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| author | Al Viro <viro@zeniv.linux.org.uk> | 2014-02-02 07:05:05 -0500 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2014-02-09 15:21:16 -0500 |
| commit | c9efe51165fa0aff57be54e3cb0201ac87f68980 (patch) | |
| tree | 2c956f57a8c176d0df62a16adc33a2d31b78a929 /drivers/char | |
| parent | d311d79de305f1ada47cadd672e6ed1b28a949eb (diff) | |
| download | lwn-c9efe51165fa0aff57be54e3cb0201ac87f68980.tar.gz lwn-c9efe51165fa0aff57be54e3cb0201ac87f68980.zip | |
fix a kmap leak in virtio_console
While we are at it, don't do kmap() under kmap_atomic(), *especially*
for a page we'd allocated with GFP_KERNEL. It's spelled "page_address",
and had that been more than that, we'd have a real trouble - kmap_high()
can block, and doing that while holding kmap_atomic() is a Bad Idea(tm).
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'drivers/char')
| -rw-r--r-- | drivers/char/virtio_console.c | 9 |
1 files changed, 3 insertions, 6 deletions
diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c index feea87cc6b8f..6928d094451d 100644 --- a/drivers/char/virtio_console.c +++ b/drivers/char/virtio_console.c @@ -890,12 +890,10 @@ static int pipe_to_sg(struct pipe_inode_info *pipe, struct pipe_buffer *buf, } else { /* Failback to copying a page */ struct page *page = alloc_page(GFP_KERNEL); - char *src = buf->ops->map(pipe, buf, 1); - char *dst; + char *src; if (!page) return -ENOMEM; - dst = kmap(page); offset = sd->pos & ~PAGE_MASK; @@ -903,9 +901,8 @@ static int pipe_to_sg(struct pipe_inode_info *pipe, struct pipe_buffer *buf, if (len + offset > PAGE_SIZE) len = PAGE_SIZE - offset; - memcpy(dst + offset, src + buf->offset, len); - - kunmap(page); + src = buf->ops->map(pipe, buf, 1); + memcpy(page_address(page) + offset, src + buf->offset, len); buf->ops->unmap(pipe, buf, src); sg_set_page(&(sgl->sg[sgl->n]), page, len, offset); |