bpf: Introduce might_sleep field in bpf_func_proto

Introduce bpf_func_proto->might_sleep to indicate a particular helper
might sleep. This will make later check whether a helper might be
sleepable or not easier.

Acked-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20221124053211.2373553-1-yhs@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Yonghong Song 2022-11-23 21:32:11 -08:00 committed by Alexei Starovoitov
parent 5a0f663f01
commit 01685c5bdd
5 changed files with 14 additions and 4 deletions

View File

@ -682,6 +682,7 @@ struct bpf_func_proto {
u64 (*func)(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
bool gpl_only;
bool pkt_access;
bool might_sleep;
enum bpf_return_type ret_type;
union {
struct {

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@ -151,6 +151,7 @@ BTF_ID_LIST_SINGLE(bpf_ima_inode_hash_btf_ids, struct, inode)
static const struct bpf_func_proto bpf_ima_inode_hash_proto = {
.func = bpf_ima_inode_hash,
.gpl_only = false,
.might_sleep = true,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_BTF_ID,
.arg1_btf_id = &bpf_ima_inode_hash_btf_ids[0],
@ -169,6 +170,7 @@ BTF_ID_LIST_SINGLE(bpf_ima_file_hash_btf_ids, struct, file)
static const struct bpf_func_proto bpf_ima_file_hash_proto = {
.func = bpf_ima_file_hash,
.gpl_only = false,
.might_sleep = true,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_BTF_ID,
.arg1_btf_id = &bpf_ima_file_hash_btf_ids[0],
@ -221,9 +223,9 @@ bpf_lsm_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
case BPF_FUNC_bprm_opts_set:
return &bpf_bprm_opts_set_proto;
case BPF_FUNC_ima_inode_hash:
return prog->aux->sleepable ? &bpf_ima_inode_hash_proto : NULL;
return &bpf_ima_inode_hash_proto;
case BPF_FUNC_ima_file_hash:
return prog->aux->sleepable ? &bpf_ima_file_hash_proto : NULL;
return &bpf_ima_file_hash_proto;
case BPF_FUNC_get_attach_cookie:
return bpf_prog_has_trampoline(prog) ? &bpf_get_attach_cookie_proto : NULL;
#ifdef CONFIG_NET

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@ -661,6 +661,7 @@ BPF_CALL_3(bpf_copy_from_user, void *, dst, u32, size,
const struct bpf_func_proto bpf_copy_from_user_proto = {
.func = bpf_copy_from_user,
.gpl_only = false,
.might_sleep = true,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_UNINIT_MEM,
.arg2_type = ARG_CONST_SIZE_OR_ZERO,
@ -691,6 +692,7 @@ BPF_CALL_5(bpf_copy_from_user_task, void *, dst, u32, size,
const struct bpf_func_proto bpf_copy_from_user_task_proto = {
.func = bpf_copy_from_user_task,
.gpl_only = true,
.might_sleep = true,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_UNINIT_MEM,
.arg2_type = ARG_CONST_SIZE_OR_ZERO,

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@ -7516,6 +7516,11 @@ static int check_helper_call(struct bpf_verifier_env *env, struct bpf_insn *insn
return -EINVAL;
}
if (!env->prog->aux->sleepable && fn->might_sleep) {
verbose(env, "helper call might sleep in a non-sleepable prog\n");
return -EINVAL;
}
/* With LD_ABS/IND some JITs save/restore skb from r1. */
changes_data = bpf_helper_changes_pkt_data(fn->func);
if (changes_data && fn->arg1_type != ARG_PTR_TO_CTX) {

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@ -1485,9 +1485,9 @@ bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
case BPF_FUNC_get_task_stack:
return &bpf_get_task_stack_proto;
case BPF_FUNC_copy_from_user:
return prog->aux->sleepable ? &bpf_copy_from_user_proto : NULL;
return &bpf_copy_from_user_proto;
case BPF_FUNC_copy_from_user_task:
return prog->aux->sleepable ? &bpf_copy_from_user_task_proto : NULL;
return &bpf_copy_from_user_task_proto;
case BPF_FUNC_snprintf_btf:
return &bpf_snprintf_btf_proto;
case BPF_FUNC_per_cpu_ptr: