xtensa: call do_syscall_trace_{enter,leave} selectively

Check whether calls to do_syscall_trace_{enter,leave} are necessary in
the system_call function. Define _TIF_WORK_MASK to a bitmask of flags
that reuire the calls. Fix comment.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

diff --git a/arch/xtensa/include/asm/thread_info.h b/arch/xtensa/include/asm/thread_info.h
index 49aa787..c823ddd 100644 (file)
--- a/arch/xtensa/include/asm/thread_info.h
+++ b/arch/xtensa/include/asm/thread_info.h
@@ -101,8 +101,6 @@ static inline struct thread_info *current_thread_info(void)
 /*
  * thread information flags
  * - these are process state flags that various assembly files may need to access
- * - pending work-to-be-done flags are in LSW
- * - other flags in MSW
  */
 #define TIF_SYSCALL_TRACE      0       /* syscall trace active */
 #define TIF_SIGPENDING         1       /* signal pending */
@@ -118,8 +116,7 @@ static inline struct thread_info *current_thread_info(void)
 #define _TIF_NEED_RESCHED      (1<<TIF_NEED_RESCHED)
 #define _TIF_SINGLESTEP                (1<<TIF_SINGLESTEP)
 
-#define _TIF_WORK_MASK         0x0000FFFE      /* work to do on interrupt/exception return */
-#define _TIF_ALLWORK_MASK      0x0000FFFF      /* work to do on any return to u-space */
+#define _TIF_WORK_MASK         (_TIF_SYSCALL_TRACE | _TIF_SINGLESTEP)
 
 /*
  * Thread-synchronous status.

diff --git a/arch/xtensa/kernel/entry.S b/arch/xtensa/kernel/entry.S
index e41c1e1..e50f512 100644 (file)
--- a/arch/xtensa/kernel/entry.S
+++ b/arch/xtensa/kernel/entry.S
@@ -1846,20 +1846,28 @@ ENTRY(system_call)
 
        /* regs->syscall = regs->areg[2] */
 
-       l32i    a3, a2, PT_AREG2
+       l32i    a7, a2, PT_AREG2
+       s32i    a7, a2, PT_SYSCALL
+
+       GET_THREAD_INFO(a4, a1)
+       l32i    a3, a4, TI_FLAGS
+       movi    a4, _TIF_WORK_MASK
+       and     a3, a3, a4
+       beqz    a3, 1f
+
        mov     a6, a2
-       s32i    a3, a2, PT_SYSCALL
        call4   do_syscall_trace_enter
-       mov     a3, a6
+       l32i    a7, a2, PT_SYSCALL
 
+1:
        /* syscall = sys_call_table[syscall_nr] */
 
        movi    a4, sys_call_table
        movi    a5, __NR_syscalls
        movi    a6, -ENOSYS
-       bgeu    a3, a5, 1f
+       bgeu    a7, a5, 1f
 
-       addx4   a4, a3, a4
+       addx4   a4, a7, a4
        l32i    a4, a4, 0
        movi    a5, sys_ni_syscall;
        beq     a4, a5, 1f
@@ -1881,6 +1889,10 @@ ENTRY(system_call)
 1:     /* regs->areg[2] = return_value */
 
        s32i    a6, a2, PT_AREG2
+       bnez    a3, 1f
+       retw
+
+1:
        mov     a6, a2
        call4   do_syscall_trace_leave
        retw

diff --git a/arch/xtensa/kernel/ptrace.c b/arch/xtensa/kernel/ptrace.c
index 86622d4..f73a6a7 100644 (file)
--- a/arch/xtensa/kernel/ptrace.c
+++ b/arch/xtensa/kernel/ptrace.c
@@ -487,13 +487,12 @@ long arch_ptrace(struct task_struct *child, long request,
        return ret;
 }
 
-unsigned long do_syscall_trace_enter(struct pt_regs *regs)
+void do_syscall_trace_enter(struct pt_regs *regs)
 {
        if (test_thread_flag(TIF_SYSCALL_TRACE) &&
            tracehook_report_syscall_entry(regs))
-               return NO_SYSCALL;
+               regs->syscall = NO_SYSCALL;
 
-       return regs->areg[2];
 }
 
 void do_syscall_trace_leave(struct pt_regs *regs)