lkml.org 
[lkml]   [2008]   [May]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
SubjectRe: [PATCH] common implementation of iterative div/mod

> It's:
> jeremy@cosworth:~/hg/xen/paravirt/linux-x86_64$ gcc -v
> Reading specs from /usr/lib/gcc/x86_64-linux/3.4.4/specs
> Configured with: ../src/configure -v
> --enable-languages=c,c++,java,f77,pascal,objc,ada,treelang --prefix=/usr
> --libexecdir=/usr/lib --with-gxx-include-dir=/usr/include/c++/3.4
> --enable-shared --with-system-zlib --enable-nls
> --without-included-gettext --program-suffix=-3.4 --enable-__cxa_atexit
> --enable-libstdcxx-allocator=mt --enable-clocale=gnu
> --enable-libstdcxx-debug --enable-java-gc=boehm --enable-java-awt=gtk
> --disable-werror x86_64-linux
> Thread model: posix
> gcc version 3.4.4 20050314 (prerelease) (Debian 3.4.3-13)
>
> I think this is still a supported compiler, isn't it?

Yes. Here's a patch. You probably didn't see problems because you either
don't have a glibc that supports the vdso or none of your programs
gets the timezone from gettimeofday() [that is very obscure obsolete
functionality anyways, normally it should be gotten from the disk locales]

-Andi




Use explicit copy in vdso_gettimeofday()

Jeremy's gcc 3.4 seems to be unable to inline a 8 byte memcpy. But
the vdso doesn't support external references. Copy the structure
members of struct timezone explicitely instead.

Signed-off-by: Andi Kleen <ak@linux.intel.com>

Index: linux/arch/x86/vdso/vclock_gettime.c
===================================================================
--- linux.orig/arch/x86/vdso/vclock_gettime.c
+++ linux/arch/x86/vdso/vclock_gettime.c
@@ -106,9 +106,9 @@ int __vdso_gettimeofday(struct timeval *
do_realtime((struct timespec *)tv);
tv->tv_usec /= 1000;
if (tz != NULL) {
- /* This relies on gcc inlining the memcpy. We'll notice
- if it ever fails to do so. */
- memcpy(tz, &gtod->sys_tz, sizeof(struct timezone));
+ /* Don't use memcpy. Some old compilers fail to inline it */
+ tz->tz_minuteswest = gtod->sys_tz.tz_minuteswest;
+ tz->tz_dsttime = gtod->sys_tz.tz_dsttime;
}
return 0;
}
\
 
 \ /
  Last update: 2008-05-14 13:23    [from the cache]
©2003-2011 Jasper Spaans