On Sun, 29 Jul 2007 19:05:05 +0200 Manfred Spraul <[EMAIL PROTECTED]> wrote:
> 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. hm. Is this a fix against ftp://ftp.kernel.org/pub/linux/kernel/people/akpm/patches/2.6/2.6.23-rc1/2.6.23-rc1-mm1/broken-out/do_poll-return-eintr-when-signalled.patch only, or does mainline also need fixing? I guess the consequences of the thing-which-this-fixes aren't huge, s I ca queue this up for 2.6.24, after Oleg's do_poll-return-eintr-when-signalled.patch? > 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); > I spied this comment in there: /* * We can actually return ERESTARTSYS instead of EINTR, but I'd * like to be certain this leads to no problems. So I return * EINTR just for safety. * * Update: ERESTARTSYS breaks at least the xview clock binary, so * I'm trying ERESTARTNOHAND which restart only when you want to. */ it is very old and perhaps is no longer relevant? - 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/
