x86: tracehook: TIF_NOTIFY_RESUME
This adds TIF_NOTIFY_RESUME support for x86, both 64-bit and 32-bit.
When set, we call tracehook_notify_resume() on the way to user mode.
Signed-off-by: Roland McGrath <roland@redhat.com>
diff --git a/arch/x86/kernel/signal_32.c b/arch/x86/kernel/signal_32.c
index 22aae16..4445d26 100644
--- a/arch/x86/kernel/signal_32.c
+++ b/arch/x86/kernel/signal_32.c
@@ -663,5 +663,10 @@
if (thread_info_flags & _TIF_SIGPENDING)
do_signal(regs);
+ if (thread_info_flags & _TIF_NOTIFY_RESUME) {
+ clear_thread_flag(TIF_NOTIFY_RESUME);
+ tracehook_notify_resume(regs);
+ }
+
clear_thread_flag(TIF_IRET);
}
diff --git a/arch/x86/kernel/signal_64.c b/arch/x86/kernel/signal_64.c
index cb7cf02..d01e3f6 100644
--- a/arch/x86/kernel/signal_64.c
+++ b/arch/x86/kernel/signal_64.c
@@ -523,6 +523,11 @@
/* deal with pending signal delivery */
if (thread_info_flags & _TIF_SIGPENDING)
do_signal(regs);
+
+ if (thread_info_flags & _TIF_NOTIFY_RESUME) {
+ clear_thread_flag(TIF_NOTIFY_RESUME);
+ tracehook_notify_resume(regs);
+ }
}
void signal_fault(struct pt_regs *regs, void __user *frame, char *where)
diff --git a/include/asm-x86/thread_info.h b/include/asm-x86/thread_info.h
index da0a675..4cd5b7b 100644
--- a/include/asm-x86/thread_info.h
+++ b/include/asm-x86/thread_info.h
@@ -71,6 +71,7 @@
* Warning: layout of LSW is hardcoded in entry.S
*/
#define TIF_SYSCALL_TRACE 0 /* syscall trace active */
+#define TIF_NOTIFY_RESUME 1 /* callback before returning to user */
#define TIF_SIGPENDING 2 /* signal pending */
#define TIF_NEED_RESCHED 3 /* rescheduling necessary */
#define TIF_SINGLESTEP 4 /* reenable singlestep on user return*/
@@ -93,6 +94,7 @@
#define TIF_BTS_TRACE_TS 27 /* record scheduling event timestamps */
#define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE)
+#define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME)
#define _TIF_SIGPENDING (1 << TIF_SIGPENDING)
#define _TIF_SINGLESTEP (1 << TIF_SINGLESTEP)
#define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED)
@@ -133,7 +135,7 @@
/* Only used for 64 bit */
#define _TIF_DO_NOTIFY_MASK \
- (_TIF_SIGPENDING|_TIF_MCE_NOTIFY)
+ (_TIF_SIGPENDING|_TIF_MCE_NOTIFY|_TIF_NOTIFY_RESUME)
/* flags to check in __switch_to() */
#define _TIF_WORK_CTXSW \