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authorAndrew Morton <akpm@osdl.org>2006-03-24 03:18:35 -0800
committerLinus Torvalds <torvalds@g5.osdl.org>2006-03-24 07:33:30 -0800
commite0661111e5441995f7a69dc4336c9f131cb9bc58 (patch)
tree47a0a0ae66a9f792e6c9edbf683cdc0b62a2d4b7
parentec9e16bacdba1da1ee15dd162384e22df5c87e09 (diff)
downloadlinux-sh-e0661111e5441995f7a69dc4336c9f131cb9bc58.tar.gz
[PATCH] RLIMIT_CPU: fix handling of a zero limit
At present the kernel doesn't honour an attempt to set RLIMIT_CPU to zero seconds. But the spec says it should, and that's what 2.4.x does. Fixing this for real would involve some complexity (such as adding a new it-has-been-set flag to the task_struct, and testing that everwhere, instead of overloading the value of it_prof_expires). Given that a 2.4 kernel won't actually send the signal until one second has expired anyway, let's just handle this case by treating the caller's zero-seconds as one second. Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Ulrich Weigand <uweigand@de.ibm.com> Cc: Cliff Wickman <cpw@sgi.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-rw-r--r--kernel/sys.c13
1 files changed, 12 insertions, 1 deletions
diff --git a/kernel/sys.c b/kernel/sys.c
index 9bdf94f3ae29..9e157e0240d4 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -1661,8 +1661,19 @@ asmlinkage long sys_setrlimit(unsigned int resource, struct rlimit __user *rlim)
it_prof_secs = cputime_to_secs(current->signal->it_prof_expires);
if (it_prof_secs == 0 || new_rlim.rlim_cur <= it_prof_secs) {
- cputime_t cputime = secs_to_cputime(new_rlim.rlim_cur);
+ unsigned long rlim_cur = new_rlim.rlim_cur;
+ cputime_t cputime;
+ if (rlim_cur == 0) {
+ /*
+ * The caller is asking for an immediate RLIMIT_CPU
+ * expiry. But we use the zero value to mean "it was
+ * never set". So let's cheat and make it one second
+ * instead
+ */
+ rlim_cur = 1;
+ }
+ cputime = secs_to_cputime(rlim_cur);
read_lock(&tasklist_lock);
spin_lock_irq(&current->sighand->siglock);
set_process_cpu_timer(current, CPUCLOCK_PROF, &cputime, NULL);