um: remove broken double fault detection

The show_stack function had some code to detect double faults. However,
the logic is wrong and it would e.g. trigger if a WARNING happened
inside an IRQ.

Remove it without trying to add a new logic. The current behaviour,
which will just fault repeatedly until the IRQ stack is used up and the
host kills UML, seems to be good enough.

Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Link: https://patch.msgid.link/20241103150506.1367695-5-benjamin@sipsolutions.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 0 insertions, 8 deletions

diff --git a/arch/um/os-Linux/signal.c b/arch/um/os-Linux/signal.c
index 1c6caa9dbd6c..52852018a3ad 100644
--- a/arch/um/os-Linux/signal.c
+++ b/arch/um/os-Linux/signal.c
@@ -487,11 +487,3 @@ void unblock_signals_hard(void)
 	unblocking = false;
 }
 #endif
-
-int os_is_signal_stack(void)
-{
-	stack_t ss;
-	sigaltstack(NULL, &ss);
-
-	return ss.ss_flags & SS_ONSTACK;
-}