Re: [PATCH v3 4/4] kernel/trace: remove calling regs_* when compiling HEXAGON

[Song Chen]

在 2022/12/23 22:15, Masami Hiramatsu (Google) 写道:
> On Mon,  5 Dec 2022 16:30:17 +0800
> Song Chen <chensong_2000@xxxxxx> wrote:
>
> > kernel test robot reports below errors:
> >
> > In file included from kernel/trace/trace_events_synth.c:22:
> > > > kernel/trace/trace_probe_kernel.h:203:9: error: call to
> > undeclared function 'regs_get_register'; ISO C99 and later
> > do not support implicit function declarations
> > [-Wimplicit-function-declaration]
> >                     val = regs_get_register(regs, code->param);
> >
> > HEXAGON doesn't define and implement those reg_* functions
> > underneath arch/hexagon as well as other archs. To remove
> > those errors, i have to include those function calls in
> > "CONFIG_HEXAGON"
> >
> > It looks ugly, but i don't know any other way to fix it,
> > this patch can be reverted after reg_* have been in place
> > in arch/hexagon.
>
> Sorry, NACK. This is too add-hoc patch and this is introduced
> by your patch. Do not introduce an issue and fix it later in
> the same series.
> Please fix it in your first patch. Maybe you should make another
> header file for those APIs.
>
> Thank you,
I tried not no add a new header file, but looks like i have to, to avoid 
triggering warnings and errors of kernel robot.

Thanks

Song

> > Signed-off-by: Song Chen <chensong_2000@xxxxxx>
> > Reported-by: kernel test robot <lkp@xxxxxxxxx>
> > ---
> >   kernel/trace/trace_probe_kernel.h | 21 +++++++++++++++++++--
> >   1 file changed, 19 insertions(+), 2 deletions(-)
> >
> > diff --git a/kernel/trace/trace_probe_kernel.h b/kernel/trace/trace_probe_kernel.h
> > index 8c42abe0dacf..7e958b7f07e5 100644
> > --- a/kernel/trace/trace_probe_kernel.h
> > +++ b/kernel/trace/trace_probe_kernel.h
> > @@ -130,8 +130,7 @@ probe_mem_read(void *dest, void *src, size_t size)
> >   	return copy_from_kernel_nofault(dest, src, size);
> >   }
> >   
> > -static nokprobe_inline unsigned long
> > -get_event_field(struct fetch_insn *code, void *rec)
> > +static unsigned long get_event_field(struct fetch_insn *code, void *rec)
> >   {
> >   	struct ftrace_event_field *field = code->data;
> >   	unsigned long val;
> > @@ -194,23 +193,41 @@ static int
> >   process_fetch_insn(struct fetch_insn *code, void *rec, void *dest,
> >   		   void *base)
> >   {
> > +#ifndef CONFIG_HEXAGON
> >   	struct pt_regs *regs = rec;
> > +#endif
> >   	unsigned long val;
> >   
> >   retry:
> >   	/* 1st stage: get value from context */
> >   	switch (code->op) {
> >   	case FETCH_OP_REG:
> > +#ifdef CONFIG_HEXAGON
> > +		val = 0;
> > +#else
> >   		val = regs_get_register(regs, code->param);
> > +#endif
> >   		break;
> >   	case FETCH_OP_STACK:
> > +#ifdef CONFIG_HEXAGON
> > +		val = 0;
> > +#else
> >   		val = regs_get_kernel_stack_nth(regs, code->param);
> > +#endif
> >   		break;
> >   	case FETCH_OP_STACKP:
> > +#ifdef CONFIG_HEXAGON
> > +		val = 0;
> > +#else
> >   		val = kernel_stack_pointer(regs);
> > +#endif
> >   		break;
> >   	case FETCH_OP_RETVAL:
> > +#ifdef CONFIG_HEXAGON
> > +		val = 0;
> > +#else
> >   		val = regs_return_value(regs);
> > +#endif
> >   		break;
> >   	case FETCH_OP_IMM:
> >   		val = code->immediate;
> > --
> > 2.25.1