path: root/include
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authorRichard Weinberger <richard@nod.at>2015-11-20 15:57:21 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2015-11-20 16:17:32 -0800
commit9d8a765211335cfdad464b90fb19f546af5706ae (patch)
tree3b21c5816e85d3e0c62720453fe4b619f88fae69 /include
parent459372545c9c0d6f491e280dccc8a54a61b60e56 (diff)
kernel/signal.c: unexport sigsuspend()
sigsuspend() is nowhere used except in signal.c itself, so we can mark it static do not pollute the global namespace. But this patch is more than a boring cleanup patch, it fixes a real issue on UserModeLinux. UML has a special console driver to display ttys using xterm, or other terminal emulators, on the host side. Vegard reported that sometimes UML is unable to spawn a xterm and he's facing the following warning: WARNING: CPU: 0 PID: 908 at include/linux/thread_info.h:128 sigsuspend+0xab/0xc0() It turned out that this warning makes absolutely no sense as the UML xterm code calls sigsuspend() on the host side, at least it tries. But as the kernel itself offers a sigsuspend() symbol the linker choose this one instead of the glibc wrapper. Interestingly this code used to work since ever but always blocked signals on the wrong side. Some recent kernel change made the WARN_ON() trigger and uncovered the bug. It is a wonderful example of how much works by chance on computers. :-) Fixes: 68f3f16d9ad0f1 ("new helper: sigsuspend()") Signed-off-by: Richard Weinberger <richard@nod.at> Reported-by: Vegard Nossum <vegard.nossum@oracle.com> Tested-by: Vegard Nossum <vegard.nossum@oracle.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: <stable@vger.kernel.org> [3.5+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include')
1 files changed, 0 insertions, 1 deletions
diff --git a/include/linux/signal.h b/include/linux/signal.h
index ab1e0392b5ac..92557bbce7e7 100644
--- a/include/linux/signal.h
+++ b/include/linux/signal.h
@@ -239,7 +239,6 @@ extern int sigprocmask(int, sigset_t *, sigset_t *);
extern void set_current_blocked(sigset_t *);
extern void __set_current_blocked(const sigset_t *);
extern int show_unhandled_signals;
-extern int sigsuspend(sigset_t *);
struct sigaction {

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