Re: [LTP] [PATCH 1/2] syscalls/getdents: Use getdents64 if SYS_getdents is not defined

[chrubis@suse.cz]

Hi!
> The problem is that for arches that don't have SYS_getdents defined,
> you will not be able to compile LTP on them so you really need to
> hide this codepath from them.
> 
> A similar commit that changes the codepath based on whether a
> particular __NR_XX is defined is this
> https://github.com/linux-test-project/ltp/commit/75201f160b9aa49af70d8f46fb1f087e63d603dd
> 
> I don't see an easy way to determine if __NR_XX is defined or not
> during runtime.

There is code that tries to address this issue in
testcases/kernel/include/linux_syscall_numbers.h
which defines macro ltp_syscall() that turns undefined
syscall numbers into ENOSYS.

The idea is to:

1) include sys/syscall.h to get the definitions system definitons

2) if your system headers are older (i.e. particular __NR_xxx is not defined)
   definitions from arch.in files are used

3) if __NR_xxx is not defined, there are stubs at the end of the header
   that defines the __NR_xxx to 0 which is then used by the ltp_syscall()
   macro to return -1 and set errno to ENOSYS

-- 
Cyril Hrubis
chrubis@suse.cz

------------------------------------------------------------------------------
Everyone hates slow websites. So do we.
Make your web apps faster with AppDynamics
Download AppDynamics Lite for free today:
http://p.sf.net/sfu/appdyn_d2d_mar
_______________________________________________
Ltp-list mailing list
Ltp-list@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/ltp-list