| From heiko.carstens@de.ibm.com Fri May 4 12:30:05 2007 |
| From: Heiko Carstens <heiko.carstens@de.ibm.com> |
| Date: Fri, 04 May 2007 21:22:11 +0200 |
| Subject: s390: Fix TCP/UDP pseudo header checksum computation. |
| To: stable@kernel.org, greg@kroah.com |
| Cc: heiko.carstens@de.ibm.com, schwidefsky@de.ibm.com |
| Message-ID: <20070504192839.425473994@de.ibm.com> |
| Content-Disposition: inline; filename=02-network.diff |
| |
| |
| From: Heiko Carstens <heiko.carstens@de.ibm.com> |
| |
| git commit f994aae1bd8e4813d59a2ed64d17585fe42d03fc changed the |
| function declaration of csum_tcpudp_nofold. Argument types were |
| changed from unsigned long to __be32 (unsigned int). Therefore we |
| lost the implicit type conversion that zeroed the upper half of the |
| registers that are used to pass parameters. Since the inline assembly |
| relied on this we ended up adding random values and wrong checksums |
| were created. |
| Showed only up on machines with more than 4GB since gcc produced code |
| where the registers that are used to pass 'saddr' and 'daddr' previously |
| contained addresses before calling this function. |
| Fix this by using 32 bit arithmetics and convert code to C, since gcc |
| produces better code than these hand-optimized versions. |
| |
| Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> |
| Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> |
| Signed-off-by: Chris Wright <chrisw@sous-sol.org> |
| |
| --- |
| include/asm-s390/checksum.h | 59 +++++++++++--------------------------------- |
| 1 file changed, 15 insertions(+), 44 deletions(-) |
| |
| --- linux-2.6.20.13.orig/include/asm-s390/checksum.h |
| +++ linux-2.6.20.13/include/asm-s390/checksum.h |
| @@ -121,50 +121,21 @@ csum_tcpudp_nofold(__be32 saddr, __be32 |
| unsigned short len, unsigned short proto, |
| __wsum sum) |
| { |
| -#ifndef __s390x__ |
| - asm volatile( |
| - " alr %0,%1\n" /* sum += saddr */ |
| - " brc 12,0f\n" |
| - " ahi %0,1\n" /* add carry */ |
| - "0:" |
| - : "+&d" (sum) : "d" (saddr) : "cc"); |
| - asm volatile( |
| - " alr %0,%1\n" /* sum += daddr */ |
| - " brc 12,1f\n" |
| - " ahi %0,1\n" /* add carry */ |
| - "1:" |
| - : "+&d" (sum) : "d" (daddr) : "cc"); |
| - asm volatile( |
| - " alr %0,%1\n" /* sum += len + proto */ |
| - " brc 12,2f\n" |
| - " ahi %0,1\n" /* add carry */ |
| - "2:" |
| - : "+&d" (sum) |
| - : "d" (len + proto) |
| - : "cc"); |
| -#else /* __s390x__ */ |
| - asm volatile( |
| - " lgfr %0,%0\n" |
| - " algr %0,%1\n" /* sum += saddr */ |
| - " brc 12,0f\n" |
| - " aghi %0,1\n" /* add carry */ |
| - "0: algr %0,%2\n" /* sum += daddr */ |
| - " brc 12,1f\n" |
| - " aghi %0,1\n" /* add carry */ |
| - "1: algfr %0,%3\n" /* sum += len + proto */ |
| - " brc 12,2f\n" |
| - " aghi %0,1\n" /* add carry */ |
| - "2: srlg 0,%0,32\n" |
| - " alr %0,0\n" /* fold to 32 bits */ |
| - " brc 12,3f\n" |
| - " ahi %0,1\n" /* add carry */ |
| - "3: llgfr %0,%0" |
| - : "+&d" (sum) |
| - : "d" (saddr), "d" (daddr), |
| - "d" (len + proto) |
| - : "cc", "0"); |
| -#endif /* __s390x__ */ |
| - return sum; |
| + __u32 csum = (__force __u32)sum; |
| + |
| + csum += (__force __u32)saddr; |
| + if (csum < (__force __u32)saddr) |
| + csum++; |
| + |
| + csum += (__force __u32)daddr; |
| + if (csum < (__force __u32)daddr) |
| + csum++; |
| + |
| + csum += len + proto; |
| + if (csum < len + proto) |
| + csum++; |
| + |
| + return (__force __wsum)csum; |
| } |
| |
| /* |
