sparc64: Prevent stack backtrace false positives on trap frames.

When we fully commit to returning back to kernel mode from
a trap, zero out the regs->magic value to prevent false
positives during stack backtraces.

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 1 insertions, 0 deletions

diff --git a/arch/sparc64/kernel/rtrap.S b/arch/sparc64/kernel/rtrap.S
index 3afacbb5781..c6fc695fe1f 100644
--- a/arch/sparc64/kernel/rtrap.S
+++ b/arch/sparc64/kernel/rtrap.S
@@ -363,6 +363,7 @@ kern_rtt:	rdpr			%canrestore, %g1
                 brz,pn                  %g1, kern_rtt_fill
                  nop
 kern_rtt_restore:
+                stw                     %g0, [%sp + PTREGS_OFF + PT_V9_MAGIC]
                 restore
                 retry