- Send the systrace_args files for all the compat ABIs to /dev/null for
now. Right now makesyscalls.sh generates a file with a hardcoded
function name, so it wouldn't work for any of the ABIs anyway. Probably
the function name should be configurable via a 'systracename' variable
and the functions should be stored in a function pointer in the sysvec
structure.
mark system calls as being MPSAFE:
- Stop conditionally acquiring Giant around system call invocations.
- Remove all of the 'M' prefixes from the master system call files.
- Remove support for the 'M' prefix from the script that generates the
syscall-related files from the master system call files.
- Don't explicitly set SYF_MPSAFE when registering nfssvc.
except for s_family (which is read-only once after it is set when the
structure is created).
- Mark svr4_sys_ioctl(), svr4_sys_getmsg(), and svr4_sys_putmsg() MPSAFE.
kern_accept() and accept1(). If another thread closed the new file
descriptor and the first thread later got an error trying to copyout the
socket address, then it would attempt to close the wrong file object. To
fix, add a struct file ** argument to kern_accept(). If it is non-NULL,
then on success kern_accept() will store a pointer to the new file object
there and not release any of the references. It is up to the calling code
to drop the references appropriately (including a call to fdclose() in case
of error to safely handle the aforementioned race). While I'm at it, go
ahead and fix the svr4 streams code to not leak the accept fd if it gets an
error trying to copyout the streams structures.
locked.
- Move all the svr4 socket cache code into svr4_socket.c, specifically
move svr4_delete_socket() over from streams.c. Make the socket cache
entry structure and svr4_head private to svr4_socket.c as a result.
- Add a mutex to protect the svr4 socket cache.
- Change svr4_find_socket() to copy the sockaddr_un struct into a
caller-supplied sockaddr_un rather than giving the caller a pointer to
our internal one. This removes the one case where code outside of
svr4_socket.c could access data in the cache.
- Add an eventhandler for process_exit and process_exec to purge the cache
of any entries for the exiting or execing process.
- Add methods to init and destroy the socket cache and call them from the
svr4 ABI module's event handler.
- Conditionally grab Giant around socreate() in streamsopen().
- Use fdclose() instead of inlining it in streamsopen() when handling
socreate() failure.
- Only allocate a stream structure and attach it to a socket in
streamsopen(). Previously, if a svr4 program performed a stream
operation on an arbitrary socket not opened via the streams device,
we would attach streams state data to it and change f_ops of the
associated struct file while it was in use. The latter was especially
not safe, and if a program wants a stream object it should open it via
the streams device anyway.
- Don't bother locking so_emuldata in the streams code now that we only
touch it right after creating a socket (in streamsopen()) or when
tearing it down when the file is closed.
- Remove D_NEEDGIANT from the streams device as it is no longer needed.
Also, call change_dir() instead of doing part of it inline (this now adds
a mac_check_vnode_chdir() call) to match fchdir() and call
mac_check_vnode_chroot() to match chroot(). Also, use the change_root()
function to do the actual change root to match chroot().
Reviewed by: rwatson
- If the WNOWAIT flag isn't specified and either of WEXITED or WTRAPPED is
set, then just call kern_wait() and let it do all the work. This means
that this function no longer has to duplicate the work to teardown
zombies that is done in kern_wait(). Instead, if the above conditions
aren't true, then it uses a simpler loop to implement WNOWAIT and/or
tracing for only stopped or continued processes. This function still
has to duplicate code from kern_wait() for the latter two cases, but
those are much simpler.
- Sync the code to handle the WCONTINUED and WSTOPPED cases with the
equivalent code in kern_wait().
- Fix several places that would return with the proctree lock still held.
- Lock the current process to prevent lost wakeup races when blocking.
ibcs2_getdents(), ibcs2_read(), ogetdirentries(), svr4_sys_getdents(),
and svr4_sys_getdents64() similar to that in getdirentries().
- Mark ibcs2_getdents(), ibcs2_read(), linux_getdents(), linux_getdents64(),
linux_readdir(), ogetdirentries(), svr4_sys_getdents(), and
svr4_sys_getdents64() MPSAFE.
use by ABI emulators.
- Alter the interface of kern_recvit() somewhat. Specifically, go ahead
and hard code UIO_USERSPACE in the uio as that's what all the callers
specify. In place, add a new uioseg to indicate what type of pointer
is in mp->msg_name. Previously it was always a userland address, but
ABI emulators may pass in kernel-side sockaddrs. Also, remove the
namelenp field and instead require the two places that used it to
explicitly copy mp->msg_namelen out to userland.
