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, 12 insertions, 0 deletions

diff --git a/arch/csky/include/asm/ptrace.h b/arch/csky/include/asm/ptrace.h
index 1e00578166f0..d0aba7b32417 100644
--- a/arch/csky/include/asm/ptrace.h
+++ b/arch/csky/include/asm/ptrace.h
@@ -5,6 +5,8 @@
 #define __ASM_CSKY_PTRACE_H
 
 #include <uapi/asm/ptrace.h>
+#include <asm/traps.h>
+#include <linux/types.h>
 
 #ifndef __ASSEMBLY__
 
@@ -20,6 +22,16 @@
 #define instruction_pointer(regs) ((regs)->pc)
 #define profile_pc(regs) instruction_pointer(regs)
 
+static inline bool in_syscall(struct pt_regs const *regs)
+{
+	return ((regs->sr >> 16) & 0xff) == VEC_TRAP0;
+}
+
+static inline void forget_syscall(struct pt_regs *regs)
+{
+	regs->sr &= ~(0xff << 16);
+}
+
 static inline unsigned long regs_return_value(struct pt_regs *regs)
 {
 	return regs->a0;