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| author | Andrew Morton <akpm@osdl.org> | 2006-03-24 03:18:35 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2006-04-17 13:16:06 -0700 |
| commit | 284a7c99c01846ee44040268529c99fc92dcc531 (patch) | |
| tree | 73722b8f455d37ce6160cebc90f6d2734ce7aee4 | |
| parent | bc5bd8ac3c6956c7ce2c838e8e2f01435b8e4e0b (diff) | |
| download | lwn-284a7c99c01846ee44040268529c99fc92dcc531.tar.gz lwn-284a7c99c01846ee44040268529c99fc92dcc531.zip | |
[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.c | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/kernel/sys.c b/kernel/sys.c index f91218a5463e..105e102e1c4a 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -1657,7 +1657,19 @@ asmlinkage long sys_setrlimit(unsigned int resource, struct rlimit __user *rlim) (cputime_eq(current->signal->it_prof_expires, cputime_zero) || new_rlim.rlim_cur <= cputime_to_secs( current->signal->it_prof_expires))) { - 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(¤t->sighand->siglock); set_process_cpu_timer(current, CPUCLOCK_PROF, |