- Use the patched kern_recvit() to replace svr4_recvit() and the stock
kern_sendit() to replace svr4_sendit().
- Use kern_bind() instead of stackgap use in ti_bind().
- Use kern_getpeername() and kern_getsockname() instead of stackgap in
svr4_stream_ti_ioctl().
- Use kern_connect() instead of stackgap in svr4_do_putmsg().
- Use kern_getpeername() and kern_accept() instead of stackgap in
svr4_do_getmsg().
- Retire the stackgap from SVR4 compat as it is no longer used.
mostly consists of pushing a few copyin's and copyout's up into
__semctl() as all the other callers were already doing the UIO_SYSSPACE
case. This also changes kern_semctl() to set the return value in a passed
in pointer to a register_t rather than td->td_retval[0] directly so that
callers can only set td->td_retval[0] if all the various copyout's succeed.
As a result of these changes, kern_semctl() no longer does copyin/copyout
(except for GETALL/SETALL) so simplify the locking to acquire the semakptr
mutex before the MAC check and hold it all the way until the end of the
big switch statement. The GETALL/SETALL cases have to temporarily drop it
while they do copyin/malloc and copyout. Also, simplify the SETALL case to
remove handling for a non-existent race condition.
shmctl(). None of the other ABI's do this (including the native FreeBSD
ABI), and uselessly trying to do a copyin() can actually result in a
bogus EFAULT if the a process specifies NULL for the optional argument
(which is what they should do in this case).
to a copied-in copy of the 'union semun' and a uioseg to indicate which
memory space the 'buf' pointer of the union points to. This is then used
in linux_semctl() and svr4_sys_semctl() to eliminate use of the stackgap.
- Mark linux_ipc() and svr4_sys_semsys() MPSAFE.
the callers if the exec either succeeds or fails early.
- Move the code to call exit1() if the exec fails after the vmspace is
gone to the bottom of kern_execve() to cut down on some code duplication.
changes in MD code are trivial, before this change, trapsignal and
sendsig use discrete parameters, now they uses member fields of
ksiginfo_t structure. For sendsig, this change allows us to pass
POSIX realtime signal value to user code.
2. Remove cpu_thread_siginfo, it is no longer needed because we now always
generate ksiginfo_t data and feed it to libpthread.
3. Add p_sigqueue to proc structure to hold shared signals which were
blocked by all threads in the proc.
4. Add td_sigqueue to thread structure to hold all signals delivered to
thread.
5. i386 and amd64 now return POSIX standard si_code, other arches will
be fixed.
6. In this sigqueue implementation, pending signal set is kept as before,
an extra siginfo list holds additional siginfo_t data for signals.
kernel code uses psignal() still behavior as before, it won't be failed
even under memory pressure, only exception is when deleting a signal,
we should call sigqueue_delete to remove signal from sigqueue but
not SIGDELSET. Current there is no kernel code will deliver a signal
with additional data, so kernel should be as stable as before,
a ksiginfo can carry more information, for example, allow signal to
be delivered but throw away siginfo data if memory is not enough.
SIGKILL and SIGSTOP have fast path in sigqueue_add, because they can
not be caught or masked.
The sigqueue() syscall allows user code to queue a signal to target
process, if resource is unavailable, EAGAIN will be returned as
specification said.
Just before thread exits, signal queue memory will be freed by
sigqueue_flush.
Current, all signals are allowed to be queued, not only realtime signals.
Earlier patch reviewed by: jhb, deischen
Tested on: i386, amd64
osf1_signal.c:1.41, amd64/amd64/trap.c:1.291, linux_socket.c:1.60,
svr4_fcntl.c:1.36, svr4_ioctl.c:1.23, svr4_ipc.c:1.18, svr4_misc.c:1.81,
svr4_signal.c:1.34, svr4_stat.c:1.21, svr4_stream.c:1.55,
svr4_termios.c:1.13, svr4_ttold.c:1.15, svr4_util.h:1.10,
ext2_alloc.c:1.43, i386/i386/trap.c:1.279, vm86.c:1.58,
unaligned.c:1.12, imgact_elf.c:1.164, ffs_alloc.c:1.133:
Now that Giant is acquired in uprintf() and tprintf(), the caller no
longer leads to acquire Giant unless it also holds another mutex that
would generate a lock order reversal when calling into these functions.
Specifically not backed out is the acquisition of Giant in nfs_socket.c
and rpcclnt.c, where local mutexes are held and would otherwise violate
the lock order with Giant.
