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Tue, 25 Feb 2025 14:16:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1740492991; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=qfaVKAV5DG/yrOTgAfOw2joz6mCOXnl87FufaNi+eAk=; b=P9NbuNX/NOnWB9V/YGtt7C3xkfpOImX4lUyBBzwEeYNK3DAIe1HZzhotkk5c2kQ1O3i1rB M7DSO7923zr9o/KryW3lJqOk1XPwtbfxbsTcQ1Ghcx8s80oON7z3ThcFc9TVeDDvGvlv2T fT+wXuIoCXo/HEaBKnzSzZGANRLd+818nRPmuUC7VQ6dWAIyEtFkvi9zciI2t6KZtXvE9+ hMIpXPG6Mvh0IiceTtxQfoEN/Z7BxV9+XUU2WNJ0p/QmUmfS+cm1+QwvslOUqdIPSU8joI lcx011hvCbmp1MC5EtfroR5YvfFYsfAv6Bs/HubijyZd26Ps0R7WjJe0WYqurg== Date: Tue, 25 Feb 2025 15:16:29 +0100 From: Louis Chauvet To: Jim Cromie , linux-kernel@vger.kernel.org, jbaron@akamai.com, gregkh@linuxfoundation.org, ukaszb@chromium.org Cc: intel-gfx-trybot@lists.freedesktop.org, dri-devel@lists.freedesktop.org, amd-gfx@lists.freedesktop.org, intel-gvt-dev@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, daniel.vetter@ffwll.ch, tvrtko.ursulin@linux.intel.com, jani.nikula@intel.com, ville.syrjala@linux.intel.com Subject: Re: [PATCH 16/63] dyndbg-API: replace DECLARE_DYNDBG_CLASSMAP Message-ID: Mail-Followup-To: Jim Cromie , linux-kernel@vger.kernel.org, jbaron@akamai.com, gregkh@linuxfoundation.org, ukaszb@chromium.org, intel-gfx-trybot@lists.freedesktop.org, dri-devel@lists.freedesktop.org, amd-gfx@lists.freedesktop.org, intel-gvt-dev@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, daniel.vetter@ffwll.ch, tvrtko.ursulin@linux.intel.com, jani.nikula@intel.com, ville.syrjala@linux.intel.com References: <20250125064619.8305-1-jim.cromie@gmail.com> <20250125064619.8305-17-jim.cromie@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20250125064619.8305-17-jim.cromie@gmail.com> X-GND-State: clean X-GND-Score: -100 X-GND-Cause: gggruggvucftvghtrhhoucdtuddrgeefvddrtddtgdekudelvdcutefuodetggdotefrodftvfcurfhrohhfihhlvgemucfitefpfffkpdcuggftfghnshhusghstghrihgsvgenuceurghilhhouhhtmecufedtudenucesvcftvggtihhpihgvnhhtshculddquddttddmnecujfgurhepfffhvfevuffkfhggtggugfgjsehtkeertddttddunecuhfhrohhmpefnohhuihhsucevhhgruhhvvghtuceolhhouhhishdrtghhrghuvhgvthessghoohhtlhhinhdrtghomheqnecuggftrfgrthhtvghrnhepudeiffduffeivdejgfejheeuudekkedvjeeuffegfefghfffkeelgffgieevudejnecuffhomhgrihhnpegsohhothhlihhnrdgtohhmnecukfhppeeltddrkeelrdduieefrdduvdejnecuvehluhhsthgvrhfuihiivgeptdenucfrrghrrghmpehinhgvthepledtrdekledrudeifedruddvjedphhgvlhhopehlohhuihhsqdgthhgruhhvvghtqdhlrghpthhophdpmhgrihhlfhhrohhmpehlohhuihhsrdgthhgruhhvvghtsegsohhothhlihhnrdgtohhmpdhnsggprhgtphhtthhopedugedprhgtphhtthhopehjihhmrdgtrhhomhhivgesghhmrghilhdrtghomhdprhgtphhtthhopehlihhnuhigqdhkvghrnhgvlhesvhhgvghrrdhkvghrnhgvlhdrohhrghdprhgtphhtthhopehjsggrrhhonhesrghkrghmrghirdgtohhmpdhrtghpthhtohepghhrvghgkhhhsehlihhnuhigfhhouhhnuggrthhiohhnr dhorhhgpdhrtghpthhtohepuhhkrghsiigssegthhhrohhmihhumhdrohhrghdprhgtphhtthhopehinhhtvghlqdhgfhigqdhtrhihsghotheslhhishhtshdrfhhrvggvuggvshhkthhophdrohhrghdprhgtphhtthhopegurhhiqdguvghvvghlsehlihhsthhsrdhfrhgvvgguvghskhhtohhprdhorhhgpdhrtghpthhtoheprghmugdqghhfgieslhhishhtshdrfhhrvggvuggvshhkthhophdrohhrgh X-GND-Sasl: louis.chauvet@bootlin.com X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Le 25/01/2025 à 07:45, Jim Cromie a écrit : > DECLARE_DYNDBG_CLASSMAP() has a design error; its usage fails a basic > K&R rule: "define once, refer many times". > > It is used across DRM core & drivers, each use re-defines the classmap > understood by that module; and all must match for the modules to > respond together when DRM.debug categories are enabled. This is > brittle; a maintenance