On Tuesday 03 May 2016 10:00:45 Catalin Marinas wrote: > On Fri, Apr 29, 2016 at 07:30:19PM +0200, Arnd Bergmann wrote: > > On Friday 29 April 2016 17:01:55 Catalin Marinas wrote: > > > On Wed, Apr 06, 2016 at 01:08:46AM +0300, Yury Norov wrote: > > > > ILP32 VDSO exports next symbols: > > > > __kernel_rt_sigreturn; > > > > __kernel_gettimeofday; > > > > __kernel_clock_gettime; > > > > __kernel_clock_getres; > > > > > > [...] > > > > > > > +$(obj)/gettimeofday-ilp32.o: $(src)/../vdso/gettimeofday.S > > > > + $(call if_changed_dep,vdso-ilp32as) > > > > > > Are struct timeval and timespec the same between ILP32 and LP64? For > > > example, __kernel_gettimeofday() assumes TVAL_TV_SEC offset defined in > > > asm-offsets.c based on the LP64 timeval. > > > > No, ilp32 uses the generic 32-bit data structures, which have a 32-bit > > time_t. I guess that means it can work for little-endian but not > > big-endian, right? > > I don't think it works for little-endian either. The LP64 struct timeval > is 16 bytes while the ILP32 one is 8 bytes. The VDSO gettimeofday is > storing 16 bytes (stp x10, x11, [x0, #TVAL_TV_SEC]) You are right. Yury asked pointed out the same thing on IRC as well. Using the 64-bit gettimeofday() will put the right number in the .tv_sec member on little-endian, but will write zeroes to tv_nsec and corrupt the memory following it. Yury also tried it out and noticed that for a (so far) unknown reason, the vdso gets never used by his glibc build, so it has not triggered any test case failures. Arnd -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
