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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt
index fd65f4e651d5540a0d41d100e8133e124ed53ed8..e1d375df4f286c8ff7240d0decff10d682bc41e5 100644 (file)
--- a/Documentation/sysctl/kernel.txt
+++ b/Documentation/sysctl/kernel.txt
@@ -559,8 +559,9 @@ scanned for a given scan.
 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.
 
 ==============================================================
 

diff --git a/kernel/exit.c b/kernel/exit.c
index 5cd8a342576504674bead1485e7541989f2f759d..b2f0aaf6bee7821a588c9f85a2f8f53eb8cdaa5c 100644 (file)
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -986,7 +986,7 @@ 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);