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x86, do_signal: Simplify the TS_RESTORE_SIGMASK logic 

1. do_signal() looks at TS_RESTORE_SIGMASK and calculates the
   mask which should be stored in the signal frame, then it
   passes "oldset" to the callees, down to setup_rt_frame().

   This is ugly, setup_rt_frame() can do this itself and nobody
   else needs this sigset_t. Move this code into setup_rt_frame.

2. do_signal() also clears TS_RESTORE_SIGMASK if handle_signal()
   succeeds.

   We can move this to setup_rt_frame() as well, this avoids the
   unnecessary checks and makes the logic more clear.

3. use set_current_blocked() instead of sigprocmask(SIG_SETMASK),
   sigprocmask() should be avoided.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Link: http://lkml.kernel.org/r/20110710182203.GA27979@redhat.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
This commit is contained in:
Oleg Nesterov 2011-07-10 20:22:03 +02:00 committed by H. Peter Anvin
parent 3982294b03
commit 9b42962074
1 changed files with 10 additions and 19 deletions
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29
arch/x86/kernel/signal.c
View File

@ -651,11 +651,15 @@ int ia32_setup_frame(int sig, struct k_sigaction *ka,
static int static int
setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
sigset_t *set, struct pt_regs *regs) struct pt_regs *regs)
{ {
int usig = signr_convert(sig); int usig = signr_convert(sig);
sigset_t *set = &current->blocked;
int ret; int ret;
if (current_thread_info()->status & TS_RESTORE_SIGMASK)
set = &current->saved_sigmask;
/* Set up the stack frame */ /* Set up the stack frame */
if (is_ia32) { if (is_ia32) {
if (ka->sa.sa_flags & SA_SIGINFO) if (ka->sa.sa_flags & SA_SIGINFO)
@ -670,12 +674,13 @@ setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
return -EFAULT; return -EFAULT;
} }
current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
return ret; return ret;
} }
static int static int
handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka, handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
sigset_t *oldset, struct pt_regs *regs) struct pt_regs *regs)
{ {
sigset_t blocked; sigset_t blocked;
int ret; int ret;
@ -710,7 +715,7 @@ handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
likely(test_and_clear_thread_flag(TIF_FORCED_TF))) likely(test_and_clear_thread_flag(TIF_FORCED_TF)))
regs->flags &= ~X86_EFLAGS_TF; regs->flags &= ~X86_EFLAGS_TF;
ret = setup_rt_frame(sig, ka, info, oldset, regs); ret = setup_rt_frame(sig, ka, info, regs);
if (ret) if (ret)
return ret; return ret;
@ -765,7 +770,6 @@ static void do_signal(struct pt_regs *regs)
struct k_sigaction ka; struct k_sigaction ka;
siginfo_t info; siginfo_t info;
int signr; int signr;
sigset_t *oldset;
/* /*
* We want the common case to go fast, which is why we may in certain * We want the common case to go fast, which is why we may in certain
@ -777,23 +781,10 @@ static void do_signal(struct pt_regs *regs)
if (!user_mode(regs)) if (!user_mode(regs))
return; return;
if (current_thread_info()->status & TS_RESTORE_SIGMASK)
oldset = &current->saved_sigmask;
else
oldset = &current->blocked;
signr = get_signal_to_deliver(&info, &ka, regs, NULL); signr = get_signal_to_deliver(&info, &ka, regs, NULL);
if (signr > 0) { if (signr > 0) {
/* Whee! Actually deliver the signal. */ /* Whee! Actually deliver the signal. */
if (handle_signal(signr, &info, &ka, oldset, regs) == 0) { handle_signal(signr, &info, &ka, regs);
/*
* A signal was successfully delivered; the saved
* sigmask will have been stored in the signal frame,
* and will be restored by sigreturn, so we can simply
* clear the TS_RESTORE_SIGMASK flag.
*/
current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
}
return; return;
} }
@ -821,7 +812,7 @@ static void do_signal(struct pt_regs *regs)
*/ */
if (current_thread_info()->status & TS_RESTORE_SIGMASK) { if (current_thread_info()->status & TS_RESTORE_SIGMASK) {
current_thread_info()->status &= ~TS_RESTORE_SIGMASK; current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL); set_current_blocked(&current->saved_sigmask);
} }
} }