diff options
Diffstat (limited to 'kernel/tools/perf/util/vdso.c')
| -rw-r--r-- | kernel/tools/perf/util/vdso.c | 321 |
1 files changed, 321 insertions, 0 deletions
diff --git a/kernel/tools/perf/util/vdso.c b/kernel/tools/perf/util/vdso.c new file mode 100644 index 000000000..5c7dd7969 --- /dev/null +++ b/kernel/tools/perf/util/vdso.c @@ -0,0 +1,321 @@ + +#include <unistd.h> +#include <stdio.h> +#include <string.h> +#include <sys/types.h> +#include <sys/stat.h> +#include <fcntl.h> +#include <stdlib.h> +#include <linux/kernel.h> + +#include "vdso.h" +#include "util.h" +#include "symbol.h" +#include "machine.h" +#include "thread.h" +#include "linux/string.h" +#include "debug.h" + +/* + * Include definition of find_vdso_map() also used in perf-read-vdso.c for + * building perf-read-vdso32 and perf-read-vdsox32. + */ +#include "find-vdso-map.c" + +#define VDSO__TEMP_FILE_NAME "/tmp/perf-vdso.so-XXXXXX" + +struct vdso_file { + bool found; + 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) +{ + static const struct vdso_info vdso_info_init = { + .vdso = { + .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)); +} + +static char *get_file(struct vdso_file *vdso_file) +{ + char *vdso = NULL; + char *buf = NULL; + void *start, *end; + size_t size; + int fd; + + if (vdso_file->found) + return vdso_file->temp_file_name; + + if (vdso_file->error || find_vdso_map(&start, &end)) + return NULL; + + size = end - start; + + buf = memdup(start, size); + if (!buf) + return NULL; + + fd = mkstemp(vdso_file->temp_file_name); + if (fd < 0) + goto out; + + if (size == (size_t) write(fd, buf, size)) + vdso = vdso_file->temp_file_name; + + close(fd); + + out: + free(buf); + + vdso_file->found = (vdso != NULL); + vdso_file->error = !vdso_file->found; + return vdso; +} + +void vdso__exit(struct machine *machine) +{ + struct vdso_info *vdso_info = machine->vdso_info; + + if (!vdso_info) + return; + + 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); +} + +static struct dso *vdso__new(struct machine *machine, const char *short_name, + const char *long_name) +{ + struct dso *dso; + + dso = dso__new(short_name); + if (dso != NULL) { + dsos__add(&machine->user_dsos, dso); + dso__set_long_name(dso, long_name, false); + } + + 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); + +#ifndef HAVE_PERF_READ_VDSO32 + if (dso_type == DSO__TYPE_32BIT) + return 0; +#endif +#ifndef HAVE_PERF_READ_VDSOX32 + if (dso_type == DSO__TYPE_X32BIT) + return 0; +#endif + + 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) +{ + struct vdso_info *vdso_info; + struct dso *dso; + + if (!machine->vdso_info) + machine->vdso_info = vdso_info__new(); + + vdso_info = machine->vdso_info; + 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; + + file = get_file(&vdso_info->vdso); + if (!file) + return NULL; + + dso = vdso__new(machine, DSO__NAME_VDSO, file); + } + + return dso; +} + +bool dso__is_vdso(struct dso *dso) +{ + return !strcmp(dso->short_name, DSO__NAME_VDSO) || + !strcmp(dso->short_name, DSO__NAME_VDSO32) || + !strcmp(dso->short_name, DSO__NAME_VDSOX32); +} |