linux-stable.git/net/bpf, branch v5.8.2

bpf: Add tests for PTR_TO_BTF_ID vs. null comparison

2020-06-30T20:21:29+00:00

Add two tests for PTR_TO_BTF_ID vs. null ptr comparison,
one for PTR_TO_BTF_ID in the ctx structure and the
other for PTR_TO_BTF_ID after one level pointer chasing.
In both cases, the test ensures condition is not
removed.

For example, for this test
 struct bpf_fentry_test_t {
     struct bpf_fentry_test_t *a;
 };
 int BPF_PROG(test7, struct bpf_fentry_test_t *arg)
 {
     if (arg == 0)
         test7_result = 1;
     return 0;
 }
Before the previous verifier change, we have xlated codes:
  int test7(long long unsigned int * ctx):
  ; int BPF_PROG(test7, struct bpf_fentry_test_t *arg)
     0: (79) r1 = *(u64 *)(r1 +0)
  ; int BPF_PROG(test7, struct bpf_fentry_test_t *arg)
     1: (b4) w0 = 0
     2: (95) exit
After the previous verifier change, we have:
  int test7(long long unsigned int * ctx):
  ; int BPF_PROG(test7, struct bpf_fentry_test_t *arg)
     0: (79) r1 = *(u64 *)(r1 +0)
  ; if (arg == 0)
     1: (55) if r1 != 0x0 goto pc+4
  ; test7_result = 1;
     2: (18) r1 = map[id:6][0]+48
     4: (b7) r2 = 1
     5: (7b) *(u64 *)(r1 +0) = r2
  ; int BPF_PROG(test7, struct bpf_fentry_test_t *arg)
     6: (b4) w0 = 0
     7: (95) exit

Signed-off-by: Yonghong Song 
Signed-off-by: Daniel Borkmann 
Acked-by: John Fastabend 
Acked-by: Andrii Nakryiko 
Link: https://lore.kernel.org/bpf/20200630171241.2523875-1-yhs@fb.com

bpf: Fix too large copy from user in bpf_test_init

2020-05-19T15:56:34+00:00

Commit bc56c919fce7 ("bpf: Add xdp.frame_sz in bpf_prog_test_run_xdp().")
recently changed bpf_prog_test_run_xdp() to use larger frames for XDP in
order to test tail growing frames (via bpf_xdp_adjust_tail) and to have
memory backing frame better resemble drivers.

The commit contains a bug, as it tries to copy the max data size from
userspace, instead of the size provided by userspace.  This cause XDP
unit tests to fail sporadically with EFAULT, an unfortunate behavior.
The fix is to only copy the size specified by userspace.

Fixes: bc56c919fce7 ("bpf: Add xdp.frame_sz in bpf_prog_test_run_xdp().")
Signed-off-by: Jesper Dangaard Brouer 
Signed-off-by: Daniel Borkmann 
Acked-by: Andrii Nakryiko 
Link: https://lore.kernel.org/bpf/158980712729.256597.6115007718472928659.stgit@firesoul

bpf: Add xdp.frame_sz in bpf_prog_test_run_xdp().

2020-05-15T04:21:56+00:00

Update the memory requirements, when adding xdp.frame_sz in BPF test_run
function bpf_prog_test_run_xdp() which e.g. is used by XDP selftests.

Specifically add the expected reserved tailroom, but also allocated a
larger memory area to reflect that XDP frames usually comes in this
format. Limit the provided packet data size to 4096 minus headroom +
tailroom, as this also reflect a common 3520 bytes MTU limit with XDP.

Note that bpf_test_init already use a memory allocation method that clears
memory.  Thus, this already guards against leaking uninit kernel memory.

Signed-off-by: Jesper Dangaard Brouer 
Signed-off-by: Alexei Starovoitov 
Link: https://lore.kernel.org/bpf/158945349549.97035.15316291762482444006.stgit@firesoul

bpf: Fix build warning regarding missing prototypes

2020-03-28T17:13:18+00:00

Fix build warnings when building net/bpf/test_run.o with W=1 due
to missing prototype for bpf_fentry_test{1..6}.

