cvs commit: src/sys/i386/i386 sys_machdep.c
jhb at freebsd.org
Fri Sep 12 14:50:45 UTC 2008
On Friday 12 September 2008 05:51:11 am Konstantin Belousov wrote:
> kib 2008-09-12 09:51:11 UTC
> FreeBSD src repository
> Modified files:
> sys/i386/i386 sys_machdep.c
> SVN rev 182960 on 2008-09-12 09:51:11Z by kib
> The user_ldt_alloc() function shall return with dt_lock locked.
> The user_ldt_free() function shall return with dt_lock unlocked.
> Error handling code in both functions do not handle this, fix it by
> doing necessary lock/unlock.
> While there, fix minor style nits.
Hmm, I had actually thought it was intentional for user_ldt_alloc() to only
return with the lock held on success and depend on a later call to another
method to drop the lock in the success case (so the locking isn't visible to
consumers of the API in theory). For example, i386_ldt_grow() depended on
this feature and is now broken (it leaks a lock on failure). I missed this
when looking at this yesterday.
- Since user_ldt_free() handles the case of there not being an LDT, the code
in exec_setregs() on i386 can be simplified to just always call
- cpu_exit() could possibly do the same. I wonder if exec_setregs() needs the
same fixup to %gs that cpu_exit() does. If so, that could possibly be moved
into user_ldt_free(). Ah, exec_setregs() does it unconditionally. I think
you could make cpu_exit() just do it unconditionally as well before calling
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