foot-gun. > > Further, its culpable in the CONFIG_DRM_USE_DYNAMIC_DEBUG=Y > regression; its use in both core & drivers obfuscates the 2 roles. > So 1st drm.ko loads, and dyndbg initializes its DRM.debug callsites, > then a drm-driver loads, but too late - it missed the DRM.debug > enablement. > > So replace it with 2 macros: > DYNDBG_CLASSMAP_DEFINE - invoked once from core - drm.ko > DYNDBG_CLASSMAP_USE - from all drm drivers and helpers. > > DYNDBG_CLASSMAP_DEFINE: it just modifies DECLARE_DYNDBG_CLASSMAP, > dropping drop the static qualifier, and exports it instead. > > DYNDBG_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 > this allows ddebug_add_module(etal) to handle users differently. > > DECLARE_DYNDBG_CLASSMAP is preserved temporarily, to decouple DRM > adaptation work and avoid compile-errs before its done. IOW, DRM gets > fixed when they commit the adopt-new-api patches, and remove the > BROKEN marking. > > 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 init-scan is repeated for classmap-users. > > To review, dyndbg's existing __dyndbg_classes[] section does: > > . catalogs the classmaps defined by a module (or builtin modules) > . tells dyndbg the module has class'd prdbgs, allowing >control > . DYNDBG_CLASSMAP_DEFINE creates classmaps in this section. > > This patch adds __dyndbg_class_users[] section: > > . catalogs uses/references to the classmap definitions. > . authorizes dyndbg to >control those class'd prdbgs in ref'g module. > . DYNDBG_CLASSMAP_USE() creates classmap-user records in this new section. > > 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 > > dynamic_debug.c has 2 changes in ddebug_add_module(), ddebug_change(): > > ddebug_add_module() already calls ddebug_attach_module_classes() > to handle classmaps DEFINEd by a module, now it also calls > ddebug_attach_user_module_classes() to handle USEd classmaps. To > avoid this work when possible, 1st scan the module's descriptors and > count the number of class'd pr_debugs. > > ddebug_attach_user_module_classes() scans the module's class_users > section, follows the refs to the parent's classmap, and calls > ddebug_apply_params() on each. It also avoids work by checking the > module's class-ct. > > 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're 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 AND 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: > > 1. define an enum for the classmap: DRM.debug has DRM_UT_{CORE,KMS,...} > multiple classes must share 0-62 classid space. > 2. DYNDBG_CLASSMAP_DEFINE(.. DRM_UT_{CORE,KMS,...}) > 3. DYNDBG_CLASSMAP_PARAM* (classmap) > 4. DYNDBG_CLASSMAP_USE() > by _submod only, skipping 2,3 > > 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, with the new ifdef _SUBMOD block invoking DYNDBG_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/N). Y/Y testing exposed a missing __align(8) in the > _METADATA macro, which M/M didn't see because the module-loader memory > placement constrains it instead. > > NB: this patch ignores a checkpatch do-while warning which is fixed by > a preceding commit, which would be wrong for declarative macros like > module_param_named() etc. > > Fixes: aad0214f3026 ("dyndbg: add DECLARE_DYNDBG_CLASSMAP macro") > Signed-off-by: Jim Cromie > --- > v9 - commit-msg tweaks > DRM:CHECK warnings on macros: add parens > extern DEFINEd _var, static classnames > change ddebug_class_user.user_mod_name to .mod_name > simplify ddebug_find_valid_class > improve vpr_cm_info msg format > wrap (base) in macro body > move __DYNDBG_CLASSMAP_CHECK above kdoc for DYNDBG_CLASSMAP_DEFINE > > v8 - split drm parts to separate commits. > preserve DECLARE_DYNDBG_CLASSMAP to decouple DRM, no flag day. > fixup block comment > > v7 - previous submission-blocking bug: > > missing __align(8) in DYNAMIC_DEBUG_DECLARE_METADATA on > ddebug_class_user caused corrupt records, but only for builtin > modules; module loader code probably pinned allocations to the right > alignment naturally, hiding the bug for typical builds. > > v6- get rid of WARN_ON_ONCE > v?