[SPARC64]: Fix race in LOAD_PER_CPU_BASE()

Since we use %g5 itself as a temporary, it can get clobbered
if we take an interrupt mid-stream and thus cause end up with
the final %g5 value too early as a result of rtrap processing.

Set %g5 at the very end, atomically, to avoid this problem.

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

1 files changed, 2 insertions, 2 deletions

diff --git a/arch/sparc64/kernel/etrap.S b/arch/sparc64/kernel/etrap.S
index db7681017299..d974d18b15be 100644
--- a/arch/sparc64/kernel/etrap.S
+++ b/arch/sparc64/kernel/etrap.S
@@ -100,7 +100,7 @@ etrap_irq:
                 stx     %i7, [%sp + PTREGS_OFF + PT_V9_I7]
                 wrpr    %g0, ETRAP_PSTATE2, %pstate
                 mov     %l6, %g6
-                LOAD_PER_CPU_BASE(%g4, %g3)
+                LOAD_PER_CPU_BASE(%g4, %g3, %l1)
                 jmpl    %l2 + 0x4, %g0
                  ldx    [%g6 + TI_TASK], %g4
 
@@ -250,7 +250,7 @@ scetrap:
                 stx     %i6, [%sp + PTREGS_OFF + PT_V9_I6]
                 mov     %l6, %g6
                 stx     %i7, [%sp + PTREGS_OFF + PT_V9_I7]
-                LOAD_PER_CPU_BASE(%g4, %g3)
+                LOAD_PER_CPU_BASE(%g4, %g3, %l1)
                 ldx     [%g6 + TI_TASK], %g4
                 done