From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oo2-f38.google.com (mail-oo2-f38.google.com [74.125.231.166]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2A785582BBC for ; Wed, 23 Sep 2026 22:35:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.125.231.166 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790202943; cv=none; b=JxhuY9ffK9CfoMfs8XFdGjwT4UIlwPiiarYk0sOqbMm9yzPqf+niibv8NgfD5gIwzMoiCEVALCWX5Dk0QmnZWdkXWKx2eWGcOchrnx0AyM4zIimzwnD82uvAucJOy8PVsE96DMxbXhtgNa55t0Oc1kZtmRJiS14BQbjscbWGFa8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790202943; c=relaxed/simple; bh=FxGWl/qZQ9hT/MhWXIIatHIxLIqLkDD4kgaac7ZQZeI=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=UvnIiy1JTrDD1tmdEg6k1X9MOh4WdfxPGwoVaaThlPyos4q6gv7UEiWk59VB4MEPb+iO98eLc0bJK4vsqg8F3WBm4z86aBZUOuhLz9TNIayzPQWNER/G8fpy6HfwxRChWX0bOZl25hd1xNMfQRNDEsvuSNr8KExP0UlxI27sMrg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=pyLOChST; arc=none smtp.client-ip=74.125.231.166 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="pyLOChST" Received: by mail-oo2-f38.google.com with SMTP id 006d021491bc7-6b1ae736c63so921972eaf.1 for ; Wed, 23 Sep 2026 15:35:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1790202936; x=1790807736; darn=vger.kernel.org; h=cc:to:in-reply-to:references:message-id:content-transfer-encoding :content-type:mime-version:subject:date:from:from:to:cc:subject:date :message-id:reply-to:content-type; bh=MRZpLbtJtk8hyONJcypVVqJfATknkih6inIizr3T0ts=; b=pyLOChSTgd8LF+g5V9NCzTu31ZTM9gbjB5DuxLYZCGPLVSNEQcOgYHp+pN2K9cyMgZ FwiotMZeeFm4SPn2N1JgLYRd2eFHItCYr+8Kp1hsygZFs8j7moQRvymUARozHgLwqiFT hX8UrqDjtxJ5b0A9XfLhadcs40m34HlVyBT9OkT0dYiCADcaHuiBYKBX0YCqQdBUWfib g22uVkiwVZQKZhNbFBTO6r54JXHyRizzDdP2dKT99rY0uGVuRnZa5/cnuq8ETLb6JB3K mnYGtP+0oxdYSyKQi9NFHXZP5/bhbemEeHB+DbtVkjwzJypKYYSm6RjyzhOaNVYWf6g0 vY/w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1790202936; x=1790807736; h=cc:to:in-reply-to:references:message-id:content-transfer-encoding :content-type:mime-version:subject:date:from:x-gm-gg :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=MRZpLbtJtk8hyONJcypVVqJfATknkih6inIizr3T0ts=; b=aeC9Fa3VWoDkV5UdK6esOYEGWBL/LnwtyJULwVBVrWcIGdcNX7p6L0mDCR3GOWr6AQ 4GbHBcVBP51QpOa9J4cccD5s1e59jp3AHCwVsL58ikJ2UoMTrUJXbVQ/gSJLEdnmdCnA X0PNrNw+9R/Y/y69XLLq+Ib579eJVZSwIthAdJ3zeSfo9LYj4dGT/UKdz5QuWPtzLb2b gh1uDntgpydc98ooinbi8O69dGkiXY1dPZ5z0oGJ1zmddl8dR5xnJkQRdOPgQRGvecmR 7w3EYN/u0JN5bzEK1A6KCWehyRzQHOuaLsN66Mi1FuCk1cGmoNFBnve7BOrxm4vA7WW9 +y6Q== X-Gm-Message-State: AFuF++lIEfyd+4+ZaGjeI8hv+B/f3F94ZV65LwzO7711fiKeJ9QvXk6W T/e3mBugUgTTPq8/kppPRXB1g3UoeYCMZpem9ZaBZM12kREBRAAtFysm X-Gm-Gg: AYBFou3GftopwpwB3vaAnW0XutiFCegDf8dK7dPtpcRb3E43mpHInLgi+ojUCCEmUxq TOPJyNylGt2eDev+Mx+mTzFnfeLCjLjrVurDsFjs0mqyH7rZTAZh/nzTR9JSUzQBqcFiUMCweGe nutRtLOqUb57eaTvKrgUt0EMleESQ+HfRLvDEyk9mW/Z6hW0Z/d8XSnJilFoKAqpzNhDv68quWB sT4BJuT3T0ui7EkCw07LCtHBAKA6TFZSoZ0aubeEi8NMRkafivbI/xRJFjAwRrfa2sgPyttZR5m