From: Hugh Dickins <hugh@veritas.com>
To: Roland Dreier <rdreier@cisco.com>
Cc: Andrew Morton <akpm@osdl.org>,
"Michael S. Tsirkin" <mst@mellanox.co.il>,
linux-kernel@vger.kernel.org
Subject: [PATCH] ib: don't doublefree pages from scatterlist
Date: Fri, 3 Feb 2006 19:51:18 +0000 (GMT) [thread overview]
Message-ID: <Pine.LNX.4.61.0602031948100.14829@goblin.wat.veritas.com> (raw)
In-Reply-To: <Pine.LNX.4.61.0602031842290.14065@goblin.wat.veritas.com>
On some architectures, mapping the scatterlist may coalesce entries:
if that coalesced list is then used for freeing the pages afterwards,
there's a danger that pages may be doubly freed (and others leaked).
Fix Infiniband's __ib_umem_release by freeing from a separate array
beyond the scatterlist: IB_UMEM_MAX_PAGE_CHUNK lowered to fit one page.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
---
Warning: untested! And please double-check the adjusted definition of
IB_UMEM_MAX_PAGE_CHUNK - the old definition was avoiding "sizeof"s, but
I don't understand why.
drivers/infiniband/core/uverbs_mem.c | 22 ++++++++++++++++------
include/rdma/ib_verbs.h | 3 +--
2 files changed, 17 insertions(+), 8 deletions(-)
--- 2.6.16-rc2/drivers/infiniband/core/uverbs_mem.c 2005-10-28 01:02:08.000000000 +0100
+++ linux/drivers/infiniband/core/uverbs_mem.c 2006-02-03 09:59:37.000000000 +0000
@@ -49,15 +49,18 @@ struct ib_umem_account_work {
static void __ib_umem_release(struct ib_device *dev, struct ib_umem *umem, int dirty)
{
struct ib_umem_chunk *chunk, *tmp;
+ struct page **sg_pages;
int i;
list_for_each_entry_safe(chunk, tmp, &umem->chunk_list, list) {
dma_unmap_sg(dev->dma_device, chunk->page_list,
chunk->nents, DMA_BIDIRECTIONAL);
+ /* Scatterlist may have been coalesced: free saved pagelist */
+ sg_pages = (struct page **) (chunk->page_list + chunk->nents);
for (i = 0; i < chunk->nents; ++i) {
if (umem->writable && dirty)
- set_page_dirty_lock(chunk->page_list[i].page);
- put_page(chunk->page_list[i].page);
+ set_page_dirty_lock(sg_pages[i]);
+ put_page(sg_pages[i]);
}
kfree(chunk);
@@ -69,11 +72,13 @@ int ib_umem_get(struct ib_device *dev, s
{
struct page **page_list;
struct ib_umem_chunk *chunk;
+ struct page **sg_pages;
unsigned long locked;
unsigned long lock_limit;
unsigned long cur_base;
unsigned long npages;
int ret = 0;
+ int nents;
int off;
int i;
@@ -121,16 +126,21 @@ int ib_umem_get(struct ib_device *dev, s
off = 0;
while (ret) {
- chunk = kmalloc(sizeof *chunk + sizeof (struct scatterlist) *
- min_t(int, ret, IB_UMEM_MAX_PAGE_CHUNK),
+ nents = min_t(int, ret, IB_UMEM_MAX_PAGE_CHUNK);
+ chunk = kmalloc(sizeof *chunk +
+ sizeof (struct scatterlist) * nents +
+ sizeof (struct page *) * nents,
GFP_KERNEL);
if (!chunk) {
ret = -ENOMEM;
goto out;
}
+ /* Save pages to be freed in array beyond scatterlist */
+ sg_pages = (struct page **) (chunk->page_list + nents);
- chunk->nents = min_t(int, ret, IB_UMEM_MAX_PAGE_CHUNK);
+ chunk->nents = nents;
for (i = 0; i < chunk->nents; ++i) {
+ sg_pages[i] =
chunk->page_list[i].page = page_list[i + off];
chunk->page_list[i].offset = 0;
chunk->page_list[i].length = PAGE_SIZE;
@@ -142,7 +152,7 @@ int ib_umem_get(struct ib_device *dev, s
DMA_BIDIRECTIONAL);
if (chunk->nmap <= 0) {
for (i = 0; i < chunk->nents; ++i)
- put_page(chunk->page_list[i].page);
+ put_page(sg_pages[i]);
kfree(chunk);
ret = -ENOMEM;
--- 2.6.16-rc2/include/rdma/ib_verbs.h 2006-02-03 09:32:50.000000000 +0000
+++ linux/include/rdma/ib_verbs.h 2006-02-03 09:59:37.000000000 +0000
@@ -696,8 +696,7 @@ struct ib_udata {
#define IB_UMEM_MAX_PAGE_CHUNK \
((PAGE_SIZE - offsetof(struct ib_umem_chunk, page_list)) / \
- ((void *) &((struct ib_umem_chunk *) 0)->page_list[1] - \
- (void *) &((struct ib_umem_chunk *) 0)->page_list[0]))
