* [PATCH] kexec: do not call kmsg_dump in crashdump
@ 2011-11-25 8:19 Dave Young
2011-11-25 9:32 ` Cong Wang
2011-11-28 22:27 ` Eric W. Biederman
0 siblings, 2 replies; 5+ messages in thread
From: Dave Young @ 2011-11-25 8:19 UTC (permalink / raw)
To: ebiederm, kexec, linux-kernel
mtd/ram oops dumper will make more functions envolved. In case crash kexec,
we should avoid kmsg dumper to ensure crashdump success.
kill kmsg_dump callback while crash dumping
Signed-off-by: Dave Young <dyoung@redhat.com>
---
kernel/kexec.c | 2 --
1 file changed, 2 deletions(-)
--- linux-2.6.orig/kernel/kexec.c 2011-11-18 16:34:18.000000000 +0800
+++ linux-2.6/kernel/kexec.c 2011-11-24 16:05:08.138660500 +0800
@@ -1094,8 +1094,6 @@ void crash_kexec(struct pt_regs *regs)
if (kexec_crash_image) {
struct pt_regs fixed_regs;
- kmsg_dump(KMSG_DUMP_KEXEC);
-
crash_setup_regs(&fixed_regs, regs);
crash_save_vmcoreinfo();
machine_crash_shutdown(&fixed_regs);
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] kexec: do not call kmsg_dump in crashdump
2011-11-25 8:19 [PATCH] kexec: do not call kmsg_dump in crashdump Dave Young
@ 2011-11-25 9:32 ` Cong Wang
2011-11-25 10:03 ` Dave Young
2011-11-28 22:27 ` Eric W. Biederman
1 sibling, 1 reply; 5+ messages in thread
From: Cong Wang @ 2011-11-25 9:32 UTC (permalink / raw)
To: Dave Young; +Cc: ebiederm, kexec, linux-kernel
On Fri, Nov 25, 2011 at 4:19 PM, Dave Young <dyoung@redhat.com> wrote:
> mtd/ram oops dumper will make more functions envolved. In case crash kexec,
> we should avoid kmsg dumper to ensure crashdump success.
>
> kill kmsg_dump callback while crash dumping
https://lkml.org/lkml/2011/2/1/33
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] kexec: do not call kmsg_dump in crashdump
2011-11-25 9:32 ` Cong Wang
@ 2011-11-25 10:03 ` Dave Young
0 siblings, 0 replies; 5+ messages in thread
From: Dave Young @ 2011-11-25 10:03 UTC (permalink / raw)
To: Cong Wang; +Cc: ebiederm, kexec, linux-kernel
On 11/25/2011 05:32 PM, Cong Wang wrote:
> On Fri, Nov 25, 2011 at 4:19 PM, Dave Young <dyoung@redhat.com> wrote:
>> mtd/ram oops dumper will make more functions envolved. In case crash kexec,
>> we should avoid kmsg dumper to ensure crashdump success.
>>
>> kill kmsg_dump callback while crash dumping
>
> https://lkml.org/lkml/2011/2/1/33
Thanks for give the link. So it's intend to be that.
I'm still confused with the KMSG_DUMP_KEXEC.
crash_kexec()
kmsg_dump(KMSG_DUMP_KEXEC)
kmsg_dump(KMSG_DUMP_PANIC)
Looks like it's equal to original logic, isn't it?
kmsg_dump(anything);
crash_kexec()
So why intruduce KMSG_DUMP_KEXEC? why not just kmsg_dump before crash_kexec?
thoughts?
--
Thanks
Dave
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] kexec: do not call kmsg_dump in crashdump
2011-11-25 8:19 [PATCH] kexec: do not call kmsg_dump in crashdump Dave Young
2011-11-25 9:32 ` Cong Wang
@ 2011-11-28 22:27 ` Eric W. Biederman
2011-11-28 22:34 ` Andrew Morton
1 sibling, 1 reply; 5+ messages in thread
From: Eric W. Biederman @ 2011-11-28 22:27 UTC (permalink / raw)
To: Dave Young; +Cc: kexec, linux-kernel, Andrew Morton
Dave Young <dyoung@redhat.com> writes:
> mtd/ram oops dumper will make more functions envolved. In case crash kexec,
> we should avoid kmsg dumper to ensure crashdump success.
>
> kill kmsg_dump callback while crash dumping
Agreed.
There is a similar? Or possibly the same patch already queued in
Andrews tree.
Eric
>
> Signed-off-by: Dave Young <dyoung@redhat.com>
> ---
> kernel/kexec.c | 2 --
> 1 file changed, 2 deletions(-)
>
> --- linux-2.6.orig/kernel/kexec.c 2011-11-18 16:34:18.000000000 +0800
> +++ linux-2.6/kernel/kexec.c 2011-11-24 16:05:08.138660500 +0800
> @@ -1094,8 +1094,6 @@ void crash_kexec(struct pt_regs *regs)
> if (kexec_crash_image) {
> struct pt_regs fixed_regs;
>
> - kmsg_dump(KMSG_DUMP_KEXEC);
> -
> crash_setup_regs(&fixed_regs, regs);
> crash_save_vmcoreinfo();
> machine_crash_shutdown(&fixed_regs);
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] kexec: do not call kmsg_dump in crashdump
2011-11-28 22:27 ` Eric W. Biederman
@ 2011-11-28 22:34 ` Andrew Morton
0 siblings, 0 replies; 5+ messages in thread
From: Andrew Morton @ 2011-11-28 22:34 UTC (permalink / raw)
To: Eric W. Biederman; +Cc: Dave Young, kexec, linux-kernel
On Mon, 28 Nov 2011 14:27:02 -0800
ebiederm@xmission.com (Eric W. Biederman) wrote:
> Dave Young <dyoung@redhat.com> writes:
>
> > mtd/ram oops dumper will make more functions envolved. In case crash kexec,
> > we should avoid kmsg dumper to ensure crashdump success.
