kern/kern_descrip.c:
Aquire Giant in fdrop_locked when file refcount hits zero, this removes
the requirement for the caller to own Giant for the most part.
kern/kern_ktrace.c:
Aquire Giant in ktrgenio, simplifies locking in upper read/write syscalls.
kern/vfs_bio.c:
Aquire Giant in bwillwrite if needed.
kern/sys_generic.c
Giant pushdown, remove Giant for:
read, pread, write and pwrite.
readv and writev aren't done yet because of the possible malloc calls
for iov to uio processing.
kern/sys_socket.c
Grab giant in the socket fo_read/write functions.
kern/vfs_vnops.c
Grab giant in the vnode fo_read/write functions.
Rev 1.2 changed the default emulation from ``elf64_sparc'' to ``elf32_sparc''
and I never noticed it after my review of rev 1.1. Backing the change of
the default emulation out, and Wa-la!, I can now build a native [and usable]
binutils. WTF, the "-m elf64_sparc" parameter handed to `ld' by `gcc'
wasn't DTRT is beyond me.
Missed a place where the pipe sleep lock was needed in order to safely grab
Giant, fix it and add an assertion to make sure this doesn't happen again.
Fix typos in the PIPE_GET_GIANT/PIPE_DROP_GIANT that could cause the
wrong mutex to get passed to PIPE_LOCK/PIPE_UNLOCK.
Fix a location where the wrong pipe was being passed to
PIPE_GET_GIANT/PIPE_DROP_GIANT.
lose if a process is preempted while pmap is temporarily switched to
another pmap.
* For SMP, drop the high-fp state when a thread is switched away from
so that if another cpu resumes that thread, it doesn't have to play
games with IPI to get ahold of the correct register values.
returns off_t in yylval.u.o. REST is the only user of yylval.u.o at the
moment.
NB: seems lukemftpd has the same bug.
PR: misc/28629
Reviewed by: ru
Approved by: ru
MFC after: 1 month
* Don't call ast() from interrupt() - if we switch, then we will miss
writing cr.eoi which will prevent the current cpu from receiving
interrupts until the current thread is resumed. The call to ast()
happens magically in exception_restore where it is safe.
* Add DDB 'show irq' command to examine interrupt hardware state.
* Use ptc.g instead of ptc.l so that TLB shootdowns are broadcast to the
coherence domain.
* Use smp_rendezvous for pmap_invalidate_all to ensure it happens on all
cpus.
* Dike out a DIAGNOSTIC printf which didn't compile.
* Protect the internals of pmap_install with cpu_critical_enter/exit.
Problem:
selwakeup required calling pfind which would cause lock order
reversals with the allproc_lock and the per-process filedesc lock.
Solution:
Instead of recording the pid of the select()'ing process into the
selinfo structure, actually record a pointer to the thread. To
avoid dereferencing a bad address all the selinfo structures that
are in use by a thread are kept in a list hung off the thread
(protected by sellock). When a selwakeup occurs the selinfo is
removed from that threads list, it is also removed on the way out
of select or poll where the thread will traverse its list removing
all the selinfos from its own list.
Problem:
Previously the PROC_LOCK was used to provide the mutual exclusion
needed to ensure proper locking, this couldn't work because there
was a single condvar used for select and poll and condvars can
only be used with a single mutex.
Solution:
Introduce a global mutex 'sellock' which is used to provide mutual
exclusion when recording events to wait on as well as performing
notification when an event occurs.
Interesting note:
schedlock is required to manipulate the per-thread TDF_SELECT
flag, however if given its own field it would not need schedlock,
also because TDF_SELECT is only manipulated under sellock one
doesn't actually use schedlock for syncronization, only to protect
against corruption.
Proc locks are no longer used in select/poll.
Portions contributed by: davidc
