bpf: Free special fields when update [lru_,]percpu_hash maps #6285
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As [lru_,]percpu_hash maps support BPF_KPTR_{REF,PERCPU}, missing
calls to 'bpf_obj_free_fields()' in 'pcpu_copy_value()' could cause the
memory referenced by BPF_KPTR_{REF,PERCPU} fields to be held until the
map gets freed.
Fix this by calling 'bpf_obj_free_fields()' after
'copy_map_value[,_long]()' in 'pcpu_copy_value()'.
Fixes: 65334e6 ("bpf: Support kptrs in percpu hashmap and percpu LRU hashmap")
Signed-off-by: Leon Hwang <[email protected]>
…ate [lru_,]percpu_hash maps Add test to verify that updating [lru_,]percpu_hash maps decrements refcount when BPF_KPTR_REF objects are involved. The tests perform the following steps: 1. Call update_elem() to insert an initial value. 2. Use bpf_refcount_acquire() to increment the refcount. 3. Store the node pointer in the map value. 4. Add the node to a linked list. 5. Probe-read the refcount and verify it is *2*. 6. Call update_elem() again to trigger refcount decrement. 7. Probe-read the refcount and verify it is *1*. Signed-off-by: Leon Hwang <[email protected]>
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Upstream branch: 11369e6 |
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At least one diff in series https://patchwork.kernel.org/project/netdevbpf/list/?series=1019486 expired. Closing PR. |
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Pull request for series with
subject: bpf: Free special fields when update [lru_,]percpu_hash maps
version: 5
url: https://patchwork.kernel.org/project/netdevbpf/list/?series=1019486