linux-kernel - Re: [PATCH] perf, tools, script: Add brstackinsn for branch stacks

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Date:   Thu, 16 Mar 2017 13:16:21 +1100
From:   Michael Ellerman <mpe@...erman.id.au>
To:     acme@...nel.org
Cc:     mingo@...nel.org, jolsa@...nel.org, linux-kernel@...r.kernel.org,
        Andi Kleen <ak@...ux.intel.com>,
        Andi Kleen <andi@...stfloor.org>
Subject: Re: [PATCH] perf, tools, script: Add brstackinsn for branch stacks

Hi acme,

Andi Kleen <andi@...stfloor.org> writes:

> diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c
> index c0783b4f7b6c..b0fdb6c032a5 100644
> --- a/tools/perf/builtin-script.c
> +++ b/tools/perf/builtin-script.c
> @@ -546,6 +555,259 @@ static void print_sample_brstacksym(struct perf_sample *sample,
>  	}
>  }
>  
> +#define MAXBB 16384UL
> +
> +static int grab_bb(u8 *buffer, u64 start, u64 end,
> +		    struct machine *machine, struct thread *thread,
> +		    bool *is64bit, u8 *cpumode, bool last)
> +{
> +	long offset, len;
> +	struct addr_location al;
> +	bool kernel;
> +
> +	if (!start || !end)
> +		return 0;
> +
> +	kernel = machine__kernel_ip(machine, start);
> +	if (kernel)
> +		*cpumode = PERF_RECORD_MISC_KERNEL;
> +	else
> +		*cpumode = PERF_RECORD_MISC_USER;
> +
> +	/*
> +	 * Block overlaps between kernel and user.
> +	 * This can happen due to ring filtering
> +	 * On Intel CPUs the entry into the kernel is filtered,
> +	 * but the exit is not. Let the caller patch it up.
> +	 */
> +	if (kernel != machine__kernel_ip(machine, end)) {
> +		printf("\tblock %" PRIx64 "-%" PRIx64 " transfers between kernel and user\n",
> +				start, end);
> +		return -ENXIO;
> +	}
> +
> +	memset(&al, 0, sizeof(al));
> +	if (end - start > MAXBB - MAXINSN) {
> +		if (last)
> +			printf("\tbrstack does not reach to final jump (%" PRIx64 "-%" PRIx64 ")\n",
> +					start, end);
> +		else
> +			printf("\tblock %" PRIx64 "-%" PRIx64 " (%ld) too long to dump\n",
> +					start, end, end - start);

This looks to be breaking the build on ppc64:

  builtin-script.c: In function ‘grab_bb’:
  builtin-script.c:595:11: error: format ‘%ld’ expects argument of type ‘long int’, but argument 4 has type ‘u64 {aka long long unsigned int}’ [-Werror=format=]
      printf("\tblock %" PRIx64 "-%" PRIx64 " (%ld) too long to dump\n", start, end, end - start);
             ^

cheers