exit: Allow oops_limit to be disabled

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/Documentation/admin-guide/sysctl/kernel.rst b/Documentation/admin-guide/sysctl/kernel.rst
index b6e68d6f297e5d1d043cc4fa517135214e5fce8a..d6f1d3892e71ee4a9c4a9963fd3b0597d9729f94 100644 (file)
--- 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 f68a9c6adfc9c151e5a98fb1f7cf79b5529205d7..f6c85101dba0f44c820859fbf02f2c50a6b19e33 100644 (file)
--- 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);