x86: jprobe bugfix

jprobe for x86-64 may cause kernel page fault when the jprobe_return()
is called from incorrect function.

- Use jprobe_saved_regs instead getting it from stack.
  (Especially on x86-64, it may get incorrect data, because
   pt_regs can not be get by using container_of(rsp))
- Change the type of stack pointer to unsigned long *.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

2 files changed, 2 insertions, 2 deletions

diff --git a/include/asm-x86/kprobes_32.h b/include/asm-x86/kprobes_32.h
index b772d5b38685..9fe8f3bddfd5 100644
--- a/include/asm-x86/kprobes_32.h
+++ b/include/asm-x86/kprobes_32.h
@@ -73,7 +73,7 @@ struct kprobe_ctlblk {
         unsigned long kprobe_status;
         unsigned long kprobe_old_eflags;
         unsigned long kprobe_saved_eflags;
-        long *jprobe_saved_esp;
+        unsigned long *jprobe_saved_esp;
         struct pt_regs jprobe_saved_regs;
         kprobe_opcode_t jprobes_stack[MAX_STACK_SIZE];
         struct prev_kprobe prev_kprobe;
diff --git a/include/asm-x86/kprobes_64.h b/include/asm-x86/kprobes_64.h
index 53f4d8507354..743d76218fc9 100644
--- a/include/asm-x86/kprobes_64.h
+++ b/include/asm-x86/kprobes_64.h
@@ -66,7 +66,7 @@ struct kprobe_ctlblk {
         unsigned long kprobe_status;
         unsigned long kprobe_old_rflags;
         unsigned long kprobe_saved_rflags;
-        long *jprobe_saved_rsp;
+        unsigned long *jprobe_saved_rsp;
         struct pt_regs jprobe_saved_regs;
         kprobe_opcode_t jprobes_stack[MAX_STACK_SIZE];
         struct prev_kprobe prev_kprobe;