[PATCH v9 02/52] test-dyndbg: fixup CLASSMAP usage error

Jim Cromie
2024-07-02T21:58:18Z

A more careful reading of logging output from test_dynamic_debug.ko
reveals:

lib/test_dynamic_debug.c:103 [test_dynamic_debug]do_cats =pmf "doing categories\n"
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, 105,106 have LOW/MID and MID/HI skew.

The enum's 1st val (explicitly initialized) was wrong; it must be
_base, not _base+1 (a DECLARE_DYNDBG_CLASSMAP param). So the last
enumeration exceeded the range of mapped class-id's, which triggered
the "class unknown" report. I coded in an error, intending to verify
err detection, then forgot, and missed that it was there.

So this patch fixes a bad usage of DECLARE_DYNDBG_CLASSMAP(), showing
that it is too error-prone. As noted in test-mod comments:

* 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 0-62 class_id space !!

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 8dd250ad022b..a01f0193a419 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);
--
2.45.2