- fix _var expanded 2x in macro > > dyndbg: > > This fn formerly returned the map which contained the class (thus > validating it), and as a side-effect set the class-id in an outvar. > > But the caller didn't use the map (after checking its not null), only > the valid class-id. So simplify the fn to return the class-id of the > validated classname, or -ENOENT when the queried classname is not > found. > > Convey more useful info in the debug-msg: print class-names[0,last], > and [base,+len] instead of the class-type printout, which is currently > always "type:DISJOINT_BITS". And drop ddebug_classmap_typenames, > which is now unused. > > [root@v6 b0-dd]# modprobe test_dynamic_debug_submod > [ 18.864962] dyndbg: loaded classmap: test_dynamic_debug [16..24] V0..V7 > [ 18.865046] dyndbg: found kp:p_level_num =0x0 > [ 18.865048] dyndbg: mapped to: test_dynamic_debug [16..24] V0..V7 > [ 18.865164] dyndbg: p_level_num: lvl:0 bits:0x0 > [ 18.865217] dyndbg: loaded classmap: test_dynamic_debug [0..10] D2_CORE..D2_DRMRES > [ 18.865297] dyndbg: found kp:p_disjoint_bits =0x0 > [ 18.865298] dyndbg: mapped to: test_dynamic_debug [0..10] D2_CORE..D2_DRMRES > [ 18.865424] dyndbg: p_disjoint_bits: classbits: 0x0 > [ 18.865472] dyndbg: module:test_dynamic_debug attached 2 classmaps > [ 18.865533] dyndbg: 23 debug prints in module test_dynamic_debug > [ 18.866558] dyndbg: loaded classmap: test_dynamic_debug_submod [16..24] V0..V7 > [ 18.866698] dyndbg: found kp:p_level_num =0x0 > [ 18.866699] dyndbg: mapped to: test_dynamic_debug_submod [16..24] V0..V7 > [ 18.866865] dyndbg: p_level_num: lvl:0 bits:0x0 > [ 18.866926] dyndbg: loaded classmap: test_dynamic_debug_submod [0..10] D2_CORE..D2_DRMRES > [ 18.867026] dyndbg: found kp:p_disjoint_bits =0x0 > [ 18.867027] dyndbg: mapped to: test_dynamic_debug_submod [0..10] D2_CORE..D2_DRMRES > [ 18.867193] dyndbg: p_disjoint_bits: classbits: 0x0 > [ 18.867255] dyndbg: module:test_dynamic_debug_submod attached 2 classmap uses > [ 18.867351] dyndbg: 23 debug prints in module test_dynamic_debug_submod > --- > MAINTAINERS | 2 +- > include/asm-generic/vmlinux.lds.h | 1 + > include/linux/dynamic_debug.h | 83 ++++++++++-- > kernel/module/main.c | 3 + > lib/Kconfig.debug | 24 +++- > lib/Makefile | 3 + > lib/dynamic_debug.c | 203 ++++++++++++++++++++++++------ > lib/test_dynamic_debug.c | 111 +++++++++++----- > lib/test_dynamic_debug_submod.c | 10 ++ Hi Jim, While reading the files test_dynamic_debug*, I was wondering, they are more samples than tests. Does it make sense to move them in samples/? There is no need to do it in this series. > 9 files changed, 355 insertions(+), 85 deletions(-) > create mode 100644 lib/test_dynamic_debug_submod.c > > diff --git a/MAINTAINERS b/MAINTAINERS > index 0fa7c5728f1e..38afccb3b71e 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -8041,7 +8041,7 @@ M: Jim Cromie > 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 > > DYNAMIC INTERRUPT MODERATION > M: Tal Gilboa > diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h > index 54504013c749..eb93fd09832b 100644 > --- a/include/asm-generic/vmlinux.lds.h > +++ b/include/asm-generic/vmlinux.lds.h > @@ -366,6 +366,7 @@ defined(CONFIG_AUTOFDO_CLANG) || defined(CONFIG_PROPELLER_CLANG) > /* implement dynamic printk debug */ \ > . = ALIGN(8); \ > BOUNDED_SECTION_BY(__dyndbg_classes, ___dyndbg_classes) \ > + BOUNDED_SECTION_BY(__dyndbg_class_users, ___dyndbg_class_users) \ > BOUNDED_SECTION_BY(__dyndbg, ___dyndbg) \ > CODETAG_SECTIONS() \ > LIKELY_PROFILE() \ > diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h > index c8102e89beb2..dc610a12b91c 100644 > --- a/include/linux/dynamic_debug.h > +++ b/include/linux/dynamic_debug.h > @@ -71,9 +71,28 @@ enum ddebug_class_map_type { > */ > }; > > +/* > + * dyndbg-classmaps are devised to support DRM.debug directly: > + * 10 enum-vals: DRM_UT_* define the categories > + * ~23 categorized *_dbg() macros, each passing a DRM_UT_* val as 1st arg > + * 2 macros below them: drm_dev_dbg, __drm_dbg > + * ~5000 calls to the categorized macros, across all of drivers/gpu/drm/ > + * > + * When CONFIG_DRM_USE_DYNAMIC_DEBUG=y, the 2 low macros are redefined > + * to invoke _dynamic_func_call_cls(). This compiles the category > + * into each callsite's class_id field, where dyndbg can select on it > + * and alter a callsite's patch-state, avoiding repeated __drm_debug > + * checks. > + * > + * To make the callsites manageable from the >control file, authors > + * provide a "classmap" of names to class_ids in use by the module(s), > + * usually by stringifying the enum-vals. Modules with multiple > + * classmaps must arrange to share the 0..62 class_id space. > + */ > + > struct ddebug_class_map { > - struct module *mod; > - const char *mod_name; /* needed for builtins */ > + const struct module *mod; /* NULL for builtins */ > + const char *mod_name; Is this change belongs to this patch? If not can you move this in a "cleanup" patch? > const char **class_names; > const int length; > const int base; /* index of 1st .class_id, allows split/shared space */ > @@ -81,11 +100,34 @@ struct ddebug_class_map { > }; > > /** > - * 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 > + * DYNDBG_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 DYNDBG_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_classes") _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 DYNDBG_CLASSMAP_DEFINE by the static replacing the > + * extern/EXPORT on the struct init. > */ > #define DECLARE_DYNDBG_CLASSMAP(_var, _maptype, _base, ...) \ > static const char *_var##_classnames[] = { __VA_ARGS__ }; \ > @@ -99,12 +141,37 @@ struct ddebug_class_map { > .class_names = _var##_classnames, \ > } > > +struct ddebug_class_user { > + char *mod_name; > + struct ddebug_class_map *map; > +}; > + > +/** > + * DYNDBG_CLASSMAP_USE - refer to a classmap, DEFINEd elsewhere. > + * @_var: name of the exported classmap var > + * > + * This tells dyndbg that the module has prdbgs with classids defined > + * in the named classmap. This qualifies "class NAME" >controls on > + * the user module, ignoring unknown names. > + */ > +#define DYNDBG_CLASSMAP_USE(_var) \ > + DYNDBG_CLASSMAP_USE_(_var, __UNIQUE_ID(ddebug_class_user)) > +#define DYNDBG_CLASSMAP_USE_(_var, _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), \ > + } > + I'm not sure I understand properly how __section works, but can we use multiple DYNDBG_CLASSMAP_USE in one module? Can we also use DYNDBG_CLASSMAP_DEFINE while also importing an other classmap DYNDBG_CLASSMAP_USE? If not, does it make sense to allow it (for