The patch titled
Use ERESTARTNOHAND if poll() is interrupted by a signal
has been added to the -mm tree. Its filename is
use-erestartnohand-if-poll-is-interrupted-by-a-signal.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: Use ERESTARTNOHAND if poll() is interrupted by a signal
From: Manfred Spraul <manfred@xxxxxxxxxxxxxxxx>
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 <manfred@xxxxxxxxxxxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Roland McGrath <roland@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/select.c | 5 ++---
1 files changed, 2 insertions(+), 3 deletions(-)
diff -puN fs/select.c~use-erestartnohand-if-poll-is-interrupted-by-a-signal fs/select.c
--- a/fs/select.c~use-erestartnohand-if-poll-is-interrupted-by-a-signal
+++ a/fs/select.c
@@ -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);
_
Patches currently in -mm which might be from manfred@xxxxxxxxxxxxxxxx are
use-erestartnohand-if-poll-is-interrupted-by-a-signal.patch
mm-debug-dump-pageframes-on-bad_page.patch
slab-leaks3-default-y.patch
-
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