| Message ID | 20220920075951.929132-3-roberto.sassu@huaweicloud.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 00f146413ccb6c84308e559281449755c83f54c5 |
| Delegated to: | BPF |
| Headers | show |
| Series | bpf: Add kfuncs for PKCS#7 signature verification | expand |
| Context | Check | Description |
|---|---|---|
| netdev/tree_selection | success | Guessing tree name failed - patch did not apply, async |
| bpf/vmtest-bpf-next-PR | success | PR summary |
| bpf/vmtest-bpf-next-VM_Test-4 | success | Logs for llvm-toolchain |
| bpf/vmtest-bpf-next-VM_Test-5 | success | Logs for set-matrix |
| bpf/vmtest-bpf-next-VM_Test-2 | success | Logs for build for x86_64 with gcc |
| bpf/vmtest-bpf-next-VM_Test-3 | success | Logs for build for x86_64 with llvm-16 |
| bpf/vmtest-bpf-next-VM_Test-1 | success | Logs for build for s390x with gcc |
| bpf/vmtest-bpf-next-VM_Test-16 | success | Logs for test_verifier on x86_64 with gcc |
| bpf/vmtest-bpf-next-VM_Test-13 | success | Logs for test_progs_no_alu32 on x86_64 with gcc |
| bpf/vmtest-bpf-next-VM_Test-14 | success | Logs for test_progs_no_alu32 on x86_64 with llvm-16 |
| bpf/vmtest-bpf-next-VM_Test-17 | success | Logs for test_verifier on x86_64 with llvm-16 |
| bpf/vmtest-bpf-next-VM_Test-7 | success | Logs for test_maps on x86_64 with gcc |
| bpf/vmtest-bpf-next-VM_Test-8 | success | Logs for test_maps on x86_64 with llvm-16 |
| bpf/vmtest-bpf-next-VM_Test-10 | success | Logs for test_progs on x86_64 with gcc |
| bpf/vmtest-bpf-next-VM_Test-11 | success | Logs for test_progs on x86_64 with llvm-16 |
| bpf/vmtest-bpf-next-VM_Test-15 | success | Logs for test_verifier on s390x with gcc |
| bpf/vmtest-bpf-next-VM_Test-9 | success | Logs for test_progs on s390x with gcc |
| bpf/vmtest-bpf-next-VM_Test-12 | success | Logs for test_progs_no_alu32 on s390x with gcc |
| bpf/vmtest-bpf-next-VM_Test-6 | success | Logs for test_maps on s390x with gcc |
| bpf/vmtest-bpf-PR | fail | merge-conflict |
On Tue, Sep 20, 2022 at 10:01 AM Roberto Sassu <roberto.sassu@huaweicloud.com> wrote: > > From: Roberto Sassu <roberto.sassu@huawei.com> > > eBPF dynamic pointers is a new feature recently added to upstream. It binds > together a pointer to a memory area and its size. The internal kernel > structure bpf_dynptr_kern is not accessible by eBPF programs in user space. > They instead see bpf_dynptr, which is then translated to the internal > kernel structure by the eBPF verifier. > > The problem is that it is not possible to include at the same time the uapi > include linux/bpf.h and the vmlinux BTF vmlinux.h, as they both contain the > definition of some structures/enums. The compiler complains saying that the > structures/enums are redefined. > > As bpf_dynptr is defined in the uapi include linux/bpf.h, this makes it > impossible to include vmlinux.h. However, in some cases, e.g. when using > kfuncs, vmlinux.h has to be included. The only option until now was to > include vmlinux.h and add the definition of bpf_dynptr directly in the eBPF > program source code from linux/bpf.h. > > Solve the problem by using the same approach as for bpf_timer (which also > follows the same scheme with the _kern suffix for the internal kernel > structure). > > Add the following line in one of the dynamic pointer helpers, > bpf_dynptr_from_mem(): > > BTF_TYPE_EMIT(struct bpf_dynptr); > > Cc: stable@vger.kernel.org > Cc: Joanne Koong <joannelkoong@gmail.com> > Fixes: 97e03f521050c ("bpf: Add verifier support for dynptrs") > Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> > Acked-by: Yonghong Song <yhs@fb.com> I tested this out and it works, however for the BPF signing use case where "bpf_dynptr_kern" is added to struct bpf_prog_aux one still ends up defining the __ksym extern with bpf_dynptr_kern. But let's discuss that when the series is posted. Tested-by: KP Singh <kpsingh@kernel.org>
diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index 41aeaf3862ec..7ce1f583b929 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -1446,6 +1446,8 @@ BPF_CALL_4(bpf_dynptr_from_mem, void *, data, u32, size, u64, flags, struct bpf_ { int err; + BTF_TYPE_EMIT(struct bpf_dynptr); + err = bpf_dynptr_check_size(size); if (err) goto error;