| Message ID | 20250125064619.8305-24-jim.cromie@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Fix CONFIG_DRM_USE_DYNAMIC_DEBUG=y | expand |
Le 25/01/2025 à 07:45, Jim Cromie a écrit : > 1. All classes used by a module (declared DYNDBG_CLASSMAP_{DEFINE,USE} > by module code) must share 0..62 class-id space; ie their respective > base,+length reservations shouldn't overlap. Overlaps would lead to > unintended changes in ddebug enablements. > > Detecting these class-id range overlaps at compile-time would be ideal > but is not obvious how; failing at modprobe at least insures that the > developer sees and fixes the conflict. > > ddebug_class_range_overlap() implements the range check, accumulating > the reserved-ids as it examines each class. It probably should use > bitmaps. > > A previous commit reworked the modprobe callchain to allow failure, > now call ddebug_class_range_overlap() to check when classid conflicts > happen, and signal that failure. > > NB: this can only happen when a module defines+uses several classmaps, > > TBD: failing modprobe is kinda harsh, maybe warn and proceed ? > > test_dynamic_debug*.ko: > > If built with -DFORCE_CLASSID_CONFLICT_MODPROBE, the modules get 2 bad > DYNDBG_CLASS_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 fail. TODO: do in submod only, since fail > of parent prevents submod from ever trying. > > Signed-off-by: Jim Cromie <jim.cromie@gmail.com> > --- > --- > lib/dynamic_debug.c | 30 ++++++++++++++++++++++++------ > lib/test_dynamic_debug.c | 11 ++++++++++- > 2 files changed, 34 insertions(+), 7 deletions(-) > > diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c > index 8afcd4111531..8e1e087e07c3 100644 > --- a/lib/dynamic_debug.c > +++ b/lib/dynamic_debug.c > @@ -1211,6 +1211,21 @@ static void ddebug_apply_params(const struct ddebug_class_map *cm, const char *m > } > } > > +static int 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; > +} > + > /* > * scan the named array: @_vec, ref'd from inside @_box, for the > * start,len of the sub-array of elements matching on ->mod_name; > @@ -1242,9 +1257,11 @@ static int ddebug_module_apply_class_maps(struct ddebug_table *dt, > struct ddebug_class_map *cm; > int i; > > - for_subvec(i, cm, &dt->info, maps) > + for_subvec(i, cm, &dt->info, maps) { > + if (ddebug_class_range_overlap(cm, reserved_ids)) > + return -EINVAL; > ddebug_apply_params(cm, cm->mod_name); > - > + } > vpr_info("module:%s attached %d classmaps\n", dt->mod_name, dt->info.maps.len); > return 0; > } > @@ -1255,10 +1272,11 @@ static int ddebug_module_apply_class_users(struct ddebug_table *dt, > struct ddebug_class_user *cli; > int i; > > - /* now iterate dt */ > - for_subvec(i, cli, &dt->info, users) > + for_subvec(i, cli, &dt->info, users) { > + if (ddebug_class_range_overlap(cli->map, reserved_ids)) > + return -EINVAL; > ddebug_apply_params(cli->map, cli->mod_name); > - > + } > vpr_info("module:%s attached %d classmap uses\n", dt->mod_name, dt->info.users.len); > return 0; > } > @@ -1311,11 +1329,11 @@ static int ddebug_add_module(struct _ddebug_info *di, const char *modname) > return rc; > } > } > + > mutex_lock(&ddebug_lock); > list_add_tail(&dt->link, &ddebug_tables); > mutex_unlock(&ddebug_lock); > > - Hi Jim, Strange line issues, can you squash it with the correct patch? Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com> Thanks, > if (dt->info.users.len) { > rc = ddebug_module_apply_class_users(dt, &reserved_ids); > if (rc) > diff --git a/lib/test_dynamic_debug.c b/lib/test_dynamic_debug.c > index b1555b0a2bb1..74b98adc4ed0 100644 > --- a/lib/test_dynamic_debug.c > +++ b/lib/test_dynamic_debug.c > @@ -81,7 +81,7 @@ enum cat_disjoint_bits { > D2_DRMRES }; > > /* numeric verbosity, V2 > V1 related */ > -enum cat_level_num { V0 = 14, V1, V2, V3, V4, V5, V6, V7 }; > +enum cat_level_num { V0 = 16, V1, V2, V3, V4, V5, V6, V7 }; > > /* recapitulate DRM's parent(drm.ko) <-- _submod(drivers,helpers) */ > #if !defined(TEST_DYNAMIC_DEBUG_SUBMOD) > @@ -90,6 +90,7 @@ enum cat_level_num { V0 = 14, V1, V2, V3, V4, V5, V6, V7 }; > * 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, > D2_CORE, > "D2_CORE", > @@ -113,6 +114,14 @@ DYNDBG_CLASSMAP_DEFINE(map_level_num, DD_CLASS_TYPE_LEVEL_NUM, > DYNDBG_CLASSMAP_PARAM(disjoint_bits, p); > DYNDBG_CLASSMAP_PARAM(level_num, p); > > +#ifdef FORCE_CLASSID_CONFLICT_MODPROBE > +/* > + * Enable with -Dflag on compile to test overlapping class-id range > + * detection. This should break on modprobe. > + */ > +DYNDBG_CLASSMAP_DEFINE(classid_range_conflict, 0, D2_CORE + 1, "D3_CORE"); > +#endif > + > #else /* TEST_DYNAMIC_DEBUG_SUBMOD */ > > /*
Im dropping the fail-on-modprobe. theres some unrelated test-mod touches I'll examine and separate if theyre good On Tue, Feb 25, 2025 at 7:27 AM Louis Chauvet <louis.chauvet@bootlin.com> wrote: > > > > Le 25/01/2025 à 07:45, Jim Cromie a écrit : > > 1. All classes used by a module (declared DYNDBG_CLASSMAP_{DEFINE,USE} > > by module code) must share 0..62 class-id space; ie their respective > > base,+length reservations shouldn't overlap. Overlaps would lead to > > unintended changes in ddebug enablements. > > > > Detecting these class-id range overlaps at compile-time would be ideal > > but is not obvious how; failing at modprobe at least insures that the > > developer sees and fixes the conflict. > > > > ddebug_class_range_overlap() implements the range check, accumulating > > the reserved-ids as it examines each class. It probably should use > > bitmaps. > > > > A previous commit reworked the modprobe callchain to allow failure, > > now call ddebug_class_range_overlap() to check when classid conflicts > > happen, and signal that failure. > > > > NB: this can only happen when a module defines+uses several classmaps, > > > > TBD: failing modprobe is kinda harsh, maybe warn and proceed ? > > > > test_dynamic_debug*.ko: > > > > If built with -DFORCE_CLASSID_CONFLICT_MODPROBE, the modules get 2 bad > > DYNDBG_CLASS_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 fail. TODO: do in submod only, since fail > > of parent prevents submod from ever trying. > > > > Signed-off-by: Jim Cromie <jim.cromie@gmail.com> > > --- > > --- > > lib/dynamic_debug.c | 30 ++++++++++++++++++++++++------ > > lib/test_dynamic_debug.c | 11 ++++++++++- > > 2 files changed, 34 insertions(+), 7 deletions(-) > > > > diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c > > index 8afcd4111531..8e1e087e07c3 100644 > > --- a/lib/dynamic_debug.c > > +++ b/lib/dynamic_debug.c > > @@ -1211,6 +1211,21 @@ static void ddebug_apply_params(const struct ddebug_class_map *cm, const char *m > > } > > } > > > > +static int 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; > > +} > > + > > /* > > * scan the named array: @_vec, ref'd from inside @_box, for the > > * start,len of the sub-array of elements matching on ->mod_name; > > @@ -1242,9 +1257,11 @@ static int ddebug_module_apply_class_maps(struct ddebug_table *dt, > > struct ddebug_class_map *cm; > > int i; > > > > - for_subvec(i, cm, &dt->info, maps) > > + for_subvec(i, cm, &dt->info, maps) { > > + if (ddebug_class_range_overlap(cm, reserved_ids)) > > + return -EINVAL; > > ddebug_apply_params(cm, cm->mod_name); > > - > > + } > > vpr_info("module:%s attached %d classmaps\n", dt->mod_name, dt->info.maps.len); > > return 0; > > } > > @@ -1255,10 +1272,11 @@ static int ddebug_module_apply_class_users(struct ddebug_table *dt, > > struct ddebug_class_user *cli; > > int i; > > > > - /* now iterate dt */ > > - for_subvec(i, cli, &dt->info, users) > > + for_subvec(i, cli, &dt->info, users) { > > + if (ddebug_class_range_overlap(cli->map, reserved_ids)) > > + return -EINVAL; > > ddebug_apply_params(cli->map, cli->mod_name); > > - > > + } > > vpr_info("module:%s attached %d classmap uses\n", dt->mod_name, dt->info.users.len); > > return 0; > > } > > @@ -1311,11 +1329,11 @@ static int ddebug_add_module(struct _ddebug_info *di, const char *modname) > > return rc; > > } > > } > > + > > mutex_lock(&ddebug_lock); > > list_add_tail(&dt->link, &ddebug_tables); > > mutex_unlock(&ddebug_lock); > > > > - > > Hi Jim, > > Strange line issues, can you squash it with the correct patch? > > Reviewed-by: Louis Chauvet <louis.chauvet@bootlin.com> > > Thanks, > > > if (dt->info.users.len) { > > rc = ddebug_module_apply_class_users(dt, &reserved_ids); > > if (rc) > > diff --git a/lib/test_dynamic_debug.c b/lib/test_dynamic_debug.c > > index b1555b0a2bb1..74b98adc4ed0 100644 > > --- a/lib/test_dynamic_debug.c > > +++ b/lib/test_dynamic_debug.c > > @@ -81,7 +81,7 @@ enum cat_disjoint_bits { > > D2_DRMRES }; > > > > /* numeric verbosity, V2 > V1 related */ > > -enum cat_level_num { V0 = 14, V1, V2, V3, V4, V5, V6, V7 }; > > +enum cat_level_num { V0 = 16, V1, V2, V3, V4, V5, V6, V7 }; > > > > /* recapitulate DRM's parent(drm.ko) <-- _submod(drivers,helpers) */ > > #if !defined(TEST_DYNAMIC_DEBUG_SUBMOD) > > @@ -90,6 +90,7 @@ enum cat_level_num { V0 = 14, V1, V2, V3, V4, V5, V6, V7 }; > > * 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, > > D2_CORE, > > "D2_CORE", > > @@ -113,6 +114,14 @@ DYNDBG_CLASSMAP_DEFINE(map_level_num, DD_CLASS_TYPE_LEVEL_NUM, > > DYNDBG_CLASSMAP_PARAM(disjoint_bits, p); > > DYNDBG_CLASSMAP_PARAM(level_num, p); > > > > +#ifdef FORCE_CLASSID_CONFLICT_MODPROBE > > +/* > > + * Enable with -Dflag on compile to test overlapping class-id range > > + * detection. This should break on modprobe. > > + */ > > +DYNDBG_CLASSMAP_DEFINE(classid_range_conflict, 0, D2_CORE + 1, "D3_CORE"); > > +#endif > > + > > #else /* TEST_DYNAMIC_DEBUG_SUBMOD */ > > > > /* > > -- > Louis Chauvet, Bootlin > Embedded Linux and Kernel engineering > https://bootlin.com >
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c index 8afcd4111531..8e1e087e07c3 100644 --- a/lib/dynamic_debug.c +++ b/lib/dynamic_debug.c @@ -1211,6 +1211,21 @@ static void ddebug_apply_params(const struct ddebug_class_map *cm, const char *m } } +static int 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; +} + /* * scan the named array: @_vec, ref'd from inside @_box, for the * start,len of the sub-array of elements matching on ->mod_name; @@ -1242,9 +1257,11 @@ static int ddebug_module_apply_class_maps(struct ddebug_table *dt, struct ddebug_class_map *cm; int i; - for_subvec(i, cm, &dt->info, maps) + for_subvec(i, cm, &dt->info, maps) { + if (ddebug_class_range_overlap(cm, reserved_ids)) + return -EINVAL; ddebug_apply_params(cm, cm->mod_name); - + } vpr_info("module:%s attached %d classmaps\n", dt->mod_name, dt->info.maps.len); return 0; } @@ -1255,10 +1272,11 @@ static int ddebug_module_apply_class_users(struct ddebug_table *dt, struct ddebug_class_user *cli; int i; - /* now iterate dt */ - for_subvec(i, cli, &dt->info, users) + for_subvec(i, cli, &dt->info, users) { + if (ddebug_class_range_overlap(cli->map, reserved_ids)) + return -EINVAL; ddebug_apply_params(cli->map, cli->mod_name); - + } vpr_info("module:%s attached %d classmap uses\n", dt->mod_name, dt->info.users.len); return 0; } @@ -1311,11 +1329,11 @@ static int ddebug_add_module(struct _ddebug_info *di, const char *modname) return rc; } } + mutex_lock(&ddebug_lock); list_add_tail(&dt->link, &ddebug_tables); mutex_unlock(&ddebug_lock); - if (dt->info.users.len) { rc = ddebug_module_apply_class_users(dt, &reserved_ids); if (rc) diff --git a/lib/test_dynamic_debug.c b/lib/test_dynamic_debug.c index b1555b0a2bb1..74b98adc4ed0 100644 --- a/lib/test_dynamic_debug.c +++ b/lib/test_dynamic_debug.c @@ -81,7 +81,7 @@ enum cat_disjoint_bits { D2_DRMRES }; /* numeric verbosity, V2 > V1 related */ -enum cat_level_num { V0 = 14, V1, V2, V3, V4, V5, V6, V7 }; +enum cat_level_num { V0 = 16, V1, V2, V3, V4, V5, V6, V7 }; /* recapitulate DRM's parent(drm.ko) <-- _submod(drivers,helpers) */ #if !defined(TEST_DYNAMIC_DEBUG_SUBMOD) @@ -90,6 +90,7 @@ enum cat_level_num { V0 = 14, V1, V2, V3, V4, V5, V6, V7 }; * 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, D2_CORE, "D2_CORE", @@ -113,6 +114,14 @@ DYNDBG_CLASSMAP_DEFINE(map_level_num, DD_CLASS_TYPE_LEVEL_NUM, DYNDBG_CLASSMAP_PARAM(disjoint_bits, p); DYNDBG_CLASSMAP_PARAM(level_num, p); +#ifdef FORCE_CLASSID_CONFLICT_MODPROBE +/* + * Enable with -Dflag on compile to test overlapping class-id range + * detection. This should break on modprobe. + */ +DYNDBG_CLASSMAP_DEFINE(classid_range_conflict, 0, D2_CORE + 1, "D3_CORE"); +#endif + #else /* TEST_DYNAMIC_DEBUG_SUBMOD */ /*
1. All classes used by a module (declared DYNDBG_CLASSMAP_{DEFINE,USE} by module code) must share 0..62 class-id space; ie their respective base,+length reservations shouldn't overlap. Overlaps would lead to unintended changes in ddebug enablements. Detecting these class-id range overlaps at compile-time would be ideal but is not obvious how; failing at modprobe at least insures that the developer sees and fixes the conflict. ddebug_class_range_overlap() implements the range check, accumulating the reserved-ids as it examines each class. It probably should use bitmaps. A previous commit reworked the modprobe callchain to allow failure, now call ddebug_class_range_overlap() to check when classid conflicts happen, and signal that failure. NB: this can only happen when a module defines+uses several classmaps, TBD: failing modprobe is kinda harsh, maybe warn and proceed ? test_dynamic_debug*.ko: If built with -DFORCE_CLASSID_CONFLICT_MODPROBE, the modules get 2 bad DYNDBG_CLASS_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 fail. TODO: do in submod only, since fail of parent prevents submod from ever trying. Signed-off-by: Jim Cromie <jim.cromie@gmail.com> --- --- lib/dynamic_debug.c | 30 ++++++++++++++++++++++++------ lib/test_dynamic_debug.c | 11 ++++++++++- 2 files changed, 34 insertions(+), 7 deletions(-)