Re: [PATCH v4 1/2] perf tools arm64: Add support for generating bpf prologue

[Masami Hiramatsu]

On Tue, 7 Feb 2017 07:34:11 +0000
He Kuang <hekuang@xxxxxxxxxx> wrote:

> Since HAVE_KPROBES can be enabled in arm64, this patch introduces
> regs_query_register_offset() to convert register name to offset for
> arm64, so the BPF prologue feature is ready to use.
> 

Ok, looks good to me.

Acked-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>

Thanks!

> Signed-off-by: He Kuang <hekuang@xxxxxxxxxx>
> ---
>  tools/perf/arch/arm64/Makefile          |  1 +
>  tools/perf/arch/arm64/util/dwarf-regs.c | 15 ++++++++++++++-
>  2 files changed, 15 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/perf/arch/arm64/Makefile b/tools/perf/arch/arm64/Makefile
> index 18b1351..eebe1ec 100644
> --- a/tools/perf/arch/arm64/Makefile
> +++ b/tools/perf/arch/arm64/Makefile
> @@ -2,3 +2,4 @@ ifndef NO_DWARF
>  PERF_HAVE_DWARF_REGS := 1
>  endif
>  PERF_HAVE_JITDUMP := 1
> +PERF_HAVE_ARCH_REGS_QUERY_REGISTER_OFFSET := 1
> diff --git a/tools/perf/arch/arm64/util/dwarf-regs.c b/tools/perf/arch/arm64/util/dwarf-regs.c
> index d49efeb..068b618 100644
> --- a/tools/perf/arch/arm64/util/dwarf-regs.c
> +++ b/tools/perf/arch/arm64/util/dwarf-regs.c
> @@ -10,17 +10,20 @@
>  
>  #include <stddef.h>
>  #include <dwarf-regs.h>
> +#include <linux/ptrace.h> /* for struct user_pt_regs */
> +#include "util.h"
>  
>  struct pt_regs_dwarfnum {
>  	const char *name;
>  	unsigned int dwarfnum;
>  };
>  
> -#define STR(s) #s
>  #define REG_DWARFNUM_NAME(r, num) {.name = r, .dwarfnum = num}
>  #define GPR_DWARFNUM_NAME(num) \
>  	{.name = STR(%x##num), .dwarfnum = num}
>  #define REG_DWARFNUM_END {.name = NULL, .dwarfnum = 0}
> +#define DWARFNUM2OFFSET(index) \
> +	(index * sizeof((struct user_pt_regs *)0)->regs[0])
>  
>  /*
>   * Reference:
> @@ -78,3 +81,13 @@ const char *get_arch_regstr(unsigned int n)
>  			return roff->name;
>  	return NULL;
>  }
> +
> +int regs_query_register_offset(const char *name)
> +{
> +	const struct pt_regs_dwarfnum *roff;
> +
> +	for (roff = regdwarfnum_table; roff->name != NULL; roff++)
> +		if (!strcmp(roff->name, name))
> +			return DWARFNUM2OFFSET(roff->dwarfnum);
> +	return -EINVAL;
> +}
> -- 
> 1.8.5.2
> 


-- 
Masami Hiramatsu <mhiramat@xxxxxxxxxx>