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);