ARC: pt_regs update #3: Remove unused gutter at start of callee_regs
This is trickier than prev two:
* context switching code saves kernel mode callee regs in the format of
struct callee_regs thus needs adjustment. This also reduces the height
of topmost kernel stack frame by 1 word.
* Since kernel stack unwinder is sensitive to height of topmost kernel
stack frame, that needs a word of adjustment too.
ptrace needs a bit of updating since pt_regs now diverges from
user_regs_struct.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
diff --git a/arch/arc/include/asm/processor.h b/arch/arc/include/asm/processor.h
index 81efbca..8c77e62 100644
--- a/arch/arc/include/asm/processor.h
+++ b/arch/arc/include/asm/processor.h
@@ -19,6 +19,7 @@
#ifndef __ASSEMBLY__
#include <asm/arcregs.h> /* for STATUS_E1_MASK et all */
+#include <asm/ptrace.h>
/* Arch specific stuff which needs to be saved per task.
* However these items are not so important so as to earn a place in
@@ -75,11 +76,15 @@
/*
* Where abouts of Task's sp, fp, blink when it was last seen in kernel mode.
- * These can't be derived from pt_regs as that would give correp user-mode val
+ * Look in process.c for details of kernel stack layout
*/
#define KSTK_ESP(tsk) (tsk->thread.ksp)
-#define KSTK_BLINK(tsk) (*((unsigned int *)((KSTK_ESP(tsk)) + (13+1+1)*4)))
-#define KSTK_FP(tsk) (*((unsigned int *)((KSTK_ESP(tsk)) + (13+1)*4)))
+
+#define KSTK_REG(tsk, off) (*((unsigned int *)(KSTK_ESP(tsk) + \
+ sizeof(struct callee_regs) + off)))
+
+#define KSTK_BLINK(tsk) KSTK_REG(tsk, 4)
+#define KSTK_FP(tsk) KSTK_REG(tsk, 0)
/*
* Do necessary setup to start up a newly executed thread.