Re: [PATCH] [BZ #19363] Use INTERNAL_SYSCALL_TIMES for Linux times

[Mike Frysinger <vapier at gentoo dot org>]

On 15 Dec 2015 07:50, H.J. Lu wrote:
> On Tue, Dec 15, 2015 at 6:58 AM, Mike Frysinger wrote:
> > On 14 Dec 2015 20:33, H.J. Lu wrote:
> >> On Mon, Dec 14, 2015 at 7:59 PM, Mike Frysinger wrote:
> >> > On 14 Dec 2015 19:27, H.J. Lu wrote:
> >> >> +  ({                                                                 \
> >> >> +    unsigned long long int resultvar;                                        \
> >> >> +    LOAD_ARGS_1 (buf)                                                        \
> >> >> +    LOAD_REGS_1                                                              \
> >> >> +    asm volatile (                                                   \
> >> >> +    "syscall\n\t"                                                    \
> >> >> +    : "=a" (resultvar)                                                       \
> >> >> +    : "0" (__NR_times) ASM_ARGS_1 : "memory", "cc", "r11", "cx");    \
> >> >
> >> > should the cc/r11/cx be made into a sysdep define ?
> >> > -mike
> >>
> >> I don't feel strongly about it.  Glibc folks work on x86-64 system calls
> >> know what they are doing.
> >
> > that sort of thinking is what leads to desync in code paths (it's not
> > obvious at all that updates to the common sysdep.h needs to also be
> > deployed to this specific file), plus gcc changes behavior over time
> > and refines asm constraints.  i'm sure you can find plenty of these
> > examples in the diff arches as i recall them going by in the past.
> >
> > not that i'm strongly saying "make the define", just taking umbrage
> > to your statement here.
> 
> It belongs a separate patch:
> 
> https://sourceware.org/git/?p=glibc.git;a=patch;h=d4f465df65a5723ede4cf933afee5582312fc603
> 
> I can submit it if we agree it is necessary.

i like it, but i leave it to your discretion ;)
-mike

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