ARM: OMAP4: sleep: Save the complete used register stack frame

OMAP4 sleep entry code even though itself don't use many CPU registers
makes call to the v7_flush_dcache_all() which uses them. Since
v7_flush_dcache_all() doesn't make use of stack, the caller must take
care of the stack frame. Otherwise it will lead to corrupted stack frame.

Fix it by saving used registers.

Reported-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Cc: Kevin Hilman <khilman@ti.com>
Signed-off-by: Kevin Hilman <khilman@ti.com>

1 files changed, 6 insertions, 2 deletions

diff --git a/arch/arm/mach-omap2/sleep44xx.S b/arch/arm/mach-omap2/sleep44xx.S
index 9f6b83d1b193..91e71d8f46f0 100644
--- a/arch/arm/mach-omap2/sleep44xx.S
+++ b/arch/arm/mach-omap2/sleep44xx.S
@@ -56,9 +56,13 @@ ppa_por_params:
  * The restore function pointer is stored at CPUx_WAKEUP_NS_PA_ADDR_OFFSET.
  * It returns to the caller for CPU INACTIVE and ON power states or in case
  * CPU failed to transition to targeted OFF/DORMANT state.
+ *
+ * omap4_finish_suspend() calls v7_flush_dcache_all() which doesn't save
+ * stack frame and it expects the caller to take care of it. Hence the entire
+ * stack frame is saved to avoid possible stack corruption.
  */
 ENTRY(omap4_finish_suspend)
-        stmfd   sp!, {lr}
+        stmfd   sp!, {r4-r12, lr}
         cmp     r0, #0x0
         beq     do_WFI                          @ No lowpower state, jump to WFI
 
@@ -226,7 +230,7 @@ scu_gp_clear:
 skip_scu_gp_clear:
         isb
         dsb
-        ldmfd   sp!, {pc}
+        ldmfd   sp!, {r4-r12, pc}
 ENDPROC(omap4_finish_suspend)
 
 /*