[LTP] [PATCH v2] syscalls: add syscall syncfs test

[Sumit Garg]

On Sat, 16 Feb 2019 at 05:47, Steve Muckle <smuckle@google.com> wrote:
>
> On 02/15/2019 05:22 AM, Cyril Hrubis wrote:
> > Hi!
> >> Thanks for the pointers. IIUC, you are referring to following change:
> >>
> >> -       TEST(syncfs(fd));
> >> +       TEST(tst_syscall(__NR_syncfs, fd));
> >>
> >> If yes, then I will incorporate it.
> >
> > The most complete solution is configure check + fallback definition.
> >
> > Have a look at:
> >
> > include/lapi/execveat.h
> > m4/ltp-execveat.m4
> > configure.ac
>
> For tests in testcases/kernel/syscalls, should the tests typically
> directly call the syscall? I'd think this is preferable to the use of C
> library wrappers as these tests (by their location in the tree) seem to
> be focused on the syscall functionality in the kernel.
>

Sounds reasonable to me. But as per following manpage text for syscall():

"Each architecture ABI has its own requirements on how system call
arguments are passed to the kernel.  For system calls that have a
glibc  wrapper  (e.g., most  system  calls), glibc handles the details
of copying arguments to the right registers in a manner suitable for
the architecture. However, when using syscall() to make a system call,
the caller might need to handle architecture-dependent details; this
requirement is most commonly encountered  on certain 32-bit
architectures."

So I am not sure how we handle this architecture specific stuff if
required in test-cases.

-Sumit

> thanks,
> steve