From: David Howells <dhowells@redhat.com>
To: netdev@vger.kernel.org
Cc: David Howells <dhowells@redhat.com>,
"David S. Miller" <davem@davemloft.net>,
Eric Dumazet <edumazet@google.com>,
Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
Willem de Bruijn <willemdebruijn.kernel@gmail.com>,
David Ahern <dsahern@kernel.org>,
Matthew Wilcox <willy@infradead.org>,
Jens Axboe <axboe@kernel.dk>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Jeroen de Borst <jeroendb@google.com>,
Catherine Sullivan <csully@google.com>,
Shailend Chand <shailend@google.com>,
Felix Fietkau <nbd@nbd.name>, John Crispin <john@phrozen.org>,
Sean Wang <sean.wang@mediatek.com>,
Mark Lee <Mark-MC.Lee@mediatek.com>,
Lorenzo Bianconi <lorenzo@kernel.org>,
Matthias Brugger <matthias.bgg@gmail.com>,
AngeloGioacchino Del Regno
<angelogioacchino.delregno@collabora.com>,
Keith Busch <kbusch@kernel.org>, Jens Axboe <axboe@fb.com>,
Christoph Hellwig <hch@lst.de>, Sagi Grimberg <sagi@grimberg.me>,
Chaitanya Kulkarni <kch@nvidia.com>,
Andrew Morton <akpm@linux-foundation.org>,
linux-arm-kernel@lists.infradead.org,
linux-mediatek@lists.infradead.org,
linux-nvme@lists.infradead.org
Subject: [PATCH net-next 05/12] mm: Make the page_frag_cache allocator handle __GFP_ZERO itself
Date: Wed, 24 May 2023 16:33:04 +0100 [thread overview]
Message-ID: <20230524153311.3625329-6-dhowells@redhat.com> (raw)
In-Reply-To: <20230524153311.3625329-1-dhowells@redhat.com>
Make the page_frag_cache allocator handle __GFP_ZERO itself rather than
passing it off to the page allocator. There may be a mix of callers, some
specifying __GFP_ZERO and some not - and even if all specify __GFP_ZERO, we
might refurbish the page, in which case the returned memory doesn't get
cleared.
This is a potential bug in the nvme over TCP driver.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: "David S. Miller" <davem@davemloft.net>
cc: Eric Dumazet <edumazet@google.com>
cc: Jakub Kicinski <kuba@kernel.org>
cc: Paolo Abeni <pabeni@redhat.com>
cc: Jens Axboe <axboe@kernel.dk>
cc: Jeroen de Borst <jeroendb@google.com>
cc: Catherine Sullivan <csully@google.com>
cc: Shailend Chand <shailend@google.com>
cc: Felix Fietkau <nbd@nbd.name>
cc: John Crispin <john@phrozen.org>
cc: Sean Wang <sean.wang@mediatek.com>
cc: Mark Lee <Mark-MC.Lee@mediatek.com>
cc: Lorenzo Bianconi <lorenzo@kernel.org>
cc: Matthias Brugger <matthias.bgg@gmail.com>
cc: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
cc: Keith Busch <kbusch@kernel.org>
cc: Jens Axboe <axboe@fb.com>
cc: Christoph Hellwig <hch@lst.de>
cc: Sagi Grimberg <sagi@grimberg.me>
cc: Chaitanya Kulkarni <kch@nvidia.com>
cc: Andrew Morton <akpm@linux-foundation.org>
cc: Matthew Wilcox <willy@infradead.org>
cc: netdev@vger.kernel.org
cc: linux-arm-kernel@lists.infradead.org
cc: linux-mediatek@lists.infradead.org
cc: linux-nvme@lists.infradead.org
cc: linux-mm@kvack.org
---
mm/page_frag_alloc.c | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/mm/page_frag_alloc.c b/mm/page_frag_alloc.c
index ffd68bfb677d..2b73c7f5d9a9 100644
--- a/mm/page_frag_alloc.c
