Dynamic debug classmaps allow modules to _DEFINE and/or _USE multiple classmaps, but this requires coordination amongst the classmaps.
Previously, class validation done by DYNAMIC_DEBUG_CLASSMAP_DEFINE at compile-time, and ddebug_class_range_overlap() at modprobe-time, was incomplete, and DYNAMIC_DEBUG_CLASSMAP_USE_ had no validation. This could allow broken classmaps, making them harder to use well. This commit improves classmap and descriptor validation: - Unify runtime overlap and bounds checking across _DEFINE'd and _USE'd classmaps in ddebug_validate_class_range(), enforcing symmetry and the <= 62 upper bound for both. - Split runtime validation out of ddebug_add_module() into dedicated helpers: ddebug_validate_classmaps() (fatal, returns boolean pass/fail) and ddebug_validate_descs() (scans callsites and emits an advisory warning once per unknown class_id). - Downgrade the global WARN_ONCE in ddebug_match_desc() to a pr_warn_ratelimited, since orphaned class IDs are now tracked and warned about early at module load. Signed-off-by: Jim Cromie <[email protected]> --- v11: . factor runtime classmap validation out of ddebug_add_module() into ddebug_validate_classmaps() and ddebug_validate_descs(). . unify overlap and bounds checking across maps and users in ddebug_validate_class_range(). v10: . fix pr_warn_ratelimited() line wrap in ddebug_match_desc(). --- lib/dynamic_debug.c | 92 ++++++++++++++++++---- lib/test_dynamic_debug.c | 16 ++-- .../selftests/dynamic_debug/dyndbg_selftest.sh | 22 +++--- 3 files changed, 99 insertions(+), 31 deletions(-) diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c index d300d44c1a82..098fd2639cb6 100644 --- a/lib/dynamic_debug.c +++ b/lib/dynamic_debug.c @@ -311,7 +311,8 @@ static bool ddebug_match_desc(const struct ddebug_query *query, /* site is class'd */ site_map = ddebug_find_map_by_class_id(di, dp->class_id); if (!site_map) { - WARN_ONCE(1, "unknown class_id %d, check %s's CLASSMAP definitions", dp->class_id, di->mod_name); + pr_warn_ratelimited("unknown class_id %d, check %s's CLASSMAP definitions\n", + dp->class_id, di->mod_name); return false; } /* module(-param) decides protection */ @@ -1507,18 +1508,80 @@ static void ddebug_apply_class_users(const struct _ddebug_info *di) __di->_vec.start = __start; \ }) -static int ddebug_class_range_overlap(struct ddebug_class_map *cm, u64 *reserved_ids) +static bool ddebug_validate_class_range(const char *modname, + const char *name, + int base, int length, + u64 *reserved_ids) { - u64 range = (((1ULL << cm->length) - 1) << cm->base); + u64 range; + if (base < 0 || length <= 0 || + base + length > _DPRINTK_CLASS_DFLT) { + pr_err("module %s: base:%d len:%d (from %s) exceeds class_id limit %d\n", + modname, base, length, name, _DPRINTK_CLASS_DFLT); + return false; + } + range = (((1ULL << length) - 1) << 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; + pr_err("module %s: [%d..%d] (from %s) conflicts with 0x%llx\n", + modname, base, base + length - 1, name, *reserved_ids); + return false; } *reserved_ids |= range; - return 0; + return true; +} + +static bool ddebug_validate_classmaps(struct _ddebug_info *di) +{ + struct ddebug_class_map *cm; + struct ddebug_class_user *cli; + u64 reserved_ids = 0; + bool valid = true; + int i; + + for_subvec(i, cm, di, maps) + if (!ddebug_validate_class_range(di->mod_name, + cm->class_names[0], + cm->base, cm->length, + &reserved_ids)) + valid = false; + + for_subvec(i, cli, di, users) { + if (!cli->map) { + pr_err("module %s: classmap not found for user\n", + di->mod_name); + valid = false; + continue; + } + if (!ddebug_validate_class_range(di->mod_name, + cli->map->class_names[0], + cli->map->base + cli->offset, + cli->map->length, + &reserved_ids)) + valid = false; + } + return valid; +} + +static void ddebug_validate_descs(struct _ddebug_info *di) +{ + struct _ddebug *dp; + u64 bad_ids = 0; + int i; + + for (i = 0; i < di->descs.len; i++) { + dp = &di->descs.start[i]; + + if (dp->class_id == _DPRINTK_CLASS_DFLT) + continue; + if (bad_ids & (1ULL << dp->class_id)) + continue; + if (!ddebug_find_map_by_class_id(di, dp->class_id)) { + pr_warn("module %s uses unknown class_id %d\n", + di->mod_name, dp->class_id); + bad_ids |= (1ULL << dp->class_id); + } + } } /* @@ -1530,7 +1593,6 @@ static int ddebug_add_module(struct _ddebug_info *di) struct ddebug_table *dt; struct ddebug_class_map *cm; struct ddebug_class_user *cli; - u64 reserved_ids = 0; int i; if (!di->descs.len) @@ -1562,10 +1624,10 @@ static int ddebug_add_module(struct _ddebug_info *di) dd_set_module_subrange(i, cm, &dt->info, maps); dd_set_module_subrange(i, cli, &dt->info, users); - /* insure 2+ classmaps share the per-module 0..62 class_id space */ - for_subvec(i, cm, &dt->info, maps) - if (ddebug_class_range_overlap(cm, &reserved_ids)) - goto cleanup; + if (!ddebug_validate_classmaps(&dt->info)) + goto cleanup; + + ddebug_validate_descs(&dt->info); /* */ @@ -1587,7 +1649,7 @@ static int ddebug_add_module(struct _ddebug_info *di) dt->info.descs.len, dt->info.mod_name); return 0; cleanup: - WARN_ONCE(1, "dyndbg multi-classmap conflict in %s\n", di->mod_name); + pr_err("dyndbg multi-classmap conflict in %s\n", di->mod_name); kfree(dt); return -EINVAL; } @@ -1674,7 +1736,7 @@ static int ddebug_module_notify(struct notifier_block *self, unsigned long val, mod->dyndbg_info.mod_name = mod->name; ret = ddebug_add_module(&mod->dyndbg_info); if (ret) - WARN(1, "Failed to allocate memory: dyndbg may not work properly.\n"); + pr_err("dyndbg: failed to add module %s: %d\n", mod->name, ret); break; case MODULE_STATE_GOING: ddebug_remove_module(mod->name); diff --git a/lib/test_dynamic_debug.c b/lib/test_dynamic_debug.c index ea81c5158b13..666b447b3740 100644 --- a/lib/test_dynamic_debug.c +++ b/lib/test_dynamic_debug.c @@ -173,14 +173,20 @@ DYNAMIC_DEBUG_CLASSMAP_DEFINE(fail_base_len, 0, 60, #endif #else /* TEST_DYNAMIC_DEBUG_SUBMOD */ - /* - * in submod/drm-drivers, use the classmaps defined in top/parent - * module above. + * In submod (drm-drivers/helpers) use the classmaps defined in + * top/parent module above. We _USE_() with offset, to test the + * non-zero case. */ - DYNAMIC_DEBUG_CLASSMAP_USE(map_disjoint_bits); -DYNAMIC_DEBUG_CLASSMAP_USE_(map_level_num, 7); +/* + * maybe force failure of runtime sanity test of classmap.length + offset < 63 + */ +#if !defined(DD_RUNTIME_CLASS_CHECK) +DYNAMIC_DEBUG_CLASSMAP_USE_(map_level_num, 8); +#else +DYNAMIC_DEBUG_CLASSMAP_USE_(map_level_num, 55); +#endif #if defined(DD_MACRO_ARGCHECK) DYNAMIC_DEBUG_CLASSMAP_USE_(fail_offset_big, 100); diff --git a/tools/testing/selftests/dynamic_debug/dyndbg_selftest.sh b/tools/testing/selftests/dynamic_debug/dyndbg_selftest.sh index 0478ef59dd0f..5de726254d91 100755 --- a/tools/testing/selftests/dynamic_debug/dyndbg_selftest.sh +++ b/tools/testing/selftests/dynamic_debug/dyndbg_selftest.sh @@ -576,12 +576,12 @@ function GOLDEN_RECORDS { #K= c518a50ba30ba8099d0dc874a27ecf16 FT_multi_query.4 #K= 91838b4012c50a1dc1d9e210ba8d68f8 FT_test_classes.1 #K= a15ec4843acd721fbdfddc0b512c8032 FT_test_classes.2 -#K= 2cee6842c9cdee5cb3bf50b2e3914813 FT_test_classes.3 -#K= 81b16613f8d444485e2bc5aa4d38d024 FT_classmap_inheritance.1 -#K= c14c8aa758e24046b3237d20e2189bf7 FT_classmap_inheritance.2 +#K= c03cd07445ca93358176130f04320ee7 FT_test_classes.3 +#K= 1489b3b72dbdfdb553cc0c6594c4face FT_classmap_inheritance.1 +#K= e11c22649735cedb6c30321378100e11 FT_classmap_inheritance.2 #K= 5d0f3701517aa3a461c8887c332bdb42 FT_classmap_inheritance.3 -#K= f444ae312fcce32444c54da757d87c41 FT_classmap_inheritance.4 -#K= 7e92245008439ee79fe2460aeaa16a9b FT_classmap_inheritance.5 +#K= d39188ded831453d90d77390546b314d FT_classmap_inheritance.4 +#K= f43e0aff8a4b38435b73d90ed8100d1b FT_classmap_inheritance.5 #K= d2e8b8c5a5b4e7b9bbe1a29460a3c07d FT_modprobe_w_param.1 #K= d2e8b8c5a5b4e7b9bbe1a29460a3c07d FT_modprobe_w_param.2 #K= 11032ef17569bd151c3806527a2428be FT_modprobe_w_param.3 @@ -592,11 +592,11 @@ function GOLDEN_RECORDS { #K= 0239d8c0808eef396782362613f675b0 FT_modprobe_w_param.8 #K= 535ab526b24a7214de41d92e94bbd52c FT_modprobe_w_param.9 #K= 0239d8c0808eef396782362613f675b0 FT_modprobe_w_param.10 -#K= a71670fec42b1b0646f0317180bafcc7 FT_modprobe_w_param.11 +#K= 7c02282dcfb73eb5ffb9629ce63360e5 FT_modprobe_w_param.11 #K= 0239d8c0808eef396782362613f675b0 FT_modprobe_w_param.12 -#K= aacdbab171b374f221f0196e6e415d09 FT_modprobe_w_param.13 +#K= b0942decc84dae237019bc2877ff02e7 FT_modprobe_w_param.13 #K= 0239d8c0808eef396782362613f675b0 FT_modprobe_w_param.14 -#K= c7eb8e25c780f58c78ed73dc1c187a02 FT_modprobe_w_param.15 +#K= efe8e3b8080c3310708b7505d60f7703 FT_modprobe_w_param.15 #K= 0239d8c0808eef396782362613f675b0 FT_modprobe_w_param.16 #K= d682c98ced7d31f1555ab474a9ebe253 FT_modprobe_w_param.17 #K= 0239d8c0808eef396782362613f675b0 FT_modprobe_w_param.18 @@ -610,11 +610,11 @@ function GOLDEN_RECORDS { #K= 0239d8c0808eef396782362613f675b0 FT_modprobe_w_param.26 #K= 66eb387a95512f679eb5cad4168b0992 FT_modprobe_w_param.27 #K= 0239d8c0808eef396782362613f675b0 FT_modprobe_w_param.28 -#K= 2583cb4637bcc2ce1e93eea4222ec76c FT_modprobe_w_param.29 +#K= 7df05523f4d61917fd7659357eeec1bc FT_modprobe_w_param.29 #K= 0239d8c0808eef396782362613f675b0 FT_modprobe_w_param.30 -#K= d592c5bf23312e705b39064c21ca68e4 FT_modprobe_w_param.31 +#K= a75600ac4e129f4315c5a50ad3a3103c FT_modprobe_w_param.31 #K= 0239d8c0808eef396782362613f675b0 FT_modprobe_w_param.32 -#K= b44d105d151123c93cfe953bacdb573f FT_modprobe_w_param.33 +#K= f43ccce73ac2b0e1529312af66a4ddfe FT_modprobe_w_param.33 #K= 0239d8c0808eef396782362613f675b0 FT_modprobe_w_param.34 #K= 4819f715ba485c493afb455542f7ab8c FT_modprobe_w_param.35 #K= 0239d8c0808eef396782362613f675b0 FT_modprobe_w_param.36 -- 2.55.0
