diff mbox series

[5.15,15/20] exit: Allow oops_limit to be disabled

Message ID	20230124185110.143857-16-ebiggers@kernel.org
State	New
Headers	Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; From: Eric Biggers <ebiggers@kernel.org> To: stable@vger.kernel.org, Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Kees Cook <keescook@chromium.org>, SeongJae Park <sj@kernel.org>, Seth Jenkins <sethjenkins@google.com>, Jann Horn <jannh@google.com>, "Eric W . Biederman" <ebiederm@xmission.com>, linux-hardening@vger.kernel.org, linux-kernel@vger.kernel.org, Jonathan Corbet <corbet@lwn.net>, Andrew Morton <akpm@linux-foundation.org>, Baolin Wang <baolin.wang@linux.alibaba.com>, "Jason A. Donenfeld" <Jason@zx2c4.com>, Eric Biggers <ebiggers@google.com>, Huang Ying <ying.huang@intel.com>, Arnd Bergmann <arnd@arndb.de>, linux-doc@vger.kernel.org Subject: [PATCH 5.15 15/20] exit: Allow oops_limit to be disabled Date: Tue, 24 Jan 2023 10:51:05 -0800 Message-Id: <20230124185110.143857-16-ebiggers@kernel.org> In-Reply-To: <20230124185110.143857-1-ebiggers@kernel.org> References: <20230124185110.143857-1-ebiggers@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk
Series	Backport oops_limit to 5.15 \| [5.15,00/20] Backport oops_limit to 5.15 [5.15,01/20] sysctl: add a new register_sysctl_init() interface [5.15,02/20] kernel/panic: move panic sysctls to its own file [5.15,03/20] panic: unset panic_on_warn inside panic() [5.15,04/20] ubsan: no need to unset panic_on_warn in ubsan_epilogue() [5.15,05/20] kasan: no need to unset panic_on_warn in end_report() [5.15,06/20] exit: Add and use make_task_dead. [5.15,07/20] objtool: Add a missing comma to avoid string concatenation [5.15,08/20] hexagon: Fix function name in die() [5.15,09/20] h8300: Fix build errors from do_exit() to make_task_dead() transition [5.15,10/20] csky: Fix function name in csky_alignment() and die() [5.15,11/20] ia64: make IA64_MCA_RECOVERY bool instead of tristate [5.15,12/20] panic: Separate sysctl logic from CONFIG_SMP [5.15,13/20] exit: Put an upper limit on how often we can oops [5.15,14/20] exit: Expose "oops_count" to sysfs [5.15,15/20] exit: Allow oops_limit to be disabled [5.15,16/20] panic: Consolidate open-coded panic_on_warn checks [5.15,17/20] panic: Introduce warn_limit [5.15,18/20] panic: Expose "warn_count" to sysfs [5.15,19/20] docs: Fix path paste-o for /sys/kernel/warn_count [5.15,20/20] exit: Use READ_ONCE() for all oops/warn limit reads

Commit Message

Eric Biggers Jan. 24, 2023, 6:51 p.m. UTC

  From: Kees Cook <keescook@chromium.org>

commit de92f65719cd672f4b48397540b9f9eff67eca40 upstream.

In preparation for keeping oops_limit logic in sync with warn_limit,
have oops_limit == 0 disable checking the Oops counter.

Cc: Jann Horn <jannh@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: Eric Biggers <ebiggers@google.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: linux-doc@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Eric Biggers <ebiggers@google.com>
---
 Documentation/admin-guide/sysctl/kernel.rst | 5 +++--
 kernel/exit.c                               | 2 +-
 2 files changed, 4 insertions(+), 3 deletions(-)

diff mbox series

Patch

diff --git a/Documentation/admin-guide/sysctl/kernel.rst b/Documentation/admin-guide/sysctl/kernel.rst
index b6e68d6f297e5..d6f1d3892e71e 100644
--- a/Documentation/admin-guide/sysctl/kernel.rst
+++ b/Documentation/admin-guide/sysctl/kernel.rst
@@ -675,8 +675,9 @@  oops_limit
 ==========
 
 Number of kernel oopses after which the kernel should panic when
-``panic_on_oops`` is not set. Setting this to 0 or 1 has the same effect
-as setting ``panic_on_oops=1``.
+``panic_on_oops`` is not set. Setting this to 0 disables checking
+the count. Setting this to  1 has the same effect as setting
+``panic_on_oops=1``. The default value is 10000.
 
 
 osrelease, ostype & version
diff --git a/kernel/exit.c b/kernel/exit.c
index f68a9c6adfc9c..f6c85101dba0f 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -941,7 +941,7 @@  void __noreturn make_task_dead(int signr)
 	 * To make sure this can't happen, place an upper bound on how often the
 	 * kernel may oops without panic().
 	 */
-	if (atomic_inc_return(&oops_count) >= READ_ONCE(oops_limit))
+	if (atomic_inc_return(&oops_count) >= READ_ONCE(oops_limit) && oops_limit)
 		panic("Oopsed too often (kernel.oops_limit is %d)", oops_limit);
 
 	do_exit(signr);