support for calling Linux syscalls directly

[H. Peter Anvin]

On 02/03/2013 07:35 PM, Michael Kerrisk wrote:
>
> So, below my (expanded) list of syscalls that don't have ful glibc
> support, categorized with respect as to whether they should be in
> glibc.
>

 From the the looks of it you're assuming library == libc, as opposed to 
making a libc/libinux distinction.

> Cheers,
>
> Michael
>
>
> STRONG CANDIDATES FOR GLIBC
>
> gettid(2)             See http://sourceware.org/bugzilla/show_bug.cgi?id=6399
> ioprio_get(2)
> ioprio_set(2)
>
> POSSIBLE CANDIDATES FOR GLIBC
>
> delete_module(2)      [calling signature changed in 2.6.x]
> finit_module(2)
> init_module(2)
> io_cancel(2)
> io_destroy(2)
> io_getevents(2)
> io_setup(2)
> io_submit(2)
> kcmp(2)
> kexec_load(2)
> perf_event_open(2)
> tgkill(2)
>
>
> ARCHITECTURE SPECIFIC, maybe candidates for glibc
>
> kern_features(2)      [Sparc94]
> s390_runtime_instr(2) [s390 specific]
> spu_create(2)         [PowerPC specific]
> spu_run(2)            [PowerPC specific]
> subpage_prot(2)       [PowerPC specific]
> utrap_install(2)      [Sparc]
>
>
> INTENDED ONLY FOR LIBC / KERNEL USE
> (No need to add a wrapper in glibc)
>
> restart_syscall(2)
>
>
> UNCERTAIN (some possibly only intended for libc use)
>
> get_robust_list(2)
> set_robust_list(2)
> get_thread_area(2)
> set_thread_area(2)
> modify_ldt(2)
> pivot_root(2)
>

modify_ldt() and pivot_root() definitely should have library 
implementations.  The others are iffier, it depends on if you consider 
them to be strictly for implementing locking primitives and TLS 
respectively.

>
> NO GLIBC WRAPPER, BUT WRAPPER IN LIBNUMA
>
> (This is an odd situation. No obvious reason why
> things are done this way.)
>
> get_mempolicy(2)
> mbind(2)
> migrate_pages(2)
> move_pages(2)
> set_mempolicy(2)
>
>
> SYSCALLS WRAPPED IN A GLIBC FUNCTION
> (No need to add a wrapper in glibc)
>
> getcpu(2)             [there is sched_getcpu(3)]
> mq_getsetattr(2)      [but there are suitable mq_*(3) wrappers]
> rt_sigqueueinfo(2)    [there is sigqueue(3)]
> rt_tgsigqueueinfo(2)  [there is pthread_sigqueue(3)]
>
>
> OBSOLETE
> (No need to add a wrapper in glibc)
>
> getdents(2)           [readdir(3) is preferred]
> query_module(2)       [obsolete]
> readdir(2)            [readdir(3) is preferred]
> sgetmask(2)           [obsolete, use sigprocmask(2) instead]
> ssetmask(2)           [obsolete, use sigprocmask(2) instead]
> sysctl(2)             [deprecated]
> tkill(2)              [obsolete]
>


-- 
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel.  I don't speak on their behalf.