x86, dumpstack: let signr=0 signal no do_exit

Change oops_end such that signr=0 signals that do_exit
is not to be called.

Currently, each use of __die is soon followed by a call
to oops_end and 'regs' is set to NULL if oops_end is expected
not to call do_exit. Change all such pairs to set signr=0
instead. On x86_64 oops_end is used 'bare' in die_nmi; use
signr=0 instead of regs=NULL there, too.

Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 5 insertions, 4 deletions

diff --git a/arch/x86/kernel/dumpstack_64.c b/arch/x86/kernel/dumpstack_64.c
index 96a5db7da8a7..ffefea611ba3 100644
--- a/arch/x86/kernel/dumpstack_64.c
+++ b/arch/x86/kernel/dumpstack_64.c
@@ -465,7 +465,7 @@ void __kprobes oops_end(unsigned long flags, struct pt_regs *regs, int signr)
 		/* Nest count reaches zero, release the lock. */
 		__raw_spin_unlock(&die_lock);
 	raw_local_irq_restore(flags);
-	if (!regs) {
+	if (!signr) {
 		oops_exit();
 		return;
 	}
@@ -509,13 +509,14 @@ int __kprobes __die(const char *str, struct pt_regs *regs, long err)
 void die(const char *str, struct pt_regs *regs, long err)
 {
 	unsigned long flags = oops_begin();
+	int sig = SIGSEGV;
 
 	if (!user_mode(regs))
 		report_bug(regs->ip, regs);
 
 	if (__die(str, regs, err))
-		regs = NULL;
-	oops_end(flags, regs, SIGSEGV);
+		sig = 0;
+	oops_end(flags, regs, sig);
 }
 
 notrace __kprobes void
@@ -539,7 +540,7 @@ die_nmi(char *str, struct pt_regs *regs, int do_panic)
 		crash_kexec(regs);
 	if (do_panic || panic_on_oops)
 		panic("Non maskable interrupt");
-	oops_end(flags, NULL, SIGBUS);
+	oops_end(flags, regs, 0);
 	nmi_exit();
 	local_irq_enable();
 	do_exit(SIGBUS);