Merge branch 'msm-core' of git://codeaurora.org/quic/kernel/dwalker/linux-msm

[pandora-kernel.git] / arch / x86 / kernel / kprobes.c

diff --git a/arch/x86/kernel/kprobes.c b/arch/x86/kernel/kprobes.c
index b43bbae..345a4b1 100644 (file)
--- a/arch/x86/kernel/kprobes.c
+++ b/arch/x86/kernel/kprobes.c
@@ -422,14 +422,22 @@ static void __kprobes set_current_kprobe(struct kprobe *p, struct pt_regs *regs,
 
 static void __kprobes clear_btf(void)
 {
-       if (test_thread_flag(TIF_DEBUGCTLMSR))
-               update_debugctlmsr(0);
+       if (test_thread_flag(TIF_BLOCKSTEP)) {
+               unsigned long debugctl = get_debugctlmsr();
+
+               debugctl &= ~DEBUGCTLMSR_BTF;
+               update_debugctlmsr(debugctl);
+       }
 }
 
 static void __kprobes restore_btf(void)
 {
-       if (test_thread_flag(TIF_DEBUGCTLMSR))
-               update_debugctlmsr(current->thread.debugctlmsr);
+       if (test_thread_flag(TIF_BLOCKSTEP)) {
+               unsigned long debugctl = get_debugctlmsr();
+
+               debugctl |= DEBUGCTLMSR_BTF;
+               update_debugctlmsr(debugctl);
+       }
 }
 
 void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri,
@@ -534,20 +542,6 @@ static int __kprobes kprobe_handler(struct pt_regs *regs)
        struct kprobe_ctlblk *kcb;
 
        addr = (kprobe_opcode_t *)(regs->ip - sizeof(kprobe_opcode_t));
-       if (*addr != BREAKPOINT_INSTRUCTION) {
-               /*
-                * The breakpoint instruction was removed right
-                * after we hit it.  Another cpu has removed
-                * either a probepoint or a debugger breakpoint
-                * at this address.  In either case, no further
-                * handling of this interrupt is appropriate.
-                * Back up over the (now missing) int3 and run
-                * the original instruction.
-                */
-               regs->ip = (unsigned long)addr;
-               return 1;
-       }
-
        /*
         * We don't want to be preempted for the entire
         * duration of kprobe processing. We conditionally
@@ -579,6 +573,19 @@ static int __kprobes kprobe_handler(struct pt_regs *regs)
                                setup_singlestep(p, regs, kcb, 0);
                        return 1;
                }
+       } else if (*addr != BREAKPOINT_INSTRUCTION) {
+               /*
+                * The breakpoint instruction was removed right
+                * after we hit it.  Another cpu has removed
+                * either a probepoint or a debugger breakpoint
+                * at this address.  In either case, no further
+                * handling of this interrupt is appropriate.
+                * Back up over the (now missing) int3 and run
+                * the original instruction.
+                */
+               regs->ip = (unsigned long)addr;
+               preempt_enable_no_resched();
+               return 1;
        } else if (kprobe_running()) {
                p = __get_cpu_var(current_kprobe);
                if (p->break_handler && p->break_handler(p, regs)) {