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| author | Kees Cook <keescook@chromium.org> | 2023-01-24 22:30:01 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-02-01 10:23:21 +0300 |
| commit | 8c99d4c4c192770e7ea622220e36f53b85152a75 (patch) | |
| tree | 52d3d3dba7794aef987b69377e1ec54a17c08cfb | |
| parent | 55eba18262cbc289ded9e7a8fe1b61a92140b59a (diff) | |
| download | linux-8c99d4c4c192770e7ea622220e36f53b85152a75.tar.xz | |
panic: Introduce warn_limit
commit 9fc9e278a5c0b708eeffaf47d6eb0c82aa74ed78 upstream.
Like oops_limit, add warn_limit for limiting the number of warnings when
panic_on_warn is not set.
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: Petr Mladek <pmladek@suse.com>
Cc: tangmeng <tangmeng@uniontech.com>
Cc: "Guilherme G. Piccoli" <gpiccoli@igalia.com>
Cc: Tiezhu Yang <yangtiezhu@loongson.cn>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: linux-doc@vger.kernel.org
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20221117234328.594699-5-keescook@chromium.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | Documentation/admin-guide/sysctl/kernel.rst | 10 | ||||
| -rw-r--r-- | kernel/panic.c | 14 |
2 files changed, 24 insertions, 0 deletions
diff --git a/Documentation/admin-guide/sysctl/kernel.rst b/Documentation/admin-guide/sysctl/kernel.rst index 470262c08858..6b0c7b650dea 100644 --- a/Documentation/admin-guide/sysctl/kernel.rst +++ b/Documentation/admin-guide/sysctl/kernel.rst @@ -1478,6 +1478,16 @@ entry will default to 2 instead of 0. 2 Unprivileged calls to ``bpf()`` are disabled = ============================================================= + +warn_limit +========== + +Number of kernel warnings after which the kernel should panic when +``panic_on_warn`` is not set. Setting this to 0 disables checking +the warning count. Setting this to 1 has the same effect as setting +``panic_on_warn=1``. The default value is 0. + + watchdog ======== diff --git a/kernel/panic.c b/kernel/panic.c index 0da47888f72e..e341366bd3e8 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -56,6 +56,7 @@ bool crash_kexec_post_notifiers; int panic_on_warn __read_mostly; unsigned long panic_on_taint; bool panic_on_taint_nousertaint = false; +static unsigned int warn_limit __read_mostly; int panic_timeout = CONFIG_PANIC_TIMEOUT; EXPORT_SYMBOL_GPL(panic_timeout); @@ -85,6 +86,13 @@ static struct ctl_table kern_panic_table[] = { .extra2 = SYSCTL_ONE, }, #endif + { + .procname = "warn_limit", + .data = &warn_limit, + .maxlen = sizeof(warn_limit), + .mode = 0644, + .proc_handler = proc_douintvec, + }, { } }; @@ -194,8 +202,14 @@ static void panic_print_sys_info(void) void check_panic_on_warn(const char *origin) { + static atomic_t warn_count = ATOMIC_INIT(0); + if (panic_on_warn) panic("%s: panic_on_warn set ...\n", origin); + + if (atomic_inc_return(&warn_count) >= READ_ONCE(warn_limit) && warn_limit) + panic("%s: system warned too often (kernel.warn_limit is %d)", + origin, warn_limit); } /** |