#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
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;
+ struct frame_tail buftail[2];
- /* hardware pte might not be valid due to dirty/accessed bit emulation
- * so we use copy_from_user and benefit from exception fixups */
- if (copy_from_user(&buftail, tail, sizeof(struct frame_tail)))
+ /* Also check accessibility of one struct frame_tail beyond */
+ if (!access_ok(VERIFY_READ, tail, sizeof(buftail)))
+ return NULL;
+ if (__copy_from_user_inatomic(buftail, tail, sizeof(buftail)))
return NULL;
- oprofile_add_trace(buftail.lr);
+ oprofile_add_trace(buftail[0].lr);
/* frame pointers should strictly progress back up the stack
* (towards higher addresses) */
- if (tail >= buftail.fp)
+ if (tail >= buftail[0].fp)
return NULL;
- return buftail.fp-1;
-}
-
-/* Compare two addresses and see if they're on the same page */
-#define CMP_ADDR_EQUAL(x,y,offset) ((((unsigned long) x) >> PAGE_SHIFT) \
- == ((((unsigned long) y) + offset) >> PAGE_SHIFT))
-
-/* check that the page(s) containing the frame tail are present */
-static int pages_present(struct frame_tail *tail)
-{
- struct mm_struct * mm = current->mm;
-
- if (!check_user_page_readable(mm, (unsigned long)tail))
- return 0;
-
- if (CMP_ADDR_EQUAL(tail, tail, 8))
- return 1;
-
- if (!check_user_page_readable(mm, ((unsigned long)tail) + 8))
- return 0;
-
- return 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);
+ return buftail[0].fp-1;
}
void arm_backtrace(struct pt_regs * const regs, unsigned int depth)
{
- struct frame_tail *tail;
- unsigned long last_address = 0;
-
- 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;
}
- while (depth-- && tail && !((unsigned long) tail & 3)) {
- if ((!CMP_ADDR_EQUAL(last_address, tail, 0)
- || !CMP_ADDR_EQUAL(last_address, tail, 8))
- && !pages_present(tail))
- return;
- last_address = (unsigned long) tail;
+ while (depth-- && tail && !((unsigned long) tail & 3))
tail = user_backtrace(tail);
- }
}
-