From nobody Sun Feb 8 13:53:08 2026 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.18]) (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 8327F1304AD for ; Mon, 25 Mar 2024 15:37:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.18 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711381023; cv=none; b=hikvVHxyIuZGonjCot+zwXc/uCxrDJd6PICYIs9viHN+in7/QgXOgE/25iS+hik3QjKVPE+JESiqVnr0vjjlQhG0qz4qIwoCf+RbZt62TKDimg+Cmb78Y54NDHxGAlV9ABYDrzd1qwW9dghfGvI8s34g6fk3p/ZYmKi6ofeCWHI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711381023; c=relaxed/simple; bh=wb4kr08JDH+NnZLnT1A79izRE8BGA+Rpd9wAnH4wDR8=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=ZGN9KUxf80VkhZlu8Jc9AyiZjr0XIyKAq3krlLVNIzF7yMwMo5D+eG+z1FjmURdK/37LIyVfYaVDUVd3h6a3eBSWfuZr6GthnNs5EMBNJLWj++KdVYhk/6GvXTzOxt2lq4VLRTIKXV5G1/MjD69Wm872C1Q+gZ0Wpek3RazWa68= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=eCpXN8qz; arc=none smtp.client-ip=192.198.163.18 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="eCpXN8qz" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1711381021; x=1742917021; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=wb4kr08JDH+NnZLnT1A79izRE8BGA+Rpd9wAnH4wDR8=; b=eCpXN8qzYwjjjQdWacQxyybs6iu3GBIE3pUnuThRqotjYRyiwMb5QEvY e11B5Da38PQ5m95E11bLmIYTxslyorBGgs8Dz1iYsES4J0uDweBG9eYpm M6N7VZ/4hCce+eFMwnFmUmy+W3FIJY75Ts2pFGpEUI1EqHrqqtTNoxJFB Xze0bJpwDxTvX/hN7v1zoiQAanj3SA7vlhWIh7OQy2o/GwWsE9n6zUL1M dL/QZrzTJucAYutVWZ28NlElll6SJE0emdj5ZNJybJO/C3946Xnkwn4Sl 3uU4CKSGG3y7AUPr8x2iLayRtc1SNQA5lGc0G9+zx9S/ncctARqH2Rqkz g==; X-IronPort-AV: E=McAfee;i="6600,9927,11023"; a="6221664" X-IronPort-AV: E=Sophos;i="6.07,153,1708416000"; d="scan'208";a="6221664" Received: from fmviesa002.fm.intel.com ([10.60.135.142]) by fmvoesa112.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 Mar 2024 08:37:00 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.07,153,1708416000"; d="scan'208";a="38758551" Received: from idirlea-mobl.ger.corp.intel.com (HELO localhost) ([10.252.55.171]) by fmviesa002-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 Mar 2024 08:36:59 -0700 From: Jani Nikula To: Andrew Morton , Greg KH , linux-kernel@vger.kernel.org Cc: jani.nikula@intel.com Subject: [RFC 4/4] kernel/panic: add verbose logging of kernel taints in backtraces Date: Mon, 25 Mar 2024 17:36:35 +0200 Message-Id: X-Mailer: git-send-email 2.39.2 In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" With nearly 20 taint flags and respective characters, it's getting a bit difficult to remember what each taint flag character means. Add verbose logging of the set taints in the format: Tainted: [P]=3DPROPRIETARY_MODULE, [W]=3DWARN in dump_stack_print_info() when there are taints. Note that the "negative flag" G is not included. Cc: Andrew Morton Cc: Greg KH Signed-off-by: Jani Nikula --- include/linux/panic.h | 8 +++++--- kernel/panic.c | 45 ++++++++++++++++++++++++++++++++----------- lib/dump_stack.c | 3 +++ 3 files changed, 42 insertions(+), 14 deletions(-) diff --git a/include/linux/panic.h b/include/linux/panic.h index 6717b15e798c..3130e0b5116b 100644 --- a/include/linux/panic.h +++ b/include/linux/panic.h @@ -77,9 +77,10 @@ static inline void set_arch_panic_timeout(int timeout, i= nt