2014-11-30 16:59:26

by Julia Lawall

Subject: [PATCH 0/8] replace memset by memzero_explicit

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>

2014-11-30 17:05:29

by Julia Lawall

Subject: [PATCH 7/8] crypto: replace memset by memzero_explicit

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 test this one.

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;
}

2014-11-30 16:59:28

by Julia Lawall

Subject: [PATCH 2/8] sparc64: replace memset by memzero_explicit

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 test these.

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;
}

2014-11-30 16:59:32

by Julia Lawall

Subject: [PATCH 6/8] crypto: replace memset by memzero_explicit

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.

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);

2014-11-30 16:59:29

by Julia Lawall

Subject: [PATCH 3/8] crypto: replace memset by memzero_explicit

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.

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;
}