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author | Hou Tao <houtao1@huawei.com> | 2022-08-10 16:05:35 +0800 |
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committer | Alexei Starovoitov <ast@kernel.org> | 2022-08-10 10:12:48 -0700 |
commit | d247049f4fd088e4e40294819a932a6057b3632c (patch) | |
tree | 206244e8fd1c6487d541dea2c9405580de17c60e /tools/testing | |
parent | bpf: Check the validity of max_rdwr_access for sock local storage map iterator (diff) | |
download | linux-dev-d247049f4fd088e4e40294819a932a6057b3632c.tar.xz linux-dev-d247049f4fd088e4e40294819a932a6057b3632c.zip |
bpf: Only allow sleepable program for resched-able iterator
When a sleepable program is attached to a hash map iterator, might_fault()
will report "BUG: sleeping function called from invalid context..." if
CONFIG_DEBUG_ATOMIC_SLEEP is enabled. The reason is that rcu_read_lock()
is held in bpf_hash_map_seq_next() and won't be released until all elements
are traversed or bpf_hash_map_seq_stop() is called.
Fixing it by reusing BPF_ITER_RESCHED to indicate that only non-sleepable
program is allowed for iterator without BPF_ITER_RESCHED. We can revise
bpf_iter_link_attach() later if there are other conditions which may
cause rcu_read_lock() or spin_lock() issues.
Signed-off-by: Hou Tao <houtao1@huawei.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20220810080538.1845898-7-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'tools/testing')
0 files changed, 0 insertions, 0 deletions