On Tue, Sep 29, 2020 at 5:20 PM Song Liu <songliubraving@xxxxxx> wrote:
>
> In preempt kernel, BPF_PROG_TEST_RUN on raw_tp triggers:
>
> [ 35.874974] BUG: using smp_processor_id() in preemptible [00000000]
> code: new_name/87
> [ 35.893983] caller is bpf_prog_test_run_raw_tp+0xd4/0x1b0
> [ 35.900124] CPU: 1 PID: 87 Comm: new_name Not tainted 5.9.0-rc6-g615bd02bf #1
> [ 35.907358] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
> BIOS 1.10.2-1ubuntu1 04/01/2014
> [ 35.916941] Call Trace:
> [ 35.919660] dump_stack+0x77/0x9b
> [ 35.923273] check_preemption_disabled+0xb4/0xc0
> [ 35.928376] bpf_prog_test_run_raw_tp+0xd4/0x1b0
> [ 35.933872] ? selinux_bpf+0xd/0x70
> [ 35.937532] __do_sys_bpf+0x6bb/0x21e0
> [ 35.941570] ? find_held_lock+0x2d/0x90
> [ 35.945687] ? vfs_write+0x150/0x220
> [ 35.949586] do_syscall_64+0x2d/0x40
> [ 35.953443] entry_SYSCALL_64_after_hwframe+0x44/0xa9
>
> Fix this by calling migrate_disable() before smp_processor_id().
>
> Fixes: 1b4d60ec162f ("bpf: Enable BPF_PROG_TEST_RUN for raw_tracepoint")
> Reported-by: Alexei Starovoitov <ast@xxxxxxxxxx>
> Signed-off-by: Song Liu <songliubraving@xxxxxx>
>
> ---
> Changes v1 => v2:
> 1. Keep rcu_read_lock/unlock() in original places. (Alexei)
> 2. Use get_cpu() instead of smp_processor_id(). (Alexei)
Applying: bpf: fix raw_tp test run in preempt kernel
Using index info to reconstruct a base tree...
error: patch failed: net/bpf/test_run.c:293
error: net/bpf/test_run.c: patch does not apply
error: Did you hand edit your patch?
