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 /kernel/bpf/syscall.c | |
| 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 'kernel/bpf/syscall.c')
| -rw-r--r-- | kernel/bpf/syscall.c | 16 |
1 files changed, 8 insertions, 8 deletions
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index e18ac7fdc210..6d575505f89c 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -2501,9 +2501,9 @@ static bool is_perfmon_prog_type(enum bpf_prog_type prog_type) } /* last field in 'union bpf_attr' used by this command */ -#define BPF_PROG_LOAD_LAST_FIELD core_relo_rec_size +#define BPF_PROG_LOAD_LAST_FIELD log_true_size -static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr) +static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr, u32 uattr_size) { enum bpf_prog_type type = attr->prog_type; struct bpf_prog *prog, *dst_prog = NULL; @@ -2653,7 +2653,7 @@ static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr) goto free_prog_sec; /* run eBPF verifier */ - err = bpf_check(&prog, attr, uattr); + err = bpf_check(&prog, attr, uattr, uattr_size); if (err < 0) goto free_used_maps; @@ -4371,9 +4371,9 @@ static int bpf_obj_get_info_by_fd(const union bpf_attr *attr, return err; } -#define BPF_BTF_LOAD_LAST_FIELD btf_log_level +#define BPF_BTF_LOAD_LAST_FIELD btf_log_true_size -static int bpf_btf_load(const union bpf_attr *attr, bpfptr_t uattr) +static int bpf_btf_load(const union bpf_attr *attr, bpfptr_t uattr, __u32 uattr_size) { if (CHECK_ATTR(BPF_BTF_LOAD)) return -EINVAL; @@ -4381,7 +4381,7 @@ static int bpf_btf_load(const union bpf_attr *attr, bpfptr_t uattr) if (!bpf_capable()) return -EPERM; - return btf_new_fd(attr, uattr); + return btf_new_fd(attr, uattr, uattr_size); } #define BPF_BTF_GET_FD_BY_ID_LAST_FIELD btf_id @@ -5059,7 +5059,7 @@ static int __sys_bpf(int cmd, bpfptr_t uattr, unsigned int size) err = map_freeze(&attr); break; case BPF_PROG_LOAD: - err = bpf_prog_load(&attr, uattr); + err = bpf_prog_load(&attr, uattr, size); break; case BPF_OBJ_PIN: err = bpf_obj_pin(&attr); @@ -5104,7 +5104,7 @@ static int __sys_bpf(int cmd, bpfptr_t uattr, unsigned int size) err = bpf_raw_tracepoint_open(&attr); break; case BPF_BTF_LOAD: - err = bpf_btf_load(&attr, uattr); + err = bpf_btf_load(&attr, uattr, size); break; case BPF_BTF_GET_FD_BY_ID: err = bpf_btf_get_fd_by_id(&attr); |