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| author | marius <marius@FreeBSD.org> | 2008-06-25 21:04:59 +0000 |
|---|---|---|
| committer | marius <marius@FreeBSD.org> | 2008-06-25 21:04:59 +0000 |
| commit | 762f29e950fd1511beb76c95c5014bb779d4f5ed (patch) | |
| tree | 21030df4cb541765bdaedd12c3aa316481b0b10e /sys/sparc64 | |
| parent | ae81de5ecb29ad447d9bdb8bacda9a37a92a4ed6 (diff) | |
| download | FreeBSD-src-762f29e950fd1511beb76c95c5014bb779d4f5ed.zip FreeBSD-src-762f29e950fd1511beb76c95c5014bb779d4f5ed.tar.gz | |
Use "__asm __volatile" rather than "__asm" for instruction sequences
that modify condition codes (the carry bit, in this case). Without
"__volatile", the compiler might add the inline assembler instructions
between unrelated code which also uses condition codes, modifying the
latter.
This prevents the TCP pseudo header checksum calculation done in
tcp_output() from having effects on other conditions when compiled
with GCC 4.2.1 at "-O2" and "options INET6" left out. [1]
Reported & tested by: Boris Kochergin [1]
MFC after: 3 days
Diffstat (limited to 'sys/sparc64')
| -rw-r--r-- | sys/sparc64/include/in_cksum.h | 14 |
1 files changed, 7 insertions, 7 deletions
diff --git a/sys/sparc64/include/in_cksum.h b/sys/sparc64/include/in_cksum.h index 2e46f46..ad08585 100644 --- a/sys/sparc64/include/in_cksum.h +++ b/sys/sparc64/include/in_cksum.h @@ -63,7 +63,7 @@ #include <sys/cdefs.h> -#define in_cksum(m, len) in_cksum_skip(m, len, 0) +#define in_cksum(m, len) in_cksum_skip(m, len, 0) static __inline void in_cksum_update(struct ip *ip) @@ -79,7 +79,7 @@ in_addword(u_short sum, u_short b) { u_long __ret, __tmp; - __asm( + __asm __volatile( "sll %2, 16, %0\n" "sll %3, 16, %1\n" "addcc %0, %1, %0\n" @@ -93,8 +93,8 @@ static __inline u_short in_pseudo(u_int sum, u_int b, u_int c) { u_long __tmp; - - __asm( + + __asm __volatile( "addcc %0, %3, %0\n" "addccc %0, %4, %0\n" "addc %0, 0, %0\n" @@ -121,11 +121,11 @@ in_cksum_hdr(struct ip *ip) * a generic implementation for both in_cksum_skip and in_cksum_hdr * should not be too much more expensive. */ -#define __LD_ADD(addr, tmp, sum, offs, mod) \ - "lduw [" #addr " + " #offs "], " #tmp "\n" \ +#define __LD_ADD(addr, tmp, sum, offs, mod) \ + "lduw [" #addr " + " #offs "], " #tmp "\n" \ "add" # mod " " #sum ", " #tmp ", " #sum "\n" - __asm( + __asm __volatile( "and %5, 3, %3\n" "andn %5, 3, %1\n" "brz,pt %3, 0f\n" |