example MFD devices can touch multiple subsystems)? > /* encapsulate linker provided built-in (or module) dyndbg data */ > struct _ddebug_info { > struct _ddebug *descs; > struct ddebug_class_map *classes; > + struct ddebug_class_user *class_users; > unsigned int num_descs; > unsigned int num_classes; > + unsigned int num_class_users; > }; > > struct ddebug_class_param { > @@ -205,7 +272,7 @@ void __dynamic_ibdev_dbg(struct _ddebug *descriptor, > * (|_no_desc): former gets callsite descriptor as 1st arg (for prdbgs) > */ > #define __dynamic_func_call_cls(id, cls, fmt, func, ...) do { \ > - DEFINE_DYNAMIC_DEBUG_METADATA_CLS(id, cls, fmt); \ > + DEFINE_DYNAMIC_DEBUG_METADATA_CLS((id), cls, fmt); \ Can you move this in a "cleanup" patch? > if (DYNAMIC_DEBUG_BRANCH(id)) \ > func(&id, ##__VA_ARGS__); \ > } while (0) > diff --git a/kernel/module/main.c b/kernel/module/main.c > index 5399c182b3cb..c394a0c6e8c6 100644 > --- a/kernel/module/main.c > +++ b/kernel/module/main.c > @@ -2546,6 +2546,9 @@ static int find_module_sections(struct module *mod, struct load_info *info) > mod->dyndbg_info.classes = section_objs(info, "__dyndbg_classes", > sizeof(*mod->dyndbg_info.classes), > &mod->dyndbg_info.num_classes); > + mod->dyndbg_info.class_users = section_objs(info, "__dyndbg_class_users", > + sizeof(*mod->dyndbg_info.class_users), > + &mod->dyndbg_info.num_class_users); > #endif > > return 0; > diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug > index f3d723705879..933f69ef87f8 100644 > --- a/lib/Kconfig.debug > +++ b/lib/Kconfig.debug > @@ -2884,12 +2884,26 @@ 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 a8155c972f02..7f66fc1c163d 100644 > --- a/lib/Makefile > +++ b/lib/Makefile > @@ -84,6 +84,7 @@ obj-$(CONFIG_TEST_SORT) += test_sort.o > obj-$(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-$(CONFIG_TEST_SCANF) += test_scanf.o > > @@ -228,6 +229,8 @@ obj-$(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 094d6e62a9d1..6bca0c6727d4 100644 > --- a/lib/dynamic_debug.c > +++ b/lib/dynamic_debug.c > @@ -43,13 +43,16 @@ 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_class_user __start___dyndbg_class_users[]; > +extern struct ddebug_class_user __stop___dyndbg_class_users[]; > > 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_class_user *class_users; > + unsigned int num_ddebugs, num_classes, num_class_users; > }; > > struct ddebug_query { > @@ -148,23 +151,35 @@ static void vpr_info_dq(const struct ddebug_query *query, const char *msg) > query->first_lineno, query->last_lineno, query->class_string); > } > > -#define __outvar /* filled by callee */ > -static struct ddebug_class_map *ddebug_find_valid_class(struct ddebug_table const *dt, > - const char *class_string, > - __outvar int *class_id) > +#define vpr_dt_info(dt_p, msg_p, ...) ({ \ > + struct ddebug_table const *_dt = dt_p; \ > + v2pr_info(msg_p " module:%s nd:%d nc:%d nu:%d\n", ##__VA_ARGS__, \ > + _dt->mod_name, _dt->num_ddebugs, _dt->num_classes, \ > + _dt->num_class_users); \ > + }) > + > +static int ddebug_find_valid_class(struct ddebug_table const *dt, const char *class_string) > { > struct ddebug_class_map *map; > + struct ddebug_class_user *cli; > int i, idx; > > - for (map = dt->classes, i = 0; i < dt->num_classes; i++, map++) { > + for (i = 0, map = dt->classes; i < dt->num_classes; i++, map++) { > idx = match_string(map->class_names, map->length, class_string); > if (idx >= 0) { > - *class_id = idx + map->base; > - return map; > + vpr_dt_info(dt, "good-class: %s.