Blackfin: add support for TIF_NOTIFY_RESUME

Signed-off-by: Barry Song <barry.song@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

3 files changed, 23 insertions, 1 deletions

diff --git a/arch/blackfin/include/asm/thread_info.h b/arch/blackfin/include/asm/thread_info.h
index afb3a8626380..a40d9368c38a 100644
--- a/arch/blackfin/include/asm/thread_info.h
+++ b/arch/blackfin/include/asm/thread_info.h
@@ -103,11 +103,13 @@ static inline struct thread_info *current_thread_info(void)
 #define TIF_RESTORE_SIGMASK     5       /* restore signal mask in do_signal() */
 #define TIF_FREEZE              6       /* is freezing for suspend */
 #define TIF_IRQ_SYNC            7       /* sync pipeline stage */
+#define TIF_NOTIFY_RESUME       8       /* callback before returning to user */
 
 /* as above, but as bit values */
 #define _TIF_SYSCALL_TRACE      (1<<TIF_SYSCALL_TRACE)
 #define _TIF_SIGPENDING         (1<<TIF_SIGPENDING)
 #define _TIF_NEED_RESCHED       (1<<TIF_NEED_RESCHED)
+#define _TIF_NOTIFY_RESUME      (1<<TIF_NOTIFY_RESUME)
 #define _TIF_POLLING_NRFLAG     (1<<TIF_POLLING_NRFLAG)
 #define _TIF_RESTORE_SIGMASK    (1<<TIF_RESTORE_SIGMASK)
 #define _TIF_FREEZE             (1<<TIF_FREEZE)
diff --git a/arch/blackfin/kernel/signal.c b/arch/blackfin/kernel/signal.c
index 9d90c18fab23..e0fd63e9e38a 100644
--- a/arch/blackfin/kernel/signal.c
+++ b/arch/blackfin/kernel/signal.c
@@ -12,6 +12,7 @@
 #include <linux/binfmts.h>
 #include <linux/freezer.h>
 #include <linux/uaccess.h>
+#include <linux/tracehook.h>
 
 #include <asm/cacheflush.h>
 #include <asm/ucontext.h>
@@ -332,3 +333,20 @@ asmlinkage void do_signal(struct pt_regs *regs)
                 sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
         }
 }
+
+/*
+ * notification of userspace execution resumption
+ */
+asmlinkage void do_notify_resume(struct pt_regs *regs)
+{
+        if (test_thread_flag(TIF_SIGPENDING) || test_thread_flag(TIF_RESTORE_SIGMASK))
+                do_signal(regs);
+
+        if (test_thread_flag(TIF_NOTIFY_RESUME)) {
+                clear_thread_flag(TIF_NOTIFY_RESUME);
+                tracehook_notify_resume(regs);
+                if (current->replacement_session_keyring)
+                        key_replace_session_keyring();
+        }
+}
+
diff --git a/arch/blackfin/mach-common/entry.S b/arch/blackfin/mach-common/entry.S
index f3f8bb46b517..b0ed0b487ff2 100644
--- a/arch/blackfin/mach-common/entry.S
+++ b/arch/blackfin/mach-common/entry.S
@@ -713,6 +713,8 @@ ENTRY(_system_call)
         cc = BITTST(r7, TIF_RESTORE_SIGMASK);
         if cc jump .Lsyscall_do_signals;
         cc = BITTST(r7, TIF_SIGPENDING);
+        if cc jump .Lsyscall_do_signals;
+        cc = BITTST(r7, TIF_NOTIFY_RESUME);
         if !cc jump .Lsyscall_really_exit;
 .Lsyscall_do_signals:
         /* Reenable interrupts.  */
@@ -721,7 +723,7 @@ ENTRY(_system_call)
 
         r0 = sp;
         SP += -12;
-        call _do_signal;
+        call _do_notify_resume;
         SP += 12;
 
 .Lsyscall_really_exit: