https://github.com/torvalds/linux
Revision cab8bd3410d448279e3bd0fbf96d31db0bf770fa authored by Hidetoshi Seto on 29 July 2009, 22:04:14 UTC, committed by Linus Torvalds on 30 July 2009, 02:10:36 UTC
commit d6580a9f15238b87e618310c862231ae3f352d2d ("kexec: sysrq: simplify sysrq-c handler") changed the behavior of sysrq-c to unconditional dereference of NULL pointer. So in cases with CONFIG_KEXEC, where crash_kexec() was directly called from sysrq-c before, now it can be said that a step of "real oops" was inserted before starting kdump. However, in contrast to oops via SysRq-c from keyboard which results in panic due to in_interrupt(), oops via "echo c > /proc/sysrq-trigger" will not become panic unless panic_on_oops=1. It means that even if dump is properly configured to be taken on panic, the sysrq-c from proc interface might not start crashdump while the sysrq-c from keyboard can start crashdump. This confuses traditional users of kdump, i.e. people who expect sysrq-c to do common behavior in both of the keyboard and proc interface. This patch brings the keyboard and proc interface behavior of sysrq-c in line, by forcing panic_on_oops=1 before oops in sysrq-c handler. And some updates in documentation are included, to clarify that there is no longer dependency with CONFIG_KEXEC, and that now the system can just crash by sysrq-c if no dump mechanism is configured. Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Ken'ichi Ohmichi <oomichi@mxs.nes.nec.co.jp> Acked-by: Neil Horman <nhorman@tuxdriver.com> Acked-by: Vivek Goyal <vgoyal@redhat.com> Cc: Brayan Arraes <brayan@yack.com.br> Cc: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent f5a55ef
Tip revision: cab8bd3410d448279e3bd0fbf96d31db0bf770fa authored by Hidetoshi Seto on 29 July 2009, 22:04:14 UTC
sysrq, kdump: make sysrq-c consistent
sysrq, kdump: make sysrq-c consistent
Tip revision: cab8bd3
File | Mode | Size |
---|---|---|
Kconfig | -rw-r--r-- | 2.5 KB |
Kconfig.iosched | -rw-r--r-- | 1.9 KB |
Makefile | -rw-r--r-- | 569 bytes |
as-iosched.c | -rw-r--r-- | 38.7 KB |
blk-barrier.c | -rw-r--r-- | 9.7 KB |
blk-core.c | -rw-r--r-- | 64.0 KB |
blk-exec.c | -rw-r--r-- | 2.6 KB |
blk-integrity.c | -rw-r--r-- | 9.9 KB |
blk-ioc.c | -rw-r--r-- | 4.0 KB |
blk-map.c | -rw-r--r-- | 8.1 KB |
blk-merge.c | -rw-r--r-- | 9.8 KB |
blk-settings.c | -rw-r--r-- | 21.3 KB |
blk-softirq.c | -rw-r--r-- | 4.1 KB |
blk-sysfs.c | -rw-r--r-- | 11.7 KB |
blk-tag.c | -rw-r--r-- | 9.9 KB |
blk-timeout.c | -rw-r--r-- | 5.7 KB |
blk.h | -rw-r--r-- | 4.5 KB |
bsg.c | -rw-r--r-- | 23.4 KB |
cfq-iosched.c | -rw-r--r-- | 63.9 KB |
compat_ioctl.c | -rw-r--r-- | 21.6 KB |
deadline-iosched.c | -rw-r--r-- | 11.4 KB |
elevator.c | -rw-r--r-- | 24.9 KB |
genhd.c | -rw-r--r-- | 29.1 KB |
ioctl.c | -rw-r--r-- | 8.6 KB |
noop-iosched.c | -rw-r--r-- | 2.6 KB |
scsi_ioctl.c | -rw-r--r-- | 18.0 KB |
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