arm: new way of handling ERESTART_RESTARTBLOCK

new "syscall start" flag; handled in syscall_trace() by switching
syscall number to that of syscall_restart(2).  Restarts of that
kind (ERESTART_RESTARTBLOCK) are handled by setting that bit;
syscall number is not modified until the actual call.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 4 insertions, 1 deletions

diff --git a/arch/arm/include/asm/thread_info.h b/arch/arm/include/asm/thread_info.h
index 2d0cfc2ba23c..680c623a3d1f 100644
--- a/arch/arm/include/asm/thread_info.h
+++ b/arch/arm/include/asm/thread_info.h
@@ -148,6 +148,7 @@ extern int vfp_restore_user_hwstate(struct user_vfp __user *,
 #define TIF_NOTIFY_RESUME       2       /* callback before returning to user */
 #define TIF_SYSCALL_TRACE       8
 #define TIF_SYSCALL_AUDIT       9
+#define TIF_SYSCALL_RESTARTSYS  10
 #define TIF_POLLING_NRFLAG      16
 #define TIF_USING_IWMMXT        17
 #define TIF_MEMDIE              18      /* is terminating due to OOM killer */
@@ -163,9 +164,11 @@ extern int vfp_restore_user_hwstate(struct user_vfp __user *,
 #define _TIF_USING_IWMMXT       (1 << TIF_USING_IWMMXT)
 #define _TIF_RESTORE_SIGMASK    (1 << TIF_RESTORE_SIGMASK)
 #define _TIF_SECCOMP            (1 << TIF_SECCOMP)
+#define _TIF_SYSCALL_RESTARTSYS (1 << TIF_SYSCALL_RESTARTSYS)
 
 /* Checks for any syscall work in entry-common.S */
-#define _TIF_SYSCALL_WORK (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT)
+#define _TIF_SYSCALL_WORK (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | \
+                           _TIF_SYSCALL_RESTARTSYS)
 
 /*
  * Change these and you break ASM code in entry-common.S