OS X BSD System Calls Reference

Re:OS X BSD System Calls Reference by wavesum on Tuesday July 07, 2015 @11:01PM (#9849546)

Why so many duplicates? For expample int nosys() is listed 185 times, each pointing to bsd/kern/subr_xxx.c

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Re:OS X BSD System Calls Reference by asveikau on Wednesday July 08, 2015 @12:13AM (#9849777)

Because when you remove items from that list or otherwise change the order, you break binary compatibility.

The C library specifies the index into this table when making a syscall. You don't want a situation where the C library and the kernel are mismatched and disagree about what the syscalls are.

The safe way to remove a syscall is to change it to return ENOSYS. All the syscalls that come after it in the table therefore retain the same index.

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Re:OS X BSD System Calls Reference by kentonv on Tuesday July 07, 2015 @11:21PM (#9849613)

nosys() is a stub which simply [EDIT: raises SIGSYS then] fails with ENOSYS, i.e. "syscall not implemented".

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