Memset on a local variable may be removed when it is called just before the
variable goes out of scope. Using memzero_explicit defeats this
optimization. The complete semantic patch that makes this change is as
follows: (http://coccinelle.lip6.fr/)
// <smpl>
@@
identifier x;
local idexpression e;
type T,T1;
@@
{
... when any
T x[...];
... when any
when exists
(
e = (T1)x
|
e = (T1)&x[0]
)
... when any
when exists
- memset
+ memzero_explicit
(x,
-0,
...)
... when != x
when != e
when strict
}
@@
identifier i,x;
local idexpression e;
type T;
@@
{
... when any
struct i x;
... when any
when exists
e = (T)&x
... when any
when exists
- memset
+ memzero_explicit
(&x,
-0,
...)
... when != x
when != e
when strict
}
// ------------------------------------------------------------------------
@@
identifier x;
type T,T1;
expression e;
@@
{
... when any
T x[...];
... when any
when exists
when != e = (T1)x
when != e = (T1)&x[0]
- memset
+ memzero_explicit
(x,
-0,
...)
... when != x
when strict
}
@@
identifier i,x;
expression e;
type T;
@@
{
... when any
struct i x;
... when any
when exists
when != e = (T)&x
- memset
+ memzero_explicit
(&x,
-0,
...)
... when != x
when strict
}
// </smpl>
From: Julia Lawall <[email protected]>
Memset on a local variable may be removed when it is called just before the
variable goes out of scope. Using memzero_explicit defeats this
optimization. A simplified version of the semantic patch that makes this
change is as follows: (http://coccinelle.lip6.fr/)
// <smpl>
@@
identifier x;
type T;
@@
{
... when any
T x[...];
... when any
when exists
- memset
+ memzero_explicit
(x,
-0,
...)
... when != x
when strict
}
// </smpl>
This change was suggested by Daniel Borkmann <[email protected]>
Signed-off-by: Julia Lawall <[email protected]>
---
Daniel Borkmann suggested that these patches could go through Herbert Xu's
cryptodev tree.
I was not able to compile this one.
v2: fixed email address
arch/arm/crypto/sha512_neon_glue.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/arm/crypto/sha512_neon_glue.c b/arch/arm/crypto/sha512_neon_glue.c
index f3452c6..b124dce 100644
--- a/arch/arm/crypto/sha512_neon_glue.c
+++ b/arch/arm/crypto/sha512_neon_glue.c
@@ -241,7 +241,7 @@ static int sha384_neon_final(struct shash_desc *desc, u8 *hash)
sha512_neon_final(desc, D);
memcpy(hash, D, SHA384_DIGEST_SIZE);
- memset(D, 0, SHA512_DIGEST_SIZE);
+ memzero_explicit(D, SHA512_DIGEST_SIZE);
return 0;
}
From: Julia Lawall <[email protected]>
Memset on a local variable may be removed when it is called just before the
variable goes out of scope. Using memzero_explicit defeats this
optimization. A simplified version of the semantic patch that makes this
change is as follows: (http://coccinelle.lip6.fr/)
// <smpl>
@@
identifier x;
type T;
@@
{
... when any
T x[...];
... when any
when exists
- memset
+ memzero_explicit
(x,
-0,
...)
... when != x
when strict
}
// </smpl>
This change was suggested by Daniel Borkmann <[email protected]>
Signed-off-by: Julia Lawall <[email protected]>
---
Daniel Borkmann suggested that these patches could go through Herbert Xu's
cryptodev tree.
