On 02/03/2015 04:08 PM, Lars Persson wrote:
> 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;
>
>
Hi,
This is now in mainline but parts of it can apply to stable as well?
Would you be willing to send a backported version for the stable trees?
Thanks a lot
--
markos
