For ELF file dsos read the e_machine from the ELF header. For kernel types assume the e_machine matches the perf tool. In other cases return EM_NONE.
Signed-off-by: Ian Rogers <irog...@google.com> --- tools/perf/util/dso.c | 54 +++++++++++++++++++++++++++++++++++++++++++ tools/perf/util/dso.h | 1 + 2 files changed, 55 insertions(+) diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c index 5c6e85fdae0d..7f2f1af4f73b 100644 --- a/tools/perf/util/dso.c +++ b/tools/perf/util/dso.c @@ -1170,6 +1170,60 @@ ssize_t dso__data_read_offset(struct dso *dso, struct machine *machine, return data_read_write_offset(dso, machine, offset, data, size, true); } +uint16_t dso__e_machine(struct dso *dso, struct machine *machine) +{ + uint16_t e_machine = EM_NONE; + int fd; + + switch (dso__binary_type(dso)) { + case DSO_BINARY_TYPE__KALLSYMS: + case DSO_BINARY_TYPE__GUEST_KALLSYMS: + case DSO_BINARY_TYPE__VMLINUX: + case DSO_BINARY_TYPE__GUEST_VMLINUX: + case DSO_BINARY_TYPE__GUEST_KMODULE: + case DSO_BINARY_TYPE__GUEST_KMODULE_COMP: + case DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE: + case DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP: + case DSO_BINARY_TYPE__KCORE: + case DSO_BINARY_TYPE__GUEST_KCORE: + case DSO_BINARY_TYPE__BPF_PROG_INFO: + case DSO_BINARY_TYPE__BPF_IMAGE: + case DSO_BINARY_TYPE__OOL: + case DSO_BINARY_TYPE__JAVA_JIT: + return EM_HOST; + case DSO_BINARY_TYPE__DEBUGLINK: + case DSO_BINARY_TYPE__BUILD_ID_CACHE: + case DSO_BINARY_TYPE__BUILD_ID_CACHE_DEBUGINFO: + case DSO_BINARY_TYPE__SYSTEM_PATH_DSO: + case DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO: + case DSO_BINARY_TYPE__FEDORA_DEBUGINFO: + case DSO_BINARY_TYPE__UBUNTU_DEBUGINFO: + case DSO_BINARY_TYPE__MIXEDUP_UBUNTU_DEBUGINFO: + case DSO_BINARY_TYPE__BUILDID_DEBUGINFO: + break; + case DSO_BINARY_TYPE__NOT_FOUND: + default: + return EM_NONE; + } + + pthread_mutex_lock(&dso__data_open_lock); + + /* + * dso__data(dso)->fd might be closed if other thread opened another + * file (dso) due to open file limit (RLIMIT_NOFILE). + */ + try_to_open_dso(dso, machine); + fd = dso__data(dso)->fd; + if (fd >= 0) { + _Static_assert(offsetof(Elf32_Ehdr, e_machine) == 18, "Unexpected offset"); + _Static_assert(offsetof(Elf64_Ehdr, e_machine) == 18, "Unexpected offset"); + if (pread(fd, &e_machine, sizeof(e_machine), 18) != sizeof(e_machine)) + e_machine = EM_NONE; + } + pthread_mutex_unlock(&dso__data_open_lock); + return e_machine; +} + /** * dso__data_read_addr - Read data from dso address * @dso: dso object diff --git a/tools/perf/util/dso.h b/tools/perf/util/dso.h index f3ca2a5e7670..ba9b83db061a 100644 --- a/tools/perf/util/dso.h +++ b/tools/perf/util/dso.h @@ -818,6 +818,7 @@ int dso__data_file_size(struct dso *dso, struct machine *machine); off_t dso__data_size(struct dso *dso, struct machine *machine); ssize_t dso__data_read_offset(struct dso *dso, struct machine *machine, u64 offset, u8 *data, ssize_t size); +uint16_t dso__e_machine(struct dso *dso, struct machine *machine); ssize_t dso__data_read_addr(struct dso *dso, struct map *map, struct machine *machine, u64 addr, u8 *data, ssize_t size); -- 2.48.1.711.g2feabab25a-goog