Re: [PATCH] crypto: blkcipher_get_spot() handling of buffer at end of page
On Mon, Sep 10, 2007 at 09:46:46PM +0200, Ingo Oeser wrote:
>
> What about using max() for this to make your intention obvious?
>
> static inline u8 *blkcipher_get_spot(u8 *start, unsigned int len)
> {
> u8 *end_page = (u8 *)(((unsigned long)(start + len - 1)) & PAGE_MASK);
> return max(start, end_page);
> }
Yes that looks sane. Could you please send a patch?
Cheers,
--
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Email: Herbert Xu ~{PmV>HI~} <[EMAIL PROTECTED]>
Home Page: http://gondor.apana.org.au/~herbert/
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Re: [PATCH] crypto: blkcipher_get_spot() handling of buffer at end of page
On Mon, Sep 10, 2007 at 09:46:46PM +0200, Ingo Oeser wrote:
What about using max() for this to make your intention obvious?
static inline u8 *blkcipher_get_spot(u8 *start, unsigned int len)
{
u8 *end_page = (u8 *)(((unsigned long)(start + len - 1)) PAGE_MASK);
return max(start, end_page);
}
Yes that looks sane. Could you please send a patch?
Cheers,
--
Visit Openswan at http://www.openswan.org/
Email: Herbert Xu ~{PmVHI~} [EMAIL PROTECTED]
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
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Re: [PATCH] crypto: blkcipher_get_spot() handling of buffer at end of page
Hi Herbert,
On Monday 10 September 2007, Herbert Xu wrote:
> On Sat, Sep 08, 2007 at 12:14:23PM +0800, Herbert Xu wrote:
> >
> > [CRYPTO] blkcipher: Fix handling of kmalloc page straddling
>
> As Bob correctly noted, I had the boolean test inverted.
> Here is the correction:
>
> [CRYPTO] blkcipher: Fix inverted test in blkcipher_get_spot
>
> The previous patch had the conditional inverted. This patch fixes it
> so that we return the original position if it does not straddle a page.
What about using max() for this to make your intention obvious?
static inline u8 *blkcipher_get_spot(u8 *start, unsigned int len)
{
u8 *end_page = (u8 *)(((unsigned long)(start + len - 1)) & PAGE_MASK);
return max(start, end_page);
}
Best Regards
Ingo Oeser
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Re: [PATCH] crypto: blkcipher_get_spot() handling of buffer at end of page
On Sat, Sep 08, 2007 at 12:14:23PM +0800, Herbert Xu wrote:
>
> [CRYPTO] blkcipher: Fix handling of kmalloc page straddling
As Bob correctly noted, I had the boolean test inverted.
Here is the correction:
[CRYPTO] blkcipher: Fix inverted test in blkcipher_get_spot
The previous patch had the conditional inverted. This patch fixes it
so that we return the original position if it does not straddle a page.
Thanks to Bob Gilligan for spotting this.
Signed-off-by: Herbert Xu <[EMAIL PROTECTED]>
Cheers,
--
Visit Openswan at http://www.openswan.org/
Email: Herbert Xu ~{PmV>HI~} <[EMAIL PROTECTED]>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
--
diff --git a/crypto/blkcipher.c b/crypto/blkcipher.c
--- a/crypto/blkcipher.c
+++ b/crypto/blkcipher.c
@@ -65,7 +65,7 @@ static inline void blkcipher_unmap_dst(s
static inline u8 *blkcipher_get_spot(u8 *start, unsigned int len)
{
u8 *end_page = (u8 *)(((unsigned long)(start + len - 1)) & PAGE_MASK);
- return start < end_page ? start : end_page;
+ return start > end_page ? start : end_page;
}
static inline unsigned int blkcipher_done_slow(struct crypto_blkcipher *tfm,
-
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Re: [PATCH] crypto: blkcipher_get_spot() handling of buffer at end of page
On Sat, Sep 08, 2007 at 12:14:23PM +0800, Herbert Xu wrote:
[CRYPTO] blkcipher: Fix handling of kmalloc page straddling
As Bob correctly noted, I had the boolean test inverted.
Here is the correction:
[CRYPTO] blkcipher: Fix inverted test in blkcipher_get_spot
The previous patch had the conditional inverted. This patch fixes it
so that we return the original position if it does not straddle a page.
Thanks to Bob Gilligan for spotting this.
Signed-off-by: Herbert Xu [EMAIL PROTECTED]
Cheers,
--
Visit Openswan at http://www.openswan.org/
Email: Herbert Xu ~{PmVHI~} [EMAIL PROTECTED]
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
--
diff --git a/crypto/blkcipher.c b/crypto/blkcipher.c
--- a/crypto/blkcipher.c
+++ b/crypto/blkcipher.c
@@ -65,7 +65,7 @@ static inline void blkcipher_unmap_dst(s
static inline u8 *blkcipher_get_spot(u8 *start, unsigned int len)
{
u8 *end_page = (u8 *)(((unsigned long)(start + len - 1)) PAGE_MASK);
- return start end_page ? start : end_page;
+ return start end_page ? start : end_page;
}
static inline unsigned int blkcipher_done_slow(struct crypto_blkcipher *tfm,
-
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Re: [PATCH] crypto: blkcipher_get_spot() handling of buffer at end of page
On Fri, Sep 07, 2007 at 05:09:17PM -0700, Bob Gilligan wrote:
>
> Proposed patch is below. We found the problem and tested this fix in
> 2.6.20, but it looks like the relevant code in blkcipher.c is the same
> in the latest tree.
