diff options
| author | Daniel Borkmann <daniel@iogearbox.net> | 2017-11-22 21:40:54 +0100 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2017-11-22 21:40:55 +0100 |
| commit | 107af8ec117b0af6e90ddfe42e568b2efd8f6ff7 (patch) | |
| tree | 1606e891bab8ee8bf102c3f0a3b4319d81a0ef2d /net | |
| parent | f1a8b8e3d98b0b3d1d88d119f52cc85d05ab3189 (diff) | |
| parent | a60dd35d2e39209fa7645945e1192bf9769872c6 (diff) | |
Merge branch 'bpf-fix-null-arg-semantics'
Gianluca Borello says:
====================
This set includes some fixes in semantics and usability issues that emerged
recently, and would be good to have them in net before the next release.
In particular, ARG_CONST_SIZE_OR_ZERO semantics was recently changed in
commit 9fd29c08e520 ("bpf: improve verifier ARG_CONST_SIZE_OR_ZERO
semantics") with the goal of letting the compiler generate simpler code
that the verifier can more easily accept.
To handle this change in semantics, a few checks in some helpers were
added, like in commit 9c019e2bc4b2 ("bpf: change helper bpf_probe_read arg2
type to ARG_CONST_SIZE_OR_ZERO"), and those checks are less than ideal
because once they make it into a released kernel bpf programs can start
relying on them, preventing the possibility of being removed later on.
This patch tries to fix the issue by introducing a new argument type
ARG_PTR_TO_MEM_OR_NULL that can be used for helpers that can receive a
<NULL, 0> tuple. By doing so, we can fix the semantics of the other helpers
that don't need <NULL, 0> and can just handle <!NULL, 0>, allowing the code
to get rid of those checks.
====================
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Diffstat (limited to 'net')
| -rw-r--r-- | net/core/filter.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/net/core/filter.c b/net/core/filter.c index 1afa17935954..6a85e67fafce 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -1646,9 +1646,9 @@ static const struct bpf_func_proto bpf_csum_diff_proto = { .gpl_only = false, .pkt_access = true, .ret_type = RET_INTEGER, - .arg1_type = ARG_PTR_TO_MEM, + .arg1_type = ARG_PTR_TO_MEM_OR_NULL, .arg2_type = ARG_CONST_SIZE_OR_ZERO, - .arg3_type = ARG_PTR_TO_MEM, + .arg3_type = ARG_PTR_TO_MEM_OR_NULL, .arg4_type = ARG_CONST_SIZE_OR_ZERO, .arg5_type = ARG_ANYTHING, }; |