[ARM] Add stacktrace support and make oprofile use it
Add support for stacktrace. Use the new stacktrace code with
oprofile instead of it's version; there's no point having
multiple versions of stacktracing in the kernel.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/oprofile/backtrace.c b/arch/arm/oprofile/backtrace.c
index 7c22c1261..f5ebf30 100644
--- a/arch/arm/oprofile/backtrace.c
+++ b/arch/arm/oprofile/backtrace.c
@@ -19,6 +19,19 @@
#include <asm/ptrace.h>
#include <asm/uaccess.h>
+#include "../kernel/stacktrace.h"
+
+static int report_trace(struct stackframe *frame, void *d)
+{
+ unsigned int *depth = d;
+
+ if (*depth) {
+ oprofile_add_trace(frame->lr);
+ (*depth)--;
+ }
+
+ return *depth == 0;
+}
/*
* The registers we're interested in are at the end of the variable
@@ -32,21 +45,6 @@
unsigned long lr;
} __attribute__((packed));
-
-#ifdef CONFIG_FRAME_POINTER
-static struct frame_tail* kernel_backtrace(struct frame_tail *tail)
-{
- oprofile_add_trace(tail->lr);
-
- /* frame pointers should strictly progress back up the stack
- * (towards higher addresses) */
- if (tail >= tail->fp)
- return NULL;
-
- return tail->fp-1;
-}
-#endif
-
static struct frame_tail* user_backtrace(struct frame_tail *tail)
{
struct frame_tail buftail[2];
@@ -67,47 +65,14 @@
return buftail[0].fp-1;
}
-/*
- * | | /\ Higher addresses
- * | |
- * --------------- stack base (address of current_thread_info)
- * | thread info |
- * . .
- * | stack |
- * --------------- saved regs->ARM_fp value if valid (frame_tail address)
- * . .
- * --------------- struct pt_regs stored on stack (struct pt_regs *)
- * | |
- * . .
- * | |
- * --------------- %esp
- * | |
- * | | \/ Lower addresses
- *
- * Thus, &pt_regs <-> stack base restricts the valid(ish) fp values
- */
-static int valid_kernel_stack(struct frame_tail *tail, struct pt_regs *regs)
-{
- unsigned long tailaddr = (unsigned long)tail;
- unsigned long stack = (unsigned long)regs;
- unsigned long stack_base = (stack & ~(THREAD_SIZE - 1)) + THREAD_SIZE;
-
- return (tailaddr > stack) && (tailaddr < stack_base);
-}
-
void arm_backtrace(struct pt_regs * const regs, unsigned int depth)
{
- struct frame_tail *tail;
-
- tail = ((struct frame_tail *) regs->ARM_fp) - 1;
+ struct frame_tail *tail = ((struct frame_tail *) regs->ARM_fp) - 1;
if (!user_mode(regs)) {
-
-#ifdef CONFIG_FRAME_POINTER
- while (depth-- && tail && valid_kernel_stack(tail, regs)) {
- tail = kernel_backtrace(tail);
- }
-#endif
+ unsigned long base = ((unsigned long)regs) & ~(THREAD_SIZE - 1);
+ walk_stackframe(regs->ARM_fp, base, base + THREAD_SIZE,
+ report_trace, &depth);
return;
}