linux/tools/testing/selftests/bpf
Yonghong Song 332270fdc8 bpf: enhance verifier to understand stack pointer arithmetic
llvm 4.0 and above generates the code like below:
....
440: (b7) r1 = 15
441: (05) goto pc+73
515: (79) r6 = *(u64 *)(r10 -152)
516: (bf) r7 = r10
517: (07) r7 += -112
518: (bf) r2 = r7
519: (0f) r2 += r1
520: (71) r1 = *(u8 *)(r8 +0)
521: (73) *(u8 *)(r2 +45) = r1
....
and the verifier complains "R2 invalid mem access 'inv'" for insn #521.
This is because verifier marks register r2 as unknown value after #519
where r2 is a stack pointer and r1 holds a constant value.

Teach verifier to recognize "stack_ptr + imm" and
"stack_ptr + reg with const val" as valid stack_ptr with new offset.

Signed-off-by: Yonghong Song <yhs@fb.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-01 11:40:23 -04:00
..
.gitignore bpf: Add test_tag to .gitignore 2017-02-10 15:56:08 -05:00
bpf_util.h bpf: provide a generic macro for percpu values for selftests 2017-04-28 15:48:15 -04:00
config
Makefile Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-04-06 08:24:51 -07:00
test_iptunnel_common.h selftests/bpf: add a test for basic XDP functionality 2017-04-01 12:45:57 -07:00
test_kmod.sh selftests: do not require bash to run bpf tests 2017-01-05 13:19:47 -07:00
test_l4lb.c bpf: fix _htons occurences in test_progs 2017-04-28 15:48:15 -04:00
test_lpm_map.c bpf: Remove bpf_sys.h from selftests 2017-02-10 15:56:08 -05:00
test_lru_map.c bpf: lru: Lower the PERCPU_NR_SCANS from 16 to 4 2017-04-17 13:55:52 -04:00
test_maps.c bpf: provide a generic macro for percpu values for selftests 2017-04-28 15:48:15 -04:00
test_pkt_access.c bpf: fix _htons occurences in test_progs 2017-04-28 15:48:15 -04:00
test_progs.c bpf: fix _htons occurences in test_progs 2017-04-28 15:48:15 -04:00
test_tag.c bpf: Remove bpf_sys.h from selftests 2017-02-10 15:56:08 -05:00
test_verifier.c bpf: enhance verifier to understand stack pointer arithmetic 2017-05-01 11:40:23 -04:00
test_xdp.c selftests/bpf: add a test for basic XDP functionality 2017-04-01 12:45:57 -07:00