hw-breakpoints: reset bits in dr6 after the corresponding exception is handled

[GitHub/mt8127/android_kernel_alcatel_ttab.git] / arch / x86 / kernel / kprobes.c

diff --git a/arch/x86/kernel/kprobes.c b/arch/x86/kernel/kprobes.c
index 7b5169d2b00026272ed26874913c42ff315befb3..b5b1848c5336e505a5a147f0497865056f34b307 100644 (file)
--- a/arch/x86/kernel/kprobes.c
+++ b/arch/x86/kernel/kprobes.c
@@ -54,6 +54,7 @@
 #include <asm/pgtable.h>
 #include <asm/uaccess.h>
 #include <asm/alternative.h>
+#include <asm/debugreg.h>
 
 void jprobe_return_end(void);
 
@@ -967,8 +968,14 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self,
                        ret = NOTIFY_STOP;
                break;
        case DIE_DEBUG:
-               if (post_kprobe_handler(args->regs))
+               if (post_kprobe_handler(args->regs)) {
+                       /*
+                        * Reset the BS bit in dr6 (pointed by args->err) to
+                        * denote completion of processing
+                        */
+                       (*(unsigned long *)ERR_PTR(args->err)) &= ~DR_STEP;
                        ret = NOTIFY_STOP;
+               }
                break;
        case DIE_GPF:
                /*