> >
> > kill kmsg_dump callback while crash dumping
>
> Agreed.
>
> There is a similar? Or possibly the same patch already queued in
> Andrews tree.
Below.
I've been sitting on this for ages because we couldn't seem to decide
whether it was desirable. I think we decided a couple of weeks ago to
merge it so I have it planned for 3.3 unless we re-re-re-decide again.
From: WANG Cong <xiyou.wangcong@gmail.com>
Subject: kexec: remove KMSG_DUMP_KEXEC
KMSG_DUMP_KEXEC is useless because we already save kernel messages inside
/proc/vmcore, and it is unsafe to allow modules to do other stuffs in a
crash dump scenario.
[akpm@linux-foundation.org: fix powerpc build]
Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com>
Reported-by: Vivek Goyal <vgoyal@redhat.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Acked-by: Jarod Wilson <jarod@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
arch/powerpc/platforms/pseries/nvram.c | 1 -
drivers/char/ramoops.c | 3 +--
drivers/mtd/mtdoops.c | 3 +--
include/linux/kmsg_dump.h | 1 -
kernel/kexec.c | 3 ---
5 files changed, 2 insertions(+), 9 deletions(-)
diff -puN arch/powerpc/platforms/pseries/nvram.c~kexec-remove-kmsg_dump_kexec arch/powerpc/platforms/pseries/nvram.c
--- a/arch/powerpc/platforms/pseries/nvram.c~kexec-remove-kmsg_dump_kexec
+++ a/arch/powerpc/platforms/pseries/nvram.c
@@ -636,7 +636,6 @@ static void oops_to_nvram(struct kmsg_du
/* These are almost always orderly shutdowns. */
return;
case KMSG_DUMP_OOPS:
- case KMSG_DUMP_KEXEC:
break;
case KMSG_DUMP_PANIC:
panicking = true;
diff -puN drivers/char/ramoops.c~kexec-remove-kmsg_dump_kexec drivers/char/ramoops.c
--- a/drivers/char/ramoops.c~kexec-remove-kmsg_dump_kexec
+++ a/drivers/char/ramoops.c
@@ -83,8 +83,7 @@ static void ramoops_do_dump(struct kmsg_
struct timeval timestamp;
if (reason != KMSG_DUMP_OOPS &&
- reason != KMSG_DUMP_PANIC &&
- reason != KMSG_DUMP_KEXEC)
+ reason != KMSG_DUMP_PANIC)
return;
/* Only dump oopses if dump_oops is set */
diff -puN drivers/mtd/mtdoops.c~kexec-remove-kmsg_dump_kexec drivers/mtd/mtdoops.c
--- a/drivers/mtd/mtdoops.c~kexec-remove-kmsg_dump_kexec
+++ a/drivers/mtd/mtdoops.c
@@ -308,8 +308,7 @@ static void mtdoops_do_dump(struct kmsg_
char *dst;
if (reason != KMSG_DUMP_OOPS &&
- reason != KMSG_DUMP_PANIC &&
- reason != KMSG_DUMP_KEXEC)
+ reason != KMSG_DUMP_PANIC)
return;
/* Only dump oopses if dump_oops is set */
diff -puN include/linux/kmsg_dump.h~kexec-remove-kmsg_dump_kexec include/linux/kmsg_dump.h
--- a/include/linux/kmsg_dump.h~kexec-remove-kmsg_dump_kexec
+++ a/include/linux/kmsg_dump.h
@@ -18,7 +18,6 @@
enum kmsg_dump_reason {
KMSG_DUMP_OOPS,
KMSG_DUMP_PANIC,
- KMSG_DUMP_KEXEC,
KMSG_DUMP_RESTART,
KMSG_DUMP_HALT,
KMSG_DUMP_POWEROFF,
diff -puN kernel/kexec.c~kexec-remove-kmsg_dump_kexec kernel/kexec.c
--- a/kernel/kexec.c~kexec-remove-kmsg_dump_kexec
+++ a/kernel/kexec.c
@@ -32,7 +32,6 @@
#include <linux/console.h>
#include <linux/vmalloc.h>
#include <linux/swap.h>
-#include <linux/kmsg_dump.h>
#include <linux/syscore_ops.h>
#include <asm/page.h>
@@ -1094,8 +1093,6 @@ void crash_kexec(struct pt_regs *regs)
if (kexec_crash_image) {
struct pt_regs fixed_regs;
- kmsg_dump(KMSG_DUMP_KEXEC);
-
crash_setup_regs(&fixed_regs, regs);
crash_save_vmcoreinfo();
machine_crash_shutdown(&fixed_regs);
_
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2011-11-28 22:34 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
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2011-11-25 8:19 [PATCH] kexec: do not call kmsg_dump in crashdump Dave Young
2011-11-25 9:32 ` Cong Wang
2011-11-25 10:03 ` Dave Young
2011-11-28 22:27 ` Eric W. Biederman
2011-11-28 22:34 ` Andrew Morton
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