| Message ID | 20190611043505.14664-4-andriin@fb.com |
|---|---|
| State | RFC |
| Delegated to: | BPF Maintainers |
| Headers | show |
| Series | BTF-defined BPF map definitions | expand |
On Mon, Jun 10, 2019 at 9:35 PM Andrii Nakryiko <andriin@fb.com> wrote: > > User and global data maps initialization has gotten pretty complicated > and unnecessarily convoluted. This patch splits out the logic for global > data map and user-defined map initialization. It also removes the > restriction of pre-calculating how many maps will be initialized, > instead allowing to keep adding new maps as they are discovered, which > will be used later for BTF-defined map definitions. > > Signed-off-by: Andrii Nakryiko <andriin@fb.com> > --- > tools/lib/bpf/libbpf.c | 244 ++++++++++++++++++++++------------------- > 1 file changed, 134 insertions(+), 110 deletions(-) > > diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c > index 9e39a0a33aeb..c931ee7e1fd2 100644 > --- a/tools/lib/bpf/libbpf.c > +++ b/tools/lib/bpf/libbpf.c > @@ -234,6 +234,7 @@ struct bpf_object { > size_t nr_programs; > struct bpf_map *maps; > size_t nr_maps; > + size_t maps_cap; > struct bpf_secdata sections; > > bool loaded; > @@ -763,12 +764,38 @@ int bpf_object__variable_offset(const struct bpf_object *obj, const char *name, > return -ENOENT; > } > > -static bool bpf_object__has_maps(const struct bpf_object *obj) > +static struct bpf_map *bpf_object__add_map(struct bpf_object *obj) > { > - return obj->efile.maps_shndx >= 0 || > - obj->efile.data_shndx >= 0 || > - obj->efile.rodata_shndx >= 0 || > - obj->efile.bss_shndx >= 0; > + struct bpf_map *new_maps; > + size_t new_cap; > + int i; > + > + if (obj->nr_maps + 1 <= obj->maps_cap) nit: how about if (obj->nr_maps < obj->maps_cap) > + return &obj->maps[obj->nr_maps++]; > + > + new_cap = max(4ul, obj->maps_cap * 3 / 2); > + new_maps = realloc(obj->maps, new_cap * sizeof(*obj->maps)); > + if (!new_maps) { > + pr_warning("alloc maps for object failed\n"); > + return ERR_PTR(-ENOMEM); > + } > + > + obj->maps_cap = new_cap; > + obj->maps = new_maps; > + > + /* zero out new maps */ > + memset(obj->maps + obj->nr_maps, 0, > + (obj->maps_cap - obj->nr_maps) * sizeof(*obj->maps)); > + /* > + * fill all fd with -1 so won't close incorrect fd (fd=0 is stdin) > + * when failure (zclose won't close negative fd)). > + */ > + for (i = obj->nr_maps; i < obj->maps_cap; i++) { > + obj->maps[i].fd = -1; > + obj->maps[i].inner_map_fd = -1; > + } > + > + return &obj->maps[obj->nr_maps++]; > } > > static int > @@ -808,29 +835,68 @@ bpf_object__init_internal_map(struct bpf_object *obj, struct bpf_map *map, > return 0; > } > > -static int bpf_object__init_maps(struct bpf_object *obj, int flags) > +static int bpf_object__init_global_data_maps(struct bpf_object *obj) > +{ > + struct bpf_map *map; > + int err; > + > + if (!obj->caps.global_data) > + return 0; > + /* > + * Populate obj->maps with libbpf internal maps. > + */ > + if (obj->efile.data_shndx >= 0) { > + map = bpf_object__add_map(obj); > + if (IS_ERR(map)) > + return PTR_ERR(map); > + err = bpf_object__init_internal_map(obj, map, LIBBPF_MAP_DATA, > + obj->efile.data, > + &obj->sections.data); > + if (err) > + return err; > + } > + if (obj->efile.rodata_shndx >= 0) { > + map = bpf_object__add_map(obj); > + if (IS_ERR(map)) > + return PTR_ERR(map); > + err = bpf_object__init_internal_map(obj, map, LIBBPF_MAP_RODATA, > + obj->efile.rodata, > + &obj->sections.rodata); > + if (err) > + return err; > + } > + if (obj->efile.bss_shndx >= 0) { > + map = bpf_object__add_map(obj); > + if (IS_ERR(map)) > + return PTR_ERR(map); > + err = bpf_object__init_internal_map(obj, map, LIBBPF_MAP_BSS, > + obj->efile.bss, NULL); > + if (err) > + return err; > + } These 3 if clause are a little too complicated. How about we call bpf_obj_add_map(obj) within bpf_object__init_internal_map()? > + return 0; > +} > + > +static int bpf_object__init_user_maps(struct bpf_object *obj, bool strict) > { > - int i, map_idx, map_def_sz = 0, nr_syms, nr_maps = 0, nr_maps_glob = 0; > - bool strict = !(flags & MAPS_RELAX_COMPAT); > Elf_Data *symbols = obj->efile.symbols; > + int i, map_def_sz = 0, nr_maps = 0, nr_syms; > Elf_Data *data = NULL; > - int ret = 0; > + Elf_Scn *scn; > + > + if (obj->efile.maps_shndx < 0) > + return 0; > > if (!symbols) > return -EINVAL; > - nr_syms = symbols->d_size / sizeof(GElf_Sym); > - > - if (obj->efile.maps_shndx >= 0) { > - Elf_Scn *scn = elf_getscn(obj->efile.elf, > - obj->efile.maps_shndx); > > - if (scn) > - data = elf_getdata(scn, NULL); > - if (!scn || !data) { > - pr_warning("failed to get Elf_Data from map section %d\n", > - obj->efile.maps_shndx); > - return -EINVAL; > - } > + scn = elf_getscn(obj->efile.elf, obj->efile.maps_shndx); > + if (scn) > + data = elf_getdata(scn, NULL); > + if (!scn || !data) { > + pr_warning("failed to get Elf_Data from map section %d\n", > + obj->efile.maps_shndx); > + return -EINVAL; > } > > /* > @@ -840,16 +906,8 @@ static int bpf_object__init_maps(struct bpf_object *obj, int flags) > * > * TODO: Detect array of map and report error. > */ > - if (obj->caps.global_data) { > - if (obj->efile.data_shndx >= 0) > - nr_maps_glob++; > - if (obj->efile.rodata_shndx >= 0) > - nr_maps_glob++; > - if (obj->efile.bss_shndx >= 0) > - nr_maps_glob++; > - } > - > - for (i = 0; data && i < nr_syms; i++) { > + nr_syms = symbols->d_size / sizeof(GElf_Sym); > + for (i = 0; i < nr_syms; i++) { > GElf_Sym sym; > > if (!gelf_getsym(symbols, i, &sym)) > @@ -858,79 +916,56 @@ static int bpf_object__init_maps(struct bpf_object *obj, int flags) > continue; > nr_maps++; > } > - > - if (!nr_maps && !nr_maps_glob) > - return 0; > - > /* Assume equally sized map definitions */ > - if (data) { > - pr_debug("maps in %s: %d maps in %zd bytes\n", obj->path, > - nr_maps, data->d_size); > - > - map_def_sz = data->d_size / nr_maps; > - if (!data->d_size || (data->d_size % nr_maps) != 0) { > - pr_warning("unable to determine map definition size " > - "section %s, %d maps in %zd bytes\n", > - obj->path, nr_maps, data->d_size); > - return -EINVAL; > - } > - } > - > - nr_maps += nr_maps_glob; > - obj->maps = calloc(nr_maps, sizeof(obj->maps[0])); > - if (!obj->maps) { > - pr_warning("alloc maps for object failed\n"); > - return -ENOMEM; > - } > - obj->nr_maps = nr_maps; > - > - for (i = 0; i < nr_maps; i++) { > - /* > - * fill all fd with -1 so won't close incorrect > - * fd (fd=0 is stdin) when failure (zclose won't close > - * negative fd)). > - */ > - obj->maps[i].fd = -1; > - obj->maps[i].inner_map_fd = -1; > + pr_debug("maps in %s: %d maps in %zd bytes\n", > + obj->path, nr_maps, data->d_size); > + > + map_def_sz = data->d_size / nr_maps; > + if (!data->d_size || (data->d_size % nr_maps) != 0) { > + pr_warning("unable to determine map definition size " > + "section %s, %d maps in %zd bytes\n", > + obj->path, nr_maps, data->d_size); > + return -EINVAL; > } > > - /* > - * Fill obj->maps using data in "maps" section. > - */ > - for (i = 0, map_idx = 0; data && i < nr_syms; i++) { > + /* Fill obj->maps using data in "maps" section. */ > + for (i = 0; i < nr_syms; i++) { > GElf_Sym sym; > const char *map_name; > struct bpf_map_def *def; > + struct bpf_map *map; > > if (!gelf_getsym(symbols, i, &sym)) > continue; > if (sym.st_shndx != obj->efile.maps_shndx) > continue; > > - map_name = elf_strptr(obj->efile.elf, > - obj->efile.strtabidx, > + map = bpf_object__add_map(obj); > + if (IS_ERR(map)) > + return PTR_ERR(map); > + > + map_name = elf_strptr(obj->efile.elf, obj->efile.strtabidx, > sym.st_name); > if (!map_name) { > pr_warning("failed to get map #%d name sym string for obj %s\n", > - map_idx, obj->path); > + i, obj->path); > return -LIBBPF_ERRNO__FORMAT; > } > > - obj->maps[map_idx].libbpf_type = LIBBPF_MAP_UNSPEC; > - obj->maps[map_idx].offset = sym.st_value; > + map->libbpf_type = LIBBPF_MAP_UNSPEC; > + map->offset = sym.st_value; > if (sym.st_value + map_def_sz > data->d_size) { > pr_warning("corrupted maps section in %s: last map \"%s\" too small\n", > obj->path, map_name); > return -EINVAL; > } > > - obj->maps[map_idx].name = strdup(map_name); > - if (!obj->maps[map_idx].name) { > + map->name = strdup(map_name); > + if (!map->name) { > pr_warning("failed to alloc map name\n"); > return -ENOMEM; > } > - pr_debug("map %d is \"%s\"\n", map_idx, > - obj->maps[map_idx].name); > + pr_debug("map %d is \"%s\"\n", i, map->name); > def = (struct bpf_map_def *)(data->d_buf + sym.st_value); > /* > * If the definition of the map in the object file fits in > @@ -939,7 +974,7 @@ static int bpf_object__init_maps(struct bpf_object *obj, int flags) > * calloc above. > */ > if (map_def_sz <= sizeof(struct bpf_map_def)) { > - memcpy(&obj->maps[map_idx].def, def, map_def_sz); > + memcpy(&map->def, def, map_def_sz); > } else { > /* > * Here the map structure being read is bigger than what > @@ -959,37 +994,30 @@ static int bpf_object__init_maps(struct bpf_object *obj, int flags) > return -EINVAL; > } > } > - memcpy(&obj->maps[map_idx].def, def, > - sizeof(struct bpf_map_def)); > + memcpy(&map->def, def, sizeof(struct bpf_map_def)); > } > - map_idx++; > } > + return 0; > +} > > - if (!obj->caps.global_data) > - goto finalize; > +static int bpf_object__init_maps(struct bpf_object *obj, int flags) > +{ > + bool strict = !