arch_default_timeout) #define TAINT_FLAGS_MAX ((1UL << TAINT_FLAGS_COUNT) - 1) =20 struct taint_flag { - char c_true; /* character printed when tainted */ - char c_false; /* character printed when not tainted */ - bool module; /* also show as a per-module taint flag */ + char c_true; /* character printed when tainted */ + char c_false; /* character printed when not tainted */ + bool module; /* also show as a per-module taint flag */ + const char *desc; /* verbose description of the set taint flag */ }; =20 extern const struct taint_flag taint_flags[TAINT_FLAGS_COUNT]; @@ -90,6 +91,7 @@ enum lockdep_ok { }; =20 extern const char *print_tainted(void); +extern const char *print_tainted_verbose(void); extern void add_taint(unsigned flag, enum lockdep_ok); extern int test_taint(unsigned flag); extern unsigned long get_taint(void); diff --git a/kernel/panic.c b/kernel/panic.c index e1f87ba51ba1..ed270d3b5f2b 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -477,6 +477,7 @@ EXPORT_SYMBOL(panic); [ TAINT_##taint ] =3D { \ .c_true =3D _c_true, .c_false =3D _c_false, \ .module =3D _module, \ + .desc =3D #taint, \ } =20 /* @@ -507,8 +508,9 @@ const struct taint_flag taint_flags[TAINT_FLAGS_COUNT] = =3D { =20 #undef TAINT_FLAG =20 -static void print_tainted_seq(struct seq_buf *s) +static void print_tainted_seq(struct seq_buf *s, bool verbose) { + const char *sep =3D ""; int i; =20 if (!tainted_mask) { @@ -522,10 +524,32 @@ static void print_tainted_seq(struct seq_buf *s) bool is_set =3D test_bit(i, &tainted_mask); char c =3D is_set ? t->c_true : t->c_false; =20 - seq_buf_putc(s, c); + if (verbose) { + if (is_set) { + seq_buf_printf(s, "%s[%c]=3D%s", sep, c, t->desc); + sep =3D ", "; + } + } else { + seq_buf_putc(s, c); + } } } =20 +static const char *_print_tainted(bool verbose) +{ + /* FIXME: what should the size be? */ + static char buf[sizeof(taint_flags)]; + struct seq_buf s; + + BUILD_BUG_ON(ARRAY_SIZE(taint_flags) !=3D TAINT_FLAGS_COUNT); + + seq_buf_init(&s, buf, sizeof(buf)); + + print_tainted_seq(&s, verbose); + + return seq_buf_str(&s); +} + /** * print_tainted - return a string to represent the kernel taint state. * @@ -536,16 +560,15 @@ static void print_tainted_seq(struct seq_buf *s) */ const char *print_tainted(void) { - static char buf[TAINT_FLAGS_COUNT + sizeof("Tainted: ")]; - struct seq_buf s; - - BUILD_BUG_ON(ARRAY_SIZE(taint_flags) !=3D TAINT_FLAGS_COUNT); - - seq_buf_init(&s, buf, sizeof(buf)); - - print_tainted_seq(&s); + return _print_tainted(false); +} =20 - return seq_buf_str(&s); +/** + * print_tainted_verbose - A more verbose version of print_tainted() + */ +const char *print_tainted_verbose(void) +{ + return _print_tainted(true); } =20 int test_taint(unsigned flag) diff --git a/lib/dump_stack.c b/lib/dump_stack.c index 222c6d6c8281..8b6b70eaf949 100644 --- a/lib/dump_stack.c +++ b/lib/dump_stack.c @@ -62,6 +62,9 @@ void dump_stack_print_info(const char *log_lvl) (int)strcspn(init_utsname()->version, " "), init_utsname()->version, BUILD_ID_VAL); =20 + if (get_taint()) + printk("%s%s\n", log_lvl, print_tainted_verbose()); + if (dump_stack_arch_desc_str[0] !=3D '\0') printk("%sHardware name: %s\n", log_lvl, dump_stack_arch_desc_str); --=20 2.39.2