Re: [PATCH v3 2/3] secure_seq: use siphash24 instead of md5_transform

[kbuild test robot]

Hi Jason,

[auto build test ERROR on linus/master]
[also build test ERROR on next-20161214]
[cannot apply to v4.9]
[if your patch is applied to the wrong git tree, please drop us a note to help 
improve the system]

url:
https://github.com/0day-ci/linux/commits/Jason-A-Donenfeld/siphash-add-cryptographically-secure-hashtable-function/20161215-041458
config: openrisc-or1ksim_defconfig (attached as .config)
compiler: or32-linux-gcc (GCC) 4.5.1-or32-1.0rc1
reproduce:
wget 
https://git.kernel.org/cgit/linux/kernel/git/wfg/lkp-tests.git/plain/sbin/make.cross
 -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# save the attached .config to linux build tree
make.cross ARCH=openrisc 

All errors (new ones prefixed by >>):

>> net/core/secure_seq.c:20:1: error: requested alignment is not a constant
   net/core/secure_seq.c: In function 'secure_tcp_sequence_number':
   net/core/secure_seq.c:99:2: error: requested alignment is not a constant
   net/core/secure_seq.c: In function 'secure_ipv4_port_ephemeral':
   net/core/secure_seq.c:119:2: error: requested alignment is not a constant

vim +20 net/core/secure_seq.c

14  #include 
15  
16  #if IS_ENABLED(CONFIG_IPV6) || IS_ENABLED(CONFIG_INET)
17  #include 
18  #include 
19  
  > 20  static u8 net_secret[SIPHASH24_KEY_LEN] __aligned(SIPHASH24_ALIGNMENT);
21  
22  static __always_inline void net_secret_init(void)
23  {

---
0-DAY kernel test infrastructureOpen Source Technology Center
https://lists.01.org/pipermail/kbuild-all   Intel Corporation


.config.gz
Description: application/gzip

[PATCH v3 2/3] secure_seq: use siphash24 instead of md5_transform

[Jason A. Donenfeld]

This gives a clear speed and security improvement. Siphash is both
faster and is more solid crypto than the aging MD5.

Rather than manually filling MD5 buffers, we simply create
a layout by a simple anonymous struct, for which gcc generates
rather efficient code.

Signed-off-by: Jason A. Donenfeld 
Cc: Andi Kleen 
Cc: David Miller 
Cc: David Laight 
---
Changes from v2->v3:

  - Structs are no longer packed, to mitigate slow byte-by-byte assignment.
  - A typo has been fixed in the port number assignment.

 net/core/secure_seq.c | 166 ++
 1 file changed, 85 insertions(+), 81 deletions(-)

diff --git a/net/core/secure_seq.c b/net/core/secure_seq.c
index 88a8e429fc3e..00eb141c981b 100644
--- a/net/core/secure_seq.c
+++ b/net/core/secure_seq.c
@@ -1,3 +1,5 @@
+/* Copyright (C) 2016 Jason A. Donenfeld . All Rights 
Reserved. */
+
 #include 
 #include 
 #include 
@@ -8,14 +10,14 @@
 #include 
 #include 
 #include 
-
+#include 
 #include 
 
 #if IS_ENABLED(CONFIG_IPV6) || IS_ENABLED(CONFIG_INET)
+#include 
 #include 
-#define NET_SECRET_SIZE (MD5_MESSAGE_BYTES / 4)
 
