1 files changed, 15 insertions, 5 deletions

diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c
index f7e3cd50ece0..98f654d466e5 100644
--- a/arch/x86/kernel/kprobes/core.c
+++ b/arch/x86/kernel/kprobes/core.c
@@ -1020,6 +1020,15 @@ int setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs)
         regs->flags &= ~X86_EFLAGS_IF;
         trace_hardirqs_off();
         regs->ip = (unsigned long)(jp->entry);
+
+        /*
+         * jprobes use jprobe_return() which skips the normal return
+         * path of the function, and this messes up the accounting of the
+         * function graph tracer to get messed up.
+         *
+         * Pause function graph tracing while performing the jprobe function.
+         */
+        pause_graph_tracing();
         return 1;
 }
 NOKPROBE_SYMBOL(setjmp_pre_handler);
@@ -1048,24 +1057,25 @@ int longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
         struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
         u8 *addr = (u8 *) (regs->ip - 1);
         struct jprobe *jp = container_of(p, struct jprobe, kp);
+        void *saved_sp = kcb->jprobe_saved_sp;
 
         if ((addr > (u8 *) jprobe_return) &&
             (addr < (u8 *) jprobe_return_end)) {
-                if (stack_addr(regs) != kcb->jprobe_saved_sp) {
+                if (stack_addr(regs) != saved_sp) {
                         struct pt_regs *saved_regs = &kcb->jprobe_saved_regs;
                         printk(KERN_ERR
                                "current sp %p does not match saved sp %p\n",
-                               stack_addr(regs), kcb->jprobe_saved_sp);
+                               stack_addr(regs), saved_sp);
                         printk(KERN_ERR "Saved registers for jprobe %p\n", jp);
                         show_regs(saved_regs);
                         printk(KERN_ERR "Current registers\n");
                         show_regs(regs);
                         BUG();
                 }
+                /* It's OK to start function graph tracing again */
+                unpause_graph_tracing();
                 *regs = kcb->jprobe_saved_regs;
-                memcpy((kprobe_opcode_t *)(kcb->jprobe_saved_sp),
-                       kcb->jprobes_stack,
-                       MIN_STACK_SIZE(kcb->jprobe_saved_sp));
+                memcpy(saved_sp, kcb->jprobes_stack, MIN_STACK_SIZE(saved_sp));
                 preempt_enable_no_resched();
                 return 1;
         }