csky: Use in_syscall & forget_syscall instead of r11_sig

We could use regs->sr 16-24 bits to detect syscall: VEC_TRAP0 and
r11_sig is no necessary for current implementation.

In this patch, we implement the in_syscall and forget_syscall which are
inspired from arm & nds32, but csky pt_regs has no syscall_num element
and we just set zero to regs->sr's vector-bits-field instead.

For ret_from_fork, current task was forked from parent which is in syscall
progress and its regs->sr has been already setted with VEC_TRAP0. See:
arch/csky/kernel/process.c: copy_thread()

Signed-off-by: Guo Ren <ren_guo@c-sky.com>

1 files changed, 9 insertions, 6 deletions

diff --git a/arch/csky/kernel/signal.c b/arch/csky/kernel/signal.c
index 207a891479d2..5a18940f0b09 100644
--- a/arch/csky/kernel/signal.c
+++ b/arch/csky/kernel/signal.c
@@ -224,7 +224,7 @@ handle_signal(struct ksignal *ksig, struct pt_regs *regs)
  * that the kernel can handle, and then we build all the user-level signal
  * handling stack-frames in one go after that.
  */
-static void do_signal(struct pt_regs *regs, int syscall)
+static void do_signal(struct pt_regs *regs)
 {
 	unsigned int retval = 0, continue_addr = 0, restart_addr = 0;
 	struct ksignal ksig;
@@ -241,7 +241,9 @@ static void do_signal(struct pt_regs *regs, int syscall)
 	/*
 	 * If we were from a system call, check for system call restarting...
 	 */
-	if (syscall) {
+	if (in_syscall(regs)) {
+		forget_syscall(regs);
+
 		continue_addr = regs->pc;
 #if defined(__CSKYABIV2__)
 		restart_addr = continue_addr - 4;
@@ -249,7 +251,6 @@ static void do_signal(struct pt_regs *regs, int syscall)
 		restart_addr = continue_addr - 2;
 #endif
 		retval = regs->a0;
-
 		/*
 		 * Prepare for system call restart.  We do this here so that a
 		 * debugger will see the already changed.
@@ -304,7 +305,9 @@ static void do_signal(struct pt_regs *regs, int syscall)
 	}
 
 no_signal:
-	if (syscall) {
+	if (in_syscall(regs)) {
+		forget_syscall(regs);
+
 		/*
 		 * Handle restarting a different system call.  As above,
 		 * if a debugger has chosen to restart at a different PC,
@@ -333,10 +336,10 @@ no_signal:
 }
 
 asmlinkage void
-do_notify_resume(unsigned int thread_flags, struct pt_regs *regs, int syscall)
+do_notify_resume(unsigned int thread_flags, struct pt_regs *regs)
 {
 	if (thread_flags & _TIF_SIGPENDING)
-		do_signal(regs, syscall);
+		do_signal(regs);
 
 	if (thread_flags & _TIF_NOTIFY_RESUME) {
 		clear_thread_flag(TIF_NOTIFY_RESUME);