%s ", map->mod_name, class_string); > + return idx + map->base; > } > } > - *class_id = -ENOENT; > - return NULL; > + for (i = 0, cli = dt->class_users; i < dt->num_class_users; i++, cli++) { > + idx = match_string(cli->map->class_names, cli->map->length, class_string); > + if (idx >= 0) { > + vpr_dt_info(dt, "class-ref: %s -> %s.%s ", > + cli->mod_name, cli->map->mod_name, class_string); > + return idx + cli->map->base; > + } > + } > + return -ENOENT; > } > > /* > @@ -173,16 +188,14 @@ static struct ddebug_class_map *ddebug_find_valid_class(struct ddebug_table cons > * callsites, normally the same as number of changes. If verbose, > * logs the changes. Takes ddebug_lock. > */ > -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; > unsigned int newflags; > 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); > @@ -194,8 +207,8 @@ 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); > - if (!map) > + valid_class = ddebug_find_valid_class(dt, query->class_string); > + if (valid_class < 0) > continue; > } else { > /* constrain query, do not touch class'd callsites */ > @@ -559,7 +572,7 @@ 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) > { > @@ -688,12 +701,12 @@ static int param_set_dyndbg_module_classes(const char *instr, > } > > /** > - * param_set_dyndbg_classes - class FOO >control > + * param_set_dyndbg_classes - set all classes in a classmap > * @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 prdbgs by their class, as given in the arguments to > - * DECLARE_DYNDBG_CLASSMAP. For LEVEL map-types, enforce relative > + * For all classes in the classmap, enable/disable them per the input > + * (depending on map_type). For LEVEL map-types, enforce relative > * levels by bitpos. > * > * Returns: 0 or <0 if error. > @@ -1038,12 +1051,17 @@ static void *ddebug_proc_next(struct seq_file *m, void *p, loff_t *pos) > static const char *ddebug_class_name(struct ddebug_table *dt, struct _ddebug *dp) > { > struct ddebug_class_map *map = dt->classes; > + struct ddebug_class_user *cli = dt->class_users; > int i; > > for (i = 0; i < dt->num_classes; i++, map++) > if (class_in_range(dp->class_id, map)) > return map->class_names[dp->class_id - map->base]; > > + for (i = 0; i < dt->num_class_users; i++, cli++) > + if (class_in_range(dp->class_id, cli->map)) > + return cli->map->class_names[dp->class_id - cli->map->base]; > + > return NULL; > } > > @@ -1124,31 +1142,129 @@ 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 *modnm) > +{ > + struct ddebug_class_param *dcp; > + > + if (kp->ops != ¶m_ops_dyndbg_classes) > + return; > + > + dcp = (struct ddebug_class_param *)kp->arg; > + > + if (map == dcp->map) { > + v2pr_info(" kp:%s.%s =0x%lx", modnm, kp->name, *dcp->bits); > + vpr_cm_info(map, " %s mapped to: ", modnm); > + ddebug_sync_classbits(kp, modnm); > + } > +} > + > +static void ddebug_apply_params(const struct ddebug_class_map *cm, const char *modnm) > +{ > + const struct kernel_param *kp; > +#if IS_ENABLED(CONFIG_MODULES) > + int i; > + > + if (cm->mod) { > + vpr_cm_info(cm, "loaded classmap: %s", modnm); > + /* 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, modnm); > + } > +#endif > + if (!cm->mod) { > + vpr_cm_info(cm, "builtin classmap: %s", modnm); > + for (kp = __start___param; kp < __stop___param; kp++) > + ddebug_match_apply_kparam(kp, cm, modnm); > + } > +} > + > +/* > + * Find this module's classmaps in a sub/whole-range of the builtin/ > + * modular classmap vector/section. Save the start and length of the > + * subrange at its edges. > + */ > +static void ddebug_attach_module_classes(struct ddebug_table *dt, > + const 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 (cm = di->classes, i = 0; i < di->num_classes; i++, cm++) { > - > + for (i = 0, cm = di->classes; i < di->num_classes; i++, cm++) { > 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); > + vpr_cm_info(cm, "classes[%d]:", i); > + if (!nc++) > dt->classes = cm; > - } > - nc++; > } > } > - if (nc) { > - dt->num_classes = nc; > - vpr_info("module:%s attached %d classes\n", dt->mod_name, nc); > + if (!nc) > + return; > + > + vpr_info("module:%s attached %d classes\n", dt->mod_name, nc); > + dt->num_classes = nc; > + > + for (i = 0, cm = dt->classes; i < dt->num_classes; i++, cm++) > + ddebug_apply_params(cm, cm->mod_name); > +} > + > +/* > + * propagates class-params thru their classmaps to class-users. this > + * means a query against the dt/module, which means it must be on the > + * list to be seen by ddebug_change. > + */ > +static void ddebug_attach_user_module_classes(struct ddebug_table *dt, > + const struct _ddebug_info *di) > +{ > + struct ddebug_class_user *cli; > + int i, nc = 0; > + > + /* > + * For builtins: scan the array, find start/length of this > + * module's refs, save to dt. For loadables, this is the > + * whole array. > + */ > + for (i = 0, cli = di->class_users; i < di->num_class_users; i++, cli++) { > + if (WARN_ON_ONCE(!cli || !cli->map || !cli->mod_name)) > + continue; > + if (!strcmp(cli->mod_name, dt->mod_name)) { > + vpr_cm_info(cli->map, "class_ref[%d] %s -> %s", i, > + cli->mod_name, cli->map->mod_name); > + if (!nc++) > + dt->class_users = cli; > + } > } > + if (!nc) > + return; > + > + dt->num_class_users = nc; > + > + /* now iterate dt */ > + for (i = 0, cli = dt->class_users; i < dt->num_class_users; i++, cli++) > + ddebug_apply_params(cli->map, cli->mod_name); > + > + vpr_dt_info(dt, "attach-client-module: "); > } > > /* > @@ -1158,6 +1274,8 @@ 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 *iter; > + int i, class_ct = 0; > > if (!di->num_descs) > return 0; > @@ -1181,13 +1299,20 @@ static int ddebug_add_module(struct _ddebug_info *di, const char *modname) > > INIT_LIST_HEAD(&dt->link); > > - if (di->classes && di->num_classes) > + for (i = 0, iter = di->descs; i < di->num_descs; i++, iter++) > + if (iter->class_id != _DPRINTK_CLASS_DFLT) > + class_ct++; > + > + if (class_ct && di->num_classes) > ddebug_attach_module_classes(dt, di); > > mutex_lock(&ddebug_lock); > list_add_tail(&dt->link, &ddebug_tables); > mutex_unlock(&ddebug_lock); > > + if (class_ct && di->num_class_users) > + ddebug_attach_user_module_classes(dt, di); > + > vpr_info("%3u debug prints in module %s\n", di->num_descs, modname); > return 0; > } > @@ -1337,8 +1462,10 @@ static int __init dynamic_debug_init(void) > struct _ddebug_info di = { > .descs = __start___dyndbg, > .classes = __start___dyndbg_classes, > + .class_users = __start___dyndbg_class_users, > .num_descs = __stop___dyndbg - __start___dyndbg, > .num_classes = __stop___dyndbg_classes - __start___dyndbg_classes, > + .num_class_users = __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 74d183ebf3e0..1838f62738c4 100644 > --- a/lib/test_dynamic_debug.c > +++ b/lib/test_dynamic_debug.c > @@ -6,11 +6,15 @@ > * Jim Cromie > */ > > -#define pr_fmt(fmt) "test_dd: " fmt > +#if defined(TEST_DYNAMIC_DEBUG_SUBMOD) > + #define pr_fmt(fmt) "test_dd_submod: " fmt > +#else > + #define pr_fmt(fmt) "test_dd: " fmt > +#endif > > #include > > -/* 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 +33,39 @@ static const struct kernel_param_ops param_ops_do_prints = { > }; > module_param_cb(do_prints, ¶m_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 DYNDBG_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, ¶m_ops_dyndbg_classes, &_flags##_model, 0600) > + module_param_cb(_flags##_##_model, ¶m_ops_dyndbg_classes, \ > + &_flags##_##_model, 0600) > +#ifdef DEBUG > +#define DYNDBG_CLASSMAP_PARAM(_model, _flags) DYNDBG_CLASSMAP_PARAM_(_model, _flags, ~0) > +#else > +#define DYNDBG_CLASSMAP_PARAM(_model, _flags) DYNDBG_CLASSMAP_PARAM_(_model, _flags, 0) > +#endif > + > +/* > + * Demonstrate/test all 4 class-typed classmaps with a sys-param. > + * > + * Each is 3 part: client-enum decl, _DEFINE, _PARAM. > + * Declare them in blocks to show patterns of use (repetitions and > + * changes) within each. > + * > + * 1st, dyndbg expects a client-provided enum-type as source of > + * category/classid truth. DRM has DRM_UT_. > + * > + * Modules with multiple CLASSMAPS must have enums with distinct > + * value-ranges, arranged below with explicit enum_sym = X inits. > + * > + * Declare all 4 enums now, for different types > + */ > > /* numeric input, independent bits */ > enum cat_disjoint_bits { > @@ -60,26 +79,51 @@ 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); > + > +/* recapitulate DRM's parent(drm.ko) <-- _submod(drivers,helpers) */ > +#if !defined(TEST_DYNAMIC_DEBUG_SUBMOD) It was not clear at first read that the test_dynamic_debug.c code is used twice. What do you think about creating a third file "common" with do_prints/do_levels/... implementations and avoid this #if !defined? > +/* > + * 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. > + */ > +DYNDBG_CLASSMAP_DEFINE(map_disjoint_bits, DD_CLASS_TYPE_DISJOINT_BITS, map_disjoint_bits is defined in both test_dynamic_debug.c and test_dynamic_debug_submodule.c, is it normal/required? > + D2_CORE, > + "D2_CORE", > + "D2_DRIVER", > + "D2_KMS", > + "D2_PRIME", > + "D2_ATOMIC", > + "D2_VBL", > + "D2_STATE", > + "D2_LEASE", > + "D2_DP", > + "D2_DRMRES"); > + > +DYNDBG_CLASSMAP_DEFINE(map_level_num, DD_CLASS_TYPE_LEVEL_NUM, > + V0, "V0", "V1", "V2", "V3", "V4", "V5", "V6", "V7"); > + > +/* > + * now add the sysfs-params > + */ > + > +DYNDBG_CLASSMAP_PARAM(disjoint_bits, p); > +DYNDBG_CLASSMAP_PARAM(level_num, p); > + > +#else /* TEST_DYNAMIC_DEBUG_SUBMOD */ > + > +/* > + * in submod/drm-drivers, use the classmaps defined in top/parent > + * module above. > + */ > + > +DYNDBG_CLASSMAP_USE(map_disjoint_bits); > +DYNDBG_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 +159,7 @@ static void do_levels(void) > > static void do_prints(void) > { > + pr_debug("do_prints:\n"); > do_cats(); > do_levels(); I just observed it, is the ordering of logs garanteed in /proc/dynamic_debug/control? When I run this test, I have this order: do_cats =_ "doing categories\n" [...] do_levels =_ "doing levels\n" [...] do_prints =_ "do_prints:\n" test_dynamic_debug_init =_ "init start\n" test_dynamic_debug_init =_ "init done\n" test_dynamic_debug_exit =_ "exited\n" Which is clearly not the code execution order. > } > diff --git a/lib/test_dynamic_debug_submod.c b/lib/test_dynamic_debug_submod.c > new file mode 100644 > index 000000000000..9a893402ce1a > --- /dev/null > +++ b/lib/test_dynamic_debug_submod.c > @@ -0,0 +1,10 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Kernel module for testing dynamic_debug > + * > + * Authors: > + * Jim Cromie > + */ > + > +#define TEST_DYNAMIC_DEBUG_SUBMOD > +#include "test_dynamic_debug.c" -- Louis Chauvet, Bootlin Embedded Linux and Kernel engineering https://bootlin.com