ARC: Fix KSTK_ESP()

/proc/<pid>/maps currently don't annotate stack vma with "[stack]"
This is because KSTK_ESP ie expected to return usermode SP of tsk while
currently it returns the kernel mode SP of a sleeping tsk.

While the fix is trivial, we also need to adjust the ARC kernel stack
unwinder to not use KSTK_SP and friends any more.

Cc: <stable@vger.kernel.org>
Reported-and-suggested-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

2 files changed, 8 insertions, 7 deletions

diff --git a/arch/arc/include/asm/processor.h b/arch/arc/include/asm/processor.h
index 4e547296831d..88398caa3989 100644
--- a/arch/arc/include/asm/processor.h
+++ b/arch/arc/include/asm/processor.h
@@ -72,18 +72,19 @@ unsigned long thread_saved_pc(struct task_struct *t);
 #define release_segments(mm)        do { } while (0)
 
 #define KSTK_EIP(tsk)   (task_pt_regs(tsk)->ret)
+#define KSTK_ESP(tsk)   (task_pt_regs(tsk)->sp)
 
 /*
  * Where abouts of Task's sp, fp, blink when it was last seen in kernel mode.
  * Look in process.c for details of kernel stack layout
  */
-#define KSTK_ESP(tsk)   (tsk->thread.ksp)
+#define TSK_K_ESP(tsk)          (tsk->thread.ksp)
 
-#define KSTK_REG(tsk, off)      (*((unsigned int *)(KSTK_ESP(tsk) + \
+#define TSK_K_REG(tsk, off)     (*((unsigned int *)(TSK_K_ESP(tsk) + \
                                         sizeof(struct callee_regs) + off)))
 
-#define KSTK_BLINK(tsk) KSTK_REG(tsk, 4)
-#define KSTK_FP(tsk)    KSTK_REG(tsk, 0)
+#define TSK_K_BLINK(tsk)        TSK_K_REG(tsk, 4)
+#define TSK_K_FP(tsk)           TSK_K_REG(tsk, 0)
 
 extern void start_thread(struct pt_regs * regs, unsigned long pc,
                          unsigned long usp);
diff --git a/arch/arc/kernel/stacktrace.c b/arch/arc/kernel/stacktrace.c
index 6492507a3d74..92320d6f737c 100644
--- a/arch/arc/kernel/stacktrace.c
+++ b/arch/arc/kernel/stacktrace.c
@@ -73,9 +73,9 @@ static void seed_unwind_frame_info(struct task_struct *tsk,
 
                 frame_info->task = tsk;
 
-                frame_info->regs.r27 = KSTK_FP(tsk);
-                frame_info->regs.r28 = KSTK_ESP(tsk);
-                frame_info->regs.r31 = KSTK_BLINK(tsk);
+                frame_info->regs.r27 = TSK_K_FP(tsk);
+                frame_info->regs.r28 = TSK_K_ESP(tsk);
+                frame_info->regs.r31 = TSK_K_BLINK(tsk);
                 frame_info->regs.r63 = (unsigned int)__switch_to;
 
                 /* In the prologue of __switch_to, first FP is saved on stack