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| author |   Daniel Borkmann <daniel@iogearbox.net> | 2016-12-18 01:52:57 +0100 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2016-12-17 21:27:44 -0500 |
| commit | aafe6ae9cee32df85eb5e8bb6dd1d918e6807b09 (patch) | |
| tree | 4aa9958d1ddf599f4ed32d491f8ab217c9747056 /kernel/bpf/verifier.c | |
| parent | Merge branch 'gtp-fixes' (diff) | |
| download | linux-dev-aafe6ae9cee32df85eb5e8bb6dd1d918e6807b09.tar.xz linux-dev-aafe6ae9cee32df85eb5e8bb6dd1d918e6807b09.zip | |
bpf: dynamically allocate digest scratch buffer
Geert rightfully complained that 7bd509e311f4 ("bpf: add prog_digest
and expose it via fdinfo/netlink") added a too large allocation of
variable 'raw' from bss section, and should instead be done dynamically:
# ./scripts/bloat-o-meter kernel/bpf/core.o.1 kernel/bpf/core.o.2
add/remove: 3/0 grow/shrink: 0/0 up/down: 33291/0 (33291)
function old new delta
raw - 32832 +32832
[...]
Since this is only relevant during program creation path, which can be
considered slow-path anyway, lets allocate that dynamically and be not
implicitly dependent on verifier mutex. Move bpf_prog_calc_digest() at
the beginning of replace_map_fd_with_map_ptr() and also error handling
stays straight forward.
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to '')
| -rw-r--r-- | kernel/bpf/verifier.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 81e267bc4640..64b7b1abe087 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -2931,6 +2931,10 @@ static int replace_map_fd_with_map_ptr(struct bpf_verifier_env *env) int insn_cnt = env->prog->len; int i, j, err; + err = bpf_prog_calc_digest(env->prog); + if (err) + return err; + for (i = 0; i < insn_cnt; i++, insn++) { if (BPF_CLASS(insn->code) == BPF_LDX && (BPF_MODE(insn->code) != BPF_MEM || insn->imm != 0)) { @@ -3178,8 +3182,6 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr) log_level = 0; } - bpf_prog_calc_digest(env->prog); - ret = replace_map_fd_with_map_ptr(env); if (ret < 0) goto skip_full_check; |