Messages in this thread Patch in this message | | | Date | Thu, 23 Feb 2006 02:05:39 +0300 | From | Oleg Nesterov <> | Subject | [PATCH 6/6] do_sigaction: don't take tasklist_lock |
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do_sigaction() does not need tasklist_lock anymore, we can simplify the code.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
--- 2.6.16-rc3/kernel/signal.c~6_DOSA 2006-02-23 01:46:17.000000000 +0300 +++ 2.6.16-rc3/kernel/signal.c 2006-02-23 02:16:08.000000000 +0300 @@ -2303,8 +2303,7 @@ sys_rt_sigqueueinfo(int pid, int sig, si return kill_proc_info(sig, &info, pid); } -int -do_sigaction(int sig, struct k_sigaction *act, struct k_sigaction *oact) +int do_sigaction(int sig, struct k_sigaction *act, struct k_sigaction *oact) { struct k_sigaction *k; sigset_t mask; @@ -2330,6 +2329,7 @@ do_sigaction(int sig, struct k_sigaction if (act) { sigdelsetmask(&act->sa.sa_mask, sigmask(SIGKILL) | sigmask(SIGSTOP)); + *k = *act; /* * POSIX 3.3.1.3: * "Setting a signal action to SIG_IGN for a signal that is @@ -2342,19 +2342,8 @@ do_sigaction(int sig, struct k_sigaction * be discarded, whether or not it is blocked" */ if (act->sa.sa_handler == SIG_IGN || - (act->sa.sa_handler == SIG_DFL && - sig_kernel_ignore(sig))) { - /* - * This is a fairly rare case, so we only take the - * tasklist_lock once we're sure we'll need it. - * Now we must do this little unlock and relock - * dance to maintain the lock hierarchy. - */ + (act->sa.sa_handler == SIG_DFL && sig_kernel_ignore(sig))) { struct task_struct *t = current; - spin_unlock_irq(&t->sighand->siglock); - read_lock(&tasklist_lock); - spin_lock_irq(&t->sighand->siglock); - *k = *act; sigemptyset(&mask); sigaddset(&mask, sig); rm_from_queue_full(&mask, &t->signal->shared_pending); @@ -2363,12 +2352,7 @@ do_sigaction(int sig, struct k_sigaction recalc_sigpending_tsk(t); t = next_thread(t); } while (t != current); - spin_unlock_irq(¤t->sighand->siglock); - read_unlock(&tasklist_lock); - return 0; } - - *k = *act; } spin_unlock_irq(¤t->sighand->siglock); - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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