Oaq9WL80inO9Rpbue2VKHXGNQZCL89wpMZ7iRoW2L7cpDDNbH2p5r/dPau5Id4+kcHWH0NKY8sp BDXaxJW+P8pkwGC7R5cMrz0NLtKMBqqUxan024AkiFWR32VM+igARqO3xd766UpTvVqo44lfX4+ O7o9JJyWD9Nwy++fYUWbg65JCTv2YAa9SQKt87Dq8uc4SILNCmNR5l21e413PiAuXgmn3aRp6xY +R7HVL19d7x/FnNezjw82REGfaPpP185d1u9bTugonP0TW+GgJJ5q60q/rCQ/pLlL5rImhGGffN b+GlAIIJkvdffw+tqTg= X-Received: by 2002:a05:6820:81cf:b0:6b7:8415:d77f with SMTP id 006d021491bc7-6d4410d98aemr809891eaf.42.1790202936233; Wed, 23 Sep 2026 15:35:36 -0700 (PDT) Received: from [100.82.231.29] (c-98-38-17-99.hsd1.co.comcast.net. [98.38.17.99]) by smtp.googlemail.com with ESMTPSA id 586e51a60fabf-491ee1ac486sm559401fac.16.2026.09.23.15.35.34 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 23 Sep 2026 15:35:35 -0700 (PDT) From: Jim Cromie Date: Wed, 23 Sep 2026 16:34:49 -0600 Subject: [PATCH v11 25/38] dyndbg: detect class_id reservation conflicts Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260923-dd-cmap-part2-clean-v11-25-9b6c217fdf2f@gmail.com> References: <20260923-dd-cmap-part2-clean-v11-0-9b6c217fdf2f@gmail.com> In-Reply-To: <20260923-dd-cmap-part2-clean-v11-0-9b6c217fdf2f@gmail.com> To: Jason Baron , Shuah Khan , Andrew Morton , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Arnd Bergmann , Luis Chamberlain , Petr Pavlu , Daniel Gomez , Sami Tolvanen , Aaron Tomlin , Jonathan Corbet , Greg Kroah-Hartman , Nathan Chancellor , Nicolas Schier , Shuah Khan , Randy Dunlap , "Rafael J. Wysocki" , Pavel Machek , Len Brown , Jonathan Corbet , Petr Mladek , Steven Rostedt , John Ogness , Sergey Senozhatsky Cc: linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-arch@vger.kernel.org, linux-modules@vger.kernel.org, linux-doc@vger.kernel.org, linux-kbuild@vger.kernel.org, linux-pm@vger.kernel.org, Jim Cromie , Louis Chauvet X-Mailer: b4 0.14.3 X-Developer-Signature: v=1; a=ed25519-sha256; t=1790202874; l=7918; i=jim.cromie@gmail.com; s=20260203; h=from:subject:message-id; bh=FxGWl/qZQ9hT/MhWXIIatHIxLIqLkDD4kgaac7ZQZeI=; b=dVnpdnVOhsyNH04hJqkbikqFWgQdXmK6tpT9ciPy6PMExQXjwbLQEkgwvbXNl4K2i2abW6I3+ D8ms/H0SYtrD+fKH1KvHYK9fntToOELaap1NkvJwjPINUlJd6IWnIpl X-Developer-Key: i=jim.cromie@gmail.com; a=ed25519; pk=C6E5ODlPQo7ZBynATXH9wg7K6HxP0pIXyf4s38Qw0XE= If a module _DEFINEs 2 or more classmaps, it must devise them to share the per-module 0..62 class-id space; ie their respective base,+length reservations cannot overlap. To detect conflicts at modprobe, add ddebug_class_range_overlap(), call it from ddebug_add_module(), and WARN and return -EINVAL when they're detected. This insures that class_id -> classname lookup has just 1 answer, so the 1st-found search in find-class-name works properly. test_dynamic_debug.c: If built with -DFORCE_CLASSID_CONFLICT, the test-modules invoke 2 conflicting DYNAMIC_DEBUG_CLASSMAP_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 WARN and fail. Signed-off-by: Jim Cromie Reviewed-by: