lkml.org 
[lkml]   [2019]   [May]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH bpf v1 1/3] selftests/bpf: Test correctness of narrow 32bit read on 64bit field
Date
Test the correctness of the 32bit narrow reads by reading both halves
of the 64 bit field and doing a binary or on them to see if we get the
original value.

This isn't really tested - the program is not being run, because
BPF_PROG_TYPE_PERF_EVENT is not supported by bpf_test_run_prog.

Signed-off-by: Krzesimir Nowak <krzesimir@kinvolk.io>
---
tools/testing/selftests/bpf/verifier/var_off.c | 15 +++++++++++++++
1 file changed, 15 insertions(+)

diff --git a/tools/testing/selftests/bpf/verifier/var_off.c b/tools/testing/selftests/bpf/verifier/var_off.c
index 8504ac937809..2668819dcc85 100644
--- a/tools/testing/selftests/bpf/verifier/var_off.c
+++ b/tools/testing/selftests/bpf/verifier/var_off.c
@@ -246,3 +246,18 @@
.result = ACCEPT,
.prog_type = BPF_PROG_TYPE_LWT_IN,
},
+{
+ "32bit loads of a 64bit field (both least and most significant words)",
+ .insns = {
+ BPF_LDX_MEM(BPF_W, BPF_REG_4, BPF_REG_1, offsetof(struct bpf_perf_event_data, sample_period)),
+ BPF_LDX_MEM(BPF_W, BPF_REG_5, BPF_REG_1, offsetof(struct bpf_perf_event_data, sample_period) + 4),
+ BPF_LDX_MEM(BPF_DW, BPF_REG_6, BPF_REG_1, offsetof(struct bpf_perf_event_data, sample_period)),
+ BPF_ALU64_IMM(BPF_LSH, BPF_REG_4, 32),
+ BPF_ALU64_REG(BPF_OR, BPF_REG_4, BPF_REG_5),
+ BPF_ALU64_REG(BPF_XOR, BPF_REG_4, BPF_REG_6),
+ BPF_MOV64_REG(BPF_REG_0, BPF_REG_4),
+ BPF_EXIT_INSN(),
+ },
+ .result = ACCEPT,
+ .prog_type = BPF_PROG_TYPE_PERF_EVENT,
+},
--
2.20.1
\
 
 \ /
  Last update: 2019-05-15 15:51    [W:0.043 / U:2.620 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site