Messages in this thread | | | Date | Wed, 19 Sep 2012 19:03:47 +0200 | From | Richard Cochran <> | Subject | Re: [PATCH 0/6][RFC] Rework vsyscall to avoid truncation/rounding issue in timekeeping core |
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On Wed, Sep 19, 2012 at 09:31:35AM -0700, John Stultz wrote:
> On powerpc, I mean magic addresses where userland can find > structures that it can use to calculate time.
...
> With powerpc, there is no arch specific kernel code involved, its > just a data structure the kernel exports that is accessible to > userland. The execution logic lives in userland libraries, or > sometimes application code itself.
I took a brief look at arch/powerpc/kernel/vdso32/gettimeofday.S and arch/powerpc/kernel/vdso64/gettimeofday.S, and I see what looks a lot like functions
$ find arch/powerpc/kernel/vdso* -name gettimeofday.S|xargs grep FUNCTION_BEGIN
arch/powerpc/kernel/vdso32/gettimeofday.S:V_FUNCTION_BEGIN(__kernel_gettimeofday) arch/powerpc/kernel/vdso32/gettimeofday.S:V_FUNCTION_BEGIN(__kernel_clock_gettime) arch/powerpc/kernel/vdso32/gettimeofday.S:V_FUNCTION_BEGIN(__kernel_clock_getres) arch/powerpc/kernel/vdso64/gettimeofday.S:V_FUNCTION_BEGIN(__kernel_gettimeofday) arch/powerpc/kernel/vdso64/gettimeofday.S:V_FUNCTION_BEGIN(__kernel_clock_gettime) arch/powerpc/kernel/vdso64/gettimeofday.S:V_FUNCTION_BEGIN(__kernel_clock_getres) arch/powerpc/kernel/vdso64/gettimeofday.S:V_FUNCTION_BEGIN(__do_get_tspec)
and I wonder whether these could be done in C instead.
Thanks, Richard
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