diff options
| author | Alexei Starovoitov <[email protected]> | 2018-12-03 22:46:05 -0800 |
|---|---|---|
| committer | Daniel Borkmann <[email protected]> | 2018-12-04 17:22:02 +0100 |
| commit | 4f7b3e82589e0de723780198ec7983e427144c0a (patch) | |
| tree | 38fa3a5035551cfe6b4e5d7d5268ca4834e353f5 /tools/perf/scripts/python/export-to-postgresql.py | |
| parent | c3494801cd1785e2c25f1a5735fa19ddcf9665da (diff) | |
bpf: improve verifier branch analysis
pathological bpf programs may try to force verifier to explode in
the number of branch states:
20: (d5) if r1 s<= 0x24000028 goto pc+0
21: (b5) if r0 <= 0xe1fa20 goto pc+2
22: (d5) if r1 s<= 0x7e goto pc+0
23: (b5) if r0 <= 0xe880e000 goto pc+0
24: (c5) if r0 s< 0x2100ecf4 goto pc+0
25: (d5) if r1 s<= 0xe880e000 goto pc+1
26: (c5) if r0 s< 0xf4041810 goto pc+0
27: (d5) if r1 s<= 0x1e007e goto pc+0
28: (b5) if r0 <= 0xe86be000 goto pc+0
29: (07) r0 += 16614
30: (c5) if r0 s< 0x6d0020da goto pc+0
31: (35) if r0 >= 0x2100ecf4 goto pc+0
Teach verifier to recognize always taken and always not taken branches.
This analysis is already done for == and != comparison.
Expand it to all other branches.
It also helps real bpf programs to be verified faster:
before after
bpf_lb-DLB_L3.o 2003 1940
bpf_lb-DLB_L4.o 3173 3089
bpf_lb-DUNKNOWN.o 1080 1065
bpf_lxc-DDROP_ALL.o 29584 28052
bpf_lxc-DUNKNOWN.o 36916 35487
bpf_netdev.o 11188 10864
bpf_overlay.o 6679 6643
bpf_lcx_jit.o 39555 38437
Reported-by: Anatoly Trosinenko <[email protected]>
Signed-off-by: Alexei Starovoitov <[email protected]>
Acked-by: Daniel Borkmann <[email protected]>
Acked-by: Edward Cree <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>
Diffstat (limited to 'tools/perf/scripts/python/export-to-postgresql.py')
0 files changed, 0 insertions, 0 deletions