diff options
| author | Andrii Nakryiko <andrii@kernel.org> | 2023-04-06 16:41:58 -0700 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2023-04-11 18:05:43 +0200 |
| commit | 47a71c1f9af0a334c9dfa97633c41de4feda4287 (patch) | |
| tree | 629b75bb5746fcdf557efc96777cb921ee1dcbbd /include | |
| parent | fa1c7d5cc404ac3b6e6b4ab6d00b07c76bd819be (diff) | |
bpf: Add log_true_size output field to return necessary log buffer size
Add output-only log_true_size and btf_log_true_size field to
BPF_PROG_LOAD and BPF_BTF_LOAD commands, respectively. It will return
the size of log buffer necessary to fit in all the log contents at
specified log_level. This is very useful for BPF loader libraries like
libbpf to be able to size log buffer correctly, but could be used by
users directly, if necessary, as well.
This patch plumbs all this through the code, taking into account actual
bpf_attr size provided by user to determine if these new fields are
expected by users. And if they are, set them from kernel on return.
We refactory btf_parse() function to accommodate this, moving attr and
uattr handling inside it. The rest is very straightforward code, which
is split from the logging accounting changes in the previous patch to
make it simpler to review logic vs UAPI changes.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Lorenz Bauer <lmb@isovalent.com>
Link: https://lore.kernel.org/bpf/20230406234205.323208-13-andrii@kernel.org
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/bpf.h | 2 | ||||
| -rw-r--r-- | include/linux/btf.h | 2 | ||||
| -rw-r--r-- | include/uapi/linux/bpf.h | 10 |
3 files changed, 12 insertions, 2 deletions
diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 002a811b6b90..2c6095bd7d69 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -2175,7 +2175,7 @@ int bpf_check_uarg_tail_zero(bpfptr_t uaddr, size_t expected_size, size_t actual_size); /* verify correctness of eBPF program */ -int bpf_check(struct bpf_prog **fp, union bpf_attr *attr, bpfptr_t uattr); +int bpf_check(struct bpf_prog **fp, union bpf_attr *attr, bpfptr_t uattr, u32 uattr_size); #ifndef CONFIG_BPF_JIT_ALWAYS_ON void bpf_patch_call_args(struct bpf_insn *insn, u32 stack_depth); diff --git a/include/linux/btf.h b/include/linux/btf.h index d53b10cc55f2..495250162422 100644 --- a/include/linux/btf.h +++ b/include/linux/btf.h @@ -125,7 +125,7 @@ extern const struct file_operations btf_fops; void btf_get(struct btf *btf); void btf_put(struct btf *btf); -int btf_new_fd(const union bpf_attr *attr, bpfptr_t uattr); +int btf_new_fd(const union bpf_attr *attr, bpfptr_t uattr, u32 uattr_sz); struct btf *btf_get_by_fd(int fd); int btf_get_info_by_fd(const struct btf *btf, const union bpf_attr *attr, diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index e3d3b5160d26..3823100b7934 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -1407,6 +1407,11 @@ union bpf_attr { __aligned_u64 fd_array; /* array of FDs */ __aligned_u64 core_relos; __u32 core_relo_rec_size; /* sizeof(struct bpf_core_relo) */ + /* output: actual total log contents size (including termintaing zero). + * It could be both larger than original log_size (if log was + * truncated), or smaller (if log buffer wasn't filled completely). + */ + __u32 log_true_size; }; struct { /* anonymous struct used by BPF_OBJ_* commands */ @@ -1492,6 +1497,11 @@ union bpf_attr { __u32 btf_size; __u32 btf_log_size; __u32 btf_log_level; + /* output: actual total log contents size (including termintaing zero). + * It could be both larger than original log_size (if log was + * truncated), or smaller (if log buffer wasn't filled completely). + */ + __u32 btf_log_true_size; }; struct { |