-static u32 net_secret[NET_SECRET_SIZE] cacheline_aligned;
+static u8 net_secret[SIPHASH24_KEY_LEN] __aligned(SIPHASH24_ALIGNMENT);
 
 static __always_inline void net_secret_init(void)
 {
@@ -44,44 +46,41 @@ static u32 seq_scale(u32 seq)
 u32 secure_tcpv6_sequence_number(const __be32 *saddr, const __be32 *daddr,
 __be16 sport, __be16 dport, u32 *tsoff)
 {
-   u32 secret[MD5_MESSAGE_BYTES / 4];
-   u32 hash[MD5_DIGEST_WORDS];
-   u32 i;
-
+   const struct {
+   struct in6_addr saddr;
+   struct in6_addr daddr;
+   __be16 sport;
+   __be16 dport;
+   char end[];
+   } __aligned(SIPHASH24_ALIGNMENT) combined = {
+   .saddr = *(struct in6_addr *)saddr,
+   .daddr = *(struct in6_addr *)daddr,
+   .sport = sport,
+   .dport = dport
+   };
+   u64 hash;
net_secret_init();
-   memcpy(hash, saddr, 16);
-   for (i = 0; i < 4; i++)
-   secret[i] = net_secret[i] + (__force u32)daddr[i];
-   secret[4] = net_secret[4] +
-   (((__force u16)sport << 16) + (__force u16)dport);
-   for (i = 5; i < MD5_MESSAGE_BYTES / 4; i++)
-   secret[i] = net_secret[i];
-
-   md5_transform(hash, secret);
-
-   *tsoff = sysctl_tcp_timestamps == 1 ? hash[1] : 0;
-   return seq_scale(hash[0]);
+   hash = siphash24((const u8 *), offsetof(typeof(combined), 
end), net_secret);
+   *tsoff = sysctl_tcp_timestamps == 1 ? (hash >> 32) : 0;
+   return seq_scale(hash);
 }
 EXPORT_SYMBOL(secure_tcpv6_sequence_number);
 
 u32 secure_ipv6_port_ephemeral(const __be32 *saddr, const __be32 *daddr,
   __be16 dport)
 {
-   u32 secret[MD5_MESSAGE_BYTES / 4];
-   u32 hash[MD5_DIGEST_WORDS];
-   u32 i;
-
+   const struct {
+   struct in6_addr saddr;
+   struct in6_addr daddr;
+   __be16 dport;
+   char end[];
+   } __aligned(SIPHASH24_ALIGNMENT) combined = {
+   .saddr = *(struct in6_addr *)saddr,
+   .daddr = *(struct in6_addr *)daddr,
+   .dport = dport
+   };
net_secret_init();
-   memcpy(hash, saddr, 16);
-   for (i = 0; i < 4; i++)
-   secret[i] = net_secret[i] + (__force u32) daddr[i];
-   secret[4] = net_secret[4] + (__force u32)dport;
-   for (i = 5; i < MD5_MESSAGE_BYTES / 4; i++)
-   secret[i] = net_secret[i];
-
-   md5_transform(hash, secret);
-
-   return hash[0];
+   return siphash24((const u8 *), offsetof(typeof(combined), 
end), net_secret);
 }
 EXPORT_SYMBOL(secure_ipv6_port_ephemeral);
 #endif
@@ -91,33 +90,39 @@ EXPORT_SYMBOL(secure_ipv6_port_ephemeral);
 u32 secure_tcp_sequence_number(__be32 saddr, __be32 daddr,
   __be16 sport, __be16 dport, u32 *tsoff)
 {
-   u32 hash[MD5_DIGEST_WORDS];
-
+   const struct {
+   __be32 saddr;
+   __be32 daddr;
+   __be16 sport;
+   __be16 dport;
+   char end[];
+   } __aligned(SIPHASH24_ALIGNMENT) combined = {
+   .saddr = saddr,
+   .daddr = daddr,
+   .sport = sport,
+   .dport = dport
+   };
+   u64 hash;
net_secret_init();
-   hash[0] = (__force u32)saddr;
-   hash[1] = (__force u32)daddr;
-   hash[2] = ((__force u16)sport << 16) + (__force u16)dport;
-   hash[3] = net_secret[15];
-
-   md5_transform(hash, net_secret);
-
-   *tsoff = sysctl_tcp_timestamps == 1 ? hash[1] : 0;
-   return seq_scale(hash[0]);
+   hash = siphash24((const u8 *),