[PATCHv3 bpf-next 07/24] bpf: Move sleepable verification code to btf_id_allow_sleepable
From: Jiri Olsa <jolsa@kernel.org>
Date: 2026-03-16 07:53:04
Also in:
linux-trace-kernel
Subsystem:
bpf [core], bpf [general] (safe dynamic programs and tools), the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Linus Torvalds
Move sleepable verification code to btf_id_allow_sleepable function. It will be used in following changes. Adding code to retrieve type's name instead of passing it from bpf_check_attach_target function, because this function will be called from another place in following changes and it's easier to retrieve the name directly in here. Signed-off-by: Jiri Olsa <jolsa@kernel.org> --- include/linux/bpf_verifier.h | 3 ++ kernel/bpf/verifier.c | 79 +++++++++++++++++++++--------------- 2 files changed, 50 insertions(+), 32 deletions(-)
diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h
index 090aa26d1c98..186726fcf52a 100644
--- a/include/linux/bpf_verifier.h
+++ b/include/linux/bpf_verifier.h@@ -932,6 +932,9 @@ static inline void bpf_trampoline_unpack_key(u64 key, u32 *obj_id, u32 *btf_id) *btf_id = key & 0x7FFFFFFF; } +int btf_id_allow_sleepable(u32 btf_id, unsigned long addr, const struct bpf_prog *prog, + const struct btf *btf); + int bpf_check_attach_target(struct bpf_verifier_log *log, const struct bpf_prog *prog, const struct bpf_prog *tgt_prog,
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index b29cd244ee27..7085688eb719 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c@@ -25059,6 +25059,52 @@ static bool is_tracing_multi_id(const struct bpf_prog *prog, u32 btf_id) return is_tracing_multi(prog->expected_attach_type) && bpf_multi_func_btf_id[0] == btf_id; } +int btf_id_allow_sleepable(u32 btf_id, unsigned long addr, const struct bpf_prog *prog, + const struct btf *btf) +{ + const struct btf_type *t; + const char *tname; + + switch (prog->type) { + case BPF_PROG_TYPE_TRACING: + t = btf_type_by_id(btf, btf_id); + if (!t) + return -EINVAL; + tname = btf_name_by_offset(btf, t->name_off); + if (!tname) + return -EINVAL; + + /* *.multi sleepable programs will pass initial sleepable check, + * the actual attached btf ids are checked later during the link + * attachment. + */ + if (is_tracing_multi_id(prog, btf_id)) + return 0; + if (!check_attach_sleepable(btf_id, addr, tname)) + return 0; + /* fentry/fexit/fmod_ret progs can also be sleepable if they are + * in the fmodret id set with the KF_SLEEPABLE flag. + */ + else { + u32 *flags = btf_kfunc_is_modify_return(btf, btf_id, prog); + + if (flags && (*flags & KF_SLEEPABLE)) + return 0; + } + break; + case BPF_PROG_TYPE_LSM: + /* LSM progs check that they are attached to bpf_lsm_*() funcs. + * Only some of them are sleepable. + */ + if (bpf_lsm_is_sleepable_hook(btf_id)) + return 0; + break; + default: + break; + } + return -EINVAL; +} + int bpf_check_attach_target(struct bpf_verifier_log *log, const struct bpf_prog *prog, const struct bpf_prog *tgt_prog,
@@ -25349,38 +25395,7 @@ int bpf_check_attach_target(struct bpf_verifier_log *log, } if (prog->sleepable) { - ret = -EINVAL; - switch (prog->type) { - case BPF_PROG_TYPE_TRACING: - /* *.multi sleepable programs will pass initial sleepable check, - * the actual attached btf ids are checked later during the link - * attachment. - */ - if (is_tracing_multi_id(prog, btf_id)) - ret = 0; - if (!check_attach_sleepable(btf_id, addr, tname)) - ret = 0; - /* fentry/fexit/fmod_ret progs can also be sleepable if they are - * in the fmodret id set with the KF_SLEEPABLE flag. - */ - else { - u32 *flags = btf_kfunc_is_modify_return(btf, btf_id, - prog); - - if (flags && (*flags & KF_SLEEPABLE)) - ret = 0; - } - break; - case BPF_PROG_TYPE_LSM: - /* LSM progs check that they are attached to bpf_lsm_*() funcs. - * Only some of them are sleepable. - */ - if (bpf_lsm_is_sleepable_hook(btf_id)) - ret = 0; - break; - default: - break; - } + ret = btf_id_allow_sleepable(btf_id, addr, prog, btf); if (ret) { module_put(mod); bpf_log(log, "%s is not sleepable\n", tname);
--
2.53.0