Em Tue, May 10, 2016 at 07:40:30AM +0000, He Kuang escreveu:
> When unwinding callchains on a different machine, vdso info should be
> provided so the unwind process won't be interrupted if address falls
> into vdso region.
>
> Currently, perf does try to read vdso binary in '.debug' folder, but
> the filename of the vdso file is generated randomly based on
> VDSO__TEMP_FILE_NAME template, such a filename is not reliable and
> users need a way to provide the path of their own vdso binary file.
But this becomes one more burden to the user :-\ Why not calculate a
build-id from the VDSO file contents, copy it to
~/.debug/.build-id/ab/cdef01020304 and insert that into the perf.data
file so that at analysis time we do all this automatically?
We can of course have a way to manually provide it, but having it as the
main way for users doesn't seem a good interface. Am I missing
something?
- Arnaldo
> Signed-off-by: He Kuang <heku...@huawei.com>
> ---
> tools/perf/builtin-script.c | 2 ++
> tools/perf/util/dso.c | 7 +++++++
> tools/perf/util/dso.h | 1 +
> tools/perf/util/symbol.c | 1 +
> tools/perf/util/symbol.h | 1 +
> 5 files changed, 12 insertions(+)
>
> diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c
> index 8f6ab2a..c88b547 100644
> --- a/tools/perf/builtin-script.c
> +++ b/tools/perf/builtin-script.c
> @@ -2001,6 +2001,8 @@ int cmd_script(int argc, const char **argv, const char
> *prefix __maybe_unused)
> "file", "vmlinux pathname"),
> OPT_STRING(0, "kallsyms", &symbol_conf.kallsyms_name,
> "file", "kallsyms pathname"),
> + OPT_STRING(0, "vdso", &symbol_conf.vdso_name,
> + "file", "vdso pathname"),
> OPT_BOOLEAN('G', "hide-call-graph", &no_callchain,
> "When printing symbols do not display call chain"),
> OPT_STRING(0, "symfs", &symbol_conf.symfs, "directory",
> diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c
> index 8e639543..6ed1cce 100644
> --- a/tools/perf/util/dso.c
> +++ b/tools/perf/util/dso.c
> @@ -13,6 +13,7 @@ char dso__symtab_origin(const struct dso *dso)
> static const char origin[] = {
> [DSO_BINARY_TYPE__KALLSYMS] = 'k',
> [DSO_BINARY_TYPE__VMLINUX] = 'v',
> + [DSO_BINARY_TYPE__VDSO] = 'D',
> [DSO_BINARY_TYPE__JAVA_JIT] = 'j',
> [DSO_BINARY_TYPE__DEBUGLINK] = 'l',
> [DSO_BINARY_TYPE__BUILD_ID_CACHE] = 'B',
> @@ -113,6 +114,11 @@ int dso__read_binary_type_filename(const struct dso *dso,
> build_id_hex, build_id_hex + 2);
> break;
>
> + case DSO_BINARY_TYPE__VDSO:
> + {
> + snprintf(filename, size, "%s", symbol_conf.vdso_name);
> + break;
> + }
> case DSO_BINARY_TYPE__VMLINUX:
> case DSO_BINARY_TYPE__GUEST_VMLINUX:
> case DSO_BINARY_TYPE__SYSTEM_PATH_DSO:
> @@ -487,6 +493,7 @@ static void try_to_open_dso(struct dso *dso, struct
> machine *machine)
> enum dso_binary_type binary_type_data[] = {
> DSO_BINARY_TYPE__BUILD_ID_CACHE,
> DSO_BINARY_TYPE__SYSTEM_PATH_DSO,
> + DSO_BINARY_TYPE__VDSO,
> DSO_BINARY_TYPE__NOT_FOUND,
> };
> int i = 0;
> diff --git a/tools/perf/util/dso.h b/tools/perf/util/dso.h
> index 0953280..05fac98 100644
> --- a/tools/perf/util/dso.h
> +++ b/tools/perf/util/dso.h
> @@ -30,6 +30,7 @@ enum dso_binary_type {
> DSO_BINARY_TYPE__KCORE,
> DSO_BINARY_TYPE__GUEST_KCORE,
> DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO,
> + DSO_BINARY_TYPE__VDSO,
> DSO_BINARY_TYPE__NOT_FOUND,
> };
>
> diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
> index e7588dc..4630751 100644
> --- a/tools/perf/util/symbol.c
> +++ b/tools/perf/util/symbol.c
> @@ -1363,6 +1363,7 @@ static bool dso__is_compatible_symtab_type(struct dso
> *dso, bool kmod,
> case DSO_BINARY_TYPE__UBUNTU_DEBUGINFO:
> case DSO_BINARY_TYPE__BUILDID_DEBUGINFO:
> case DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO:
> + case DSO_BINARY_TYPE__VDSO:
> return !kmod && dso->kernel == DSO_TYPE_USER;
>
> case DSO_BINARY_TYPE__KALLSYMS:
> diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h
> index c8b7544..4e6910e 100644
> --- a/tools/perf/util/symbol.h
> +++ b/tools/perf/util/symbol.h
> @@ -114,6 +114,7 @@ struct symbol_conf {
> report_hierarchy;
> const char *vmlinux_name,
> *kallsyms_name,
> + *vdso_name,
> *source_prefix,
> *field_sep;
> const char *default_guest_vmlinux_name,
> --
> 1.8.5.2
