Register 2 is alredy overwritten by the return value when
syscall_trace_leave() is called.
Signed-off-by: Lars Persson <larper@xxxxxxxx>
---
arch/mips/include/asm/syscall.h | 8 +-------
arch/mips/include/asm/thread_info.h | 1 +
arch/mips/kernel/ptrace.c | 2 ++
3 files changed, 4 insertions(+), 7 deletions(-)
diff --git a/arch/mips/include/asm/syscall.h b/arch/mips/include/asm/syscall.h
index bb79637..6499d93 100644
--- 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 99eea59..e4440f9 100644
--- 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 9d1487d..5104528 100644
--- 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;
--
1.7.10.4
