When running bpf selftest (./test_progs -j), the following warnings
showed up:
$ ./test_progs -t arena_atomics
...
BUG: using smp_processor_id() in preemptible [00000000] code: kworker/u19:0/12501
caller is bpf_mem_free+0x128/0x330
...
Call Trace:
<TASK>
dump_stack_lvl
check_preemption_disabled
bpf_mem_free
range_tree_destroy
arena_map_free
bpf_map_free_deferred
process_scheduled_works
...
For selftests arena_htab and arena_list, similar smp_process_id() BUGs are
dumped, and the following are two stack trace:
<TASK>
dump_stack_lvl
check_preemption_disabled
bpf_mem_alloc
range_tree_set
arena_map_alloc
map_create
...
<TASK>
dump_stack_lvl
check_preemption_disabled
bpf_mem_alloc
range_tree_clear
arena_vm_fault
do_pte_missing
handle_mm_fault
do_user_addr_fault
...
Add migrate_{disable,enable}() around related bpf_mem_{alloc,free}()
calls to fix the issue.
Fixes: b795379757eb ("bpf: Introduce range_tree data structure and use it in bpf arena")
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20241115060354.2832495-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Introduce range_tree data structure and use it in bpf arena to track
ranges of allocated pages. range_tree is a large bitmap that is
implemented as interval tree plus rbtree. The contiguous sequence of
bits represents unallocated pages.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/bpf/20241108025616.17625-2-alexei.starovoitov@gmail.com
