Re: N32 fallocate syscall

[David Daney <ddaney@caviumnetworks.com>]

Joseph S. Myers wrote:
> The N32 syscall table uses sys_fallocate instead of sys32_fallocate.  
> However, glibc expects to be using the syscall version with 32-bit 
> arguments on N32, which should work with sys32_fallocate but not 
> sys_fallocate.
> 
> What should the N32 interface for this syscall be?  My inclination is that 
> glibc is right not to do anything special and different from other 32-bit 
> ABIs here, and so sys32_fallocate should be used.
> 

The prototype for that would be something like:

sys_fallocate(int32_t, int32_t, int64_t, int64_t);

The N32 and N64 ABIs treat this identically, the parameters are passed
in a0, a1, a2, and a3.  As you noted, the current (2.6.28-rc8) kernel
sources follow the ABI for N32 and N64.  I think the kernel is
correct.

If glibc is not using the ABI calling convention for both N32 and N64 (I
haven't checked), it should probably be fixed.

> (glibc is also expecting the 32-bit version for N64, but that's a clear 
> bug in glibc that I'll be fixing.)
> 

David Daney