hi Louis, On Tue, Feb 25, 2025 at 7:16 AM Louis Chauvet <louis.chauvet@xxxxxxxxxxx> wrote: > > > > 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 <jim.cromie@xxxxxxxxx> > > --- > > 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 <jim.cromie@xxxxxxxxx> > > 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 <talgi@xxxxxxxxxx> > > 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 { > > */ > > }; > > > > +/* BTW, Im gonna refine this ... > > + * 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? It belongs, insofar as the mod field is actually NULL checked to determine builtin vs modular, mod_name is backup. Also its more specific than "needed for builtins" But, grumble, ya, the above was an existing test, not a new one. OTOH - I guess Ive just written the cleanup commit msg :-) > > > 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? > Yes, its supposed to work that way. I havent tested that specific scenario (yet), but a _USEr module, like test-dynamic-debug-submod, could also _DEFINE its own, as long as it honors the class-id mapping it is using and therefore sharing. The on-modprobe conflict check should catch this condition. And __section (ISTM) accumulates entries, typically static struct var initializations. AFAICT, scanning the sections is how these { scoped statics } are often reachable. For example, dd's _METADATA_ builds a { static _ddebug } for every pr_debug. They all go into the __dyndbg section (renamed with _descriptors suffix soon), in the order their respective definer objects are linked. include/asm-generic/vmlinux.lds.h then places the __dyndbg_* sections into DATA, along with lots of other freight, for the various mechanisms they serve. > If not, does it make sense to allow it (for example MFD devices can > touch multiple subsystems)? We have another use case ! Do you know your way around that case ? Note that DEFINEr & USEr calls set up linkage dependencies, As long as these are consistent with other module deps, it should work. > > > /* 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 <jim.cromie@xxxxxxxxx> > > */ > > > > -#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 <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 +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_<CORE,DRIVER,KMS,etc>. > > + * > > + * 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. > Yes, that was a miss. Now in big comment block at the top of both, right before the pr-fmt mod-name shortening for the logs. > What do you think about creating a third file "common" with > do_prints/do_levels/... implementations and avoid this #if !defined? > I'd rather not. I think the multi-module usage is sufficiently interconnected (common enum, parent side, clone side) that all-in-one presentation helps to communicate this "linkage". I hope the new comments clearly elucidate this. PLMK if not. > > +/* > > + * 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? Its the enum : cat_disjoint_bits, that is defined for both. the _DEFINE itself is right after the ifdef TEST_MOD_SUBMOD. do you think it needs a better MOD_SUBMOD name ? or an ifndef ? > > > + 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? > Yes. the fully ordered table/__section is pretty important. If its not true for descriptors, its probably not true for class-maps or users either and the list-iter --> vector-block conversion a few commits ago isnt solid either. its also an explicit assumption under these commits 773beabbb8e8 dyndbg: reverse module.callsite walk in cat control 2ad556f70043 dyndbg: reverse module walk in cat control All in all, I think something would have broken by now. > 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. Youre correct. the control file reflects compile link order. Im pretty sure the appearance of init 1st in control derives from init/builtin.a being built 1st and/or linked 1st. > > > } > > 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 <jim.cromie@xxxxxxxxx> > > + */ > > + > > +#define TEST_DYNAMIC_DEBUG_SUBMOD > > +#include "test_dynamic_debug.c" > > -- > Louis Chauvet, Bootlin > Embedded Linux and Kernel engineering > https://bootlin.com > thanks again Lous, Jim