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| author | Alexei Starovoitov <ast@kernel.org> | 2019-04-26 19:05:44 -0700 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2019-04-26 19:05:44 -0700 |
| commit | 3745dc24aa7a6a45771a6b441194b857ac615cfc (patch) | |
| tree | 9fe461c7f01adec95c4f66d9a4748afa3348643b /kernel/bpf/syscall.c | |
| parent | 34b8ab091f9ef57a2bb3c8c8359a0a03a8abf2f9 (diff) | |
| parent | e950e843367d7990b9d7ea964e3c33876d477c4b (diff) | |
| download | linux-next-3745dc24aa7a6a45771a6b441194b857ac615cfc.tar.gz | |
Merge branch 'writeable-bpf-tracepoints'
Matt Mullins says:
====================
This adds an opt-in interface for tracepoints to expose a writable context to
BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE programs that are attached, while
supporting read-only access from existing BPF_PROG_TYPE_RAW_TRACEPOINT
programs, as well as from non-BPF-based tracepoints.
The initial motivation is to support tracing that can be observed from the
remote end of an NBD socket, e.g. by adding flags to the struct nbd_request
header. Earlier attempts included adding an NBD-specific tracepoint fd, but in
code review, I was recommended to implement it more generically -- as a result,
this patchset is far simpler than my initial try.
v4->v5:
* rebased onto bpf-next/master and fixed merge conflicts
* "tools: sync bpf.h" also syncs comments that have previously changed
in bpf-next
v3->v4:
* fixed a silly copy/paste typo in include/trace/events/bpf_test_run.h
(_TRACE_NBD_H -> _TRACE_BPF_TEST_RUN_H)
* fixed incorrect/misleading wording in patch 1's commit message,
since the pointer cannot be directly dereferenced in a
BPF_PROG_TYPE_RAW_TRACEPOINT
* cleaned up the error message wording if the prog_tests fail
* Addressed feedback from Yonghong
* reject non-pointer-sized accesses to the buffer pointer
* use sizeof(struct nbd_request) as one-byte-past-the-end in
raw_tp_writable_reject_nbd_invalid.c
* use BPF_MOV64_IMM instead of BPF_LD_IMM64
v2->v3:
* Andrew addressed Josef's comments:
* C-style commenting in nbd.c
* Collapsed identical events into a single DECLARE_EVENT_CLASS.
This saves about 2kB of kernel text
v1->v2:
* add selftests
* sync tools/include/uapi/linux/bpf.h
* reject variable offset into the buffer
* add string representation of PTR_TO_TP_BUFFER to reg_type_str
====================
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'kernel/bpf/syscall.c')
| -rw-r--r-- | kernel/bpf/syscall.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index b0de49598341..ae141e745f92 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -1789,12 +1789,16 @@ static int bpf_raw_tracepoint_open(const union bpf_attr *attr) } raw_tp->btp = btp; - prog = bpf_prog_get_type(attr->raw_tracepoint.prog_fd, - BPF_PROG_TYPE_RAW_TRACEPOINT); + prog = bpf_prog_get(attr->raw_tracepoint.prog_fd); if (IS_ERR(prog)) { err = PTR_ERR(prog); goto out_free_tp; } + if (prog->type != BPF_PROG_TYPE_RAW_TRACEPOINT && + prog->type != BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE) { + err = -EINVAL; + goto out_put_prog; + } err = bpf_probe_register(raw_tp->btp, prog); if (err) |