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

Masami Hiramatsu
2017-02-07T13:43:23Z

On Tue, 7 Feb 2017 07:34:11 +0000
He Kuang <hekuang@huawei.com> 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@kernel.org>

Thanks!

> Signed-off-by: He Kuang <hekuang@huawei.com>
> ---
> 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@kernel.org>