[Letux-kernel] MIPS: bug: gettimeofday syscall broken on CI20 board

Thomas Bogendoerfer tsbogend at alpha.franken.de
Thu Nov 28 16:07:21 CET 2019

On Thu, Nov 28, 2019 at 02:48:46PM +0100, H. Nikolaus Schaller wrote:
> What still does not fit into the picture is the errno = 1 i.e. EPERM.
> Maybe I have to study the libc code that tries to read the ELF symbols
> you have mentioned. It may fail for unknown reasons.

to understand vdso you might look at arch/mips/vdso and lib/vdso
kernel sources.

And if I understand it correctly you neither have a working high resolution
timer usable bei do_hres() in lib/vdso/gettimeofday.c or a working
gettimeofday_fallback(), which is enabled via CONFIG_MIPS_CLOCK_VSYSCALL
and needs either CSRC_R4K or CLKSRC_MIPS_GIC.


Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
good idea.                                                [ RFC1925, 2.3 ]

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