From: Adrian Hunter <adrian.hun...@intel.com> 'perf record' post-processes the event stream to create a list of build-ids for object files for which sample events have been recorded. That results in those object files being recorded in the build-id cache.
In the case of VDSO, perf tools reads it from memory and copies it into a temporary file, which as decribed above, gets added to the build-id cache. Then when the perf.data file is processed by other tools, the build-id of VDSO is listed in the perf.data file and the VDSO can be read from the build-id cache. In that case the name of the map, the short name of the DSO, and the entry in the build-id cache are all "[vdso]". However, in the 64-bit case, there also can be 32-bit compatibility VDSOs. A previous patch added programs "perf-read-vdso32" and "perf read-vdsox32". This patch uses those programs to read the correct VDSO for a thread and create a temporary file just as for the 64-bit VDSO. The map name and the entry in the build-id cache are still "[vdso]" but the DSO short name becomes "[vdso32]" and "[vdsox32]" respectively. Signed-off-by: Adrian Hunter <adrian.hun...@intel.com> Cc: David Ahern <dsah...@gmail.com> Cc: Frederic Weisbecker <fweis...@gmail.com> Cc: Jiri Olsa <jo...@redhat.com> Cc: Namhyung Kim <namhy...@gmail.com> Cc: Paul Mackerras <pau...@samba.org> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Stephane Eranian <eran...@google.com> Link: http://lkml.kernel.org/r/1414061124-26830-16-git-send-email-adrian.hun...@intel.com Signed-off-by: Arnaldo Carvalho de Melo <a...@redhat.com> --- tools/perf/util/vdso.c | 170 ++++++++++++++++++++++++++++++++++++++++++++++++- tools/perf/util/vdso.h | 4 +- 2 files changed, 172 insertions(+), 2 deletions(-) diff --git a/tools/perf/util/vdso.c b/tools/perf/util/vdso.c index f51390a1ed51..69daef6a17d5 100644 --- a/tools/perf/util/vdso.c +++ b/tools/perf/util/vdso.c @@ -12,6 +12,7 @@ #include "util.h" #include "symbol.h" #include "machine.h" +#include "thread.h" #include "linux/string.h" #include "debug.h" @@ -28,10 +29,15 @@ struct vdso_file { bool error; char temp_file_name[sizeof(VDSO__TEMP_FILE_NAME)]; const char *dso_name; + const char *read_prog; }; struct vdso_info { struct vdso_file vdso; +#if BITS_PER_LONG == 64 + struct vdso_file vdso32; + struct vdso_file vdsox32; +#endif }; static struct vdso_info *vdso_info__new(void) @@ -41,6 +47,18 @@ static struct vdso_info *vdso_info__new(void) .temp_file_name = VDSO__TEMP_FILE_NAME, .dso_name = DSO__NAME_VDSO, }, +#if BITS_PER_LONG == 64 + .vdso32 = { + .temp_file_name = VDSO__TEMP_FILE_NAME, + .dso_name = DSO__NAME_VDSO32, + .read_prog = "perf-read-vdso32", + }, + .vdsox32 = { + .temp_file_name = VDSO__TEMP_FILE_NAME, + .dso_name = DSO__NAME_VDSOX32, + .read_prog = "perf-read-vdsox32", + }, +#endif }; return memdup(&vdso_info_init, sizeof(vdso_info_init)); @@ -92,6 +110,12 @@ void vdso__exit(struct machine *machine) if (vdso_info->vdso.found) unlink(vdso_info->vdso.temp_file_name); +#if BITS_PER_LONG == 64 + if (vdso_info->vdso32.found) + unlink(vdso_info->vdso32.temp_file_name); + if (vdso_info->vdsox32.found) + unlink(vdso_info->vdsox32.temp_file_name); +#endif zfree(&machine->vdso_info); } @@ -110,6 +134,143 @@ static struct dso *vdso__new(struct machine *machine, const char *short_name, return dso; } +#if BITS_PER_LONG == 64 + +static enum dso_type machine__thread_dso_type(struct machine *machine, + struct thread *thread) +{ + enum dso_type dso_type = DSO__TYPE_UNKNOWN; + struct map *map; + struct dso *dso; + + map = map_groups__first(thread->mg, MAP__FUNCTION); + for (; map ; map = map_groups__next(map)) { + dso = map->dso; + if (!dso || dso->long_name[0] != '/') + continue; + dso_type = dso__type(dso, machine); + if (dso_type != DSO__TYPE_UNKNOWN) + break; + } + + return dso_type; +} + +static int vdso__do_copy_compat(FILE *f, int fd) +{ + char buf[4096]; + size_t count; + + while (1) { + count = fread(buf, 1, sizeof(buf), f); + if (ferror(f)) + return -errno; + if (feof(f)) + break; + if (count && writen(fd, buf, count) != (ssize_t)count) + return -errno; + } + + return 0; +} + +static int vdso__copy_compat(const char *prog, int fd) +{ + FILE *f; + int err; + + f = popen(prog, "r"); + if (!f) + return -errno; + + err = vdso__do_copy_compat(f, fd); + + if (pclose(f) == -1) + return -errno; + + return err; +} + +static int vdso__create_compat_file(const char *prog, char *temp_name) +{ + int fd, err; + + fd = mkstemp(temp_name); + if (fd < 0) + return -errno; + + err = vdso__copy_compat(prog, fd); + + if (close(fd) == -1) + return -errno; + + return err; +} + +static const char *vdso__get_compat_file(struct vdso_file *vdso_file) +{ + int err; + + if (vdso_file->found) + return vdso_file->temp_file_name; + + if (vdso_file->error) + return NULL; + + err = vdso__create_compat_file(vdso_file->read_prog, + vdso_file->temp_file_name); + if (err) { + pr_err("%s failed, error %d\n", vdso_file->read_prog, err); + vdso_file->error = true; + return NULL; + } + + vdso_file->found = true; + + return vdso_file->temp_file_name; +} + +static struct dso *vdso__findnew_compat(struct machine *machine, + struct vdso_file *vdso_file) +{ + const char *file_name; + struct dso *dso; + + dso = dsos__find(&machine->user_dsos, vdso_file->dso_name, true); + if (dso) + return dso; + + file_name = vdso__get_compat_file(vdso_file); + if (!file_name) + return NULL; + + return vdso__new(machine, vdso_file->dso_name, file_name); +} + +static int vdso__dso_findnew_compat(struct machine *machine, + struct thread *thread, + struct vdso_info *vdso_info, + struct dso **dso) +{ + enum dso_type dso_type; + + dso_type = machine__thread_dso_type(machine, thread); + switch (dso_type) { + case DSO__TYPE_32BIT: + *dso = vdso__findnew_compat(machine, &vdso_info->vdso32); + return 1; + case DSO__TYPE_X32BIT: + *dso = vdso__findnew_compat(machine, &vdso_info->vdsox32); + return 1; + case DSO__TYPE_UNKNOWN: + case DSO__TYPE_64BIT: + default: + return 0; + } +} + +#endif + struct dso *vdso__dso_findnew(struct machine *machine, struct thread *thread __maybe_unused) { @@ -123,6 +284,11 @@ struct dso *vdso__dso_findnew(struct machine *machine, if (!vdso_info) return NULL; +#if BITS_PER_LONG == 64 + if (vdso__dso_findnew_compat(machine, thread, vdso_info, &dso)) + return dso; +#endif + dso = dsos__find(&machine->user_dsos, DSO__NAME_VDSO, true); if (!dso) { char *file; @@ -139,5 +305,7 @@ struct dso *vdso__dso_findnew(struct machine *machine, bool dso__is_vdso(struct dso *dso) { - return !strcmp(dso->short_name, DSO__NAME_VDSO); + return !strcmp(dso->short_name, DSO__NAME_VDSO) || + !strcmp(dso->short_name, DSO__NAME_VDSO32) || + !strcmp(dso->short_name, DSO__NAME_VDSOX32); } diff --git a/tools/perf/util/vdso.h b/tools/perf/util/vdso.h index af9d6929a215..d97da1616f0c 100644 --- a/tools/perf/util/vdso.h +++ b/tools/perf/util/vdso.h @@ -7,7 +7,9 @@ #define VDSO__MAP_NAME "[vdso]" -#define DSO__NAME_VDSO "[vdso]" +#define DSO__NAME_VDSO "[vdso]" +#define DSO__NAME_VDSO32 "[vdso32]" +#define DSO__NAME_VDSOX32 "[vdsox32]" static inline bool is_vdso_map(const char *filename) { -- 1.9.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