(flags & MAPS_RELAX_COMPAT); > + int err; > > - /* > - * Populate rest of obj->maps with libbpf internal maps. > - */ > - if (obj->efile.data_shndx >= 0) > - ret = bpf_object__init_internal_map(obj, &obj->maps[map_idx++], > - LIBBPF_MAP_DATA, > - obj->efile.data, > - &obj->sections.data); > - if (!ret && obj->efile.rodata_shndx >= 0) > - ret = bpf_object__init_internal_map(obj, &obj->maps[map_idx++], > - LIBBPF_MAP_RODATA, > - obj->efile.rodata, > - &obj->sections.rodata); > - if (!ret && obj->efile.bss_shndx >= 0) > - ret = bpf_object__init_internal_map(obj, &obj->maps[map_idx++], > - LIBBPF_MAP_BSS, > - obj->efile.bss, NULL); > -finalize: > - if (!ret) > + err = bpf_object__init_user_maps(obj, strict); > + if (err) > + return err; > + > + err = bpf_object__init_global_data_maps(obj); > + if (err) > + return err; > + > + if (obj->nr_maps) { > qsort(obj->maps, obj->nr_maps, sizeof(obj->maps[0]), > compare_bpf_map); > - return ret; > + } > + return 0; > } > > static bool section_have_execinstr(struct bpf_object *obj, int idx) > @@ -1262,14 +1290,10 @@ static int bpf_object__elf_collect(struct bpf_object *obj, int flags) > return -LIBBPF_ERRNO__FORMAT; > } > err = bpf_object__load_btf(obj, btf_data, btf_ext_data); > - if (err) > - return err; > - if (bpf_object__has_maps(obj)) { > + if (!err) > err = bpf_object__init_maps(obj, flags); > - if (err) > - return err; > - } > - err = bpf_object__init_prog_names(obj); > + if (!err) > + err = bpf_object__init_prog_names(obj); > return err; > } > > -- > 2.17.1 >
On Sat, Jun 15, 2019 at 2:02 PM Song Liu <liu.song.a23@gmail.com> wrote: > > On Mon, Jun 10, 2019 at 9:35 PM Andrii Nakryiko <andriin@fb.com> wrote: > > > > User and global data maps initialization has gotten pretty complicated > > and unnecessarily convoluted. This patch splits out the logic for global > > data map and user-defined map initialization. It also removes the > > restriction of pre-calculating how many maps will be initialized, > > instead allowing to keep adding new maps as they are discovered, which > > will be used later for BTF-defined map definitions. > > > > Signed-off-by: Andrii Nakryiko <andriin@fb.com> Ooops, wrong thread...
On Sat, Jun 15, 2019 at 2:03 PM Song Liu <liu.song.a23@gmail.com> wrote: > > On Mon, Jun 10, 2019 at 9:35 PM Andrii Nakryiko <andriin@fb.com> wrote: > > > > User and global data maps initialization has gotten pretty complicated > > and unnecessarily convoluted. This patch splits out the logic for global > > data map and user-defined map initialization. It also removes the > > restriction of pre-calculating how many maps will be initialized, > > instead allowing to keep adding new maps as they are discovered, which > > will be used later for BTF-defined map definitions. > > > > Signed-off-by: Andrii Nakryiko <andriin@fb.com> > > --- > > tools/lib/bpf/libbpf.c | 244 ++++++++++++++++++++++------------------- > > 1 file changed, 134 insertions(+), 110 deletions(-) > > > > diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c > > index 9e39a0a33aeb..c931ee7e1fd2 100644 > > --- a/tools/lib/bpf/libbpf.c > > +++ b/tools/lib/bpf/libbpf.c > > @@ -234,6 +234,7 @@ struct bpf_object { > > size_t nr_programs; > > struct bpf_map *maps; > > size_t nr_maps; > > + size_t maps_cap; > > struct bpf_secdata sections; > > > > bool loaded; > > @@ -763,12 +764,38 @@ int