This aligns this code more with the eventual locking of ttys.
Suggested by: bde
as they both interact with the tty code (!MPSAFE) and may sleep if the
tty buffer is full (per comment).
Modify all consumers of uprintf() and tprintf() to hold Giant around
calls into these functions. In most cases, this means adding an
acquisition of Giant immediately around the function. In some cases
(nfs_timer()), it means acquiring Giant higher up in the callout.
With these changes, UFS no longer panics on SMP when either blocks are
exhausted or inodes are exhausted under load due to races in the tty
code when running without Giant.
NB: Some reduction in calls to uprintf() in the svr4 code is probably
desirable.
NB: In the case of nfs_timer(), calling uprintf() while holding a mutex,
or even in a callout at all, is a bad idea, and will generate warnings
and potential upset. This needs to be fixed, but was a problem before
this change.
NB: uprintf()/tprintf() sleeping is generally a bad ideas, as is having
non-MPSAFE tty code.
MFC after: 1 week
IFF_DRV_RUNNING, as well as the move from ifnet.if_flags to
ifnet.if_drv_flags. Device drivers are now responsible for
synchronizing access to these flags, as they are in if_drv_flags. This
helps prevent races between the network stack and device driver in
maintaining the interface flags field.
Many __FreeBSD__ and __FreeBSD_version checks maintained and continued;
some less so.
Reviewed by: pjd, bz
MFC after: 7 days
in the build still due to some #undef's in svr4.h, but if you hack around
that and add some missing entries to syscalls.master, then this file will
now compile. The changes involved proc -> thread, using FreeBSD syscall
names instead of NetBSD, and axeing syscallarg() and retval arguments.
Approved by: re (scottl)
audit event identifier associated with each system call, which will
be stored by makesyscalls.sh in the sy_auevent field of struct sysent.
For now, default the audit identifier on all system calls to AUE_NULL,
but in the near future, other BSM event identifiers will be used. The
mapping of system calls to event identifiers is many:one due to
multiple system calls that map to the same end functionality across
compatibility wrappers, ABI wrappers, etc.
Submitted by: wsalamon
Obtained from: TrustedBSD Project
the type of object represented by the handle argument.
- Allow vm_mmap() to map device memory via cdev objects in addition to
vnodes and anonymous memory. Note that mmaping a cdev directly does not
currently perform any MAC checks like mapping a vnode does.
- Unbreak the DRM getbufs ioctl by having it call vm_mmap() directly on the
cdev the ioctl is acting on rather than trying to find a suitable vnode
to map from.
Reviewed by: alc, arch@
svr4_do_getmsg(). In principle this bug could disclose data from
kernel memory, but in practice, the SVR4 emulation layer is probably
not functional enough to cause the relevant code path to be executed.
In any case, the emulator has been disconnected from the build since
5.0-RELEASE.
Found by: Coverity Prevent analysis tool
o change the mapping arrays to have a zero offset rather than base 1;
this eliminates lots of signo adjustments and brings the code
back inline with the original netbsd code
o purge use of SVR4_SIGTBLZ; SVR4_NSIG is the only definition for
how big a mapping array is
o change the mapping loops to explicitly ignore signal 0
o purge some bogus code from bsd_to_svr4_sigset
o adjust svr4_sysentvec to deal with the mapping table change
Enticed into fixing by: Coverity Prevent analysis tool
Glanced at by: marcel, jhb
former is callable from user space and the latter from the kernel one. Make
kernel version take additional argument which tells if the respective call
should check for additional restrictions for sending signals to suid/sugid
applications or not.
Make all emulation layers using non-checked version, since signal numbers in
emulation layers can have different meaning that in native mode and such
protection can cause misbehaviour.
As a result remove LIBTHR from the signals allowed to be delivered to a
suid/sugid application.
Requested (sorta) by: rwatson
MFC after: 2 weeks
the semantics in that the returned filename to use is now a kernel
pointer rather than a user space pointer. This required changing the
arguments to the CHECKALT*() macros some and changing the various system
calls that used pathnames to use the kern_foo() functions that can accept
kernel space filename pointers instead of calling the system call
directly.
- Use kern_open(), kern_access(), kern_msgctl(), kern_execve(),
kern_mkfifo(), kern_mknod(), kern_statfs(), kern_fstatfs(),
kern_setitimer(), kern_stat(), kern_lstat(), kern_fstat(), kern_utimes(),
kern_pathconf(), and kern_unlink().
