Messages in this thread Patch in this message |  | | | Date | Wed, 8 Apr 2009 16:09:40 GMT | | From | Oleg Nesterov <> | | Subject | [tip:timers/urgent] posix-timers: fix RLIMIT_CPU && fork() |
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Commit-ID: 6279a751fe096a21dc7704e918d570d3ff06e769 Gitweb: http://git.kernel.org/tip/6279a751fe096a21dc7704e918d570d3ff06e769 Author: Oleg Nesterov <oleg@redhat.com> AuthorDate: Fri, 27 Mar 2009 01:06:07 +0100 Committer: Ingo Molnar <mingo@elte.hu> CommitDate: Wed, 8 Apr 2009 17:51:38 +0200
posix-timers: fix RLIMIT_CPU && fork()
See http://bugzilla.kernel.org/show_bug.cgi?id=12911
copy_signal() copies signal->rlim, but RLIMIT_CPU is "lost". Because posix_cpu_timers_init_group() sets cputime_expires.prof_exp = 0 and thus fastpath_timer_check() returns false unless we have other expired cpu timers.
Change copy_signal() to set cputime_expires.prof_exp if we have RLIMIT_CPU. Also, set cputimer.running = 1 in that case. This is not strictly necessary, but imho makes sense.
Reported-by: Peter Lojkin <ia6432@inbox.ru> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Peter Lojkin <ia6432@inbox.ru> Cc: Roland McGrath <roland@redhat.com> Cc: stable@kernel.org LKML-Reference: <20090327000607.GA10104@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
--- kernel/fork.c | 13 +++++++++---- 1 files changed, 9 insertions(+), 4 deletions(-) diff --git a/kernel/fork.c b/kernel/fork.c index 4854c2c..9b51a1b 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -808,6 +808,12 @@ static void posix_cpu_timers_init_group(struct signal_struct *sig) sig->cputime_expires.virt_exp = cputime_zero; sig->cputime_expires.sched_exp = 0; + if (sig->rlim[RLIMIT_CPU].rlim_cur != RLIM_INFINITY) { + sig->cputime_expires.prof_exp = + secs_to_cputime(sig->rlim[RLIMIT_CPU].rlim_cur); + sig->cputimer.running = 1; + } + /* The timer lists. */ INIT_LIST_HEAD(&sig->cpu_timers[0]); INIT_LIST_HEAD(&sig->cpu_timers[1]); @@ -823,11 +829,8 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk) atomic_inc(¤t->signal->live); return 0; } - sig = kmem_cache_alloc(signal_cachep, GFP_KERNEL); - - if (sig) - posix_cpu_timers_init_group(sig); + sig = kmem_cache_alloc(signal_cachep, GFP_KERNEL); tsk->signal = sig; if (!sig) return -ENOMEM; @@ -865,6 +868,8 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk) memcpy(sig->rlim, current->signal->rlim, sizeof sig->rlim); task_unlock(current->group_leader); + posix_cpu_timers_init_group(sig); + acct_init_pacct(&sig->pacct); tty_audit_fork(sig);
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