This is the mail archive of the
libc-alpha@sourceware.org
mailing list for the glibc project.
Re: [PATCH v2] ARM: VDSO support
- From: Nathan Lynch <Nathan_Lynch at codesourcery dot com>
- To: Joseph Myers <joseph at codesourcery dot com>
- Cc: <libc-alpha at sourceware dot org>
- Date: Mon, 1 Jun 2015 15:16:46 -0500
- Subject: Re: [PATCH v2] ARM: VDSO support
- Authentication-results: sourceware.org; auth=none
- References: <1432933107-21117-1-git-send-email-nathan_lynch at codesourcery dot com> <alpine dot DEB dot 2 dot 10 dot 1506011953300 dot 18155 at digraph dot polyomino dot org dot uk>
On 06/01/2015 02:59 PM, Joseph Myers wrote:
> On Fri, 29 May 2015, Nathan Lynch wrote:
>
>> diff --git a/sysdeps/unix/sysv/linux/arm/Versions b/sysdeps/unix/sysv/linux/arm/Versions
>> index a251b0fd7d87..7bc5936372bb 100644
>> --- a/sysdeps/unix/sysv/linux/arm/Versions
>> +++ b/sysdeps/unix/sysv/linux/arm/Versions
>> @@ -10,5 +10,7 @@ libc {
>> GLIBC_PRIVATE {
>> # A copy of sigaction lives in libpthread, and needs these.
>> __default_sa_restorer; __default_rt_sa_restorer;
>> + __vdso_clock_gettime;
>> + __vdso_gettimeofday;
>
> That existing comment certainly doesn't explain why the VDSO symbols are
> exported.
>
> Now, __vdso_clock_gettime is presumably exported (on this and other
> architectures) because of an INTERNAL_VSYSCALL use in
> nptl/pthread_cond_timedwait.c. But why do you need an export of
> __vdso_gettimeofday that no other architecture has?
I confess I didn't quite understand what this was for. Your comments
clarify the situation for me -- the export of __vdso_gettimeofday is
unneeded. I will remove it, and add explanation for the export of
__vdso_clock_gettime.
>> + void *p = _dl_vdso_vsym ("__vdso_gettimeofday", &linux26);
>> + PTR_MANGLE (p);
>> + VDSO_SYMBOL(gettimeofday) = p;
>> +
>> + p = _dl_vdso_vsym ("__vdso_clock_gettime", &linux26);
>> + PTR_MANGLE (p);
>> + VDSO_SYMBOL(clock_gettime) = p;
>
> Missing space before '(' in calls to VDSO_SYMBOL.
I will fix these.