- use a marker knote from the stack instead of allocating and freeing on
each scan.
- add more KASSERTS
- introduce a KN_BUSY bit that indicates that the knote is currently being
scanned, so that knote_detach does not end up deleting it when the file
descriptor gets closed and we don't end up using/trashing free memory from
the scan.
- in close, invalidate f_data and f_type early to prevent accidental re-use
- add a DIAGNOSTIC for when we use unsupported fd's and a KASSERT for f_event
being NULL.
on EPIPE for all file descriptor types:
- provide O_NOSIGPIPE for open,kqueue1,pipe2,dup3,fcntl(F_{G,S}ETFL) [NetBSD]
- provide SOCK_NOSIGPIPE for socket,socketpair [NetBSD]
- provide SO_NOSIGPIPE for {g,s}seckopt [NetBSD/FreeBSD/MacOSX]
- provide F_{G,S}ETNOSIGPIPE for fcntl [MacOSX]
set close-on-exec on creation (http://udrepper.livejournal.com/20407.html).
- Add F_DUPFD_CLOEXEC to fcntl(2).
- Add MSG_CMSG_CLOEXEC to recvmsg(2) for unix file descriptor passing.
- Add dup3(2) syscall with a flags argument for O_CLOEXEC, O_NONBLOCK.
- Add pipe2(2) syscall with a flags argument for O_CLOEXEC, O_NONBLOCK.
- Add flags SOCK_CLOEXEC, SOCK_NONBLOCK to the socket type parameter
for socket(2) and socketpair(2).
- Add new paccept(2) syscall that takes an additional sigset_t to alter
the sigmask temporarily and a flags argument to set SOCK_CLOEXEC,
SOCK_NONBLOCK.
- Add new mode character 'e' to fopen(3) and popen(3) to open pipes
and file descriptors for close on exec.
- Add new kqueue1(2) syscall with a new flags argument to open the
kqueue file descriptor with O_CLOEXEC, O_NONBLOCK.
* Fix the system calls that take socklen_t arguments to actually do so.
* Don't include userland header files (signal.h) from system header files
(rump_syscallargs.h).
* Bump libc version for the new syscalls.
while the loop body is executed -- at least in the EVFILT_PROC / exit
case a race condition exists which can cause this
fixes a panic triggered eg by tests/kernel/kqueue/proc1
Rename real routines to proc_find() and pgrp_find(), remove PFIND_* flags
and have consistent behaviour. Provide proc_find_raw() for special cases.
Fix memory leak in sysctl_proc_corename().
COMPAT_LINUX: rework ptrace() locking, minimise differences between
different versions per-arch.
Note: while this change adds some formal cosmetics for COMPAT_DARWIN and
COMPAT_IRIX - locking there is utterly broken (for ages).
Fixes PR/43176.
read/write/accept, then the expectation is that the blocked thread will
exit and the close complete.
Since only one fd is affected, but many fd can refer to the same file,
the close code can only request the fs code unblock with ERESTART.
Fixed for pipes and sockets, ERESTART will only be generated after such
a close - so there should be no change for other programs.
Also rename fo_abort() to fo_restart() (this used to be fo_drain()).
Fixes PR/26567
do drain' in many places, whereas fo_drain() was called in order to force
blocking read()/write() etc calls to return to userspace so that a close()
call from a different thread can complete.
In the sockets code comment out the broken code in the inner function,
it was being called from compat code.
- Avoid atomics in more places.
- Remove the per-descriptor mutex, and just use filedesc_t::fd_lock.
It was only being used to synchronize close, and in any case we needed
to take fd_lock to free the descriptor slot.
- Optimize certain paths for the <NDFDFILE case.
- Sprinkle more comments and assertions.
- Cache more stuff in filedesc_t.
- Fix numerous minor bugs spotted along the way.
- Restructure how the open files array is maintained, for clarity and so
that we can eliminate the membar_consumer() call in fd_getfile(). This is
mostly syntactic sugar; the main functional change is that fd_nfiles now
lives alongside the open file array.
Some measurements with libmicro:
- simple file syscalls are like close() are between 1 to 10% faster.
- some nice improvements, e.g. poll(1000) which is ~50% faster.
than one active reference to a file descriptor. It should dislodge threads
sleeping while holding a reference to the descriptor. Implemented only for
sockets but should be extended to pipes, fifos, etc.
