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| author | Roman Gushchin <guro@fb.com> | 2018-04-23 18:09:21 +0100 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2018-04-23 23:20:11 +0200 |
| commit | 6899b32b5b2dee358936b82b8363b716607a138f (patch) | |
| tree | c03f591222ed167114beaf85729104667c187b88 /include/linux/bpf.h | |
| parent | 77621f024d6be732e43366a42203486b6ec89acd (diff) | |
| download | linux-6899b32b5b2dee358936b82b8363b716607a138f.tar.gz linux-6899b32b5b2dee358936b82b8363b716607a138f.tar.bz2 linux-6899b32b5b2dee358936b82b8363b716607a138f.zip | |
bpf: disable and restore preemption in __BPF_PROG_RUN_ARRAY
Running bpf programs requires disabled preemption,
however at least some* of the BPF_PROG_RUN_ARRAY users
do not follow this rule.
To fix this bug, and also to make it not happen in the future,
let's add explicit preemption disabling/re-enabling
to the __BPF_PROG_RUN_ARRAY code.
* for example:
[ 17.624472] RIP: 0010:__cgroup_bpf_run_filter_sk+0x1c4/0x1d0
...
[ 17.640890] inet6_create+0x3eb/0x520
[ 17.641405] __sock_create+0x242/0x340
[ 17.641939] __sys_socket+0x57/0xe0
[ 17.642370] ? trace_hardirqs_off_thunk+0x1a/0x1c
[ 17.642944] SyS_socket+0xa/0x10
[ 17.643357] do_syscall_64+0x79/0x220
[ 17.643879] entry_SYSCALL_64_after_hwframe+0x42/0xb7
Signed-off-by: Roman Gushchin <guro@fb.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Diffstat (limited to 'include/linux/bpf.h')
| -rw-r--r-- | include/linux/bpf.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 486e65e3db26..dc586cc64bc2 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -351,6 +351,7 @@ int bpf_prog_array_copy(struct bpf_prog_array __rcu *old_array, struct bpf_prog **_prog, *__prog; \ struct bpf_prog_array *_array; \ u32 _ret = 1; \ + preempt_disable(); \ rcu_read_lock(); \ _array = rcu_dereference(array); \ if (unlikely(check_non_null && !_array))\ @@ -362,6 +363,7 @@ int bpf_prog_array_copy(struct bpf_prog_array __rcu *old_array, } \ _out: \ rcu_read_unlock(); \ + preempt_enable_no_resched(); \ _ret; \ }) |