diff options
author | Masoud Asgharifard Sharbiani <masouds@google.com> | 2007-07-22 05:12:28 -0400 |
---|---|---|
committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-07-22 14:03:37 -0400 |
commit | abd4f7505bafdd6c5319fe3cb5caf9af6104e17a (patch) | |
tree | a543fce720331dbf6194a2c0471f36b7727b9736 /kernel | |
parent | 5fa63fccc579ac609fc7f86d29ccb3a2edf910d7 (diff) |
x86: i386-show-unhandled-signals-v3
This patch makes the i386 behave the same way that x86_64 does when a
segfault happens. A line gets printed to the kernel log so that tools
that need to check for failures can behave more uniformly between
debug.show_unhandled_signals sysctl variable to 0 (or by doing echo 0 >
/proc/sys/debug/exception-trace)
Also, all of the lines being printed are now using printk_ratelimit() to
deny the ability of DoS from a local user with a program like the
following:
main()
{
while (1)
if (!fork()) *(int *)0 = 0;
}
This new revision also includes the fix that Andrew did which got rid of
new sysctl that was added to the system in earlier versions of this.
Also, 'show-unhandled-signals' sysctl has been renamed back to the old
'exception-trace' to avoid breakage of people's scripts.
AK: Enabling by default for i386 will be likely controversal, but let's see what happens
AK: Really folks, before complaining just fix your segfaults
AK: I bet this will find a lot of silent issues
Signed-off-by: Masoud Sharbiani <masouds@google.com>
Signed-off-by: Andi Kleen <ak@suse.de>
[ Personally, I've found the complaints useful on x86-64, so I'm all for
this. That said, I wonder if we could do it more prettily.. -Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel')
-rw-r--r-- | kernel/signal.c | 10 | ||||
-rw-r--r-- | kernel/sysctl.c | 10 |
2 files changed, 20 insertions, 0 deletions
diff --git a/kernel/signal.c b/kernel/signal.c index 39d122753bac..ef8156a6aad5 100644 --- a/kernel/signal.c +++ b/kernel/signal.c | |||
@@ -255,6 +255,16 @@ flush_signal_handlers(struct task_struct *t, int force_default) | |||
255 | } | 255 | } |
256 | } | 256 | } |
257 | 257 | ||
258 | int unhandled_signal(struct task_struct *tsk, int sig) | ||
259 | { | ||
260 | if (is_init(tsk)) | ||
261 | return 1; | ||
262 | if (tsk->ptrace & PT_PTRACED) | ||
263 | return 0; | ||
264 | return (tsk->sighand->action[sig-1].sa.sa_handler == SIG_IGN) || | ||
265 | (tsk->sighand->action[sig-1].sa.sa_handler == SIG_DFL); | ||
266 | } | ||
267 | |||
258 | 268 | ||
259 | /* Notify the system that a driver wants to block all signals for this | 269 | /* Notify the system that a driver wants to block all signals for this |
260 | * process, and wants to be notified if any signals at all were to be | 270 | * process, and wants to be notified if any signals at all were to be |
diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 222299844ad1..ddebf3f2affe 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c | |||
@@ -1203,6 +1203,16 @@ static ctl_table fs_table[] = { | |||
1203 | }; | 1203 | }; |
1204 | 1204 | ||
1205 | static ctl_table debug_table[] = { | 1205 | static ctl_table debug_table[] = { |
1206 | #ifdef CONFIG_X86 | ||
1207 | { | ||
1208 | .ctl_name = CTL_UNNUMBERED, | ||
1209 | .procname = "exception-trace", | ||
1210 | .data = &show_unhandled_signals, | ||
1211 | .maxlen = sizeof(int), | ||
1212 | .mode = 0644, | ||
1213 | .proc_handler = proc_dointvec | ||
1214 | }, | ||
1215 | #endif | ||
1206 | { .ctl_name = 0 } | 1216 | { .ctl_name = 0 } |
1207 | }; | 1217 | }; |
1208 | 1218 | ||