[PATCH 5.4 196/222] um: Dont trace irqflags during shutdown

Greg Kroah-Hartman
2020-01-22T13:28:46Z

From: Johannes Berg <johannes.berg@intel.com>

commit 5c1f33e2a03c0b8710b5d910a46f1e1fb0607679 upstream.

In the main() code, we eventually enable signals just before
exec() or exit(), in order to to not have signals pending and
delivered *after* the exec().

I've observed SIGSEGV loops at this point, and the reason seems
to be the irqflags tracing; this makes sense as the kernel is
no longer really functional at this point. Since there's really
no reason to use unblock_signals_trace() here (I had just done
a global search & replace), use the plain unblock_signals() in
this case to avoid going into the no longer functional kernel.

Fixes: 0dafcbe128d2 ("um: Implement TRACE_IRQFLAGS_SUPPORT")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
arch/um/os-Linux/main.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/um/os-Linux/main.c
+++ b/arch/um/os-Linux/main.c
@@ -170,7 +170,7 @@ int __init main(int argc, char **argv, c
* that they won't be delivered after the exec, when
* they are definitely not expected.
*/
- unblock_signals_trace();
+ unblock_signals();

os_info("\n");
/* Reboot */