bpf_object__variable_offset(const struct bpf_object *obj, const char *name, > > return -ENOENT; > > } > > > > -static bool bpf_object__has_maps(const struct bpf_object *obj) > > +static struct bpf_map *bpf_object__add_map(struct bpf_object *obj) > > { > > - return obj->efile.maps_shndx >= 0 || > > - obj->efile.data_shndx >= 0 || > > - obj->efile.rodata_shndx >= 0 || > > - obj->efile.bss_shndx >= 0; > > + struct bpf_map *new_maps; > > + size_t new_cap; > > + int i; > > + > > + if (obj->nr_maps + 1 <= obj->maps_cap) > nit: how about if (obj->nr_maps < obj->maps_cap) yep, will do > > > + return &obj->maps[obj->nr_maps++]; > > + > > + new_cap = max(4ul, obj->maps_cap * 3 / 2); > > + new_maps = realloc(obj->maps, new_cap * sizeof(*obj->maps)); > > + if (!new_maps) { > > + pr_warning("alloc maps for object failed\n"); > > + return ERR_PTR(-ENOMEM); > > + } > > + > > + obj->maps_cap = new_cap; > > + obj->maps = new_maps; > > + > > + /* zero out new maps */ > > + memset(obj->maps + obj->nr_maps, 0, > > + (obj->maps_cap - obj->nr_maps) * sizeof(*obj->maps)); > > + /* > > + * fill all fd with -1 so won't close incorrect fd (fd=0 is stdin) > > + * when failure (zclose won't close negative fd)). > > + */ > > + for (i = obj->nr_maps; i < obj->maps_cap; i++) { > > + obj->maps[i].fd = -1; > > + obj->maps[i].inner_map_fd = -1; > > + } > > + > > + return &obj->maps[obj->nr_maps++]; > > } > > > > static int > > @@ -808,29 +835,68 @@ bpf_object__init_internal_map(struct bpf_object *obj, struct bpf_map *map, > > return 0; > > } > > > > -static int bpf_object__init_maps(struct bpf_object *obj, int flags) > > +static int bpf_object__init_global_data_maps(struct bpf_object *obj) > > +{ > > + struct bpf_map *map; > > + int err; > > + > > + if (!obj->caps.global_data) > > + return 0; > > + /* > > + * Populate obj->maps with libbpf internal maps. > > + */ > > + if (obj->efile.data_shndx >= 0) { > > + map = bpf_object__add_map(obj); > > + if (IS_ERR(map)) > > + return PTR_ERR(map); > > + err = bpf_object__init_internal_map(obj, map, LIBBPF_MAP_DATA, > > + obj->efile.data, > > + &obj->sections.data); > > + if (err) > > + return err; > > + } > > + if (obj->efile.rodata_shndx >= 0) { > > + map = bpf_object__add_map(obj); > > + if (IS_ERR(map)) > > + return PTR_ERR(map); > > + err = bpf_object__init_internal_map(obj, map, LIBBPF_MAP_RODATA, > > + obj->efile.rodata, > > + &obj->sections.rodata); > > + if (err) > > + return err; > > + } > > + if (obj->efile.bss_shndx >= 0) { > > + map = bpf_object__add_map(obj); > > + if (IS_ERR(map)) > > + return PTR_ERR(map); > > + err = bpf_object__init_internal_map(obj, map, LIBBPF_MAP_BSS, > > + obj->efile.bss, NULL); > > + if (err) > > + return err; > > + } > > These 3 if clause are a little too complicated. How about we call > bpf_obj_add_map(obj) within bpf_object__init_internal_map()? Yeah, totally, not sure why I did it this way :) > > > + return 0; > > +} > > + > > +static int bpf_object__init_user_maps(struct bpf_object *obj, bool strict) > > { <snip>