Fixes the case of a multithreaded process doing something like the
following, which would have hung until the process got a signal.
thr0 accept(fd, ...)
thr1 close(fd)
we no longer need to guard against access from hardware interrupt handlers.
Additionally, if cloning a process with CLONE_SIGHAND, arrange to have the
child process share the parent's lock so that signal state may be kept in
sync. Partially addresses PR kern/37437.
proclist_mutex and proclist_lock into a single adaptive mutex (proc_lock).
Implications:
- Inspecting process state requires thread context, so signals can no longer
be sent from a hardware interrupt handler. Signal activity must be
deferred to a soft interrupt or kthread.
- As the proc state locking is simplified, it's now safe to take exit()
and wait() out from under kernel_lock.
- The system spends less time at IPL_SCHED, and there is less lock activity.
we have unlocked the kqueue to check its state, leave it queued and
re-check later.
- knote_dequeue: fold into knote_detach since nothing else uses it.
- Note a couple more problems.
- Redo reference counting to be sane. LWPs accessing files take a short
term reference on the local file descriptor. This is the most common
case. While a file is in a process descriptor table, a reference is
held to the file. The file reference count only changes during control
operations like open() or close(). Code that comes at files from an
unusual direction (i.e. foreign to the process) like procfs or sysctl
takes a reference on the file (f_count), and not on a descriptor.
- Remove knowledge of reference counting and locking from most code that
deals with files.
- Make the usual case of file descriptor lookup lockless.
- Make kqueue MP and MT safe. PR kern/38098, PR kern/38137.
- Fix numerous file handling bugs, and bugs in the descriptor code that
affected multithreaded processes.
- Split descriptor system calls out into sys_descrip.c.
- A few stylistic changes: KNF, remove unused casts now that caddr_t is
gone. Replace dumb gotos with loop control in a few places.
- Don't do redundant pointer passing (struct proc, lwp, filedesc *) unless
the routine is likely to be inlined. Most of the time it's about the
current process.
- Add a lot of missing selinit() and seldestroy() calls.
- Merge selwakeup() and selnotify() calls into a single selnotify().
- Add an additional 'events' argument to selnotify() call. It will
indicate which event (POLL_IN, POLL_OUT, etc) happen. If unknown,
zero may be used.
Note: please pass appropriate value of 'events' where possible.
Proposed on: <tech-kern>
- Add a KAUTH_PROCESS_SCHEDULER action, to handle scheduler related
requests, and add specific requests for set/get scheduler policy and
set/get scheduler parameters.
- Add a KAUTH_PROCESS_KEVENT_FILTER action, to handle kevent(2) related
requests.
- Add a KAUTH_DEVICE_TTY_STI action to handle requests to TIOCSTI.
- Add requests for the KAUTH_PROCESS_CANSEE action, indicating what
process information is being looked at (entry itself, args, env,
open files).
- Add requests for the KAUTH_PROCESS_RLIMIT action indicating set/get.
- Add requests for the KAUTH_PROCESS_CORENAME action indicating set/get.
- Make bsd44 secmodel code handle the newly added rqeuests appropriately.
All of the above make it possible to issue finer-grained kauth(9) calls in
many places, removing some KAUTH_GENERIC_ISSUSER requests.
- Remove the "CAN" from KAUTH_PROCESS_CAN{KTRACE,PROCFS,PTRACE,SIGNAL}.
Discussed with christos@ and yamt@.
int foo(struct lwp *l, void *v, register_t *retval)
to:
int foo(struct lwp *l, const struct foo_args *uap, register_t *retval)
Fixup compat code to not write into 'uap' and (in some cases) to actually
pass a correctly formatted 'uap' structure with the right name to the
next routine.
A few 'compat' routines that just call standard ones have been deleted.
All the 'compat' code compiles (along with the kernels required to test
build it).
98% done by automated scripts.
P_*/L_* naming convention, and rename the in-kernel flags to avoid
conflict. (P_ -> PK_, L_ -> LW_ ). Add back the (now unused) LSDEAD
constant.
Restores source compatibility with pre-newlock2 tools like ps or top.
Reviewed by Andrew Doran.
