->class_id, cli->map))
-			return cli->map->class_names[dp->class_id - cli->map->base];
+		if (ddebug_class_user_in_range(dp->class_id, cli))
+			return cli->map->class_names[dp->class_id - cli->map->base - cli->offset];
 
 	return NULL;
 }
-- 
2.52.0

[PATCH v7 31/31] docs/dyndbg: add classmap info to howto

[Jim Cromie]

Describe the 3 API macros providing dynamic_debug's classmaps

DYNAMIC_DEBUG_CLASSMAP_DEFINE - create & export a classmap
DYNAMIC_DEBUG_CLASSMAP_USE    - refer to exported map
DYNAMIC_DEBUG_CLASSMAP_PARAM  - bind control param to the classmap
DYNAMIC_DEBUG_CLASSMAP_PARAM_REF + use module's storage - __drm_debug

NB: The _DEFINE & _USE model makes the user dependent on the definer,
just like EXPORT_SYMBOL(__drm_debug) already does.

cc: linux-doc@vger.kernel.org
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 .../admin-guide/dynamic-debug-howto.rst       | 135 ++++++++++++++++--
 1 file changed, 123 insertions(+), 12 deletions(-)

diff --git a/Documentation/admin-guide/dynamic-debug-howto.rst b/Documentation/admin-guide/dynamic-debug-howto.rst
index 89ee15d7ae58..c85266ee8eed 100644
--- a/Documentation/admin-guide/dynamic-debug-howto.rst
+++ b/Documentation/admin-guide/dynamic-debug-howto.rst
@@ -146,6 +146,9 @@ keywords are::
   "1-30" is valid range but "1 - 30" is not.
 
 
+Keywords
+--------
+
 The meanings of each keyword are:
 
 func
@@ -194,16 +197,6 @@ format
 	format "nfsd: SETATTR"  // a neater way to match a format with whitespace
 	format 'nfsd: SETATTR'  // yet another way to match a format with whitespace
 
-class
-    The given class_name is validated against each module, which may
-    have declared a list of known class_names.  If the class_name is
-    found for a module, callsite & class matching and adjustment
-    proceeds.  Examples::
-
-	class DRM_UT_KMS	# a DRM.debug category
-	class JUNK		# silent non-match
-	// class TLD_*		# NOTICE: no wildcard in class names
-
 line
     The given line number or range of line numbers is compared
     against the line number of each ``pr_debug()`` callsite.  A single
@@ -218,6 +211,25 @@ line
 	line -1605          // the 1605 lines from line 1 to line 1605
 	line 1600-          // all lines from line 1600 to the end of the file
 
+class
+
+    The given class_name is validated against each module, which may
+    have declared a list of class_names it accepts.  If the class_name
+    accepted by a module, callsite & class matching and adjustment
+    proceeds.  Examples::
+
+	class DRM_UT_KMS	# a drm.debug category
+	class JUNK		# silent non-match
+	// class TLD_*		# NOTICE: no wildcard in class names
+
+.. note::
+
+    Unlike other keywords, classes are "name-to-change", not
+    "omitting-constraint-allows-change".  See Dynamic Debug Classmaps
+
+Flags
+-----
+
 The flags specification comprises a change operation followed
 by one or more flag characters.  The change operation is one
 of the characters::
@@ -238,11 +250,15 @@ The flags are::
   s    Include the source file name
   l    Include line number
 
+.. note::
+
+   * To query without changing	``+_`` or ``-_``.
+   * To clear all flags		``=_`` or ``-fslmpt``.
+
 For ``print_hex_dump_debug()`` and ``print_hex_dump_bytes()``, only
 the ``p`` flag has meaning, other flags are ignored.
 
-Note the regexp ``^[-+=][fslmpt_]+$`` matches a flags specification.
-To clear all flags at once, use ``=_`` or ``-fslmpt``.
+The regexp ``^[-+=][fslmpt_]+$`` matches a flags specification.
 
