[PATCH] powerpc: Don't use toc in decrementer_iSeries_masked

Since 404849bbd2bfd62e05b36f4753f6e1af6050a824 we've been using
LOAD_REG_ADDRBASE, which uses the toc pointer, in decrementer_iSeries_masked.

This can explode if we take the decrementer interrupt while we're in a module,
because the toc pointer in r2 will be the module's toc pointer.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 3 insertions, 2 deletions

diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S
index 308268466342..415659629394 100644
--- a/arch/powerpc/kernel/head_64.S
+++ b/arch/powerpc/kernel/head_64.S
@@ -749,11 +749,12 @@ iSeries_secondary_smp_loop:
 
         .globl decrementer_iSeries_masked
 decrementer_iSeries_masked:
+        /* We may not have a valid TOC pointer in here. */
         li      r11,1
         ld      r12,PACALPPACAPTR(r13)
         stb     r11,LPPACADECRINT(r12)
-        LOAD_REG_ADDRBASE(r12,tb_ticks_per_jiffy)
-        lwz     r12,ADDROFF(tb_ticks_per_jiffy)(r12)
+        LOAD_REG_IMMEDIATE(r12, tb_ticks_per_jiffy)
+        lwz     r12,0(r12)
         mtspr   SPRN_DEC,r12
         /* fall through */