+ (sizeof(struct scatterlist) + sizeof(struct page *)))
struct ib_umem_object {
struct ib_uobject uobject;
next prev parent reply other threads:[~2006-02-03 19:50 UTC|newest]
Thread overview: 99+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20051129092432.0f5742f0.akpm@osdl.org>
2005-11-29 18:34 ` Fw: crash on x86_64 - mm related? Ryan Richter
[not found] ` <Pine.LNX.4.63.0511292147120.5739@kai.makisara.local>
2005-11-29 20:31 ` Ryan Richter
2005-11-29 20:48 ` Kai Makisara
2005-11-29 20:58 ` Ryan Richter
2005-11-29 21:36 ` Kai Makisara
2005-11-30 5:12 ` Kai Makisara
2005-12-01 19:18 ` Kai Makisara
2005-12-01 19:38 ` Linus Torvalds
2005-12-01 19:56 ` Ryan Richter
2005-12-01 20:21 ` Hugh Dickins
2005-12-01 21:44 ` Kai Makisara
2005-12-02 18:03 ` Ryan Richter
2005-12-02 18:43 ` Jesper Juhl
2005-12-02 19:12 ` Hugh Dickins
2005-12-02 19:44 ` Ryan Richter
2005-12-02 20:40 ` Hugh Dickins
2005-12-03 17:29 ` Ryan Richter
2005-12-06 16:08 ` Ryan Richter
2005-12-06 20:31 ` Hugh Dickins
2005-12-06 20:43 ` Ryan Richter
2005-12-07 18:37 ` Hugh Dickins
2005-12-08 2:26 ` Ryan Richter
2005-12-12 16:54 ` Ryan Richter
2005-12-12 17:40 ` Linus Torvalds
2005-12-12 17:45 ` James Bottomley
2005-12-12 18:04 ` Ryan Richter
2005-12-12 18:09 ` Linus Torvalds
2005-12-12 18:24 ` James Bottomley
2005-12-15 19:09 ` Ryan Richter
2005-12-16 4:01 ` James Bottomley
2005-12-17 3:31 ` Ryan Richter
2005-12-26 23:42 ` Ryan Richter
2005-12-27 16:21 ` Kai Makisara
2006-01-03 19:03 ` Ryan Richter
2006-01-04 17:27 ` Ryan Richter
2006-01-04 21:48 ` Kai Makisara
2006-01-05 5:40 ` Ryan Richter
2006-01-05 20:12 ` Ryan Richter
2006-01-05 21:18 ` Linus Torvalds
2006-01-08 22:36 ` Ryan Richter
2006-01-09 3:31 ` Ryan Richter
2006-01-09 4:07 ` Linus Torvalds
2006-01-09 5:13 ` Andrew Morton
2006-01-09 5:45 ` Ryan Richter
2006-01-09 5:57 ` Andrew Morton
2006-01-09 9:44 ` Hugh Dickins
2006-01-09 18:53 ` Ryan Richter
2006-01-09 19:31 ` Hugh Dickins
2006-01-09 20:05 ` Ryan Richter
2006-01-18 0:12 ` Ryan Richter
2006-01-18 16:00 ` Hugh Dickins
2006-02-03 19:46 ` Hugh Dickins
2006-02-03 19:51 ` Hugh Dickins [this message]
2006-02-03 23:13 ` [PATCH] ib: don't doublefree pages from scatterlist Roland Dreier
2006-02-03 19:53 ` [PATCH] st: " Hugh Dickins
2006-02-03 20:38 ` Mike Christie
2006-02-03 21:16 ` Hugh Dickins
2006-02-04 12:10 ` Kai Makisara
2006-02-04 15:01 ` Hugh Dickins
2006-02-03 19:55 ` [PATCH] ipr: " Hugh Dickins
2006-02-03 22:06 ` Brian King
2006-02-04 0:26 ` Hugh Dickins
2006-02-05 21:35 ` Brian King
2006-02-06 9:32 ` Hugh Dickins
2006-02-06 9:46 ` David S. Miller
2006-02-06 14:46 ` Brian King
2006-02-06 16:45 ` Hugh Dickins
2006-02-06 17:38 ` James Bottomley
2006-02-06 19:15 ` Brian King
2006-02-06 21:11 ` Andi Kleen
2006-02-06 21:49 ` David S. Miller
2006-02-06 22:11 ` Hugh Dickins
2006-02-06 22:13 ` Andi Kleen
2006-02-07 3:09 ` Ryan Richter
2006-02-11 22:38 ` Ryan Richter
2006-02-12 18:57 ` Hugh Dickins
2006-02-12 21:29 ` Andi Kleen
2006-02-13 17:21 ` Hugh Dickins
2006-02-06 15:02 ` James Bottomley
2006-02-06 17:01 ` Hugh Dickins
2006-02-03 19:56 ` [PATCH] osst: " Hugh Dickins
2006-02-03 21:10 ` Fw: crash on x86_64 - mm related? Ryan Richter
2006-02-04 11:58 ` Kai Makisara
2006-02-04 14:46 ` Hugh Dickins
2006-01-05 22:09 ` Kai Makisara
2006-01-04 18:26 ` Ryan Richter
2005-12-07 18:30 ` Ryan Richter
2005-12-07 18:56 ` Hugh Dickins
2005-12-07 19:06 ` Ryan Richter
2005-12-06 17:57 ` Ryan Richter
2005-12-01 20:28 ` James Bottomley
2005-12-01 21:17 ` Kai Makisara
2005-12-02 13:45 ` Hugh Dickins
2005-12-02 17:59 ` Kai Makisara
2005-12-02 18:55 ` Hugh Dickins
2005-12-02 19:46 ` Kai Makisara
2005-12-02 20:47 ` Hugh Dickins
2005-12-04 9:29 ` Kai Makisara
2005-12-01 19:53 ` Ryan Richter
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