implement shm_open(2) and shm_unlink(2) in the kernel:
- Each shared memory file descriptor is associated with a swap-backed vm
object which provides the backing store. Each descriptor starts off with
a size of zero, but the size can be altered via ftruncate(2). The shared
memory file descriptors also support fstat(2). read(2), write(2),
ioctl(2), select(2), poll(2), and kevent(2) are not supported on shared
memory file descriptors.
- shm_open(2) and shm_unlink(2) are now implemented as system calls that
manage shared memory file descriptors. The virtual namespace that maps
pathnames to shared memory file descriptors is implemented as a hash
table where the hash key is generated via the 32-bit Fowler/Noll/Vo hash
of the pathname.
- As an extension, the constant 'SHM_ANON' may be specified in place of the
path argument to shm_open(2). In this case, an unnamed shared memory
file descriptor will be created similar to the IPC_PRIVATE key for
shmget(2). Note that the shared memory object can still be shared among
processes by sharing the file descriptor via fork(2) or sendmsg(2), but
it is unnamed. This effectively serves to implement the getmemfd() idea
bandied about the lists several times over the years.
- The backing store for shared memory file descriptors are garbage
collected when they are not referenced by any open file descriptors or
the shm_open(2) virtual namespace.
Submitted by: dillon, peter (previous versions)
Submitted by: rwatson (I based this on his version)
Reviewed by: alc (suggested converting getmemfd() to shm_open())
-d destdir option. For an automounted src tree using the logical cwd
in the Makefile keeps amd(8)'s mount timeout refreshed. Code to check
$PWD's validity cribbed from pwd(1).
Discussed on hackers@.
As ncurses has the limitation that it returns the first matched key symbol,
you can not use END in ncurses based program, like mutt, with xterm.
- Add @8 (kp_enter) definition for xterm so you can use ENTER in xterm with
ncurses based program.
I also found that NetBSD's xterm does the same thing.
PR: 100150
Reported by: Arseny Nasokin <tarc at tarc.po.cs.msu.su>
Discussed with: Thomas Dickey, Ulrich Spoerlein <uspoerlein at gmail.com>
Reviewed by: freebsd-arch@
MFC after: 2 month
assertion hit in swapoff_one() when we un-mount a swap partition. We
should be using curthread where we used thread0 before. This change
also replaces the thread argument with a credential argument, as the
MAC framework only requires the cred.
It should be noted that this allows the machine to be rebooted without
panicing with "cannot differ from curthread or NULL" when MAC is enabled.
Submitted by: rwatson
Reviewed by: attilio
MFC after: 2 weeks
definition files that are used only for extracting symbols. This is useful
for inter-module dependencies and files containing only enum-definitions.
MFC after: 4 weeks
current state, it can handle all but four of the 991 zip files (including
jar files) I was able to identify in the ports tree. The remaining four
are two self-extracting archives and two which have garbage preceding the
first local header. This limitation is a feature of libarchive(3) which
I am currently working to resolve.
The code is unnecessarily large due to the need to emulate the exact
command-line syntax and behaviour of ports/unzip. My initial incompatible
implementation was one quarter the size of the one I am committing here.
the rejected mail reports to tally the rejects per blacklist without
providing details about individual sender hosts. The default configuration
keeps the reports in their original form.
MFC after: 1 week
dev2udev() when a tty was being detached concurrently with the sysctl
handler:
- Hold the 'tty_list_mutex' lock while we read all the fields out of the
struct tty for copying out later. Previously the pty(4) and pts(4)
destroy routines could set t_dev to NULL, drop their reference on the
tty and destroy the cdev while the sysctl handler was attempting to
invoke dev2udev() on the cdev being destroyed. This happened when the
sysctl handler read the value of t_dev prior to it being set to NULL
either due to it being stale or due to timing races. By holding the
list lock we guarantee that the destroy routines will block in ttyrel()
in that case and not destroy the cdev until after we've copied all of our
data. We may see a NULL cdev pointer or we may see the previous value,
but the previous value will no longer point to a destroyed cdev if we
see it.
- Fix the ttyfree() routine used by tty device drivers in their detach
methods to use ttyrel() on the tty so we don't leak them. Also, fix it
to use the same order of operations as pty/pts destruction (set t_dev
NULL, ttyrel(), destroy_dev()) so it cooperates with the sysctl handler.
MFC after: 3 days
Tested by: avatar
This makes it possible to support ftruncate() on non-vnode file types in
the future.
- 'struct fileops' grows a 'fo_truncate' method to handle an ftruncate() on
a given file descriptor.
- ftruncate() moves to kern/sys_generic.c and now just fetches a file
object and invokes fo_truncate().
- The vnode-specific portions of ftruncate() move to vn_truncate() in
vfs_vnops.c which implements fo_truncate() for vnode file types.
- Non-vnode file types return EINVAL in their fo_truncate() method.
Submitted by: rwatson
add correct locking to the operation of unmounting.
This will prevent debugging kernels from panicking if mounting a
non-hpfs partition (I'm not sure if this can be a problem with a
successful mounting operation though).
MFC: 3 days
CVSROOT/config file options that control keyword expansion. cvs-1.12 has
its own $Id$ expansion controls and they're configured in CVSROOT/config
rather than CVSROOT/options. The problem is that current cvs-1.11.x
doesn't understand the future keywords.....
Add trivial forward support for the new keywords for when cvs-1.12
hits the tree down the road. CVSROOT/options won't be going away - cvsup
uses it.
pv_list_count from struct md_page. Ever since Peter rewrote the pv
entry allocator for amd64 and i386 pv_list_count has been correctly
maintained but otherwise unused.
- spell 16384 as 16384 and not as BKVASIZE. 16384 is (not quite) just a
magic size that works well in practice. BKVASIZE should be MAXBSIZE
(65536), but is 16384 because i386's don't have enough kva for it to
be MAXBSIZE; 16384 works (not so well) for it for much the same reasons
that it works well in the heuristic.
- expand and/or add comments about this and other details.
- don't explicitly inline this function.
- fix some other style bugs.
ABI override binary isn't found. This could probably be smoother, but
it is what I did in p4 change #126891 on 2007/09/27. It should solve
the "ld-elf32.so.1"-in-chroot problem.
default. This has the disadvantage of rendering the datasize resource
limit irrelevant, but without this change, legitimate uses of more
memory than will fit in the data segment are thwarted by default.
Fix chunk_alloc_mmap() to work correctly if initial mapping is not
chunk-aligned and mapping extension fails.