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 9e39a0a33aeb..c931ee7e1fd2 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -234,6 +234,7 @@ struct bpf_object { size_t nr_programs; struct bpf_map *maps; size_t nr_maps; + size_t maps_cap; struct bpf_secdata sections; bool loaded; @@ -763,12 +764,38 @@ int bpf_object__variable_offset(const struct bpf_object *obj, const char *name, return -ENOENT; } -static bool bpf_object__has_maps(const struct bpf_object *obj) +static struct bpf_map *bpf_object__add_map(struct bpf_object *obj) { - return obj->efile.maps_shndx >= 0 || - obj->efile.data_shndx >= 0 || - obj->efile.rodata_shndx >= 0 || - obj->efile.bss_shndx >= 0; + struct bpf_map *new_maps; + size_t new_cap; + int i; + + if (obj->nr_maps + 1 <= obj->maps_cap) + return &obj->maps[obj->nr_maps++]; + + new_cap = max(4ul, obj->maps_cap * 3 / 2); + new_maps = realloc(obj->maps, new_cap * sizeof(*obj->maps)); + if (!new_maps) { + pr_warning("alloc maps for object failed\n"); + return ERR_PTR(-ENOMEM); + } + + obj->maps_cap = new_cap; + obj->maps = new_maps; + + /* zero out new maps */ + memset(obj->maps + obj->nr_maps, 0, + (obj->maps_cap - obj->nr_maps) * sizeof(*obj->maps)); + /* + * fill all fd with -1 so won't close incorrect fd (fd=0 is stdin) + * when failure (zclose won't close negative fd)). + */ + for (i = obj->nr_maps; i < obj->maps_cap; i++) { + obj->maps[i].fd = -1; + obj->maps[i].inner_map_fd = -1; + } + + return &obj->maps[obj->nr_maps++]; } static int @@ -808,29 +835,68 @@ bpf_object__init_internal_map(struct bpf_object *obj, struct bpf_map *map, return 0; } -static int bpf_object__init_maps(struct bpf_object *obj, int flags) +static int bpf_object__init_global_data_maps(struct bpf_object *obj) +{ + struct bpf_map *map; + int err; + + if (!obj->caps.global_data) + return 0; + /* + * Populate obj->maps with libbpf internal maps. + */ + if (obj->efile.data_shndx >= 0) { + map = bpf_object__add_map(obj); + if (IS_ERR(map)) + return PTR_ERR(map); + err = bpf_object__init_internal_map(obj, map, LIBBPF_MAP_DATA, + obj->efile.data, + &obj->sections.data); + if (err) + return err; + } + if (obj->efile.rodata_shndx >= 0) { + map = bpf_object__add_map(obj); + if (IS_ERR(map)) + return PTR_ERR(map); + err = bpf_object__init_internal_map(obj, map, LIBBPF_MAP_RODATA, + obj->efile.rodata, + &obj->sections.rodata); + if (err) + return err; + } + if (obj->efile.bss_shndx >= 0) { + map = bpf_object__add_map(obj); + if (IS_ERR(map)) + return PTR_ERR(map); + err = bpf_object__init_internal_map(obj, map, LIBBPF_MAP_BSS, + obj->efile.bss, NULL); + if (err) + return err; + } + return 0; +} + +static int bpf_object__init_user_maps(struct bpf_object *obj, bool strict) { - int i, map_idx, map_def_sz = 0, nr_syms, nr_maps = 0, nr_maps_glob = 0; - bool strict = !(flags & MAPS_RELAX_COMPAT); Elf_Data *symbols = obj->efile.symbols; + int i, map_def_sz = 0, nr_maps = 0, nr_syms; Elf_Data *data = NULL; - int ret = 0; + Elf_Scn *scn; + + if (obj->efile.maps_shndx < 0) + return 0; if (!symbols) return -EINVAL; - nr_syms = symbols->d_size / sizeof(GElf_Sym); - - if (obj->efile.maps_shndx >= 0) { - Elf_Scn *scn = elf_getscn(obj->efile.elf, - obj->efile.maps_shndx); - if (scn) - data = elf_getdata(scn, NULL); - if (!scn || !data) { - pr_warning("failed to get Elf_Data from