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| author |  Alexander Lobakin <aleksander.lobakin@intel.com>
| 2024-02-15 12:39:05 +0100 |
|---|---|---|
| committer |  Jakub Kicinski <kuba@kernel.org>
| 2024-02-19 11:48:00 -0800 |
| commit | 56ef27e3abe6d6453b1f4f6127041f3a65d7cbc9 (patch) | |
| tree | 4a0ffd10e40a1afcc6d41ab566b4d87ed1dc3809 /net/core/skbuff.c | |
| parent | dt-bindings: net: fec: add iommus property (diff) | |
| download | linux-56ef27e3abe6d6453b1f4f6127041f3a65d7cbc9.tar.gz linux-56ef27e3abe6d6453b1f4f6127041f3a65d7cbc9.tar.bz2 linux-56ef27e3abe6d6453b1f4f6127041f3a65d7cbc9.zip | |
page_pool: disable direct recycling based on pool->cpuid on destroy
Now that direct recycling is performed basing on pool->cpuid when set,
memory leaks are possible:
1. A pool is destroyed.
2. Alloc cache is emptied (it's done only once).
3. pool->cpuid is still set.
4. napi_pp_put_page() does direct recycling basing on pool->cpuid.
5. Now alloc cache is not empty, but it won't ever be freed.
In order to avoid that, rewrite pool->cpuid to -1 when unlinking NAPI to
make sure no direct recycling will be possible after emptying the cache.
This involves a bit of overhead as pool->cpuid now must be accessed
via READ_ONCE() to avoid partial reads.
Rename page_pool_unlink_napi() -> page_pool_disable_direct_recycling()
to reflect what it actually does and unexport it.
Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/r/20240215113905.96817-1-aleksander.lobakin@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/core/skbuff.c')
| -rw-r--r-- | net/core/skbuff.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 0d9a489e6ae1..b41856585c24 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -1018,7 +1018,7 @@ bool napi_pp_put_page(struct page *page, bool napi_safe) unsigned int cpuid = smp_processor_id(); allow_direct = napi && READ_ONCE(napi->list_owner) == cpuid; - allow_direct |= (pp->cpuid == cpuid); + allow_direct |= READ_ONCE(pp->cpuid) == cpuid; } /* Driver set this to memory recycling info. Reset it on recycle. |