From nobody Sun Feb 8 11:07:08 2026 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.7]) (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 E4313156F20 for ; Fri, 31 May 2024 09:05:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.7 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717146326; cv=none; b=oP/lVUWPckRph7uk/Oho0T+7skTgl9OvZDD6t59HdUuqkcYfhoJj6ZIHnoBOnqLOdrLhxeK1HdD+2LYKhbcNBHCi82nHQqEYdUoJbY0VTUN3ZJ2/ukB/F8fAFBuFVnMF7TJXkFLFWOxCrYa2lY5BqEH2x50UKwflsrwI/fB99tE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717146326; c=relaxed/simple; bh=T30Nd2PdPbzDqMDHg57Y0dcrPInQXZHw0rwiqt2FO94=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=sD34uo2DnuEG8sDe0IG6yU1c7dZMQIp5f6ksXg3bifiQfyfkkuGpKcwmiAyBWMTrrBc8JrCM7IMOdmRuf6tTdg23Rgj2f45bqPaXZ4U85rXy2F7r0hZFxdEh3rbz8oF0+PXah+UyyWGpQxhr8C9HqnTHmlMprFIFgZPUd7UDU2Q= 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=E+0lQjkh; arc=none smtp.client-ip=192.198.163.7 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="E+0lQjkh" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1717146325; x=1748682325; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=T30Nd2PdPbzDqMDHg57Y0dcrPInQXZHw0rwiqt2FO94=; b=E+0lQjkhmUfaiIaHuXy5A+9ZBAn74baZxdAm0Y/dH8s+xK97Vj5GdTJQ 2qEbvNgaINHlDarKv71P4m6mdEDuQAiZWa1KAElDvH9s5qvWo5U+lXAuw eH5QqRFyFrDH0ieZaMjs9Y++Ac75oD7zKf1q+2pV2mkFJudJrcUUEbYPs +llfWlo9M0+DbymIrjMYRkZHOpY1MNH4RRGvePGz8qlApRD9U1F1GuJF+ wGk6jG4sjOtZvLN+V+2m3VZvq2dD5RI55V8EJZtvYEJKdYMV16ASpQgAR PlOJKk+/aWmEFMFEdr4Q/a5ew6ac1rItcGVrmXBT5/YQqm6GJwF30SvqN w==; X-CSE-ConnectionGUID: Pobw1BBtRuS3GEPxv1r1aQ== X-CSE-MsgGUID: 7S4CBYy4SRaxsdFmSgDjXg== X-IronPort-AV: E=McAfee;i="6600,9927,11088"; a="39074088" X-IronPort-AV: E=Sophos;i="6.08,203,1712646000"; d="scan'208";a="39074088" Received: from fmviesa003.fm.intel.com ([10.60.135.143]) by fmvoesa101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 31 May 2024 02:05:24 -0700 X-CSE-ConnectionGUID: OryVlFjhQYuJzdh1bD8L9Q== X-CSE-MsgGUID: JtkIRRQETMON7xeoJg0Vuw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.08,203,1712646000"; d="scan'208";a="40543256" Received: from bergbenj-mobl1.ger.corp.intel.com (HELO localhost) ([10.245.246.190]) by fmviesa003-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 31 May 2024 02:05:23 -0700 From: Jani Nikula To: linux-kernel@vger.kernel.org Cc: jani.nikula@intel.com, Andrew Morton , Greg KH Subject: [PATCH 4/4] kernel/panic: add verbose logging of kernel taints in backtraces Date: Fri, 31 May 2024 12:04:57 +0300 Message-Id: <7321e306166cb2ca2807ab8639e665baa2462e9c.1717146197.git.jani.nikula@intel.com> 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 Reviewed-by: Greg Kroah-Hartman --- 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 8f7bb94ad7d8..a914f2fcf9ad 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -476,6 +476,7 @@ EXPORT_SYMBOL(panic); [ TAINT_##taint ] =3D { \ .c_true =3D _c_true, .c_false =3D _c_false, \ .module =3D _module, \ + .desc =3D #taint, \ } =20 /* @@ -506,8 +507,9 @@ 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) { @@ -521,10 +523,32 @@ 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. * @@ -535,16 +559,15 @@ 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