map section %d\n", - obj->efile.maps_shndx); - return -EINVAL; - } + scn = elf_getscn(obj->efile.elf, obj->efile.maps_shndx); + if (scn) + data = elf_getdata(scn, NULL); + if (!scn || !data) { + pr_warning("failed to get Elf_Data from map section %d\n", + obj->efile.maps_shndx); + return -EINVAL; } /* @@ -840,16 +906,8 @@ static int bpf_object__init_maps(struct bpf_object *obj, int flags) * * TODO: Detect array of map and report error. */ - if (obj->caps.global_data) { - if (obj->efile.data_shndx >= 0) - nr_maps_glob++; - if (obj->efile.rodata_shndx >= 0) - nr_maps_glob++; - if (obj->efile.bss_shndx >= 0) - nr_maps_glob++; - } - - for (i = 0; data && i < nr_syms; i++) { + nr_syms = symbols->d_size / sizeof(GElf_Sym); + for (i = 0; i < nr_syms; i++) { GElf_Sym sym; if (!gelf_getsym(symbols, i, &sym)) @@ -858,79 +916,56 @@ static int bpf_object__init_maps(struct bpf_object *obj, int flags) continue; nr_maps++; } - - if (!nr_maps && !nr_maps_glob) - return 0; - /* Assume equally sized map definitions */ - if (data) { - pr_debug("maps in %s: %d maps in %zd bytes\n", obj->path, - nr_maps, data->d_size); - - map_def_sz = data->d_size / nr_maps; - if (!data->d_size || (data->d_size % nr_maps) != 0) { - pr_warning("unable to determine map definition size " - "section %s, %d maps in %zd bytes\n", - obj->path, nr_maps, data->d_size); - return -EINVAL; - } - } - - nr_maps += nr_maps_glob; - obj->maps = calloc(nr_maps, sizeof(obj->maps[0])); - if (!obj->maps) { - pr_warning("alloc maps for object failed\n"); - return -ENOMEM; - } - obj->nr_maps = nr_maps; - - for (i = 0; i < nr_maps; i++) { - /* - * fill all fd with -1 so won't close incorrect - * fd (fd=0 is stdin) when failure (zclose won't close - * negative fd)). - */ - obj->maps[i].fd = -1; - obj->maps[i].inner_map_fd = -1; + pr_debug("maps in %s: %d maps in %zd bytes\n", + obj->path, nr_maps, data->d_size); + + map_def_sz = data->d_size / nr_maps; + if (!data->d_size || (data->d_size % nr_maps) != 0) { + pr_warning("unable to determine map definition size " + "section %s, %d maps in %zd bytes\n", + obj->path, nr_maps, data->d_size); + return -EINVAL; } - /* - * Fill obj->maps using data in "maps" section. - */ - for (i = 0, map_idx = 0; data && i < nr_syms; i++) { + /* Fill obj->maps using data in "maps" section. */ + for (i = 0; i < nr_syms; i++) { GElf_Sym sym; const char *map_name; struct bpf_map_def *def; + struct bpf_map *map; if (!gelf_getsym(symbols, i, &sym)) continue; if (sym.st_shndx != obj->efile.maps_shndx) continue; - map_name = elf_strptr(obj->efile.elf, - obj->efile.strtabidx, + map = bpf_object__add_map(obj); + if (IS_ERR(map)) + return PTR_ERR(map); + + map_name = elf_strptr(obj->efile.elf, obj->efile.strtabidx, sym.st_name); if (!map_name) { pr_warning("failed to get map #%d name sym string for obj %s\n", - map_idx, obj->path); + i, obj->path); return -LIBBPF_ERRNO__FORMAT; } - obj->maps[map_idx].libbpf_type = LIBBPF_MAP_UNSPEC; - obj->maps[map_idx].offset = sym.st_value; + map->libbpf_type = LIBBPF_MAP_UNSPEC; + map->offset = sym.st_value; if (sym.st_value + map_def_sz > data->d_size) { pr_warning("corrupted maps section in %s: last map \"%s\" too small\n", obj->path, map_name); return -EINVAL; } - obj->maps[map_idx].name = strdup(map_name); - if (!obj->maps[map_idx].name) { + map->name = strdup(map_name); + if (!map->name) { pr_warning("failed to alloc map name\n"); return -ENOMEM; } - pr_debug("map %d is \"%s\"\n", map_idx, - obj->maps[map_idx].name); + pr_debug("map %d is \"%s\"\n", i, map->name); def = (struct bpf_map_def *)(data->d_buf + sym.st_value); /* * If the definition of the map in the object file fits in @@ -939,7 +974,7 @@ static int bpf_object__init_maps(struct bpf_object *obj, int flags) * calloc above. */ if (map_def_sz <= sizeof(struct bpf_map_def)) { - memcpy(&obj->maps[map_idx].def, def, map_def_sz); + memcpy(&map->def, def, map_def_sz); } else { /* * Here the map structure being read is bigger than what @@ -959,37 +994,30 @@ static int bpf_object__init_maps(struct bpf_object *obj, int flags) return -EINVAL; } } - memcpy(&obj->maps[map_idx].def, def, - sizeof(struct bpf_map_def)); + memcpy(&map->def, def, sizeof(struct bpf_map_def)); } - map_idx++; } + return 0; +} - if (!obj->caps.global_data) - goto finalize; +static int bpf_object__init_maps(struct bpf_object *obj, int flags) +{ + bool strict = !(flags & MAPS_RELAX_COMPAT); + int err; - /* - * Populate rest of obj->maps with libbpf internal maps. - */ - if (obj->efile.data_shndx >= 0) - ret = bpf_object__init_internal_map(obj, &obj->maps[map_idx++], - LIBBPF_MAP_DATA, - obj->efile.data, - &obj->sections.data); - if (!ret && obj->efile.rodata_shndx >= 0) - ret = bpf_object__init_internal_map(obj, &obj->maps[map_idx++], - LIBBPF_MAP_RODATA, - obj->efile.rodata, - &obj->sections.rodata); - if (!ret && obj->efile.bss_shndx >= 0) - ret = bpf_object__init_internal_map(obj, &obj->maps[map_idx++], - LIBBPF_MAP_BSS, - obj->efile.bss, NULL); -finalize: - if (!ret) + err = bpf_object__init_user_maps(obj, strict); + if (err) + return err; + + err = bpf_object__init_global_data_maps(obj); + if (err) + return err; + + if (obj->nr_maps) { qsort(obj->maps, obj->nr_maps, sizeof(obj->maps[0]), compare_bpf_map); - return ret; + } + return 0; } static bool section_have_execinstr(struct bpf_object *obj, int idx) @@ -1262,14 +1290,10 @@ static int bpf_object__elf_collect(struct bpf_object *obj, int flags) return -LIBBPF_ERRNO__FORMAT; } err = bpf_object__load_btf(obj, btf_data, btf_ext_data); - if (err) - return err; - if (bpf_object__has_maps(obj)) { + if (!err) err = bpf_object__init_maps(obj, flags); - if (err) - return err; - } - err = bpf_object__init_prog_names(obj); + if (!err) + err = bpf_object__init_prog_names(obj); return err; }
User and global data maps initialization has gotten pretty complicated and unnecessarily convoluted. This patch splits out the logic for global data map and user-defined map initialization. It also removes the restriction of pre-calculating how many maps will be initialized, instead allowing to keep adding new maps as they are discovered, which will be used later for BTF-defined map definitions. Signed-off-by: Andrii Nakryiko <andriin@fb.com> --- tools/lib/bpf/libbpf.c | 244 ++++++++++++++++++++++------------------- 1 file changed, 134 insertions(+), 110 deletions(-)