From: Anders Roxell <anders.roxell@linaro.org>
To: ast@kernel.org, daniel@iogearbox.net
Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
Anders Roxell <anders.roxell@linaro.org>,
Arnd Bergmann <arnd@arndb.de>
Subject: [PATCH v2] bpf: test_bpf: turn of preemption in function __run_once
Date: Fri, 22 Feb 2019 09:46:52 +0100 [thread overview]
Message-ID: <20190222084652.1326-1-anders.roxell@linaro.org> (raw)
When running BPF test suite the following splat occurs:
[ 415.930950] test_bpf: #0 TAX jited:0
[ 415.931067] BUG: assuming atomic context at lib/test_bpf.c:6674
[ 415.946169] in_atomic(): 0, irqs_disabled(): 0, pid: 11556, name: modprobe
[ 415.953176] INFO: lockdep is turned off.
[ 415.957207] CPU: 1 PID: 11556 Comm: modprobe Tainted: G W 5.0.0-rc7-next-20190220 #1
[ 415.966328] Hardware name: HiKey Development Board (DT)
[ 415.971592] Call trace:
[ 415.974069] dump_backtrace+0x0/0x160
[ 415.977761] show_stack+0x24/0x30
[ 415.981104] dump_stack+0xc8/0x114
[ 415.984534] __cant_sleep+0xf0/0x108
[ 415.988145] test_bpf_init+0x5e0/0x1000 [test_bpf]
[ 415.992971] do_one_initcall+0x90/0x428
[ 415.996837] do_init_module+0x60/0x1e4
[ 416.000614] load_module+0x1de0/0x1f50
[ 416.004391] __se_sys_finit_module+0xc8/0xe0
[ 416.008691] __arm64_sys_finit_module+0x24/0x30
[ 416.013255] el0_svc_common+0x78/0x130
[ 416.017031] el0_svc_handler+0x38/0x78
[ 416.020806] el0_svc+0x8/0xc
Rework so that preemption is disabled when we loop over function
'BPF_PROG_RUN(...)'.
Commit 568f196756ad ("bpf: check that BPF programs run with preemption disabled")
highlighted the issue.
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
---
lib/test_bpf.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/lib/test_bpf.c b/lib/test_bpf.c
index f3e570722a7e..0845f635f404 100644
--- a/lib/test_bpf.c
+++ b/lib/test_bpf.c
@@ -6668,12 +6668,14 @@ static int __run_one(const struct bpf_prog *fp, const void *data,
u64 start, finish;
int ret = 0, i;
+ preempt_disable();
start = ktime_get_ns();
for (i = 0; i < runs; i++)
ret = BPF_PROG_RUN(fp, data);
finish = ktime_get_ns();
+ preempt_enable();
*duration = finish - start;
do_div(*duration, runs);
--
2.20.1
next reply other threads:[~2019-02-22 8:47 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-22 8:46 Anders Roxell [this message]
2019-02-25 21:28 ` [PATCH v2] bpf: test_bpf: turn of preemption in function __run_once Daniel Borkmann
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