[PATCH v2 18/31] perf dwarf-regs: Move x86 dwarf-regs out of arch
Masami Hiramatsu (Google)
mhiramat at kernel.org
Mon Oct 7 01:34:53 PDT 2024
On Sat, 5 Oct 2024 12:55:28 -0700
Ian Rogers <irogers at google.com> wrote:
> Move arch/x86/util/dwarf-regs.c to util/dwarf-regs-x86.c and compile
> in unconditionally. To avoid get_arch_regnum being duplicated, rename
> to get_x86_regnum and add to get_dwarf_regnum switch.
>
> For get_arch_regstr, this was unused on x86 unless the machine type
> was EM_NONE. Map that case to EM_HOST and remove get_arch_regstr from
> dwarf-regs-x86.c.
>
Hmm, I'm not sure this change. I feel like to keep the arch dependent
part under arch/ directory. But if this is just for reverse mapping of
regname -> regnum, since we already have regnum -> regname maps in the
header file, we can reimplement get_dwarf_regnum() as a generic function.
And that is what you does in this series, correct?
If so, can you make a generic get_dwarf_regnum() at first, and remove
the architecture dependent part which is not needed anymore.
That should be more simpler to review.
Thank you,
> Signed-off-by: Ian Rogers <irogers at google.com>
> ---
> tools/perf/arch/x86/util/Build | 3 ---
> tools/perf/util/Build | 1 +
> .../dwarf-regs.c => util/dwarf-regs-x86.c} | 24 +------------------
> tools/perf/util/dwarf-regs.c | 17 +++++++++++++
> tools/perf/util/include/dwarf-regs.h | 8 +++++++
> 5 files changed, 27 insertions(+), 26 deletions(-)
> rename tools/perf/{arch/x86/util/dwarf-regs.c => util/dwarf-regs-x86.c} (77%)
>
> diff --git a/tools/perf/arch/x86/util/Build b/tools/perf/arch/x86/util/Build
> index 9705cda4f240..70af491a6dd7 100644
> --- a/tools/perf/arch/x86/util/Build
> +++ b/tools/perf/arch/x86/util/Build
> @@ -12,9 +12,6 @@ perf-util-y += evsel.o
> perf-util-y += iostat.o
> perf-util-y += env.o
>
> -perf-util-$(CONFIG_LIBDW) += dwarf-regs.o
> -perf-util-$(CONFIG_BPF_PROLOGUE) += dwarf-regs.o
> -
> perf-util-$(CONFIG_LOCAL_LIBUNWIND) += unwind-libunwind.o
> perf-util-$(CONFIG_LIBDW_DWARF_UNWIND) += unwind-libdw.o
>
> diff --git a/tools/perf/util/Build b/tools/perf/util/Build
> index 1d08608b7e1b..c2221ef431f3 100644
> --- a/tools/perf/util/Build
> +++ b/tools/perf/util/Build
> @@ -202,6 +202,7 @@ endif
> perf-util-$(CONFIG_LIBDW) += probe-finder.o
> perf-util-$(CONFIG_LIBDW) += dwarf-aux.o
> perf-util-$(CONFIG_LIBDW) += dwarf-regs.o
> +perf-util-$(CONFIG_LIBDW) += dwarf-regs-x86.o
> perf-util-$(CONFIG_LIBDW) += debuginfo.o
> perf-util-$(CONFIG_LIBDW) += annotate-data.o
>
> diff --git a/tools/perf/arch/x86/util/dwarf-regs.c b/tools/perf/util/dwarf-regs-x86.c
> similarity index 77%
> rename from tools/perf/arch/x86/util/dwarf-regs.c
> rename to tools/perf/util/dwarf-regs-x86.c
> index 530905118cd4..7a55c65e8da6 100644
> --- a/tools/perf/arch/x86/util/dwarf-regs.c
> +++ b/tools/perf/util/dwarf-regs-x86.c
> @@ -11,28 +11,6 @@
> #include <linux/kernel.h> /* for ARRAY_SIZE */
> #include <dwarf-regs.h>
>
> -#define DEFINE_DWARF_REGSTR_TABLE 1
> -#include "dwarf-regs-table.h"
> -
> -/* Return architecture dependent register string (for kprobe-tracer) */
> -const char *get_arch_regstr(unsigned int n)
> -{
> -#if defined(__i386__)
> - size_t len = ARRAY_SIZE(x86_32_regstr_tbl);
