Hi Andrew,
poll() returns -EINTR if a signal is pending.
EINTR is a bad choice: it means that poll returns to user space if the
task is stopped by SIGSTOP/SIGCONT or by the freezer.
select() and ppoll() both use ERESTARTNOHAND, this avoids a return to
user space for signals that are handled by the kernel.
The patch switches poll() to ERESTARTNOHAND.
Tested with FC6. Patch against 2.6.23-rc1-mm1.
Signed-off-by: Manfred Spraul <[email protected]>
--- 2.6/fs/select.c 2007-07-28 20:31:51.000000000 +0200
+++ build-2.6/fs/select.c 2007-07-28 21:21:52.000000000 +0200
@@ -621,7 +621,7 @@ static int do_poll(unsigned int nfds, s
if (!count) {
count = wait->error;
if (signal_pending(current))
- count = -EINTR;
+ count = -ERESTARTNOHAND;
}
if (count || !*timeout)
break;
@@ -774,7 +774,7 @@ asmlinkage long sys_ppoll(struct pollfd
ret = do_sys_poll(ufds, nfds, &timeout);
/* We can restart this syscall, usually */
- if (ret == -EINTR) {
+ if (ret == -ERESTARTNOHAND) {
/*
* Don't restore the signal mask yet. Let do_signal() deliver
* the signal on the way back to userspace, before the signal
@@ -785,7 +785,6 @@ asmlinkage long sys_ppoll(struct pollfd
sizeof(sigsaved));
set_thread_flag(TIF_RESTORE_SIGMASK);
}
- ret = -ERESTARTNOHAND;
} else if (sigmask)
sigprocmask(SIG_SETMASK, &sigsaved, NULL);
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
