Re: [PATCH bpf] bpf: fix selftests/bpf test_kmod.sh failure when CONFIG_BPF_JIT_ALWAYS_ON=y

2018-02-04 Thread Daniel Borkmann
On 02/03/2018 07:37 AM, Yonghong Song wrote:
> With CONFIG_BPF_JIT_ALWAYS_ON is defined in the config file,
> tools/testing/selftests/bpf/test_kmod.sh failed like below:
[...]
> With this logic, Test #297 always gets return value -ENOTSUPP
> when CONFIG_BPF_JIT_ALWAYS_ON is defined, causing the test failure.
> 
> This patch fixed the failure by marking Test #297 as expected failure
> when CONFIG_BPF_JIT_ALWAYS_ON is defined.
> 
> Fixes: 290af86629b2 (bpf: introduce BPF_JIT_ALWAYS_ON config)
> Signed-off-by: Yonghong Song 

Applied to bpf tree, thanks Yonghong!


[PATCH bpf] bpf: fix selftests/bpf test_kmod.sh failure when CONFIG_BPF_JIT_ALWAYS_ON=y

2018-02-02 Thread Yonghong Song
With CONFIG_BPF_JIT_ALWAYS_ON is defined in the config file,
tools/testing/selftests/bpf/test_kmod.sh failed like below:
  [root@localhost bpf]# ./test_kmod.sh
  sysctl: setting key "net.core.bpf_jit_enable": Invalid argument
  [ JIT enabled:0 hardened:0 ]
  [  132.175681] test_bpf: #297 BPF_MAXINSNS: Jump, gap, jump, ... FAIL to 
prog_create err=-524 len=4096
  [  132.458834] test_bpf: Summary: 348 PASSED, 1 FAILED, [340/340 JIT'ed]
  [ JIT enabled:1 hardened:0 ]
  [  133.456025] test_bpf: #297 BPF_MAXINSNS: Jump, gap, jump, ... FAIL to 
prog_create err=-524 len=4096
  [  133.730935] test_bpf: Summary: 348 PASSED, 1 FAILED, [340/340 JIT'ed]
  [ JIT enabled:1 hardened:1 ]
  [  134.769730] test_bpf: #297 BPF_MAXINSNS: Jump, gap, jump, ... FAIL to 
prog_create err=-524 len=4096
  [  135.050864] test_bpf: Summary: 348 PASSED, 1 FAILED, [340/340 JIT'ed]
  [ JIT enabled:1 hardened:2 ]
  [  136.442882] test_bpf: #297 BPF_MAXINSNS: Jump, gap, jump, ... FAIL to 
prog_create err=-524 len=4096
  [  136.821810] test_bpf: Summary: 348 PASSED, 1 FAILED, [340/340 JIT'ed]
  [root@localhost bpf]#

The test_kmod.sh load/remove test_bpf.ko multiple times with different
settings for sysctl net.core.bpf_jit_{enable,harden}. The failed test #297
of test_bpf.ko is designed such that JIT always fails.

Commit 290af86629b2 (bpf: introduce BPF_JIT_ALWAYS_ON config)
introduced the following tightening logic:
...
if (!bpf_prog_is_dev_bound(fp->aux)) {
fp = bpf_int_jit_compile(fp);
#ifdef CONFIG_BPF_JIT_ALWAYS_ON
if (!fp->jited) {
*err = -ENOTSUPP;
return fp;
}
#endif
...
With this logic, Test #297 always gets return value -ENOTSUPP
when CONFIG_BPF_JIT_ALWAYS_ON is defined, causing the test failure.

This patch fixed the failure by marking Test #297 as expected failure
when CONFIG_BPF_JIT_ALWAYS_ON is defined.

Fixes: 290af86629b2 (bpf: introduce BPF_JIT_ALWAYS_ON config)
Signed-off-by: Yonghong Song 
---
 lib/test_bpf.c | 31 ++-
 1 file changed, 26 insertions(+), 5 deletions(-)

diff --git a/lib/test_bpf.c b/lib/test_bpf.c
index 4cd9ea9..b4e2234 100644
--- a/lib/test_bpf.c
+++ b/lib/test_bpf.c
@@ -83,6 +83,7 @@ struct bpf_test {
__u32 result;
} test[MAX_SUBTESTS];
int (*fill_helper)(struct bpf_test *self);
+   int expected_errcode; /* used when FLAG_EXPECTED_FAIL is set in the aux 
*/
__u8 frag_data[MAX_DATA];
int stack_depth; /* for eBPF only, since tests don't call verifier */
 };
@@ -2026,7 +2027,9 @@ static struct bpf_test tests[] = {
},
CLASSIC | FLAG_NO_DATA | FLAG_EXPECTED_FAIL,
{ },
-   { }
+   { },
+   .fill_helper = NULL,
+   .expected_errcode = -EINVAL,
},
{
"check: div_k_0",
@@ -2036,7 +2039,9 @@ static struct bpf_test tests[] = {
},
CLASSIC | FLAG_NO_DATA | FLAG_EXPECTED_FAIL,
{ },
-   { }
+   { },
+   .fill_helper = NULL,
+   .expected_errcode = -EINVAL,
},
{
"check: unknown insn",
@@ -2047,7 +2052,9 @@ static struct bpf_test tests[] = {
},
CLASSIC | FLAG_EXPECTED_FAIL,
{ },
-   { }
+   { },
+   .fill_helper = NULL,
+   .expected_errcode = -EINVAL,
},
{
"check: out of range spill/fill",
@@ -2057,7 +2064,9 @@ static struct bpf_test tests[] = {
},
CLASSIC | FLAG_NO_DATA | FLAG_EXPECTED_FAIL,
{ },
-   { }
+   { },
+   .fill_helper = NULL,
+   .expected_errcode = -EINVAL,
},
{
"JUMPS + HOLES",
@@ -2149,6 +2158,8 @@ static struct bpf_test tests[] = {
CLASSIC | FLAG_NO_DATA | FLAG_EXPECTED_FAIL,
{ },
{ },
+   .fill_helper = NULL,
+   .expected_errcode = -EINVAL,
},
{
"check: LDX + RET X",
@@ -2159,6 +2170,8 @@ static struct bpf_test tests[] = {
CLASSIC | FLAG_NO_DATA | FLAG_EXPECTED_FAIL,
{ },
{ },
+   .fill_helper = NULL,
+   .expected_errcode = -EINVAL,
},
{   /* Mainly checking JIT here. */
"M[]: alt STX + LDX",
@@ -2333,6 +2346,8 @@ static struct bpf_test tests[] = {
CLASSIC | FLAG_NO_DATA | FLAG_EXPECTED_FAIL,
{ },
{ },
+   .fill_helper = NULL,
+   .expected_errcode = -EINVAL,
},
{   /* Passes checker but fails during runtime. */
"LD [SKF_AD_OFF-1]",
@@ -5395,6 +5410,7 @@ static struct bpf_test tests[] = {