Re: [PATCH] LinuxPPS - definitive version

From: Rodolfo Giometti
Date: Tue Jul 24 2007 - 10:30:58 EST


On Tue, Jul 24, 2007 at 02:49:02PM +0100, David Woodhouse wrote:
>
> I think you still haven't quite got the 32-bit vs. 64-bit compatibility
> right. Remember that on i386, the alignment of a uint64_t is only 4
> bytes, while on most other architectures it's 8 bytes. On i386, there
> will be no padding between the two consecutive 'struct pps_ktime'
> members of struct pps_kinfo and struct pps_kparams. But on most
> platforms there will be padding to ensure correct alignment.
>
> The simple fix is probably to make the 'nsec' member a 64-bit integer
> too. Then it'll be the same for i386 and x86_64 and you won't need a
> compatibility syscall routine.

By doing:

struct pps_ktime {
__u64 sec;
- __u32 nsec;
+ __u64 nsec;
};

I got:

GEN .version
CHK include/linux/compile.h
UPD include/linux/compile.h
CC init/version.o
LD init/built-in.o
LD .tmp_vmlinux1
drivers/built-in.o: In function `sys_time_pps_fetch':
(.text+0x5f05e): undefined reference to `__udivdi3'
make: *** [.tmp_vmlinux1] Error 1

I suppose the problem is here:

ticks = to.sec * HZ;
ticks += to.nsec / (NSEC_PER_SEC / HZ);

Suggestions? :)

Rodolfo

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