diff options
| author | Michael Kerrisk <michael.kerrisk@gmx.net> | 2004-08-01 20:31:12 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2004-08-01 20:31:12 -0700 |
| commit | 81fd00e2e58911325c794b6f98d683ecb7db2b04 (patch) | |
| tree | 10dc7924c324e3aade4e92c373161cca0cdaf020 /kernel | |
| parent | b0b6a9b776df159db5759b669a4bd6c73f91a5a4 (diff) | |
| download | history-81fd00e2e58911325c794b6f98d683ecb7db2b04.tar.gz | |
[PATCH] Off-by-one error for SIGXCPU / RLIMIT_CPU checking
There is a lonstanding off-by-one error that results from an incorrect
comparison when checking whether a process has consumed CPU time in
excess of its RLIMIT_CPU limits.
This means, for example, that if we use setrlimit() to set the soft CPU
limit (rlim_cur) to 5 seconds and the hard limit (rlim_max) to 10 seconds,
then the process only receives a SIGXCPU signal after consuming 6 seconds
of CPU time, and, if it continues consuming CPU after handling that
signal, only receives SIGKILL after consuming 11 seconds of CPU time.
The fix is trivial.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/timer.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/timer.c b/kernel/timer.c index 56b315bc53cf1b..4850abbeacdce6 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -792,12 +792,12 @@ static inline void do_process_times(struct task_struct *p, psecs = (p->utime += user); psecs += (p->stime += system); - if (psecs / HZ > p->rlim[RLIMIT_CPU].rlim_cur) { + if (psecs / HZ >= p->rlim[RLIMIT_CPU].rlim_cur) { /* Send SIGXCPU every second.. */ if (!(psecs % HZ)) send_sig(SIGXCPU, p, 1); /* and SIGKILL when we go over max.. */ - if (psecs / HZ > p->rlim[RLIMIT_CPU].rlim_max) + if (psecs / HZ >= p->rlim[RLIMIT_CPU].rlim_max) send_sig(SIGKILL, p, 1); } } |