diff options
| author | Eric Sandeen <sandeen@redhat.com> | 2008-07-28 15:46:39 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-07-28 16:30:21 -0700 |
| commit | 7fcba054373d5dfc43d26e243a5c9b92069972ee (patch) | |
| tree | 3503fba122a654946b5455bc95fa3978cbc4f68b /fs/ecryptfs | |
| parent | 25947d5ac56004378d8c2d31ebf22600d5bc0c02 (diff) | |
| download | linux-7fcba054373d5dfc43d26e243a5c9b92069972ee.tar.bz2 | |
eCryptfs: use page_alloc not kmalloc to get a page of memory
With SLUB debugging turned on in 2.6.26, I was getting memory corruption
when testing eCryptfs. The root cause turned out to be that eCryptfs was
doing kmalloc(PAGE_CACHE_SIZE); virt_to_page() and treating that as a nice
page-aligned chunk of memory. But at least with SLUB debugging on, this
is not always true, and the page we get from virt_to_page does not
necessarily match the PAGE_CACHE_SIZE worth of memory we got from kmalloc.
My simple testcase was 2 loops doing "rm -f fileX; cp /tmp/fileX ." for 2
different multi-megabyte files. With this change I no longer see the
corruption.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Acked-by: Michael Halcrow <mhalcrow@us.ibm.com>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: <stable@kernel.org> [2.6.25.x, 2.6.26.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/ecryptfs')
| -rw-r--r-- | fs/ecryptfs/crypto.c | 30 |
1 files changed, 18 insertions, 12 deletions
diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c index 7b99917ffadc..06db79d05c12 100644 --- a/fs/ecryptfs/crypto.c +++ b/fs/ecryptfs/crypto.c @@ -475,8 +475,8 @@ int ecryptfs_encrypt_page(struct page *page) { struct inode *ecryptfs_inode; struct ecryptfs_crypt_stat *crypt_stat; - char *enc_extent_virt = NULL; - struct page *enc_extent_page; + char *enc_extent_virt; + struct page *enc_extent_page = NULL; loff_t extent_offset; int rc = 0; @@ -492,14 +492,14 @@ int ecryptfs_encrypt_page(struct page *page) page->index); goto out; } - enc_extent_virt = kmalloc(PAGE_CACHE_SIZE, GFP_USER); - if (!enc_extent_virt) { + enc_extent_page = alloc_page(GFP_USER); + if (!enc_extent_page) { rc = -ENOMEM; ecryptfs_printk(KERN_ERR, "Error allocating memory for " "encrypted extent\n"); goto out; } - enc_extent_page = virt_to_page(enc_extent_virt); + enc_extent_virt = kmap(enc_extent_page); for (extent_offset = 0; extent_offset < (PAGE_CACHE_SIZE / crypt_stat->extent_size); extent_offset++) { @@ -527,7 +527,10 @@ int ecryptfs_encrypt_page(struct page *page) } } out: - kfree(enc_extent_virt); + if (enc_extent_page) { + kunmap(enc_extent_page); + __free_page(enc_extent_page); + } return rc; } @@ -609,8 +612,8 @@ int ecryptfs_decrypt_page(struct page *page) { struct inode *ecryptfs_inode; struct ecryptfs_crypt_stat *crypt_stat; - char *enc_extent_virt = NULL; - struct page *enc_extent_page; + char *enc_extent_virt; + struct page *enc_extent_page = NULL; unsigned long extent_offset; int rc = 0; @@ -627,14 +630,14 @@ int ecryptfs_decrypt_page(struct page *page) page->index); goto out; } - enc_extent_virt = kmalloc(PAGE_CACHE_SIZE, GFP_USER); - if (!enc_extent_virt) { + enc_extent_page = alloc_page(GFP_USER); + if (!enc_extent_page) { rc = -ENOMEM; ecryptfs_printk(KERN_ERR, "Error allocating memory for " "encrypted extent\n"); goto out; } - enc_extent_page = virt_to_page(enc_extent_virt); + enc_extent_virt = kmap(enc_extent_page); for (extent_offset = 0; extent_offset < (PAGE_CACHE_SIZE / crypt_stat->extent_size); extent_offset++) { @@ -662,7 +665,10 @@ int ecryptfs_decrypt_page(struct page *page) } } out: - kfree(enc_extent_virt); + if (enc_extent_page) { + kunmap(enc_extent_page); + __free_page(enc_extent_page); + } return rc; } |