 
 Debug messages during Boot Process
@@ -394,3 +410,98 @@ just a shortcut for ``print_hex_dump(KERN_DEBUG)``.
 For ``print_hex_dump_debug()``/``print_hex_dump_bytes()``, format string is
 its ``prefix_str`` argument, if it is constant string; or ``hexdump``
 in case ``prefix_str`` is built dynamically.
+
+.. _dyndbg-classmaps:
+
+Dynamic Debug Classmaps
+=======================
+
+The "class" keyword selects prdbgs based on author supplied,
+domain-oriented names.  This complements the nested-scope keywords:
+module, file, function, line.
+
+The main difference from the others: classes must be named to be
+changed.  This protects them from unintended overwrite::
+
+  # IOW this cannot undo any drm.debug settings
+  :#> ddcmd -p
+
+This protection is needed; /sys/module/drm/parameters/debug is ABI.
+drm.debug is authoritative when dyndbg is not used, dyndbg-under-DRM
+is an implementation detail, and must not behave erratically, just
+because another admin fed >control something unrelated.
+
+So each class must be enabled individually (no wildcards)::
+
+  :#> ddcmd class DRM_UT_CORE +p
+  :#> ddcmd class DRM_UT_KMS +p
+  # or more selectively
+  :#> ddcmd class DRM_UT_CORE module drm +p
+
+That makes direct >control wordy and annoying, but it is a secondary
+interface; it is not intended to replace the ABI, just slide in
+underneath and reimplement the guaranteed behavior.  So DRM would keep
+using the convenient way, and be able to trust it::
+
+  :#> echo 0x1ff > /sys/module/drm/parameters/debug
+
+That said, since the sysfs/kparam is the ABI, if the author omits the
+CLASSMAP_PARAM, theres no ABI to guard, and he probably wants a less
+pedantic >control interface.  In this case, protection is dropped.
+
+Dynamic Debug Classmap API
+==========================
+
+DYNAMIC_DEBUG_CLASSMAP_DEFINE(clname,type,_base,classnames) - this maps
+classnames (a list of strings) onto class-ids consecutively, starting
+at _base.
+
+DYNAMIC_DEBUG_CLASSMAP_USE(clname) & _USE_(clname,_base) - modules
+call this to refer to the var _DEFINEd elsewhere (and exported).
+
+DYNAMIC_DEBUG_CLASSMAP_PARAM(clname) - creates the sysfs/kparam,
+maps/exposes bits 0..N as class-names.
+
+Classmaps are opt-in: modules invoke _DEFINE or _USE to authorize
+dyndbg to update those named classes.  "class FOO" queries are
+validated against the classes defined or used by the module, this
+finds the classid to alter; classes are not directly selectable by
+their classid.
+
+Classnames are global in scope, so subsystems (module-groups) should
+prepend a subsystem name; unqualified names like "CORE" are discouraged.
+
+NB: It is an inherent API limitation (due to class_id's int type) that
+the following are possible:
+
+  // these errors should be caught in review
+  __pr_debug_cls(0, "fake DRM_UT_CORE msg");  // this works
+  __pr_debug_cls(62, "un-known classid msg"); // this compiles, does nothing
+
+There are 2 types of classmaps:
+
+* DD_CLASS_TYPE_DISJOINT_BITS: classes are independent, like drm.debug
+* DD_CLASS_TYPE_LEVEL_NUM: classes are relative, ordered (V3 > V2)
+
+DYNAMIC_DEBUG_CLASSMAP_PARAM - modelled after module_param_cb, it
+refers to a DEFINEd classmap, and associates it to the param's
+data-store.  This state is then applied to DEFINEr and USEr modules
+when they're modprobed.
+
+The PARAM interface also enforces the DD_CLASS_TYPE_LEVEL_NUM relation
+amongst the contained classnames; all classes are independent in the
+control parser itself.  There is no implied meaning in names like "V4"
+or "PL_ERROR" vs "PL_WARNING".
+
+Modules or subsystems (drm & drivers) can define multiple classmaps,
+as long as they (all the classmaps) share the limited 0..62
+per-module-group _class_id range, without overlap.
+
+If a module encounters a conflict between 2 classmaps it is _USEing or
+_DEFINEing, it can invoke the extended _USE_(name,_base) macro to
+de-conflict the respective ranges.
+
+``#define DEBUG`` will enable all pr_debugs in scope, including any
+class'd ones.  This won't be reflected in the PARAM readback value,
+but the class'd pr_debug callsites can be forced off by toggling the
+classmap-kparam all-on then all-off.
-- 
2.52.0