> -#else
> - size_t len = ARRAY_SIZE(x86_64_regstr_tbl);
> -#endif
> -
> - if (n >= len)
> - return NULL;
> -
> -#if defined(__i386__)
> - return x86_32_regstr_tbl[n];
> -#else
> - return x86_64_regstr_tbl[n];
> -#endif
> -}
> -
> struct dwarf_regs_idx {
> const char *name;
> int idx;
> @@ -58,7 +36,7 @@ static const struct dwarf_regs_idx x86_regidx_table[] = {
> { "rip", DWARF_REG_PC },
> };
>
> -int get_arch_regnum(const char *name)
> +int get_x86_regnum(const char *name)
> {
> unsigned int i;
>
> diff --git a/tools/perf/util/dwarf-regs.c b/tools/perf/util/dwarf-regs.c
> index 86b3ef638fbb..eac99a246737 100644
> --- a/tools/perf/util/dwarf-regs.c
> +++ b/tools/perf/util/dwarf-regs.c
> @@ -32,9 +32,17 @@
> const char *get_dwarf_regstr(unsigned int n, unsigned int machine,
> unsigned int flags __maybe_unused)
> {
> +#if EM_HOST == EM_X86_64 || EM_HOST == EM_386
> + if (machine == EM_NONE) {
> + /* Generic arch - use host arch */
> + machine = EM_HOST;
> + }
> +#endif
> switch (machine) {
> +#if EM_HOST != EM_X86_64 && EM_HOST != EM_386
> case EM_NONE: /* Generic arch - use host arch */
> return get_arch_regstr(n);
> +#endif
> case EM_386:
> return __get_dwarf_regstr(x86_32_regstr_tbl, n);
> case EM_X86_64:
> @@ -65,10 +73,12 @@ const char *get_dwarf_regstr(unsigned int n, unsigned int machine,
> return NULL;
> }
>
> +#if EM_HOST != EM_X86_64 && EM_HOST != EM_386
> __weak int get_arch_regnum(const char *name __maybe_unused)
> {
> return -ENOTSUP;
> }
> +#endif
>
> /* Return DWARF register number from architecture register name */
> int get_dwarf_regnum(const char *name, unsigned int machine, unsigned int flags __maybe_unused)
> @@ -90,9 +100,16 @@ int get_dwarf_regnum(const char *name, unsigned int machine, unsigned int flags
> machine = EM_HOST;
> }
> switch (machine) {
> +#if EM_HOST != EM_X86_64 && EM_HOST != EM_386
> case EM_HOST:
> reg = get_arch_regnum(regname);
> break;
> +#endif
> + case EM_X86_64:
> + fallthrough;
> + case EM_386:
> + reg = get_x86_regnum(regname);
> + break;
> default:
> pr_err("ELF MACHINE %x is not supported.\n", machine);
> }
> diff --git a/tools/perf/util/include/dwarf-regs.h b/tools/perf/util/include/dwarf-regs.h
> index 925525405e2d..062623aefd5a 100644
> --- a/tools/perf/util/include/dwarf-regs.h
> +++ b/tools/perf/util/include/dwarf-regs.h
> @@ -79,7 +79,10 @@
> #define DWARF_REG_FB 0xd3affb /* random number */
>
> #ifdef HAVE_LIBDW_SUPPORT
> +#if !defined(__x86_64__) && !defined(__i386__)
> const char *get_arch_regstr(unsigned int n);
> +#endif
> +
> /**
> * get_dwarf_regstr() - Returns ftrace register string from DWARF regnum.
> * @n: DWARF register number.
> @@ -88,7 +91,12 @@ const char *get_arch_regstr(unsigned int n);
> */
> const char *get_dwarf_regstr(unsigned int n, unsigned int machine, unsigned int flags);
>
> +int get_x86_regnum(const char *name);
> +
> +#if !defined(__x86_64__) && !defined(__i386__)
> int get_arch_regnum(const char *name);
> +#endif
> +
> /*
> * get_dwarf_regnum - Returns DWARF regnum from register name
> * name: architecture register name
> --
> 2.47.0.rc0.187.ge670bccf7e-goog
>
--
Masami Hiramatsu (Google) <mhiramat at kernel.org>
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