From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9F4195427F5; Wed, 16 Sep 2026 15:33:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789572785; cv=none; b=dBieX16L2kqOU5sNIym7Uhgd7DDx7USdnhiWTyLFLqiUGdczz7KJAmJ2ICGOPgIhsUjItuevIGGPzrVgUf4M65wth/a5PMV5jkspyZq3HzFpS4IgMeg3EaE9k7DfW/F5+eM8KgApMTZmjVG++MMnOpwhaopiuty50QaMmI0u/4M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789572785; c=relaxed/simple; bh=cK/Sahy3bNvWbjqvdDSyRK3pOigTpWzlzP6m3eBJhZI=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=O8DmtBXE/2GKpxFjaALyOLJzq88nrDIgvvX+dSV0h1mtPIkKt83AeuDctN5n9uso9t1mjFEFPdX5tKV5q3aHBLSamtn9AStpSfFUQSvO9VcLhfsSncvtFVZdlmm9s8a5/w6REQ6tytrD5fOgy/b/dSzayWGAA3YhhXbLYGXAIzo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=AQ1Tyr5V; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="AQ1Tyr5V" Received: by smtp.kernel.org (Postfix) with ESMTPS id 24FB5C4AF16; Wed, 16 Sep 2026 15:33:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1789572783; bh=cK/Sahy3bNvWbjqvdDSyRK3pOigTpWzlzP6m3eBJhZI=; h=From:Date:Subject:References:In-Reply-To:To:Cc:Reply-To:From; b=AQ1Tyr5VUgTVPndE2BG+sT4XMJnnyfQkX77pwn2kKRZKPFe3tMO8j3THoIlhxJhTr +qVZqdvabFnaWRvtZPp8/d+5RPq0A70IDxGHtQ/LeWbiGMvhP0jhyKeHt3gMJtfS3L K76EAfwR63sZL9fWsQu9SAYMG2yViHFyZuIVMG2TADgXpyhhzPZfLmA0lS/tm+ST68 GJ6jTp9WuTQKuBg+uzKWsh3080AH/ijjeXJneQlwrHqKeLlE5j1aTGDTO4/PYJmrej OXazcdLuKFdYnpcqc0m7Kj4tkls4Dty6xf63v29Gu7UVcCi0BAVmqdAevcNJKYP51W CAxwp6U1YccHg== Received: from aws-us-west-2-korg-lkml-1.web.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.lore.kernel.org (Postfix) with ESMTP id 10DBBC982C9; Wed, 16 Sep 2026 15:33:03 +0000 (UTC) From: Jim Cromie via B4 Relay Date: Wed, 16 Sep 2026 09:33:25 -0600 Subject: [PATCH v10 33/38] dyndbg: harden classmap and descriptor validation 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: <20260916-dd-cmap-part2-clean-v10-33-af4cf4767707@gmail.com> References: <20260916-dd-cmap-part2-clean-v10-0-af4cf4767707@gmail.com> In-Reply-To: <20260916-dd-cmap-part2-clean-v10-0-af4cf4767707@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 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 X-Mailer: b4 0.14.3 X-Developer-Signature: v=1; a=ed25519-sha256; t=1789572777; l=9553; i=jim.cromie@gmail.com; s=20260203; h=from:subject:message-id; bh=nVFWnFKk0QgFo8thqqeslt7rKlx+zalXosrMpbqoT/M=; b=HjX+eUvHojWORc3aN6sS1EcixM4R5BxkavlY5DAiN/HRS2V5h377CNjRsgFDeciopyiA/XGdn 7YYA3T+SZWxCGh5hAVPTLpIegxifalHI9iGY11AjOpH9bXXs0ADMZzC X-Developer-Key: i=jim.cromie@gmail.com; a=ed25519; pk=C6E5ODlPQo7ZBynATXH9wg7K6HxP0pIXyf4s38Qw0XE= X-Endpoint-Received: by B4 Relay for jim.cromie@gmail.com/20260203 with auth_id=958 X-Original-From: Jim Cromie Reply-To: jim.cromie@gmail.com From: Jim Cromie 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: - Add run-time overlap checks for _USEd classmaps in ddebug_add_module() to prevent collisions between private maps and imported APIs. - Scan module descriptors at load time to print a single warning per missing class_id, rather than waiting for a user query to trip over it. - 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 --- v10: . fix pr_warn_ratelimited() line wrap in ddebug_match_desc(). --- lib/dynamic_debug.c | 68 ++++++++++++++++++++-- lib/test_dynamic_debug.c | 16 +++-- .../selftests/dynamic_debug/dyndbg_selftest.sh | 22 +++---- 3 files changed, 84 insertions(+), 22 deletions(-) diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c index ac54a0499369..eb28831a6cb2 100644 --- a/lib/dynamic_debug.c +++ b/lib/dynamic_debug.c @@ -317,7 +317,8 @@ 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 */ @@ -1490,6 +1491,23 @@ static int ddebug_class_range_overlap(struct ddebug_class_map *cm, u64 *reserved return 0; } +static int ddebug_class_user_overlap(struct ddebug_class_user *cli, + u64 *reserved_ids) +{ + struct ddebug_class_map *cm = cli->map; + int base = cm->base + cli->offset; + u64 range = (((1ULL << cm->length) - 1) << base); + + if (range & *reserved_ids) { + pr_err("module %s: [%d..%d] (from %s) conflicts with %llx\n", + cli->mod_name, base, 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. @@ -1500,7 +1518,8 @@ static int ddebug_add_module(struct _ddebug_info *di) struct ddebug_class_map *cm; struct ddebug_class_user *cli; u64 reserved_ids = 0; - int i; + u64 bad_ids = 0; + int i, err = 0; if (!di->descs.len) return 0; @@ -1531,10 +1550,47 @@ 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 */ + /* validate the per-module shared 0..62 class_id space */ for_subvec(i, cm, &dt->info, maps) if (ddebug_class_range_overlap(cm, &reserved_ids)) - goto cleanup; + err = -EINVAL; + + for_subvec(i, cli, &dt->info, users) { + cm = cli->map; + if (!cm) { + pr_err("module %s: classmap not found for user\n", di->mod_name); + err = -EINVAL; + continue; + } + + if (cm->base + cm->length + cli->offset > _DPRINTK_CLASS_DFLT) { + pr_err("module %s: base:%d + classes.len:%d + cli.offset:%d must be <= %d\n", + di->mod_name, cm->base, cm->length, + cli->offset, _DPRINTK_CLASS_DFLT); + err = -EINVAL; + continue; + } + + if (ddebug_class_user_overlap(cli, &reserved_ids)) + err = -EINVAL; + } + if (err) + goto cleanup; + + /* validate all class_ids against module's classmaps/users */ + for (i = 0; i < dt->info.descs.len; i++) { + struct _ddebug *dp = &dt->info.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(&dt->info, dp->class_id)) { + pr_warn("module %s uses unknown class_id %d\n", + dt->info.mod_name, dp->class_id); + bad_ids |= (1ULL << dp->class_id); + } + } mutex_lock(&ddebug_lock); list_add_tail(&dt->link, &ddebug_tables); @@ -1546,7 +1602,7 @@ 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; } @@ -1633,7 +1689,7 @@ 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 7c10a1ddc630..fe5b885398f3 100644 --- a/lib/test_dynamic_debug.c +++ b/lib/test_dynamic_debug.c @@ -161,14 +161,20 @@ 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 a91a0ffa92d4..ef5f41ca7f7d 100755 --- a/tools/testing/selftests/dynamic_debug/dyndbg_selftest.sh +++ b/tools/testing/selftests/dynamic_debug/dyndbg_selftest.sh @@ -583,12 +583,12 @@ function GOLDEN_RECORDS { #K= c518a50ba30ba8099d0dc874a27ecf16 FT_multi_query.4 #K= 8f18ea82c09460434b6e9e4cd12543e8 FT_test_classes.1 #K= a15ec4843acd721fbdfddc0b512c8032 FT_test_classes.2 -#K= 20d4545f9753e677e72e3adf52527fd3 FT_test_classes.3 -#K= 934d8677872fe26bd636a6c3d6416aa2 FT_classmap_inheritance.1 -#K= cd1389958807063baa1ea4b06c61fa02 FT_classmap_inheritance.2 +#K= bc074e657d8d7f0bbc960e4dfa8de25d FT_test_classes.3 +#K= a60284143b51b5d13c4562f7f4a2e807 FT_classmap_inheritance.1 +#K= 1d43471dca765597d88a1be25d776c92 FT_classmap_inheritance.2 #K= 0708a283f0f1959135c797e36119e4af FT_classmap_inheritance.3 -#K= 05f6efb80299d24cde65174f64d97308 FT_classmap_inheritance.4 -#K= 7e92245008439ee79fe2460aeaa16a9b FT_classmap_inheritance.5 +#K= a0b9a8a9530706b85c4f8bf911607db0 FT_classmap_inheritance.4 +#K= f43e0aff8a4b38435b73d90ed8100d1b FT_classmap_inheritance.5 #K= 53d1b6875b65c79cfd759e209ae50b11 FT_modprobe_w_param.1 #K= 53d1b6875b65c79cfd759e209ae50b11 FT_modprobe_w_param.2 #K= 79d912e2aeb04dea70f9c7e701333f0a FT_modprobe_w_param.3 @@ -599,11 +599,11 @@ function GOLDEN_RECORDS { #K= 6a320774e2b535ceb89d6cdde6f5d0fb FT_modprobe_w_param.8 #K= f9cee4512e5604603e0262fba4bea223 FT_modprobe_w_param.9 #K= 6a320774e2b535ceb89d6cdde6f5d0fb FT_modprobe_w_param.10 -#K= b6a62433165f6423b81417f782551ab9 FT_modprobe_w_param.11 +#K= 7c645692e3e3796d4d3b8604c49583f7 FT_modprobe_w_param.11 #K= 6a320774e2b535ceb89d6cdde6f5d0fb FT_modprobe_w_param.12 -#K= de89753b843449d11da14240c4da4cad FT_modprobe_w_param.13 +#K= e995f70c0509334a33aec40ada9e6e6c FT_modprobe_w_param.13 #K= 6a320774e2b535ceb89d6cdde6f5d0fb FT_modprobe_w_param.14 -#K= 1d966d0cae735457791c93a86e9e1650 FT_modprobe_w_param.15 +#K= 72f97ca3e8f4c3e7f34fbe91de62e223 FT_modprobe_w_param.15 #K= 6a320774e2b535ceb89d6cdde6f5d0fb FT_modprobe_w_param.16 #K= 1aacb7c196a8354c46c60c73d78c6bf2 FT_modprobe_w_param.17 #K= 6a320774e2b535ceb89d6cdde6f5d0fb FT_modprobe_w_param.18 @@ -617,11 +617,11 @@ function GOLDEN_RECORDS { #K= 6a320774e2b535ceb89d6cdde6f5d0fb FT_modprobe_w_param.26 #K= 7fa4c84490c42c750986614c3539d56a FT_modprobe_w_param.27 #K= 6a320774e2b535ceb89d6cdde6f5d0fb FT_modprobe_w_param.28 -#K= 1eb866a813551061cd73178ba7833543 FT_modprobe_w_param.29 +#K= fc098897aa3e1472a536e7ae8069c84f FT_modprobe_w_param.29 #K= 6a320774e2b535ceb89d6cdde6f5d0fb FT_modprobe_w_param.30 -#K= a9e7424ed7b02696b5e12108971792dd FT_modprobe_w_param.31 +#K= 38ea63fed62a0308241325e57020b28e FT_modprobe_w_param.31 #K= 6a320774e2b535ceb89d6cdde6f5d0fb FT_modprobe_w_param.32 -#K= 5323d7746d983cdcfda4866255cd5123 FT_modprobe_w_param.33 +#K= 4b896adb5e7cfcc79f9ffa879d791f37 FT_modprobe_w_param.33 #K= 6a320774e2b535ceb89d6cdde6f5d0fb FT_modprobe_w_param.34 #K= 7f961a7d3facd89bdd4b9d8e7b5541e9 FT_modprobe_w_param.35 #K= 6a320774e2b535ceb89d6cdde6f5d0fb FT_modprobe_w_param.36 -- 2.55.0