ARCv2: save r30 on kernel entry as gcc uses it for code-gen

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 <vgupta@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

2 files changed, 3 insertions, 1 deletions

diff --git a/arch/arc/include/asm/entry-arcv2.h b/arch/arc/include/asm/entry-arcv2.h
index b5ff87e6f4b7..aee1a77934cf 100644
--- 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
 
diff --git a/arch/arc/include/asm/ptrace.h b/arch/arc/include/asm/ptrace.h
index 69095da1fcfd..47111d565a95 100644
--- 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;