v2: fixed email address
arch/x86/crypto/sha256_ssse3_glue.c | 2 +-
arch/x86/crypto/sha512_ssse3_glue.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/x86/crypto/sha512_ssse3_glue.c b/arch/x86/crypto/sha512_ssse3_glue.c
index 26a5898..0b6af26 100644
--- a/arch/x86/crypto/sha512_ssse3_glue.c
+++ b/arch/x86/crypto/sha512_ssse3_glue.c
@@ -219,7 +219,7 @@ static int sha384_ssse3_final(struct shash_desc *desc, u8 *hash)
sha512_ssse3_final(desc, D);
memcpy(hash, D, SHA384_DIGEST_SIZE);
- memset(D, 0, SHA512_DIGEST_SIZE);
+ memzero_explicit(D, SHA512_DIGEST_SIZE);
return 0;
}
diff --git a/arch/x86/crypto/sha256_ssse3_glue.c b/arch/x86/crypto/sha256_ssse3_glue.c
index 4dc100d..8fad72f 100644
--- a/arch/x86/crypto/sha256_ssse3_glue.c
+++ b/arch/x86/crypto/sha256_ssse3_glue.c
@@ -211,7 +211,7 @@ static int sha224_ssse3_final(struct shash_desc *desc, u8 *hash)
sha256_ssse3_final(desc, D);
memcpy(hash, D, SHA224_DIGEST_SIZE);
- memset(D, 0, SHA256_DIGEST_SIZE);
+ memzero_explicit(D, SHA256_DIGEST_SIZE);
return 0;
}
From: Julia Lawall <[email protected]>
Memset on a local variable may be removed when it is called just before the
variable goes out of scope. Using memzero_explicit defeats this
optimization. A simplified version of the semantic patch that makes this
change is as follows: (http://coccinelle.lip6.fr/)
// <smpl>
@@
identifier x;
type T;
@@
{
... when any
T x[...];
... when any
when exists
- memset
+ memzero_explicit
(x,
-0,
...)
... when != x
when strict
}
// </smpl>
This change was suggested by Daniel Borkmann <[email protected]>
Signed-off-by: Julia Lawall <[email protected]>
---
Daniel Borkmann suggested that these patches could go through Herbert Xu's
cryptodev tree.
v2: fixed email address
arch/powerpc/crypto/sha1.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/powerpc/crypto/sha1.c b/arch/powerpc/crypto/sha1.c
index 0f88c7b..d3feba5 100644
--- a/arch/powerpc/crypto/sha1.c
+++ b/arch/powerpc/crypto/sha1.c
@@ -66,7 +66,7 @@ static int sha1_update(struct shash_desc *desc, const u8 *data,
src = data + done;
} while (done + 63 < len);
- memset(temp, 0, sizeof(temp));
+ memzero_explicit(temp, sizeof(temp));
partial = 0;
}
memcpy(sctx->buffer + partial, src, len - done);
From: Julia Lawall <[email protected]>
Memset on a local variable may be removed when it is called just before the
variable goes out of scope. Using memzero_explicit defeats this
optimization. A simplified version of the semantic patch that makes this
change is as follows: (http://coccinelle.lip6.fr/)
// <smpl>
@@
identifier x;
type T;
@@
{
... when any
T x[...];
... when any
when exists
- memset
+ memzero_explicit
(x,
-0,
...)
... when != x
when strict
}
// </smpl>
This change was suggested by Daniel Borkmann <[email protected]>
Signed-off-by: Julia Lawall <[email protected]>
---
Daniel Borkmann suggested that these patches could go through Herbert Xu's
cryptodev tree.
I was not able to compile these.
