On 10/05/16 12:49, Hekuang wrote: > hi > > 在 2016/5/10 16:08, Adrian Hunter 写道: >> On 10/05/16 10:40, He Kuang wrote: >>> 32-bit programs can be run on 64-bit machines, so we should choose >>> unwind methods according to 'thread->map' instead of the host >>> architecture. >>> >>> This patch adds methods to test whether a dso is 64-bit or 32-bit by >>> the class info in elf. >> What about using dso->is_64_bit set by dso__load_sym() ? > > I've noticed this variable, but it's value is not as its name said: > > util/dso.c: 1067 dso->is_64_bit = (sizeof(void *) == 8);
That is just initialization i.e. before we know what it is we assume it is the same as the host. > > This is only related to the host architecture. > > A closer one is 'is_64_bit' in 'struct symsrc', but the value is assigned > after dso > loaded. So I think we should provide individual methods to get that value. Are you saying you don't load dsos? Or that is_64_bit is set incorrectly? > > Thanks. > >> >>> Signed-off-by: He Kuang <[email protected]> >>> --- >>> tools/perf/util/symbol-elf.c | 16 +++++++++++++++ >>> tools/perf/util/symbol.c | 49 >>> ++++++++++++++++++++++++++++++++++++++++++++ >>> tools/perf/util/symbol.h | 2 ++ >>> 3 files changed, 67 insertions(+) >>> >>> diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c >>> index 3f9d679..9f290b9 100644 >>> --- a/tools/perf/util/symbol-elf.c >>> +++ b/tools/perf/util/symbol-elf.c >>> @@ -636,6 +636,22 @@ bool __weak elf__needs_adjust_symbols(GElf_Ehdr ehdr) >>> return ehdr.e_type == ET_EXEC || ehdr.e_type == ET_REL; >>> } >>> +int elf_is_64_bit(char *name) >>> +{ >>> + Elf *elf; >>> + int fd; >>> + >>> + fd = open(name, O_RDONLY); >>> + if (fd < 0) >>> + return -1; >>> + >>> + elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL); >>> + if (elf == NULL) >>> + return -1; >>> + >>> + return (gelf_getclass(elf) == ELFCLASS64); >>> +} >>> + >>> int symsrc__init(struct symsrc *ss, struct dso *dso, const char *name, >>> enum dso_binary_type type) >>> { >>> diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c >>> index 4630751..592bf8c 100644 >>> --- a/tools/perf/util/symbol.c >>> +++ b/tools/perf/util/symbol.c >>> @@ -1395,6 +1395,55 @@ static bool dso__is_compatible_symtab_type(struct >>> dso *dso, bool kmod, >>> } >>> } >>> +int dso_is_64_bit(struct dso *dso, struct map *map) >>> +{ >>> + char *name; >>> + u_int i; >>> + bool kmod; >>> + char *root_dir = (char *) ""; >>> + struct machine *machine; >>> + >>> + if (map->groups && map->groups->machine) >>> + machine = map->groups->machine; >>> + else >>> + machine = NULL; >>> + >>> + if (machine) >>> + root_dir = machine->root_dir; >>> + >>> + name = malloc(PATH_MAX); >>> + if (!name) >>> + return -1; >>> + >>> + kmod = dso->symtab_type == DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE || >>> + dso->symtab_type == DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP || >>> + dso->symtab_type == DSO_BINARY_TYPE__GUEST_KMODULE || >>> + dso->symtab_type == DSO_BINARY_TYPE__GUEST_KMODULE_COMP; >>> + >>> + /* >>> + * Iterate over candidate debug images. >>> + * Keep track of "interesting" ones (those which have a symtab, dynsym, >>> + * and/or opd section) for processing. >>> + */ >>> + for (i = 0; i < DSO_BINARY_TYPE__SYMTAB_CNT; i++) { >>> + enum dso_binary_type symtab_type = binary_type_symtab[i]; >>> + >>> + if (!dso__is_compatible_symtab_type(dso, kmod, symtab_type)) >>> + continue; >>> + >>> + if (dso__read_binary_type_filename(dso, symtab_type, >>> + root_dir, name, PATH_MAX)) >>> + continue; >>> + >>> + if (!is_regular_file(name)) >>> + continue; >>> + >>> + return elf_is_64_bit(name); >>> + } >>> + >>> + return -1; >>> +} >>> + >>> int dso__load(struct dso *dso, struct map *map, symbol_filter_t filter) >>> { >>> char *name; >>> diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h >>> index 4e6910e..d33fbf4 100644 >>> --- a/tools/perf/util/symbol.h >>> +++ b/tools/perf/util/symbol.h >>> @@ -308,6 +308,8 @@ int setup_list(struct strlist **list, const char >>> *list_str, >>> const char *list_name); >>> int setup_intlist(struct intlist **list, const char *list_str, >>> const char *list_name); >>> +int elf_is_64_bit(char *name); >>> +int dso_is_64_bit(struct dso *dso, struct map *map); >>> #ifdef HAVE_LIBELF_SUPPORT >>> bool elf__needs_adjust_symbols(GElf_Ehdr ehdr); >>> >> > > >