Good catch!
I've fixed this slightly differently. Also, the kmalloc size
in the case where it does straddle a page isn't enough either.
[CRYPTO] blkcipher: Fix handling of kmalloc page straddling
The function blkcipher_get_spot tries to return a buffer of
the specified length that does not straddle a page. It has
an off-by-one bug so it may advance a page unnecessarily.
What's worse, one of its callers doesn't provide a buffer
that's sufficiently long for this operation.
This patch fixes both problems. Thanks to Bob Gilligan for
diagnosing this problem and providing a fix.
Signed-off-by: Herbert Xu <[EMAIL PROTECTED]>
Cheers,
--
Visit Openswan at http://www.openswan.org/
Email: Herbert Xu ~{PmV>HI~} <[EMAIL PROTECTED]>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
--
diff --git a/crypto/blkcipher.c b/crypto/blkcipher.c
index 7755834..469cb7f 100644
--- a/crypto/blkcipher.c
+++ b/crypto/blkcipher.c
@@ -59,11 +59,13 @@ static inline void blkcipher_unmap_dst(struct
blkcipher_walk *walk)
scatterwalk_unmap(walk->dst.virt.addr, 1);
}
+/* Get a spot of the specified length that does not straddle a page.
+ * The caller needs to ensure that there is enough space for this operation.
+ */
static inline u8 *blkcipher_get_spot(u8 *start, unsigned int len)
{
- if (offset_in_page(start + len) < len)
- return (u8 *)((unsigned long)(start + len) & PAGE_MASK);
- return start;
+ u8 *end_page = (u8 *)(((unsigned long)(start + len - 1)) & PAGE_MASK);
+ return start < end_page ? start : end_page;
}
static inline unsigned int blkcipher_done_slow(struct crypto_blkcipher *tfm,
@@ -155,7 +157,8 @@ static inline int blkcipher_next_slow(struct blkcipher_desc
*desc,
if (walk->buffer)
goto ok;
- n = bsize * 2 + (alignmask & ~(crypto_tfm_ctx_alignment() - 1));
+ n = bsize * 3 - (alignmask + 1) +
+ (alignmask & ~(crypto_tfm_ctx_alignment() - 1));
walk->buffer = kmalloc(n, GFP_ATOMIC);
if (!walk->buffer)
return blkcipher_walk_done(desc, walk, -ENOMEM);
-
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Re: [PATCH] crypto: blkcipher_get_spot() handling of buffer at end of page
On Fri, Sep 07, 2007 at 05:09:17PM -0700, Bob Gilligan wrote:
Proposed patch is below. We found the problem and tested this fix in
2.6.20, but it looks like the relevant code in blkcipher.c is the same
in the latest tree.
Good catch!
I've fixed this slightly differently. Also, the kmalloc size
in the case where it does straddle a page isn't enough either.
[CRYPTO] blkcipher: Fix handling of kmalloc page straddling
The function blkcipher_get_spot tries to return a buffer of
the specified length that does not straddle a page. It has
an off-by-one bug so it may advance a page unnecessarily.
What's worse, one of its callers doesn't provide a buffer
that's sufficiently long for this operation.
This patch fixes both problems. Thanks to Bob Gilligan for
diagnosing this problem and providing a fix.
Signed-off-by: Herbert Xu [EMAIL PROTECTED]
Cheers,
--
Visit Openswan at http://www.openswan.org/
Email: Herbert Xu ~{PmVHI~} [EMAIL PROTECTED]
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
--
diff --git a/crypto/blkcipher.c b/crypto/blkcipher.c
index 7755834..469cb7f 100644
--- a/crypto/blkcipher.c
+++ b/crypto/blkcipher.c
@@ -59,11 +59,13 @@ static inline void blkcipher_unmap_dst(struct
blkcipher_walk *walk)
scatterwalk_unmap(walk-dst.virt.addr, 1);
}
+/* Get a spot of the specified length that does not straddle a page.
+ * The caller needs to ensure that there is enough space for this operation.
+ */
static inline u8 *blkcipher_get_spot(u8 *start, unsigned int len)
{
- if (offset_in_page(start + len) len)
- return (u8 *)((unsigned long)(start + len) PAGE_MASK);
- return start;
+ u8 *end_page = (u8 *)(((unsigned long)(start + len - 1)) PAGE_MASK);
+ return start end_page ? start : end_page;
}
static inline unsigned int blkcipher_done_slow(struct crypto_blkcipher *tfm,
@@ -155,7 +157,8 @@ static inline int blkcipher_next_slow(struct blkcipher_desc
*desc,
if (walk-buffer)
goto ok;
- n = bsize * 2 + (alignmask ~(crypto_tfm_ctx_alignment() - 1));
+ n = bsize * 3 - (alignmask + 1) +
+ (alignmask ~(crypto_tfm_ctx_alignment() - 1));
walk-buffer = kmalloc(n, GFP_ATOMIC);
if (!walk-buffer)
return blkcipher_walk_done(desc, walk, -ENOMEM);
-
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