Louis Chauvet --- v11: . only increment mod_ct when ddebug_add_module() returns 0. Sashiko review complaint (patch 25): "Is it intentional to unconditionally increment mod_ct here? By changing this from a fatal error to a warn-and-continue, if ddebug_add_module() fails, the inflated mod_ct will cause inaccurate initialization logs (vpr_info) and an incorrect calculation for memory used by ddebug tables. Should the increment only happen on success?" v9: . make ddebug_add_module() failure non-fatal during dynamic_debug_init(), logging warning and continuing instead of tearing down all tables kernel-wide. v2: RvB after SoB old-v9 - fix WARN() by adding new 1st arg 1. old-v12 - drop maybe_unused on range-overlap fn --- lib/dynamic_debug.c | 73 ++++++++++++++++++++++++++++-------------------- lib/test_dynamic_debug.c | 8 ++++++ 2 files changed, 50 insertions(+), 31 deletions(-) diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c index 8c314a52d8f9..64ad70738d95 100644 --- a/lib/dynamic_debug.c +++ b/lib/dynamic_debug.c @@ -1102,18 +1102,19 @@ static void *ddebug_proc_next(struct seq_file *m, void *p, loff_t *pos) return dp; } -static bool ddebug_class_in_range(const int class_id, const struct ddebug_class_map *map) +static bool ddebug_class_map_in_range(const int class_id, const struct ddebug_class_map *map) { + if (!map) + return false; return (class_id >= map->base && class_id < map->base + map->length); } -static bool ddebug_user_class_in_range(const int class_id, const struct ddebug_class_user *cli) +static bool ddebug_class_user_in_range(const int class_id, const struct ddebug_class_user *user) { - if (!cli || !cli->map) + if (!user) return false; - int base = cli->map->base + cli->offset; - return (class_id >= base && class_id < base + cli->map->length); + return ddebug_class_map_in_range(class_id - user->offset, user->map); } static const char *ddebug_class_name(struct _ddebug_info *di, struct _ddebug *dp) @@ -1123,11 +1124,11 @@ static const char *ddebug_class_name(struct _ddebug_info *di, struct _ddebug *dp int i; for_subvec(i, map, di, maps) - if (ddebug_class_in_range(dp->class_id, map)) + if (ddebug_class_map_in_range(dp->class_id, map)) return map->class_names[dp->class_id - map->base]; for_subvec(i, cli, di, users) - if (ddebug_user_class_in_range(dp->class_id, cli)) + if (ddebug_class_user_in_range(dp->class_id, cli)) return cli->map->class_names[dp->class_id - cli->map->base - cli->offset]; return NULL; @@ -1396,6 +1397,20 @@ 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) +{ + 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; +} + /* * Allocate a new ddebug_table for the given module * and add it to the global list. @@ -1405,6 +1420,7 @@ 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) @@ -1436,6 +1452,13 @@ 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; + + /* + */ mutex_lock(&ddebug_lock); list_add_tail(&dt->link, &ddebug_tables); mutex_unlock(&ddebug_lock); @@ -1453,6 +1476,10 @@ static int ddebug_add_module(struct _ddebug_info *di) vpr_info("%3u debug prints in module %s\n", dt->info.descs.len, dt->info.mod_name); return 0; +cleanup: + WARN_ONCE(1, "dyndbg multi-classmap conflict in %s\n", di->mod_name); + kfree(dt); + return -EINVAL; } /* helper for ddebug_dyndbg_(boot|module)_param_cb */ @@ -1495,14 +1522,14 @@ int ddebug_dyndbg_module_param_cb(char *param, char *val, const char *module) return ddebug_dyndbg_param_cb(param, val, module, -ENOENT); } +#ifdef CONFIG_MODULES + static void ddebug_table_free(struct ddebug_table *dt) { list_del_init(&dt->link); kfree(dt); } -#ifdef CONFIG_MODULES - /* * Called in response to a module being unloaded. Removes * any ddebug_table's which point at the module. @@ -1554,18 +1581,6 @@ static struct notifier_block ddebug_module_nb = { #endif /* CONFIG_MODULES */ -static void ddebug_remove_all_tables(void) -{ - mutex_lock(&ddebug_lock); - while (!list_empty(&ddebug_tables)) { - struct ddebug_table *dt = list_entry(ddebug_tables.next, - struct ddebug_table, - link); - ddebug_table_free(dt); - } - mutex_unlock(&ddebug_lock); -} - static __initdata int ddebug_init_success; static int __init dynamic_debug_init_control(void) @@ -1636,9 +1651,9 @@ static int __init dynamic_debug_init(void) di.mod_name = modname; ret = ddebug_add_module(&di); if (ret) - goto out_err; - - mod_ct++; + pr_warn("failed to add built-in module %s: %d\n", modname, ret); + else + mod_ct++; iter_mod_start = iter; modname = iter->modname; @@ -1651,9 +1666,9 @@ static int __init dynamic_debug_init(void) di.mod_name = modname; ret = ddebug_add_module(&di); if (ret) - goto out_err; - - mod_ct++; + pr_warn("failed to add built-in module %s: %d\n", modname, ret); + else + mod_ct++; ddebug_init_success = 1; vpr_info("%d prdebugs in %d modules, %d KiB in ddebug tables, %d kiB in __dyndbg_descs section\n", @@ -1676,10 +1691,6 @@ static int __init dynamic_debug_init(void) 0, 0, 0, NULL, &ddebug_dyndbg_boot_param_cb); kfree(cmdline); return 0; - -out_err: - ddebug_remove_all_tables(); - return 0; } /* Allow early initialization for boot messages via boot param */ early_initcall(dynamic_debug_init); diff --git a/lib/test_dynamic_debug.c b/lib/test_dynamic_debug.c index 34e51996aa20..3a69cc3cae6d 100644 --- a/lib/test_dynamic_debug.c +++ b/lib/test_dynamic_debug.c @@ -128,6 +128,14 @@ DYNAMIC_DEBUG_CLASSMAP_DEFINE(map_disjoint_bits, DD_CLASS_TYPE_DISJOINT_BITS, DYNAMIC_DEBUG_CLASSMAP_DEFINE(map_level_num, DD_CLASS_TYPE_LEVEL_NUM, V1, "V1", "V2", "V3", "V4", "V5", "V6", "V7"); +#ifdef FORCE_CLASSID_CONFLICT +/* + * Enable with -Dflag on compile to test overlapping class-id range + * detection. This should warn on modprobes. + */ +DYNAMIC_DEBUG_CLASSMAP_DEFINE(classid_range_conflict, 0, D2_CORE + 1, "D3_CORE"); +#endif + #else /* TEST_DYNAMIC_DEBUG_SUBMOD */ /* -- 2.55.0