MIPS: Fix syscall_get_nr for the syscall exit tracing.

Register 2 is alredy overwritten by the return value when
syscall_trace_leave() is called.

Signed-off-by: Lars Persson <larper@axis.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9187/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

diff --git a/arch/mips/include/asm/syscall.h b/arch/mips/include/asm/syscall.h
index bb7963753730d817117f209e6bac10f4943a0b56..6499d93ae68d7096d63416a349d9afcdcc0cb3ae 100644 (file)
--- a/arch/mips/include/asm/syscall.h
+++ b/arch/mips/include/asm/syscall.h
@@ -29,13 +29,7 @@
 static inline long syscall_get_nr(struct task_struct *task,
                                  struct pt_regs *regs)
 {
-       /* O32 ABI syscall() - Either 64-bit with O32 or 32-bit */
-       if ((config_enabled(CONFIG_32BIT) ||
-           test_tsk_thread_flag(task, TIF_32BIT_REGS)) &&
-           (regs->regs[2] == __NR_syscall))
-               return regs->regs[4];
-       else
-               return regs->regs[2];
+       return current_thread_info()->syscall;
 }
 
 static inline unsigned long mips_get_syscall_arg(unsigned long *arg,

diff --git a/arch/mips/include/asm/thread_info.h b/arch/mips/include/asm/thread_info.h
index 99eea59604e984b61907a5a6a82feeca9660a609..e4440f92b366f7a1d90e4af10dd2477acdf0223a 100644 (file)
--- a/arch/mips/include/asm/thread_info.h
+++ b/arch/mips/include/asm/thread_info.h
@@ -36,6 +36,7 @@ struct thread_info {
                                                 */
        struct restart_block    restart_block;
        struct pt_regs          *regs;
+       long                    syscall;        /* syscall number */
 };
 
 /*

diff --git a/arch/mips/kernel/ptrace.c b/arch/mips/kernel/ptrace.c
index 9d1487d832932a0b3dcb4d2c694e773e753a8767..51045281259403c55fcefac09d510f874a3047bb 100644 (file)
--- a/arch/mips/kernel/ptrace.c
+++ b/arch/mips/kernel/ptrace.c
@@ -770,6 +770,8 @@ asmlinkage long syscall_trace_enter(struct pt_regs *regs, long syscall)
        long ret = 0;
        user_exit();
 
+       current_thread_info()->syscall = syscall;
+
        if (secure_computing() == -1)
                return -1;