Re: [PATCH] NDS32: perf_event_cpu: fix 2 build errors

[Greentime Hu]

Randy Dunlap <rdunlap@xxxxxxxxxxxxx> 於 2021年9月26日 週日 下午1:58寫道：
>
> ../arch/nds32/kernel/perf_event_cpu.c: In function 'unwind_frame_kernel':
> ../arch/nds32/include/asm/current.h:10:13: error: '$r25' undeclared (first use in this function)
>    10 | #define tsk $r25
> ../arch/nds32/kernel/perf_event_cpu.c:1255:50: note: in expansion of macro 'tsk'
>  1255 |                                                 (tsk, &graph, frame->lp, NULL);
>
> ../arch/nds32/kernel/perf_event_cpu.c:1257:27: error: assignment to 'long unsigned int' from 'long unsigned int *' makes integer from pointer without a cast [-Werror=int-conversion]
>  1257 |                 frame->sp = ((unsigned long *)frame->sp) + 1;
>
> For $r25, use the register function for current() instead.
>
> Fixes: c8b34461705e ("nds32: Add perf call-graph support.")
> Signed-off-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
> Cc: Nickhu <nickhu@xxxxxxxxxxxxx>
> Cc: Greentime Hu <green.hu@xxxxxxxxx>
> Cc: Vincent Chen <deanbo422@xxxxxxxxx>
> ---
> Please check the frame->sp cast/arithmetic.
>
>  arch/nds32/kernel/perf_event_cpu.c |    4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> --- linux-next-20210917.orig/arch/nds32/kernel/perf_event_cpu.c
> +++ linux-next-20210917/arch/nds32/kernel/perf_event_cpu.c
> @@ -1252,9 +1252,9 @@ static int unwind_frame_kernel(struct st
>                  */
>                 if (__kernel_text_address(frame->lp))
>                         frame->lp = ftrace_graph_ret_addr
> -                                               (tsk, &graph, frame->lp, NULL);
> +                                       (current, &graph, frame->lp, NULL);
>
> -               frame->sp = ((unsigned long *)frame->sp) + 1;
> +               frame->sp = (unsigned long)(((unsigned long *)frame->sp)) + 1;
>
>                 return 0;
>         } else {

Loop in Alan and KC.