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| author | HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com> | 2015-06-30 14:57:46 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-06-30 19:44:57 -0700 |
| commit | 5375b708f2547f70cd2bee2fd8663ab7035f9551 (patch) | |
| tree | 4dbcb4086adbf7de22f11a8887fda9fb25b3db87 | |
| parent | f45d85ff1f3f13d5b67fecb291edc6a771db0c53 (diff) | |
| download | linux-5375b708f2547f70cd2bee2fd8663ab7035f9551.tar.gz linux-5375b708f2547f70cd2bee2fd8663ab7035f9551.tar.bz2 linux-5375b708f2547f70cd2bee2fd8663ab7035f9551.zip | |
kernel/panic/kexec: fix "crash_kexec_post_notifiers" option issue in oops path
Commit f06e5153f4ae2e ("kernel/panic.c: add "crash_kexec_post_notifiers"
option for kdump after panic_notifers") introduced
"crash_kexec_post_notifiers" kernel boot option, which toggles wheather
panic() calls crash_kexec() before panic_notifiers and dump kmsg or after.
The problem is that the commit overlooks panic_on_oops kernel boot option.
If it is enabled, crash_kexec() is called directly without going through
panic() in oops path.
To fix this issue, this patch adds a check to "crash_kexec_post_notifiers"
in the condition of kexec_should_crash().
Also, put a comment in kexec_should_crash() to explain not obvious things
on this patch.
Signed-off-by: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
Acked-by: Baoquan He <bhe@redhat.com>
Tested-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
Cc: Baoquan He <bhe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | include/linux/kernel.h | 3 | ||||
| -rw-r--r-- | kernel/kexec.c | 11 | ||||
| -rw-r--r-- | kernel/panic.c | 2 |
3 files changed, 15 insertions, 1 deletions
diff --git a/include/linux/kernel.h b/include/linux/kernel.h index 5acf5b70866d..0dfa4e31563d 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -439,6 +439,9 @@ extern int panic_on_unrecovered_nmi; extern int panic_on_io_nmi; extern int panic_on_warn; extern int sysctl_panic_on_stackoverflow; + +extern bool crash_kexec_post_notifiers; + /* * Only to be used by arch init code. If the user over-wrote the default * CONFIG_PANIC_TIMEOUT, honor it. diff --git a/kernel/kexec.c b/kernel/kexec.c index 7a36fdcca5bf..a785c1015e25 100644 --- a/kernel/kexec.c +++ b/kernel/kexec.c @@ -84,6 +84,17 @@ struct resource crashk_low_res = { int kexec_should_crash(struct task_struct *p) { + /* + * If crash_kexec_post_notifiers is enabled, don't run + * crash_kexec() here yet, which must be run after panic + * notifiers in panic(). + */ + if (crash_kexec_post_notifiers) + return 0; + /* + * There are 4 panic() calls in do_exit() path, each of which + * corresponds to each of these 4 conditions. + */ if (in_interrupt() || !p->pid || is_global_init(p) || panic_on_oops) return 1; return 0; diff --git a/kernel/panic.c b/kernel/panic.c index 774614f72cbd..04e91ff7560b 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -32,7 +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; +bool crash_kexec_post_notifiers; int panic_on_warn __read_mostly; int panic_timeout = CONFIG_PANIC_TIMEOUT; |