diff options
| -rw-r--r-- | Documentation/sysrq.txt | 7 | ||||
| -rw-r--r-- | drivers/char/sysrq.c | 8 |
2 files changed, 9 insertions, 6 deletions
diff --git a/Documentation/sysrq.txt b/Documentation/sysrq.txt index cf42b820ff9..d56a0177542 100644 --- a/Documentation/sysrq.txt +++ b/Documentation/sysrq.txt @@ -66,7 +66,8 @@ On all - write a character to /proc/sysrq-trigger. e.g.: 'b' - Will immediately reboot the system without syncing or unmounting your disks. -'c' - Will perform a kexec reboot in order to take a crashdump. +'c' - Will perform a system crash by a NULL pointer dereference. + A crashdump will be taken if configured. 'd' - Shows all locks that are held. @@ -141,8 +142,8 @@ useful when you want to exit a program that will not let you switch consoles. re'B'oot is good when you're unable to shut down. But you should also 'S'ync and 'U'mount first. -'C'rashdump can be used to manually trigger a crashdump when the system is hung. -The kernel needs to have been built with CONFIG_KEXEC enabled. +'C'rash can be used to manually trigger a crashdump when the system is hung. +Note that this just triggers a crash if there is no dump mechanism available. 'S'ync is great when your system is locked up, it allows you to sync your disks and will certainly lessen the chance of data loss and fscking. Note diff --git a/drivers/char/sysrq.c b/drivers/char/sysrq.c index 0db35857e4d..5d7a02f63e1 100644 --- a/drivers/char/sysrq.c +++ b/drivers/char/sysrq.c @@ -35,7 +35,6 @@ #include <linux/spinlock.h> #include <linux/vt_kern.h> #include <linux/workqueue.h> -#include <linux/kexec.h> #include <linux/hrtimer.h> #include <linux/oom.h> @@ -124,9 +123,12 @@ static struct sysrq_key_op sysrq_unraw_op = { static void sysrq_handle_crash(int key, struct tty_struct *tty) { char *killer = NULL; + + panic_on_oops = 1; /* force panic */ + wmb(); *killer = 1; } -static struct sysrq_key_op sysrq_crashdump_op = { +static struct sysrq_key_op sysrq_crash_op = { .handler = sysrq_handle_crash, .help_msg = "Crash", .action_msg = "Trigger a crash", @@ -401,7 +403,7 @@ static struct sysrq_key_op *sysrq_key_table[36] = { */ NULL, /* a */ &sysrq_reboot_op, /* b */ - &sysrq_crashdump_op, /* c & ibm_emac driver debug */ + &sysrq_crash_op, /* c & ibm_emac driver debug */ &sysrq_showlocks_op, /* d */ &sysrq_term_op, /* e */ &sysrq_moom_op, /* f */ |