From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 0C83132D0EE; Thu, 25 Jun 2026 18:44:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782413048; cv=none; b=sExNgxeRjsLmaEIJh/vtk8p1OdULMpJd/05jUztt/UGHVVyDTRpAQDnqQCIm4Zl2yAXHnw/9KiHg+B6IY/p3PanD3C/mMTi9idOF7wOAWGD6rZS05qJHfTdRmQZvarKnA+EHfzYjJVetYud4x4pCgMJcgND7KvHt8UnOSzu1KjY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782413048; c=relaxed/simple; bh=F2uxKDdtJnWKy4kV5XnJdI06LPPwqPGWBUVBpr01Yyc=; h=Date:To:From:Subject:Message-Id; b=lB0m2gNf4UoxhdNjQYiebpiWY1AfCTEFWC2Ztka/S16v9iVzhbUkwW1vunupSgEEqzNcVFQ55nW3ABYGPsLwqazZRXasYfvd+XGwy4WT2soAS/uN/o/ILSA5o6d0QrFS9gvkToflxewi1GUo47ZgJ/KMCWHAhlQ0czeqMvf6XZk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=S21NH9UY; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="S21NH9UY" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 979F51F000E9; Thu, 25 Jun 2026 18:44:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1782413046; bh=Or07ehHupwO+bng52SQuFjf0hv15bPXloBBOZyo0X6E=; h=Date:To:From:Subject; b=S21NH9UYl0miJXaPanwJxwZWs/q6c2TLn6Xzkh6AZG+/8xDtfg2kdIo0YEJ1v+qa5 X+6KVh4f29iSDwqZWum99rza20COuLbIdgqbPILQ8rV0R9OJqxJZk8LTUiQnrADgiG VzFiLm68PdwkyKjahKA5XskTWq4hrHJkCuxFJVw0= Date: Thu, 25 Jun 2026 11:44:06 -0700 To: mm-commits@vger.kernel.org,stable@vger.kernel.org,pmladek@suse.com,npiggin@gmail.com,mpe@ellerman.id.au,maddy@linux.ibm.com,dianders@chromium.org,include@grrlz.net,akpm@linux-foundation.org From: Andrew Morton Subject: + watchdog-use-sys_info_with_filter-to-avoid-duplicate-backtraces.patch added to mm-hotfixes-unstable branch Message-Id: <20260625184406.979F51F000E9@smtp.kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: watchdog: use sys_info_with_filter() to avoid duplicate backtraces has been added to the -mm mm-hotfixes-unstable branch. Its filename is watchdog-use-sys_info_with_filter-to-avoid-duplicate-backtraces.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/watchdog-use-sys_info_with_filter-to-avoid-duplicate-backtraces.patch This patch will later appear in the mm-hotfixes-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via various branches at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there most days ------------------------------------------------------ From: Bradley Morgan Subject: watchdog: use sys_info_with_filter() to avoid duplicate backtraces Date: Thu, 25 Jun 2026 15:25:56 +0000 The watchdog prints all CPU backtraces itself. When the watchdog mask contains only SYS_INFO_ALL_BT, stripping that bit leaves zero and sys_info(0) falls back to kernel_sys_info. Use sys_info_with_filter() so an explicit all_bt mask does not request the global default. Link: https://lore.kernel.org/20260625152558.7450-3-include@grrlz.net Fixes: a9af76a78760 ("watchdog: add sys_info sysctls to dump sys info on system lockup") Signed-off-by: Bradley Morgan Cc: Doug Anderson Cc: Madhavan Srinivasan Cc: Michael Ellerman Cc: Nicholas Piggin Cc: Petr Mladek Cc: Signed-off-by: Andrew Morton --- kernel/watchdog.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) --- a/kernel/watchdog.c~watchdog-use-sys_info_with_filter-to-avoid-duplicate-backtraces +++ a/kernel/watchdog.c @@ -208,6 +208,7 @@ void watchdog_hardlockup_check(unsigned { int hardlockup_all_cpu_backtrace; unsigned int this_cpu; + unsigned long si_mask; unsigned long flags; if (per_cpu(watchdog_hardlockup_touched, cpu)) { @@ -216,7 +217,8 @@ void watchdog_hardlockup_check(unsigned return; } - hardlockup_all_cpu_backtrace = (hardlockup_si_mask & SYS_INFO_ALL_BT) ? + si_mask = READ_ONCE(hardlockup_si_mask); + hardlockup_all_cpu_backtrace = (si_mask & SYS_INFO_ALL_BT) ? 1 : sysctl_hardlockup_all_cpu_backtrace; /* * Check for a hardlockup by making sure the CPU's timer @@ -286,7 +288,7 @@ void watchdog_hardlockup_check(unsigned clear_bit_unlock(0, &hard_lockup_nmi_warn); } - sys_info(hardlockup_si_mask & ~SYS_INFO_ALL_BT); + sys_info_with_filter(si_mask, SYS_INFO_ALL_BT); if (hardlockup_panic) nmi_panic(regs, "Hard LOCKUP"); @@ -798,6 +800,7 @@ static enum hrtimer_restart watchdog_tim struct pt_regs *regs = get_irq_regs(); int softlockup_all_cpu_backtrace; int duration, thresh_count; + unsigned long si_mask; unsigned long flags; if (!watchdog_enabled) @@ -809,7 +812,8 @@ static enum hrtimer_restart watchdog_tim if (panic_in_progress()) return HRTIMER_NORESTART; - softlockup_all_cpu_backtrace = (softlockup_si_mask & SYS_INFO_ALL_BT) ? + si_mask = READ_ONCE(softlockup_si_mask); + softlockup_all_cpu_backtrace = (si_mask & SYS_INFO_ALL_BT) ? 1 : sysctl_softlockup_all_cpu_backtrace; watchdog_hardlockup_kick(); @@ -900,7 +904,7 @@ static enum hrtimer_restart watchdog_tim } add_taint(TAINT_SOFTLOCKUP, LOCKDEP_STILL_OK); - sys_info(softlockup_si_mask & ~SYS_INFO_ALL_BT); + sys_info_with_filter(si_mask, SYS_INFO_ALL_BT); thresh_count = duration / get_softlockup_thresh(); if (softlockup_panic && thresh_count >= softlockup_panic) _ Patches currently in -mm which might be from include@grrlz.net are sys_info-add-helper-for-callers-that-print-some-sys_info-on-their-own.patch watchdog-use-sys_info_with_filter-to-avoid-duplicate-backtraces.patch powerpc-watchdog-use-sys_info_with_filter-to-avoid-duplicate-backtraces.patch panic-use-sys_info_with_filter-to-avoid-duplicate-backtraces.patch lib-string-fix-memchr_inv-for-large-ranges.patch