On Tue, Aug 16, 2022 at 01:12:12PM -0700, Stanislav Fomichev wrote:
> diff --git a/include/linux/bpf.h b/include/linux/bpf.h
> index a627a02cf8ab..c302d2de073a 100644
> --- a/include/linux/bpf.h
> +++ b/include/linux/bpf.h
> @@ -1948,6 +1948,10 @@ struct bpf_prog *bpf_prog_by_id(u32 id);
> struct bpf_link *bpf_link_by_id(u32 id);
>
> const struct bpf_func_proto *bpf_base_func_proto(enum bpf_func_id func_id);
> +const struct bpf_func_proto *
> +cgroup_common_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog);
> +const struct bpf_func_proto *
> +cgroup_current_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog);
> void bpf_task_storage_free(struct task_struct *task);
> bool bpf_prog_has_kfunc_call(const struct bpf_prog *prog);
> const struct btf_func_model *
> @@ -2154,6 +2158,18 @@ bpf_base_func_proto(enum bpf_func_id func_id)
> return NULL;
> }
>
> +static inline const struct bpf_func_proto *
> +cgroup_common_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
> +{
> + return NULL;
> +}
> +
> +static inline const struct bpf_func_proto *
> +cgroup_current_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
> +{
> + return NULL;
> +}
> +
There two new functions are implemented in cgroup.c which only compiles with
CONFIG_CGROUP_BPF. I think the change in bpf.h here should be done in
bpf-cgroup.h instead. Otherwise, the changes in filter.c in the next patch will
have issue in resolving these functions when CONFIG_CGROUP_BPF is not set.
> -#define BPF_STRTOX_BASE_MASK 0x1F
> -
> -static int __bpf_strtoull(const char *buf, size_t buf_len, u64 flags,
> - unsigned long long *res, bool *is_negative)
> -{
> - unsigned int base = flags & BPF_STRTOX_BASE_MASK;
> - const char *cur_buf = buf;
> - size_t cur_len = buf_len;
> - unsigned int consumed;
> - size_t val_len;
> - char str[64];
> -
> - if (!buf || !buf_len || !res || !is_negative)
> - return -EINVAL;
> -
> - if (base != 0 && base != 8 && base != 10 && base != 16)
> - return -EINVAL;
> -
> - if (flags & ~BPF_STRTOX_BASE_MASK)
> - return -EINVAL;
> -
> - while (cur_buf < buf + buf_len && isspace(*cur_buf))
> - ++cur_buf;
> -
> - *is_negative = (cur_buf < buf + buf_len && *cur_buf == '-');
> - if (*is_negative)
> - ++cur_buf;
> -
> - consumed = cur_buf - buf;
> - cur_len -= consumed;
> - if (!cur_len)
> - return -EINVAL;
> -
> - cur_len = min(cur_len, sizeof(str) - 1);
> - memcpy(str, cur_buf, cur_len);
> - str[cur_len] = '\0';
> - cur_buf = str;
> -
> - cur_buf = _parse_integer_fixup_radix(cur_buf, &base);
> - val_len = _parse_integer(cur_buf, base, res);
> -
> - if (val_len & KSTRTOX_OVERFLOW)
> - return -ERANGE;
> -
> - if (val_len == 0)
> - return -EINVAL;
> -
> - cur_buf += val_len;
> - consumed += cur_buf - str;
> -
> - return consumed;
> -}
> -
> -static int __bpf_strtoll(const char *buf, size_t buf_len, u64 flags,
> - long long *res)
> -{
> - unsigned long long _res;
> - bool is_negative;
> - int err;
> -
> - err = __bpf_strtoull(buf, buf_len, flags, &_res, &is_negative);
> - if (err < 0)
> - return err;
> - if (is_negative) {
> - if ((long long)-_res > 0)
> - return -ERANGE;
> - *res = -_res;
> - } else {
> - if ((long long)_res < 0)
> - return -ERANGE;
> - *res = _res;
> - }
> - return err;
> -}
> -
> -BPF_CALL_4(bpf_strtol, const char *, buf, size_t, buf_len, u64, flags,
> - long *, res)
> -{
> - long long _res;
> - int err;
> -
> - err = __bpf_strtoll(buf, buf_len, flags, &_res);
> - if (err < 0)
> - return err;
> - if (_res != (long)_res)
> - return -ERANGE;
> - *res = _res;
> - return err;
> -}
> -
> -const struct bpf_func_proto bpf_strtol_proto = {
> - .func = bpf_strtol,
> - .gpl_only = false,
> - .ret_type = RET_INTEGER,
> - .arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY,
> - .arg2_type = ARG_CONST_SIZE,
> - .arg3_type = ARG_ANYTHING,
> - .arg4_type = ARG_PTR_TO_LONG,
> -};
> -
> -BPF_CALL_4(bpf_strtoul, const char *, buf, size_t, buf_len, u64, flags,
> - unsigned long *, res)
> -{
> - unsigned long long _res;
> - bool is_negative;
> - int err;
> -
> - err = __bpf_strtoull(buf, buf_len, flags, &_res, &is_negative);
> - if (err < 0)
> - return err;
> - if (is_negative)
> - return -EINVAL;
> - if (_res != (unsigned long)_res)
> - return -ERANGE;
> - *res = _res;
> - return err;
> -}
> -
> -const struct bpf_func_proto bpf_strtoul_proto = {
This should be useful in general other than cgroup bpf.
It may end up moving back to helpers.c soon.
How about take this chance to add it to bpf_base_func_proto()
which already has another string helper bpf_strncmp_proto?
> - .func = bpf_strtoul,
> - .gpl_only = false,
> - .ret_type = RET_INTEGER,
> - .arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY,
> - .arg2_type = ARG_CONST_SIZE,
> - .arg3_type = ARG_ANYTHING,
> - .arg4_type = ARG_PTR_TO_LONG,
> -};
> -#endif
