diff options
| author | Delyan Kratunov <delyank@fb.com> | 2022-03-22 00:29:18 +0100 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2022-03-30 14:06:59 +0200 |
| commit | 522574fd7864e091d473765102e866414979b2ab (patch) | |
| tree | 97879dee0c4610beb021ee2b915a844f6b23fbf9 | |
| parent | Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf (diff) | |
| download | linux-522574fd7864e091d473765102e866414979b2ab.tar.xz linux-522574fd7864e091d473765102e866414979b2ab.zip | |
bpftool: Explicit errno handling in skeletons
Andrii noticed that since f97b8b9bd630 ("bpftool: Fix a bug in subskeleton
code generation") the subskeleton code allows bpf_object__destroy_subskeleton
to overwrite the errno that subskeleton__open would return with. While this
is not currently an issue, let's make it future-proof.
This patch explicitly tracks err in subskeleton__open and skeleton__create
(i.e. calloc failure is explicitly ENOMEM) and ensures that errno is -err on
the error return path. The skeleton code had to be changed since maps and
progs codegen is shared with subskeletons.
Fixes: f97b8b9bd630 ("bpftool: Fix a bug in subskeleton code generation")
Signed-off-by: Delyan Kratunov <delyank@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/3b6bfbb770c79ae64d8de26c1c1bd9d53a4b85f8.camel@fb.com
| -rw-r--r-- | tools/bpf/bpftool/gen.c | 22 |
1 files changed, 15 insertions, 7 deletions
diff --git a/tools/bpf/bpftool/gen.c b/tools/bpf/bpftool/gen.c index 91af2850b505..7678af364793 100644 --- a/tools/bpf/bpftool/gen.c +++ b/tools/bpf/bpftool/gen.c @@ -828,8 +828,10 @@ codegen_maps_skeleton(struct bpf_object *obj, size_t map_cnt, bool mmaped) s->map_cnt = %zu; \n\ s->map_skel_sz = sizeof(*s->maps); \n\ s->maps = (struct bpf_map_skeleton *)calloc(s->map_cnt, s->map_skel_sz);\n\ - if (!s->maps) \n\ + if (!s->maps) { \n\ + err = -ENOMEM; \n\ goto err; \n\ + } \n\ ", map_cnt ); @@ -870,8 +872,10 @@ codegen_progs_skeleton(struct bpf_object *obj, size_t prog_cnt, bool populate_li s->prog_cnt = %zu; \n\ s->prog_skel_sz = sizeof(*s->progs); \n\ s->progs = (struct bpf_prog_skeleton *)calloc(s->prog_cnt, s->prog_skel_sz);\n\ - if (!s->progs) \n\ + if (!s->progs) { \n\ + err = -ENOMEM; \n\ goto err; \n\ + } \n\ ", prog_cnt ); @@ -1182,10 +1186,13 @@ static int do_skeleton(int argc, char **argv) %1$s__create_skeleton(struct %1$s *obj) \n\ { \n\ struct bpf_object_skeleton *s; \n\ + int err; \n\ \n\ s = (struct bpf_object_skeleton *)calloc(1, sizeof(*s));\n\ - if (!s) \n\ + if (!s) { \n\ + err = -ENOMEM; \n\ goto err; \n\ + } \n\ \n\ s->sz = sizeof(*s); \n\ s->name = \"%1$s\"; \n\ @@ -1206,7 +1213,7 @@ static int do_skeleton(int argc, char **argv) return 0; \n\ err: \n\ bpf_object__destroy_skeleton(s); \n\ - return -ENOMEM; \n\ + return err; \n\ } \n\ \n\ static inline const void *%2$s__elf_bytes(size_t *sz) \n\ @@ -1466,12 +1473,12 @@ static int do_subskeleton(int argc, char **argv) \n\ obj = (struct %1$s *)calloc(1, sizeof(*obj)); \n\ if (!obj) { \n\ - errno = ENOMEM; \n\ + err = -ENOMEM; \n\ goto err; \n\ } \n\ s = (struct bpf_object_subskeleton *)calloc(1, sizeof(*s));\n\ if (!s) { \n\ - errno = ENOMEM; \n\ + err = -ENOMEM; \n\ goto err; \n\ } \n\ s->sz = sizeof(*s); \n\ @@ -1483,7 +1490,7 @@ static int do_subskeleton(int argc, char **argv) s->var_cnt = %2$d; \n\ s->vars = (struct bpf_var_skeleton *)calloc(%2$d, sizeof(*s->vars));\n\ if (!s->vars) { \n\ - errno = ENOMEM; \n\ + err = -ENOMEM; \n\ goto err; \n\ } \n\ ", @@ -1538,6 +1545,7 @@ static int do_subskeleton(int argc, char **argv) return obj; \n\ err: \n\ %1$s__destroy(obj); \n\ + errno = -err; \n\ return NULL; \n\ } \n\ \n\ |