[PATCH v3 2/2] kernel/panic/kexec: fix "crash_kexec_post_notifiers" option issue in oops path
The commit f06e5153f4ae2e2f3b0300f0e260e40cb7fefd45 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 Acked-by: Baoquan He Tested-by: Hidehiro Kawai Reviewed-by: Masami Hiramatsu --- include/linux/kernel.h |3 +++ kernel/kexec.c | 11 +++ kernel/panic.c |2 +- 3 files changed, 15 insertions(+), 1 deletion(-) diff --git a/include/linux/kernel.h b/include/linux/kernel.h index 3a5b48e..bd5331c 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -438,6 +438,9 @@ 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 7a36fdc..a785c10 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 774614f..04e91ff 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; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[PATCH v3 2/2] kernel/panic/kexec: fix crash_kexec_post_notifiers option issue in oops path
The commit f06e5153f4ae2e2f3b0300f0e260e40cb7fefd45 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.hatay...@jp.fujitsu.com Acked-by: Baoquan He b...@redhat.com Tested-by: Hidehiro Kawai hidehiro.kawai...@hitachi.com Reviewed-by: Masami Hiramatsu masami.hiramatsu...@hitachi.com --- include/linux/kernel.h |3 +++ kernel/kexec.c | 11 +++ kernel/panic.c |2 +- 3 files changed, 15 insertions(+), 1 deletion(-) diff --git a/include/linux/kernel.h b/include/linux/kernel.h index 3a5b48e..bd5331c 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -438,6 +438,9 @@ 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 7a36fdc..a785c10 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 774614f..04e91ff 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; -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/