Re: [PATCH] perf tools: Support bpf prologue for arm64

[Arnaldo Carvalho de Melo <acme@kernel.org>]

Em Sat, Aug 29, 2015 at 03:16:52AM +0000, He Kuang escreveu:
> This patch implements arch_get_reg_info() for arm64 to enable
> HAVE_BPF_PROLOGUE feature. For arm64, structure pt_regs is not composed
> by fields of register names but an array of regs, so here we simply
> multiply fixed register size by index number to get the byte offset.

Hi Jean, Will, are you ok with this? Can I have Acked-by or Reviewed-by
tags from you?

He, please try to add the authors of the files you change in the CC
list.

- Arnaldo
 
> Signed-off-by: He Kuang <hekuang@huawei.com>
> ---
>  tools/perf/arch/arm64/Makefile          |  1 +
>  tools/perf/arch/arm64/util/dwarf-regs.c | 26 ++++++++++++++++++++++++++
>  2 files changed, 27 insertions(+)
> 
> diff --git a/tools/perf/arch/arm64/Makefile b/tools/perf/arch/arm64/Makefile
> index 7fbca17..1256e6e 100644
> --- a/tools/perf/arch/arm64/Makefile
> +++ b/tools/perf/arch/arm64/Makefile
> @@ -1,3 +1,4 @@
>  ifndef NO_DWARF
>  PERF_HAVE_DWARF_REGS := 1
>  endif
> +PERF_HAVE_ARCH_GET_REG_INFO := 1
> diff --git a/tools/perf/arch/arm64/util/dwarf-regs.c b/tools/perf/arch/arm64/util/dwarf-regs.c
> index d49efeb..cb2c50a 100644
> --- a/tools/perf/arch/arm64/util/dwarf-regs.c
> +++ b/tools/perf/arch/arm64/util/dwarf-regs.c
> @@ -10,6 +10,10 @@
>  
>  #include <stddef.h>
>  #include <dwarf-regs.h>
> +#include <string.h>
> +#include <linux/ptrace.h>
> +
> +#define PT_REG_SIZE (sizeof(((struct user_pt_regs *)0)->regs[0]))
>  
>  struct pt_regs_dwarfnum {
>  	const char *name;
> @@ -78,3 +82,25 @@ const char *get_arch_regstr(unsigned int n)
>  			return roff->name;
>  	return NULL;
>  }
> +
> +#ifdef HAVE_BPF_PROLOGUE
> +int arch_get_reg_info(const char *name, int *offset)
> +{
> +	const struct pt_regs_dwarfnum *roff;
> +
> +	if (!name || !offset)
> +		return -1;
> +
> +	for (roff = regdwarfnum_table; roff->name != NULL; roff++) {
> +		if (!strcmp(roff->name, name)) {
> +			if (roff->dwarfnum < 0)
> +				return -1;
> +
> +			*offset = roff->dwarfnum * PT_REG_SIZE;
> +			return 0;
> +		}
> +	}
> +
> +	return -1;
> +}
> +#endif
> -- 
> 1.8.5.2