Re: Add private syscalls to support NPTL

Maxim Kuvyrkov
2009-08-18T07:15:12Z

Andreas Schwab wrote:
> Maxim Kuvyrkov <maxim@codesourcery.com> writes:
>
>> diff --git a/arch/m68k/include/asm/unistd.h b/arch/m68k/include/asm/unistd.h
>> index aa29a86..619677c 100644
>> --- a/arch/m68k/include/asm/unistd.h
>> +++ b/arch/m68k/include/asm/unistd.h
>> @@ -335,9 +335,16 @@
>> #define __NR_preadv 329
>> #define __NR_pwritev 330
>>
>> +/* Private syscalls. */
>> +#define __M68K_NR_read_tp 0xffffffff
>> +#define __M68K_NR_write_tp 0xfffffffe
>> +#define __M68K_NR_atomic_cmpxchg_32 0xfffffffd
>> +#define __M68K_NR_atomic_barrier 0xfffffffc
>
> I don't see the need for these weird syscall numbers.

The need would be (a) use numbers that are very unlikely to used for
normal syscalls, and (b) using -1..-4 for the syscall numbers works out
quite nicely for the code in entry.S. It adds just a couple of
instructions to the execution path.

Do you think it's better to assign different numbers to the
m68k-specific syscall?

--
Maxim