diff mbox series

[bpf,2/7] bpf: Handle bpf_mprog_query with NULL entry

Message ID 20231006220655.1653-2-daniel@iogearbox.net (mailing list archive)
State Accepted
Commit edfa9af0a73ecc2000d7bb81d0b0fd3158cc9a65
Delegated to: BPF
Headers show
Series [bpf,1/7] bpf: Fix BPF_PROG_QUERY last field check | expand

Checks

Context Check Description
bpf/vmtest-bpf-VM_Test-0 success Logs for ShellCheck
netdev/series_format warning Series does not have a cover letter
netdev/tree_selection success Clearly marked for bpf
netdev/fixes_present success Fixes tag present in non-next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 1365 this patch: 1365
netdev/cc_maintainers warning 11 maintainers not CCed: song@kernel.org ast@kernel.org netdev@vger.kernel.org andrii@kernel.org yonghong.song@linux.dev jolsa@kernel.org kpsingh@kernel.org john.fastabend@gmail.com sdf@google.com haoluo@google.com martin.lau@linux.dev
netdev/build_clang success Errors and warnings before: 1388 this patch: 1388
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 1389 this patch: 1389
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 40 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
bpf/vmtest-bpf-VM_Test-1 success Logs for build for aarch64 with gcc
bpf/vmtest-bpf-VM_Test-2 success Logs for build for s390x with gcc
bpf/vmtest-bpf-VM_Test-3 success Logs for build for x86_64 with gcc
bpf/vmtest-bpf-VM_Test-4 success Logs for build for x86_64 with llvm-16
bpf/vmtest-bpf-VM_Test-5 success Logs for set-matrix
bpf/vmtest-bpf-VM_Test-6 success Logs for test_maps on aarch64 with gcc
bpf/vmtest-bpf-VM_Test-7 success Logs for test_maps on s390x with gcc
bpf/vmtest-bpf-VM_Test-8 success Logs for test_maps on x86_64 with gcc
bpf/vmtest-bpf-VM_Test-9 success Logs for test_maps on x86_64 with llvm-16
bpf/vmtest-bpf-VM_Test-10 success Logs for test_progs on aarch64 with gcc
bpf/vmtest-bpf-VM_Test-11 success Logs for test_progs on s390x with gcc
bpf/vmtest-bpf-VM_Test-12 success Logs for test_progs on x86_64 with gcc
bpf/vmtest-bpf-VM_Test-13 success Logs for test_progs on x86_64 with llvm-16
bpf/vmtest-bpf-VM_Test-14 success Logs for test_progs_no_alu32 on aarch64 with gcc
bpf/vmtest-bpf-VM_Test-15 success Logs for test_progs_no_alu32 on s390x with gcc
bpf/vmtest-bpf-VM_Test-16 success Logs for test_progs_no_alu32 on x86_64 with gcc
bpf/vmtest-bpf-VM_Test-17 success Logs for test_progs_no_alu32 on x86_64 with llvm-16
bpf/vmtest-bpf-VM_Test-18 success Logs for test_progs_no_alu32_parallel on aarch64 with gcc
bpf/vmtest-bpf-VM_Test-20 success Logs for test_progs_no_alu32_parallel on x86_64 with llvm-16
bpf/vmtest-bpf-VM_Test-19 success Logs for test_progs_no_alu32_parallel on x86_64 with gcc
bpf/vmtest-bpf-VM_Test-21 success Logs for test_progs_parallel on aarch64 with gcc
bpf/vmtest-bpf-VM_Test-22 success Logs for test_progs_parallel on x86_64 with gcc
bpf/vmtest-bpf-VM_Test-23 success Logs for test_progs_parallel on x86_64 with llvm-16
bpf/vmtest-bpf-VM_Test-24 success Logs for test_verifier on aarch64 with gcc
bpf/vmtest-bpf-VM_Test-25 success Logs for test_verifier on s390x with gcc
bpf/vmtest-bpf-VM_Test-26 success Logs for test_verifier on x86_64 with gcc
bpf/vmtest-bpf-VM_Test-27 success Logs for test_verifier on x86_64 with llvm-16
bpf/vmtest-bpf-VM_Test-28 success Logs for veristat
bpf/vmtest-bpf-PR success PR summary

Commit Message

Daniel Borkmann Oct. 6, 2023, 10:06 p.m. UTC 
Improve consistency for bpf_mprog_query() API and let the latter also handle
a NULL entry as can be the case for tcx. Instead of returning -ENOENT, we
copy a count of 0 and revision of 1 to user space, so that this can be fed
into a subsequent bpf_mprog_attach() call as expected_revision. A BPF self-
test as part of this series has been added to assert this case.

Suggested-by: Lorenz Bauer <lmb@isovalent.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
---
 kernel/bpf/mprog.c | 10 ++++++----
 kernel/bpf/tcx.c   |  8 +-------
 2 files changed, 7 insertions(+), 11 deletions(-)
diff mbox series

Patch

diff --git a/kernel/bpf/mprog.c b/kernel/bpf/mprog.c
index 007d98c799e2..1394168062e8 100644
--- a/kernel/bpf/mprog.c
+++ b/kernel/bpf/mprog.c
@@ -401,14 +401,16 @@  int bpf_mprog_query(const union bpf_attr *attr, union bpf_attr __user *uattr,
 	struct bpf_mprog_cp *cp;
 	struct bpf_prog *prog;
 	const u32 flags = 0;
+	u32 id, count = 0;
+	u64 revision = 1;
 	int i, ret = 0;
-	u32 id, count;
-	u64 revision;
 
 	if (attr->query.query_flags || attr->query.attach_flags)
 		return -EINVAL;
-	revision = bpf_mprog_revision(entry);
-	count = bpf_mprog_total(entry);
+	if (entry) {
+		revision = bpf_mprog_revision(entry);
+		count = bpf_mprog_total(entry);
+	}
 	if (copy_to_user(&uattr->query.attach_flags, &flags, sizeof(flags)))
 		return -EFAULT;
 	if (copy_to_user(&uattr->query.revision, &revision, sizeof(revision)))
diff --git a/kernel/bpf/tcx.c b/kernel/bpf/tcx.c
index 13f0b5dc8262..1338a13a8b64 100644
--- a/kernel/bpf/tcx.c
+++ b/kernel/bpf/tcx.c
@@ -123,7 +123,6 @@  int tcx_prog_query(const union bpf_attr *attr, union bpf_attr __user *uattr)
 {
 	bool ingress = attr->query.attach_type == BPF_TCX_INGRESS;
 	struct net *net = current->nsproxy->net_ns;
-	struct bpf_mprog_entry *entry;
 	struct net_device *dev;
 	int ret;
 
@@ -133,12 +132,7 @@  int tcx_prog_query(const union bpf_attr *attr, union bpf_attr __user *uattr)
 		ret = -ENODEV;
 		goto out;
 	}
-	entry = tcx_entry_fetch(dev, ingress);
-	if (!entry) {
-		ret = -ENOENT;
-		goto out;
-	}
-	ret = bpf_mprog_query(attr, uattr, entry);
+	ret = bpf_mprog_query(attr, uattr, tcx_entry_fetch(dev, ingress));
 out:
 	rtnl_unlock();
 	return ret;