This is the mail archive of the libc-alpha@sourceware.org mailing list for the glibc project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

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


On Tue, Dec 15, 2015 at 6:58 AM, Mike Frysinger <vapier@gentoo.org> 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.

-- 
H.J.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]