[PATCH] ARM: pass syscall return value to sys_exit tracepoint

[Will Deacon]

On Sat, Dec 01, 2012 at 01:38:54PM +0000, Andrew Gabbasov wrote:
> sys_exit tracepoint expects the syscall return value as a second
> argument, rather than syscall number.
> 
> Signed-off-by: Andrew Gabbasov <andrew_gabbasov at mentor.com>
> ---
>  arch/arm/kernel/ptrace.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/arm/kernel/ptrace.c b/arch/arm/kernel/ptrace.c
> index 739db3a..4206da7 100644
> --- a/arch/arm/kernel/ptrace.c
> +++ b/arch/arm/kernel/ptrace.c
> @@ -956,7 +956,7 @@ asmlinkage int syscall_trace_exit(struct pt_regs *regs, int scno)
>  {
>  	scno = ptrace_syscall_trace(regs, scno, PTRACE_SYSCALL_EXIT);
>  	if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
> -		trace_sys_exit(regs, scno);
> +		trace_sys_exit(regs, regs->ARM_r0);
>  	audit_syscall_exit(regs);
>  	return scno;
>  }

It might be worth stashing the return value into a local variable prior to
the ptrace_syscall_trace invocation, just in case a debugger decides to
rewrite the child's registers.

Will