Instead of declaring prototypes, turn off warnings with
__diag_{push,ignore,pop} as pointed out by Alexei.

Signed-off-by: Jean-Philippe Menil 
Signed-off-by: Daniel Borkmann 
Link: https://lore.kernel.org/bpf/20200327204713.28050-1-jpmenil@gmail.com

bpf: Add selftests for BPF_MODIFY_RETURN

2020-03-04T21:41:06+00:00

Test for two scenarios:

  * When the fmod_ret program returns 0, the original function should
    be called along with fentry and fexit programs.
  * When the fmod_ret program returns a non-zero value, the original
    function should not be called, no side effect should be observed and
    fentry and fexit programs should be called.

The result from the kernel function call and whether a side-effect is
observed is returned via the retval attr of the BPF_PROG_TEST_RUN (bpf)
syscall.

Signed-off-by: KP Singh 
Signed-off-by: Alexei Starovoitov 
Acked-by: Andrii Nakryiko 
Acked-by: Daniel Borkmann 
Link: https://lore.kernel.org/bpf/20200304191853.1529-8-kpsingh@chromium.org

bpf: Add test ops for BPF_PROG_TYPE_TRACING

2020-03-04T21:41:06+00:00

The current fexit and fentry tests rely on a different program to
exercise the functions they attach to. Instead of doing this, implement
the test operations for tracing which will also be used for
BPF_MODIFY_RETURN in a subsequent patch.

Also, clean up the fexit test to use the generated skeleton.

Signed-off-by: KP Singh 
Signed-off-by: Alexei Starovoitov 
Acked-by: Andrii Nakryiko 
Acked-by: Daniel Borkmann 
Link: https://lore.kernel.org/bpf/20200304191853.1529-7-kpsingh@chromium.org

bpf: Add gso_size to __sk_buff

2020-03-04T00:23:59+00:00

BPF programs may want to know whether an skb is gso. The canonical
answer is skb_is_gso(skb), which tests that gso_size != 0.

Expose this field in the same manner as gso_segs. That field itself
is not a sufficient signal, as the comment in skb_shared_info makes
clear: gso_segs may be zero, e.g., from dodgy sources.

Also prepare net/bpf/test_run for upcoming BPF_PROG_TEST_RUN tests
of the feature.

Signed-off-by: Willem de Bruijn 
Signed-off-by: Alexei Starovoitov 
Link: https://lore.kernel.org/bpf/20200303200503.226217-2-willemdebruijn.kernel@gmail.com

bpf/tests: Use migrate disable instead of preempt disable

2020-02-25T00:20:09+00:00

Replace the preemption disable/enable with migrate_disable/enable() to
reflect the actual requirement and to allow PREEMPT_RT to substitute it
with an actual migration disable mechanism which does not disable
preemption.

[ tglx: Switched it over to migrate disable ]

Signed-off-by: David S. Miller 
Signed-off-by: Thomas Gleixner 
Signed-off-by: Alexei Starovoitov 
Link: https://lore.kernel.org/bpf/20200224145643.785306549@linutronix.de

bpf: Allow to change skb mark in test_run

2019-12-19T01:05:58+00:00

allow to pass skb's mark field into bpf_prog_test_run ctx
for BPF_PROG_TYPE_SCHED_CLS prog type. that would allow
to test bpf programs which are doing decision based on this
field

Signed-off-by: Nikita V. Shirokov 
Signed-off-by: Alexei Starovoitov

bpf: Expose __sk_buff wire_len/gso_segs to BPF_PROG_TEST_RUN

2019-12-13T23:26:53+00:00

wire_len should not be less than real len and is capped by GSO_MAX_SIZE.
gso_segs is capped by GSO_MAX_SEGS.

v2:
* set wire_len to skb->len when passed wire_len is 0 (Alexei Starovoitov)

Signed-off-by: Stanislav Fomichev 
Signed-off-by: Alexei Starovoitov 
Cc: Martin KaFai Lau 
Link: https://lore.kernel.org/bpf/20191213223028.161282-1-sdf@google.com