+++ b/mm/page_frag_alloc.c
@@ -23,7 +23,10 @@ static struct folio *page_frag_cache_refill(struct page_frag_cache *nc,
gfp_t gfp_mask)
{
struct folio *folio = NULL;
- gfp_t gfp = gfp_mask;
+ gfp_t gfp;
+
+ gfp_mask &= ~__GFP_ZERO;
+ gfp = gfp_mask;
#if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
gfp_mask |= __GFP_NOWARN | __GFP_NORETRY | __GFP_NOMEMALLOC;
@@ -71,6 +74,7 @@ void *page_frag_alloc_align(struct page_frag_cache *nc,
{
struct folio *folio = nc->folio;
size_t offset;
+ void *p;
WARN_ON_ONCE(!is_power_of_2(align));
@@ -133,7 +137,10 @@ void *page_frag_alloc_align(struct page_frag_cache *nc,
offset &= ~(align - 1);
nc->offset = offset;
- return folio_address(folio) + offset;
+ p = folio_address(folio) + offset;
+ if (gfp_mask & __GFP_ZERO)
+ return memset(p, 0, fragsz);
+ return p;
}
EXPORT_SYMBOL(page_frag_alloc_align);
next prev parent reply other threads:[~2023-05-24 15:33 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-24 15:32 [PATCH net-next 00/12] splice, net: Replace sendpage with sendmsg(MSG_SPLICE_PAGES), part 3 David Howells
2023-05-24 15:33 ` [PATCH net-next 01/12] mm: Move the page fragment allocator from page_alloc.c into its own file David Howells
2023-05-24 15:33 ` [PATCH net-next 02/12] mm: Provide a page_frag_cache allocator cleanup function David Howells
2023-05-24 15:33 ` [PATCH net-next 03/12] mm: Make the page_frag_cache allocator alignment param a pow-of-2 David Howells
2023-05-27 15:54 ` Alexander H Duyck
2023-11-30 9:00 ` Yunsheng Lin
2023-06-16 15:28 ` David Howells
2023-06-16 16:06 ` Alexander Duyck
2023-05-24 15:33 ` [PATCH net-next 04/12] mm: Make the page_frag_cache allocator use multipage folios David Howells
2023-05-26 11:56 ` Yunsheng Lin
2023-05-27 15:47 ` Alexander H Duyck
2023-05-26 12:47 ` David Howells
2023-05-26 14:06 ` Mika Penttilä
2023-05-27 0:50 ` Jakub Kicinski
2023-05-24 15:33 ` David Howells [this message]
2023-05-27 0:57 ` [PATCH net-next 05/12] mm: Make the page_frag_cache allocator handle __GFP_ZERO itself Jakub Kicinski
2023-05-27 15:54 ` Alexander Duyck
2023-05-24 15:33 ` [PATCH net-next 06/12] mm: Make the page_frag_cache allocator use per-cpu David Howells
2023-05-27 1:02 ` Jakub Kicinski
2023-05-24 15:33 ` [PATCH net-next 07/12] net: Clean up users of netdev_alloc_cache and napi_frag_cache David Howells
2023-05-24 15:33 ` [PATCH net-next 08/12] net: Copy slab data for sendmsg(MSG_SPLICE_PAGES) David Howells
2023-05-24 15:33 ` [PATCH net-next 09/12] tls/sw: Support MSG_SPLICE_PAGES David Howells
2023-05-27 1:08 ` Jakub Kicinski
2023-05-30 22:26 ` Bug in short splice to socket? David Howells
2023-05-31 0:32 ` Jakub Kicinski
2023-05-24 15:33 ` [PATCH net-next 10/12] tls/sw: Convert tls_sw_sendpage() to use MSG_SPLICE_PAGES David Howells
2023-05-27 1:13 ` Jakub Kicinski
2023-05-24 15:33 ` [PATCH net-next 11/12] tls/device: Support MSG_SPLICE_PAGES David Howells
2023-05-24 15:33 ` [PATCH net-next 12/12] tls/device: Convert tls_device_sendpage() to use MSG_SPLICE_PAGES David Howells
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