On 24 Oct 2025, at 18:56, Ilya Maximets wrote:
> In a few places the list sizes are checked without holding the lock.
> While this probably speeds up the processing a bit, it's technically
> incorrect as the access is not atomic. Caught by thread-safety
> analyzer of clang 21, as it now properly supports GUARDED annotations
> on structure fields:
>
> lib/ipf.c:1117:33:
> error: reading the value pointed to by 'frag_exp_list' requires
> holding any mutex [-Werror,-Wthread-safety-analysis]
> 1117 | if (ovs_list_is_empty(&ipf->frag_exp_list)) {
> | ^
> lib/ipf.c:1154:33:
> error: reading the value pointed to by 'reassembled_pkt_list'
> requires holding any mutex [-Werror,-Wthread-safety-analysis]
> 1154 | if (ovs_list_is_empty(&ipf->reassembled_pkt_list)) {
> | ^
>
> Not trying to fix the actual non-atomic access to the list as getting
> the wrong result in these particular calls will not meaningfully
> impact the correctness of the code, but taking the lock before checking
> will likely reduce performance.
>
> For now, just working around the problem by turning off thread safety
> analysis for these particular calls. The new _unsafe() access function
> is also a bit more obvious in a way that it's more clear that these
> calls should not be relied upon for logic that requires precision.
>
> Signed-off-by: Ilya Maximets <[email protected]>
hanks for fixing this, Ilya. I guess this will do for now.
Acked-by: Eelco Chaudron <[email protected]>
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