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Hi Stepan, > 06.05.2019 в 16:26:59 +0200 Lukasz Majewski написал: > > > > > > > > I believe that the only 32-bit architecture without > > > > > > > __NR_clock_settime64 is x32. > > > > > > > > > > > > Ok, I see. > > > > > > > > > > > > Please correct me - would it be feasible to just #undef > > > > > > __ASSYME_TIME64_SYSCALLS for x32 ? > > > > > > > > > > You'll need to know whether to use __NR_clock_settime64 or > > > > > __NR_clock_settime in cases where __TIMESIZE == 64 and > > > > > __WORDSIZE == 32. > > > > > > Please correct me, but I do have some doubts here. > > > > > > As x32 now uses 64 bit time (and has TIMESIZE==64) - it uses the > > > clock_settime call (with in-kernel broken tv_nsec padding > > > clearing - but for this the fix is in its way to upstream). > > > > > > Why does it need to also support clock_settime64 ? > > > > I was too eager to send the mail. > > > > It is connected with your proposition to use __WORDSIZE for #ifdef > > on __ASSUME_TIME64_SYSCALLS. > > > > As x32 has __WORDSIZE=32 (but __TIMESIZE=64), it would fall into > > "category" of archs using explicit 64 bit calls (i.e. > > clock_settime64). > > > > However, for it - those shall be replaced with syscalls used up > > till now (i.e. clock_settime). > > > > Am I right here ? > > x32 has __WORDSIZE==32 and __TIMESIZE==64. Future 32-bit > architectures should have __WORDSIZE==32 and __TIMESIZE==64 too. And > the only difference in implementation of clock_settime64 function > there should be name of syscall (ignoring possible padding clearing > issues). For ARM, x86 there shall be call to clock_settime64 syscall For x32 there shall be call to clock_settime syscall (which is supporting 64 bit anyway - despite the ignoring possible padding clearing issue). > > > > > > One way would be by defining __ASSUME_TIME64_SYSCALLS > > > > > unconditionally on x32 and then defining __NR_clock_settime64 > > > > > to __NR_clock_settime when __ASSUME_TIME64_SYSCALLS is > > > > > defined while __NR_clock_settime64 isn't. > > I think now that with this scheme __ASSUME_TIME64_SYSCALLS should be > defined unconditionally for the __WORDSIZE==64 case too. With this > there will be no need to use __TIMESIZE inside clock_settime64 > function. __TIMESIZE describes interfaces provided by glibc, and has > no relation with kernel interfaces used by glibc. > > #ifdef __ASSUME_TIME64_SYSCALLS > call __NR_clock_settime64 (possibly defined to __NR_clock_settime) > #else > call __NR_clock_settime64 with fallback to __NR_clock_settime on > ENOSYS #endif I rather thought about something like: __clock_settime64 (clockid_t clock_id, const struct __timespec64 *tp) { <overflow check> #ifdef __ASSUME_TIME64_SYSCALLS # ifdef __NR_clock_settime64 int ret = INLINE_SYSCALL_CALL (clock_settime64, clock_id, tp); if (ret == 0 || errno != ENOSYS) return ret; # endif /* Fall back to syscall supporting 32bit struct timespec. */ struct timespec ts32; valid_timespec64_to_timespec (tp, &ts32); return INLINE_SYSCALL_CALL (clock_settime, clock_id, &ts32); #else /* 64 bit machines + x32 */ return INLINE_SYSCALL_CALL (clock_settime, clock_id, tp); #endif } In the above pseudo code we assume that __ASSUME_TIME64_SYSCALLS is #undef'ed for x32 (so it is treated as a 'special case' - in the same way as x86_64). Best regards, Lukasz Majewski -- DENX Software Engineering GmbH, Managing Director: Wolfgang Denk HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-59 Fax: (+49)-8142-66989-80 Email: lukma@denx.de
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