[PATCH 4.9 53/54] ARCv2: save r30 on kernel entry as gcc uses it for code-gen

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Vineet Gupta <vgu...@synopsys.com>

commit ecd43afdbe72017aefe48080631eb625e177ef4d upstream.

This is not exposed to userspace debugers yet, which can be done
independently as a seperate patch !

Signed-off-by: Vineet Gupta <vgu...@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>

---
 arch/arc/include/asm/entry-arcv2.h |    2 ++
 arch/arc/include/asm/ptrace.h      |    2 +-
 2 files changed, 3 insertions(+), 1 deletion(-)

--- a/arch/arc/include/asm/entry-arcv2.h
+++ b/arch/arc/include/asm/entry-arcv2.h
@@ -16,6 +16,7 @@
        ;
        ; Now manually save: r12, sp, fp, gp, r25
 
+       PUSH    r30
        PUSH    r12
 
        ; Saving pt_regs->sp correctly requires some extra work due to the way
@@ -72,6 +73,7 @@
        POPAX   AUX_USER_SP
 1:
        POP     r12
+       POP     r30
 
 .endm
 
--- a/arch/arc/include/asm/ptrace.h
+++ b/arch/arc/include/asm/ptrace.h
@@ -84,7 +84,7 @@ struct pt_regs {
        unsigned long fp;
        unsigned long sp;       /* user/kernel sp depending on where we came 
from  */
 
-       unsigned long r12;
+       unsigned long r12, r30;
 
        /*------- Below list auto saved by h/w -----------*/
        unsigned long r0, r1, r2, r3, r4, r5, r6, r7, r8, r9, r10, r11;