Commit 004429956b4875e6bc2a31833f75363ce48cbea9
Committed by
Linus Torvalds
Linus Torvalds
1 parent
b311e921b3
Exists in
master
and in
20 other branches
handle recursive calls to bust_spinlocks()
Various architectures may call bust_spinlocks() recursively; the function itself, however, doesn't appear to be meant to be called in this manner. Nevertheless, this doesn't appear to be a problem as long as bust_spinlocks(0) doesn't get called twice in a row (otherwise, unblank_screen() may enter the scheduler). However, at least on i386 die() has been capable of returning (and on other architectures this should really be that way, too) when notify_die() returns NOTIFY_STOP. Short of getting a reply to a respective query, this patch makes bust_spinlocks() increment/decrement oops_in_progress, and wake klogd only when the count drops back to zero. Signed-off-by: Jan Beulich <jbeulich@novell.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Showing 1 changed file with 3 additions and 3 deletions Inline Diff
lib/bust_spinlocks.c
| 1 | /* | 1 | /* |
| 2 | * lib/bust_spinlocks.c | 2 | * lib/bust_spinlocks.c |
| 3 | * | 3 | * |
| 4 | * Provides a minimal bust_spinlocks for architectures which don't have one of their own. | 4 | * Provides a minimal bust_spinlocks for architectures which don't have one of their own. |
| 5 | * | 5 | * |
| 6 | * bust_spinlocks() clears any spinlocks which would prevent oops, die(), BUG() | 6 | * bust_spinlocks() clears any spinlocks which would prevent oops, die(), BUG() |
| 7 | * and panic() information from reaching the user. | 7 | * and panic() information from reaching the user. |
| 8 | */ | 8 | */ |
| 9 | 9 | ||
| 10 | #include <linux/kernel.h> | 10 | #include <linux/kernel.h> |
| 11 | #include <linux/spinlock.h> | 11 | #include <linux/spinlock.h> |
| 12 | #include <linux/tty.h> | 12 | #include <linux/tty.h> |
| 13 | #include <linux/wait.h> | 13 | #include <linux/wait.h> |
| 14 | #include <linux/vt_kern.h> | 14 | #include <linux/vt_kern.h> |
| 15 | 15 | ||
| 16 | 16 | ||
| 17 | void __attribute__((weak)) bust_spinlocks(int yes) | 17 | void __attribute__((weak)) bust_spinlocks(int yes) |
| 18 | { | 18 | { |
| 19 | if (yes) { | 19 | if (yes) { |
| 20 | oops_in_progress = 1; | 20 | ++oops_in_progress; |
| 21 | } else { | 21 | } else { |
| 22 | #ifdef CONFIG_VT | 22 | #ifdef CONFIG_VT |
| 23 | unblank_screen(); | 23 | unblank_screen(); |
| 24 | #endif | 24 | #endif |
| 25 | oops_in_progress = 0; | 25 | if (--oops_in_progress == 0) |
| 26 | wake_up_klogd(); | 26 | wake_up_klogd(); |
| 27 | } | 27 | } |
| 28 | } | 28 | } |
| 29 | 29 | ||
| 30 | 30 | ||
| 31 | 31 |