Looks good to me. +1 on this revised specification.
- Garrett
Roger A. Faulkner wrote:
>> Date: Thu, 03 Dec 2009 00:30:10 -0800
>> From: Mike Shapiro <mws at sun.com>
>> Subject: Re: delete obsolete system call traps [PSARC/2009/657]
>> To: "Roger A. Faulkner" <Roger.Faulkner at sun.com>
>> Cc: psarc-ext at sac.sfbay.sun.com, Bart.Smaalders at sun.com,
>>
> Bryan.Cantrill at sun.com, Michael.Shapiro at sun.com, Darrin.Johnson at
> sun.com
>
> ...
>
>> I certainly agree some of this is implementation and doesn't matter.
>> And from a technical perspective, because the current DTrace syscall
>> provider advertises the sysent table names and not the sub-coded man
>> page (2) view of system calls (something we intend to rectify
>> someday), we marked those names as Private in our stability mechanism.
>>
>> But from a practical perspective, I'm very uncomfortable with the *at
>> part of this project, whereby extremely well-known fundamental names
>> used extensively by users of DTrace based on long-standing
>> fundamentals like syscall::open:entry just go away, essentially for no
>> benefit.
>>
>
> I discussed this matter offline with Michael Shapiro and Bryan Cantrill.
>
> While it is unfortunate that the current DTrace syscall provider
> has caused the syscall trap table to have become a public interface,
> DTrace usage is widespread enough to warrent keeping unchanged what
> Mike refers to as "extremely well-known fundamental names used
> extensively by users of DTrace based on long-standing fundamentals
> like syscall::open:entry".
>
> This not a tenable long-term solution. The kernel <-> user-level
> syscall trap interface has never been a Solaris public interface.
> The long-term solution is to implement what Mike refers to as
> "the sub-coded man page (2) view of system calls" in the DTrace
> syscall provider.
>
> In the interim, for the current PSARC case for deleting obsolete
> system call traps, I am changing the proposal as follows:
>
> ===========================================================
>
> Retain these old system call traps;
> make sure they are called from libc as always so that
> existing DTrace scripts continue to work as always:
> open()
> open64()
> stat()
> lstat()
> fstat()
> stat64()
> lstat64()
> fstat64()
> rename()
> unlink()
> rmdir()
> chown()
> lchown()
> fchown()
> access()
>
> Delete these in favor of open*(path, O_WRONLY | O_CREAT | O_TRUNC, mode):
> creat()
> creat64()
>
> Delete this in favor of fcntl(F_DUPFD):
> dup()
>
> Delete these from i386 code in favor of *stat() amd mknod()
> (they should have been deleted when COFF support was dropped):
> _xstat()
> _lxstat()
> _fxstat()
> _xmknod()
>
> Delete these (they are never called from libc):
> exec()
> fork1()
> forkall()
> poll()
> utime()
> utimes()
> umount()
> wait()
> lwp_mutex_lock()
> lwp_sema_wait()
>
> Delete this:
> fsat()
> in favor of individual (new) system call traps for each of its subcodes:
> openat()
> openat64()
> fstatat()
> fstatat64()
> renameat()
> unlinkat()
> fchownat()
> faccessat()
>
> ===========================================================
>
> Roger Faulkner
>
>
