Re: [PATCH v3] asm-generic ABI: Allow statx syscall despite fstatat64, fstat64

[Vineet Gupta <vineetg76 at gmail dot com>]

On 2/24/20 4:29 PM, Vineet Gupta wrote:
> An old version of asm-generic syscall ABI (e.g. ARC 2013) provided
> fstat[at]64 syscalls for implementing the stat family.
> 
> These sycalls are passthru (no interworking/itemized-copy needed
> between kernel and user structs since they are binary comaptible).
> However with switch to 64-bit time_t the compatibily goes away so we
> need explicit interworking. Luckily such code already exists albeit it
> uses the statx syscall.
> 
> So this patch reworks the asm-generic based stat functions to use the
> statx code-path if the arch so desires. It essentially reworks the commit
> 6bbfc5c09fc5b5e3 ("Add statx conditionals for wordsize-32 *xstat.c")
> 
> This will be used by ARC port for 64-bit time_t. But it has no real
> bearing on 64-bit and can just be independently opted-in by an arch port
> provided the ABI supports it.

Oh wait. Can we avoid this churn by simply undef __NR_fstat64 and __NR_fstatat64
from ARC sysdep.h ? And it will then automatically fallback to statx code !