module private type, when private type mutex is locked/unlocked, thread
critical region is entered or leaved. These changes makes fork()
async-signal safe which required by POSIX. Note that user's atfork handler
still needs to be async-signal safe, but it is not problem of libthr, it
is user's responsiblity.
some cases we want to improve:
1) if a thread signal got a signal while in cancellation point,
it is possible the TDP_WAKEUP may be eaten by signal handler
if the handler called some interruptibly system calls.
2) In signal handler, we want to disable cancellation.
3) When thread holding some low level locks, it is better to
disable signal, those code need not to worry reentrancy,
sigprocmask system call is avoided because it is a bit expensive.
The signal handler wrapper works in this way:
1) libthr installs its signal handler if user code invokes sigaction
to install its handler, the user handler is recorded in internal
array.
2) when a signal is delivered, libthr's signal handler is invoke,
libthr checks if thread holds some low level lock or is in critical
region, if it is true, the signal is buffered, and all signals are
masked, once the thread leaves critical region, correct signal
mask is restored and buffered signal is processed.
3) before user signal handler is invoked, cancellation is temporarily
disabled, after user signal handler is returned, cancellation state
is restored, and pending cancellation is rescheduled.
not change interrupt vector if it is not pointing the ROM itself. Actually,
we just fail shadowing altogether if that is the case because the shadowed
copy will be useless for sure and POST may not be relocatable or useful.
While I'm here, fix a debugging message under bootverbose, really. r211829
fixed one case but broke another. Mea Culpa.
or not by comparing reported TX consumer index with saved index. So
remove unnecessary check done after freeing transmitted mbufs.
While I'm here nuke unnecessary variable initializations.
tag. All controllers that are not BCM5755 or higher have 4GB
boundary DMA bug. Previously bge(4) used 32bit DMA address to
workaround the bug(r199670). However this caused the use of bounce
buffers such that it resulted in poor performance for systems which
have more than 4GB memory. Because bus_dma(9) honors boundary
restriction requirement of DMA tag for dynamic buffers, having a
separate TX/RX mbuf DMA tag will greatly reduce the possibility of
using bounce buffers. For DMA buffers allocated with
bus_dmamem_alloc(9), now bge(4) explicitly checks whether the
requested memory region crossed the boundary or not.
With this change, only the DMA buffer that crossed the boundary
will use 32bit DMA address. Other DMA buffers are not affected as
separate DMA tag is created for each DMA buffer.
Even if 32bit DMA address space is used for a buffer, the chance to
use bounce buffer is still very low as the size of buffer is small.
This change should eliminate most usage of bounce buffers on
systems that have more than 4GB memory.
More correct fix would be teaching bus_dma(9) to honor boundary
restriction for buffers created with bus_dmamem_alloc(9) but it
seems that is not easy.
While I'm here cleanup bge_dma_map_addr() and remove unnecessary
member variables in bge_dmamap_arg structure.
Tested by: marcel
gnu/lib/libobjc and sys/boot/i386/boot2, so it also works when using
absolute paths and/or options, as in CC="/absolute/path/clang -foo".
Approved by: rpaulo (mentor)
the existing code was very platform specific, and broken for SMP systems
trying to reboot from KDB.
- Add a new PLATFORM_RESET() method to the platform KOBJ interface, and
migrate existing reset functions into platform modules.
- Modify the OF_reboot() routine to submit the request by hand to avoid
the IPIs involved in the regular openfirmware() routine. This fixes
reboot from KDB on SMP machines.
- Move non-KDB reset and poweroff functions on the Powermac platform
into the relevant power control drivers (cuda, pmu, smu), instead of
using them through the Open Firmware backdoor.
- Rename platform_chrp to platform_powermac since it has become
increasingly Powermac specific. When we gain support for IBM systems,
we will grow a new platform_chrp.
signals, because it is managed by debugger, however a normal signal sent to
a interruptibly sleeping thread wakes up the thread so it will handle the
signal when the process leaves the stopped state.
PR: 150138
MFC after: 1 week
of the lower level vnode is incremented to greater than 1 when
the upper level vnode's v_usecount is greater than one. This
is necessary for the NFS clients, so that they will do a silly
rename of the file instead of actually removing it when the
file is still in use. It is "racy", since the v_usecount is
incremented in many places in the kernel with
minimal synchronization, but an extraneous silly rename is
preferred to not doing a silly rename when it is required.
The only other file systems that currently check the value
of v_usecount in their VOP_REMOVE() functions are nwfs and
smbfs. These file systems choose to fail a remove when the
v_usecount is greater than 1 and I believe will function
more correctly with this patch, as well.
Tested by: to.my.trociny at gmail.com
Submitted by: to.my.trociny at gmail.com (earlier version)
Reviewed by: kib
MFC after: 2 weeks
limited to async-signal safe functions in the child process), move all hooks
execution to the main (non-threaded) process.
Do it by maintaining connection (socketpair) between child and parent
and sending events from the child to parent, so it can execute the hook.
This is step in right direction for others reasons too. For example there is
one less problem to drop privs in worker processes.
MFC after: 2 weeks
Obtained from: Wheel Systems Sp. z o.o. http://www.wheelsystems.com
heavy I/O load.
Many thanks to LSI for continuing to support FreeBSD.
PR: kern/149968
Submitted by: LSI (Tom Couch)
Reported by: Kai Kockro <kkockro web de>
Tested by: Kai Kockro, jpaetzel
MFC after: 7 days
least one execute bit set, otherwise execve(2) will return EACCES even
for an user with PRIV_VFS_EXEC privilege.
Add the check also to vaccess(9), vaccess_acl_nfs4(9) and
vaccess_acl_posix1e(9). This makes access(2) to better agree with
execve(2). Because ZFS doesn't use vaccess(9) for VEXEC, add the check
to zfs_freebsd_access() too. There may be other file systems which are
not using vaccess*() functions and need to be handled separately.
PR: kern/125009
Reviewed by: bde, trasz
Approved by: pjd (ZFS part)
