linux-stable.git/tools/testing/selftests/bpf/verifier/array_access.c, branch linux-5.4.y

selftests/bpf: Mask bpf_csum_diff() return value to 16 bits in test_verifier

2021-03-17T16:03:33+00:00

commit 6185266c5a853bb0f2a459e3ff594546f277609b upstream.

The verifier test labelled "valid read map access into a read-only array
2" calls the bpf_csum_diff() helper and checks its return value. However,
architecture implementations of csum_partial() (which is what the helper
uses) differ in whether they fold the return value to 16 bit or not. For
example, x86 version has ...

	if (unlikely(odd)) {
		result = from32to16(result);
		result = ((result >> 8) & 0xff) | ((result & 0xff) << 8);
	}

... while generic lib/checksum.c does:

	result = from32to16(result);
	if (odd)
		result = ((result >> 8) & 0xff) | ((result & 0xff) << 8);

This makes the helper return different values on different architectures,
breaking the test on non-x86. To fix this, add an additional instruction
to always mask the return value to 16 bits, and update the expected return
value accordingly.

Fixes: fb2abb73e575 ("bpf, selftest: test {rd, wr}only flags and direct value access")
Signed-off-by: Yauheni Kaliuta 
Signed-off-by: Daniel Borkmann 
Link: https://lore.kernel.org/bpf/20210228103017.320240-1-yauheni.kaliuta@redhat.com
Signed-off-by: Greg Kroah-Hartman

selftests/bpf: fix "valid read map access into a read-only array 1" on s390

2019-07-18T20:49:21+00:00

This test looks up a 32-bit map element and then loads it using a 64-bit
load. This does not work on s390, which is a big-endian machine.

Since the point of this test doesn't seem to be loading a smaller value
using a larger load, simply use a 32-bit load.

Signed-off-by: Ilya Leoshkevich 
Signed-off-by: Alexei Starovoitov

bpf, selftest: test {rd, wr}only flags and direct value access

2019-04-10T00:05:47+00:00

Extend test_verifier with various test cases around the two kernel
extensions, that is, {rd,wr}only map support as well as direct map
value access. All passing, one skipped due to xskmap not present
on test machine:

  # ./test_verifier
  [...]
  #948/p XDP pkt read, pkt_meta' <= pkt_data, bad access 1 OK
  #949/p XDP pkt read, pkt_meta' <= pkt_data, bad access 2 OK
  #950/p XDP pkt read, pkt_data <= pkt_meta', good access OK
  #951/p XDP pkt read, pkt_data <= pkt_meta', bad access 1 OK
  #952/p XDP pkt read, pkt_data <= pkt_meta', bad access 2 OK
  Summary: 1410 PASSED, 1 SKIPPED, 0 FAILED

Signed-off-by: Daniel Borkmann 
Acked-by: Martin KaFai Lau 
Signed-off-by: Alexei Starovoitov

selftests: bpf: break up test_verifier

2019-01-28T05:37:45+00:00

Break up the first 10 kLoC of test verifier test cases
out into smaller files.  Looks like git line counting
gets a little flismy above 16 bit integers, so we need
two commits to break up test_verifier.

Signed-off-by: Jakub Kicinski 
Acked-by: Jiong Wang 
Signed-off-by: Alexei Starovoitov