v2: fixed email address
arch/sparc/crypto/sha256_glue.c | 2 +-
arch/sparc/crypto/sha512_glue.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/sparc/crypto/sha512_glue.c b/arch/sparc/crypto/sha512_glue.c
index 9fff885..11eb36c 100644
--- a/arch/sparc/crypto/sha512_glue.c
+++ b/arch/sparc/crypto/sha512_glue.c
@@ -139,7 +139,7 @@ static int sha384_sparc64_final(struct shash_desc *desc, u8 *hash)
sha512_sparc64_final(desc, D);
memcpy(hash, D, 48);
- memset(D, 0, 64);
+ memzero_explicit(D, 64);
return 0;
}
diff --git a/arch/sparc/crypto/sha256_glue.c b/arch/sparc/crypto/sha256_glue.c
index 41f27cc..285268c 100644
--- a/arch/sparc/crypto/sha256_glue.c
+++ b/arch/sparc/crypto/sha256_glue.c
@@ -135,7 +135,7 @@ static int sha224_sparc64_final(struct shash_desc *desc, u8 *hash)
sha256_sparc64_final(desc, D);
memcpy(hash, D, SHA224_DIGEST_SIZE);
- memset(D, 0, SHA256_DIGEST_SIZE);
+ memzero_explicit(D, SHA256_DIGEST_SIZE);
return 0;
}
On 30 November 2014 at 18:03, Julia Lawall <[email protected]> wrote:
> From: Julia Lawall <[email protected]>
>
> Memset on a local variable may be removed when it is called just before the
> variable goes out of scope. Using memzero_explicit defeats this
> optimization. A simplified version of the semantic patch that makes this
> change is as follows: (http://coccinelle.lip6.fr/)
>
> // <smpl>
> @@
> identifier x;
> type T;
> @@
>
> {
> ... when any
> T x[...];
> ... when any
> when exists
> - memset
> + memzero_explicit
> (x,
> -0,
> ...)
> ... when != x
> when strict
> }
> // </smpl>
>
> This change was suggested by Daniel Borkmann <[email protected]>
>
> Signed-off-by: Julia Lawall <[email protected]>
>
> ---
> Daniel Borkmann suggested that these patches could go through Herbert Xu's
> cryptodev tree.
>
> I was not able to compile this one.
>
Builds fine for me
Acked-by: Ard Biesheuvel <[email protected]>
> v2: fixed email address
>
> arch/arm/crypto/sha512_neon_glue.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/arm/crypto/sha512_neon_glue.c b/arch/arm/crypto/sha512_neon_glue.c
> index f3452c6..b124dce 100644
> --- a/arch/arm/crypto/sha512_neon_glue.c
> +++ b/arch/arm/crypto/sha512_neon_glue.c
> @@ -241,7 +241,7 @@ static int sha384_neon_final(struct shash_desc *desc, u8 *hash)
> sha512_neon_final(desc, D);
>
> memcpy(hash, D, SHA384_DIGEST_SIZE);
> - memset(D, 0, SHA512_DIGEST_SIZE);
> + memzero_explicit(D, SHA512_DIGEST_SIZE);
>
> return 0;
> }
>
>
> _______________________________________________
> linux-arm-kernel mailing list
> [email protected]
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
On Sun, 2014-11-30 at 18:03 +0100, Julia Lawall wrote:
> From: Julia Lawall <[email protected]>
>
> Memset on a local variable may be removed when it is called just before the
> variable goes out of scope. Using memzero_explicit defeats this
> optimization. A simplified version of the semantic patch that makes this
>
> Signed-off-by: Julia Lawall <[email protected]>
>
> ---
> Daniel Borkmann suggested that these patches could go through Herbert Xu's
> cryptodev tree.
That's fine by me:
Acked-by: Michael Ellerman <[email protected]>
cheers
On Sun, Nov 30, 2014 at 06:03:43PM +0100, Julia Lawall wrote:
> From: Julia Lawall <[email protected]>
>
> Memset on a local variable may be removed when it is called just before the
> variable goes out of scope. Using memzero_explicit defeats this
> optimization. A simplified version of the semantic patch that makes this
> change is as follows: (http://coccinelle.lip6.fr/)
>
> // <smpl>
> @@
> identifier x;
> type T;
> @@
>
> {
> ... when any
> T x[...];
> ... when any
> when exists
> - memset
> + memzero_explicit
> (x,
> -0,
> ...)
> ... when != x
> when strict
> }
> // </smpl>
>
> This change was suggested by Daniel Borkmann <[email protected]>
>
> Signed-off-by: Julia Lawall <[email protected]>
Applied patches 2, 3, 6, 7.
--
Email: Herbert Xu <[email protected]>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt