diff options
| -rw-r--r-- | Documentation/kernel-parameters.txt | 8 | ||||
| -rw-r--r-- | kernel/panic.c | 23 |
2 files changed, 29 insertions, 2 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 9973a7e2e0ac..b9f67781c577 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -2361,6 +2361,14 @@ bytes respectively. Such letter suffixes can also be entirely omitted. timeout < 0: reboot immediately Format: <timeout> + crash_kexec_post_notifiers + Run kdump after running panic-notifiers and dumping + kmsg. This only for the users who doubt kdump always + succeeds in any situation. + Note that this also increases risks of kdump failure, + because some panic notifiers can make the crashed + kernel more unstable. + parkbd.port= [HW] Parallel port number the keyboard adapter is connected to, default is 0. Format: <parport#> diff --git a/kernel/panic.c b/kernel/panic.c index d02fa9fef46a..62e16cef9cc2 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -32,6 +32,7 @@ static unsigned long tainted_mask; static int pause_on_oops; static int pause_on_oops_flag; static DEFINE_SPINLOCK(pause_on_oops_lock); +static bool crash_kexec_post_notifiers; int panic_timeout = CONFIG_PANIC_TIMEOUT; EXPORT_SYMBOL_GPL(panic_timeout); @@ -112,9 +113,11 @@ void panic(const char *fmt, ...) /* * If we have crashed and we have a crash kernel loaded let it handle * everything else. - * Do we want to call this before we try to display a message? + * If we want to run this after calling panic_notifiers, pass + * the "crash_kexec_post_notifiers" option to the kernel. */ - crash_kexec(NULL); + if (!crash_kexec_post_notifiers) + crash_kexec(NULL); /* * Note smp_send_stop is the usual smp shutdown function, which @@ -131,6 +134,15 @@ void panic(const char *fmt, ...) kmsg_dump(KMSG_DUMP_PANIC); + /* + * If you doubt kdump always works fine in any situation, + * "crash_kexec_post_notifiers" offers you a chance to run + * panic_notifiers and dumping kmsg before kdump. + * Note: since some panic_notifiers can make crashed kernel + * more unstable, it can increase risks of the kdump failure too. + */ + crash_kexec(NULL); + bust_spinlocks(0); if (!panic_blink) @@ -472,6 +484,13 @@ EXPORT_SYMBOL(__stack_chk_fail); core_param(panic, panic_timeout, int, 0644); core_param(pause_on_oops, pause_on_oops, int, 0644); +static int __init setup_crash_kexec_post_notifiers(char *s) +{ + crash_kexec_post_notifiers = true; + return 0; +} +early_param("crash_kexec_post_notifiers", setup_crash_kexec_post_notifiers); + static int __init oops_setup(char *s) { if (!s) |