for a signal, because kernel stack is swappable, this causes page fault
in kernel under heavy swapping case. Fix this bug by eliminating unneeded
code.
create kernel threads and call rfork(2) with RFTHREAD flag set in this case,
which puts parent and child into the same threading group. As a result
all threads that belong to the same program end up in the same threading
group.
This is similar to what linuxthreads port does, though in this case we don't
have a luxury of having access to the source code and there is no definite
way to differentiate linux_clone() called for threading purposes from other
uses, so that we have to resort to heuristics.
Allow SIGTHR to be delivered between all processes in the same threading
group previously it has been blocked for s[ug]id processes.
This also should improve locking of the same file descriptor from different
threads in programs running under linux compat layer.
PR: kern/72922
Reported by: Andriy Gapon <avg@icyb.net.ua>
Idea suggested by: rwatson
place.
This moves the dependency on GCC's and other compiler's features into
the central sys/cdefs.h file, while the individual source files can
then refer to #ifdef __COMPILER_FEATURE_FOO where they by now used to
refer to #if __GNUC__ > 3.1415 && __BARC__ <= 42.
By now, GCC and ICC (the Intel compiler) have been actively tested on
IA32 platforms by netchild. Extension to other compilers is supposed
to be possible, of course.
Submitted by: netchild
Reviewed by: various developers on arch@, some time ago
sleeping, so in do_tdsignal, we no longer need to test td_waitset.
now td_waitset is only used to give a thread higher priority when
delivering signal to multithreads process.
This also fixes a bug:
when a thread in sigwait states was suspended and later resumed
by SIGCONT, it can no longer receive signals belong to waitset.
debug.cpufreq.lowest tunable and sysctl. Some systems seem to have problems
with the lowest frequencies so setting this prevents them from being
available or used.
owned by a process when it forks, and creates a matching set of references
for the child process, as prescribed by POSIX.
In order to avoid races with other threads in the parent process during
fork(), it is necessary to allocate a temporary reference list while
holding the sem_lock, then transfer those references to the new process
once the sem_lock is released. The implementation is inefficient but
appears functional; in order to improve the efficiency, it will be
necessary to modify the existing structures and logic, which generally
rely on O(n) operations over the global set of semaphores.
PAGE_SIZE.
Unlike originator of the PR suggests retain MAXSHELLCMDLEN definition
(he has been proposing to replace it with PAGE_SIZE everywhere), not only
this reduced the diff significantly, but prevents code obfuscation and also
allows to increase/decrease this parameter easily if needed.
PR: kern/64196
Submitted by: Magnus Bäckström <b@etek.chalmers.se>
doesn't change functionality, but makes code more logical.
Obtained from: DrafonFlyBSD
o Use VOP_GETATTR() to obtain actual size of file and parse no more than that.
Previously, we parsed MAXSHELLCMDLEN characters regardless of the actual file
size. This makes the following working:
$ printf '#!/bin/echo' > /tmp/test.sh
$ chmod 755 /tmp/test.sh
$ /tmp/test.sh
Previously, attempts to execve() that shell script has been failing with bogus
ENAMETOOLONG.
PR: kern/64196
Submitted by: Magnus B.ckstr.m <b@etek.chalmers.se>
script. Otherwise it's possible to panic kernel by constructing a shell
script with first line not ending in '\n'.
Also, treat '\0' as line terminating character, which may me useful in
some situations.
Submitted by: gad
when trim'ing space off the back of a chain; this is indirect
solution to a potential null ptr deref
Noticed by: Coverity Prevent analysis tool (null ptr deref)
Reviewed by: dg, rwatson
vn_extattr_rm. This is meant to catch conditions where IO_NODELOCKED
has been specified without the vnode being locked.
Discussed with: rwatson
MFC after: 1 week
object on to the zone allocator. It should be noted that uma_zalloc(9)
uses bzero to zero out the object so there probably wont be any
real performance benefit. If UMA grows the ability to supply
zeroed zones more efficiently in the future, we will not have to
modify all the existing consumers.
Discussed with: rwatson,julian
MFC after: 1 week
has been set. Assert that this is the case so that we catch filesystems
who are using naked VOP_LOCKs in illegal cases.
Sponsored by: Isilon Systems, Inc.
considered to be as good as an exclusive lock, although there is still a
possibility of someone acquiring a VOP LOCK while xlock is held.
Sponsored by: Isilon Systems, Inc.
List devfs_dirents rather than vnodes off their shared struct cdev, this
saves a pointer field in the vnode at the expense of a field in the
devfs_dirent. There are often 100 times more vnodes so this is bargain.
In addition it makes it harder for people to try to do stypid things like
"finding the vnode from cdev".
Since DEVFS handles all VCHR nodes now, we can do the vnode related
cleanup in devfs_reclaim() instead of in dev_rel() and vgonel().
Similarly, we can do the struct cdev related cleanup in dev_rel()
instead of devfs_reclaim().
rename idestroy_dev() to destroy_devl() for consistency.
Add LIST_ENTRY de_alias to struct devfs_dirent.
Remove v_specnext from struct vnode.
Change si_hlist to si_alist in struct cdev.
String new devfs vnodes' devfs_dirent on si_alist when
we create them and take them off in devfs_reclaim().
Fix devfs_revoke() accordingly. Also don't clear fields
devfs_reclaim() will clear when called from vgone();
Let devfs_reclaim() call dev_rel() instead of vgonel().
Move the usecount tracking from dev_rel() to devfs_reclaim(),
and let dev_rel() take a struct cdev argument instead of vnode.
Destroy SI_CHEAPCLONE devices in dev_rel() (instead of
devfs_reclaim()) when they are no longer used. (This
should maybe happen in devfs_close() instead.)
a socket from a regular socket to a listening socket able to accept new
connections. As part of this state transition, solisten() calls into the
protocol to update protocol-layer state. There were several bugs in this
implementation that could result in a race wherein a TCP SYN received
in the interval between the protocol state transition and the shortly
following socket layer transition would result in a panic in the TCP code,
as the socket would be in the TCPS_LISTEN state, but the socket would not
have the SO_ACCEPTCONN flag set.
This change does the following:
- Pushes the socket state transition from the socket layer solisten() to
to socket "library" routines called from the protocol. This permits
the socket routines to be called while holding the protocol mutexes,
preventing a race exposing the incomplete socket state transition to TCP
after the TCP state transition has completed. The check for a socket
layer state transition is performed by solisten_proto_check(), and the
actual transition is performed by solisten_proto().
- Holds the socket lock for the duration of the socket state test and set,
and over the protocol layer state transition, which is now possible as
the socket lock is acquired by the protocol layer, rather than vice
versa. This prevents additional state related races in the socket
layer.
This permits the dual transition of socket layer and protocol layer state
to occur while holding locks for both layers, making the two changes
atomic with respect to one another. Similar changes are likely require
elsewhere in the socket/protocol code.
Reported by: Peter Holm <peter@holm.cc>
Review and fixes from: emax, Antoine Brodin <antoine.brodin@laposte.net>
Philosophical head nod: gnn
only call the protocol's pru_rcvd() if the protocol has the flag
PR_WANTRCVD set. This brings that instance of pru_rcvd() into line with
the rest, which do check the flag.
MFC after: 3 days
of the global UNIX domain socket mutex: no protection is needed that
early in the setup of the UNIX domain socket and socket structures.
MFC after: 3 days
patch from kan@).
Pull bufobj_invalbuf() out of vinvalbuf() and make g_vfs call it on
close. This is not yet a generally safe function, but for this very
specific use it is safe. This solves the problem with buffers not
being flushed by unmount or after failed mount attempts.
