libthr does not obey WITHOUT_SYSCALL_COMPAT
deischen at freebsd.org
Sun Mar 8 22:23:25 PDT 2009
On Mon, 9 Mar 2009, David Xu wrote:
> Daniel Eischen wrote:
>> On Mon, 9 Mar 2009, David Xu wrote:
>>> Pawel Worach wrote:
>>>> If libc is built using WITHOUT_SYSCALL_COMPAT applications linked with
>>>> libthr end up having unresolved symbols since libthr references
>>>> __fcntl_compat unconditionally.
>>>> Here is a patch to make libthr also obey WITHOUT_SYSCALL_COMPAT
>> I never got around to replying to this...
>> I don't quite understand why __fcntl_compat is there. We have
>> F_GETFD, F_SETFD, F_DUPFD, F_DUP2FD, F_GETFL, F_SETFL, F_GETOWN,
>> and F_SETOWN according to fcntl(2). But thr_syscalls.c only
>> handles F_DUPFD, F_SETFD, F_SETFL, F_GETFD, and F_GETFL, leaving
>> F_DUP2FD, F_GETOWN, and F_SETOWN to be handled by the default
>> case. And the default case does nothing now if WITHOUT_SYSCALL_COMPAT
>> is defined. So how do F_DUP2FD, F_GETOWN, and F_SETOWN get
>> Do we really need to call __sys_fcntl_compat() from libthr?
>> When did the ABI change, before or after libc.so.7?
> I don't know when it appeared. Would this patch eliminate the shit ?
I think so. But I think for future ABI changes to cancellation
points, wouldn't we need syscall wrappers in libc? Reason, libc
and libthr are now symbol-versioned, so there will no longer be
library bumps for ABI changes. But if a syscall is a cancellation
point and libthr has to play games with it, like fcntl, I think
there should be a wrapper around it in libc. If the ABI changes,
then both libc and libthr would need to provide a compat version
for it. I think. ;-)
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