multithreaded status of the process.
The stopped state must be cleared before P_WEXIT is set. A stop
signal delivered just before first PROC_LOCK() block in exit1(9) would
put the process into pending stop with P_WEXIT set or assertion
triggered. Also recheck for the suspension after failed
thread_single(9) call, since process lock could be dropped.
Reported and tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
- Threads lifetime cycle, in particular, counting of the threads in
the process, and interlocking with process mutex and thread lock.
The main reason of this is that turnstile locks are after thread
locks, so you e.g. cannot unlock blockable mutex (think process
mutex) while owning thread lock.
- Virtual and profiling itimers, since the timers activation is done
from the clock interrupt context. Replace the p_slock by p_itimmtx
and PROC_ITIMLOCK().
- Profiling code (profil(2)), for similar reason. Replace the p_slock
by p_profmtx and PROC_PROFLOCK().
- Resource usage accounting. Need for the spinlock there is subtle,
my understanding is that spinlock blocks context switching for the
current thread, which prevents td_runtime and similar fields from
changing (updates are done at the mi_switch()). Replace the p_slock
by p_statmtx and PROC_STATLOCK().
The split is done mostly for code clarity, and should not affect
scalability.
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Prior to the change it would always return initproc for non-traced processes.
This fixes ps apparently always returning 1 as ppid.
Pointy hat: mjg
Reported by: many
MFC after: 1 week
Previously they were uncoditionally reparented to init. In effect
it was possible that tracee was never returned to original parent.
Reviewed by: kib
MFC after: 1 week
One problem is inferior(9) looping due to the process tree becoming a
graph instead of tree if the parent is traced by child. Another issue
is due to the use of p_oppid to restore the original parent/child
relationship, because real parent could already exited and its pid
reused (noted by mjg).
Add the function proc_realparent(9), which calculates the parent for
given process. It uses the flag P_TREE_FIRST_ORPHAN to detect the head
element of the p_orphan list and than stepping back to its container
to find the parent process. If the parent has already exited, the
init(8) is returned.
Move the P_ORPHAN and the new helper flag from the p_flag* to new
p_treeflag field of struct proc, which is protected by proctree lock
instead of proc lock, since the orphans relationship is managed under
the proctree_lock already.
The remaining uses of p_oppid in ptrace(PT_DETACH) and process
reapping are replaced by proc_realparent(9).
Phabric: D417
Reviewed by: jhb
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
further refinement is required as some device drivers intended to be
portable over FreeBSD versions rely on __FreeBSD_version to decide whether
to include capability.h.
MFC after: 3 weeks
requires process descriptors to work and having PROCDESC in GENERIC
seems not enough, especially that we hope to have more and more consumers
in the base.
MFC after: 3 days
In its stead use the Solaris / illumos approach of emulating '-' (dash)
in probe names with '__' (two consecutive underscores).
Reviewed by: markj
MFC after: 3 weeks
option, unbreak the lock tracing release semantic by embedding
calls to LOCKSTAT_PROFILE_RELEASE_LOCK() direclty in the inlined
version of the releasing functions for mutex, rwlock and sxlock.
Failing to do so skips the lockstat_probe_func invokation for
unlocking.
- As part of the LOCKSTAT support is inlined in mutex operation, for
kernel compiled without lock debugging options, potentially every
consumer must be compiled including opt_kdtrace.h.
Fix this by moving KDTRACE_HOOKS into opt_global.h and remove the
dependency by opt_kdtrace.h for all files, as now only KDTRACE_FRAMES
is linked there and it is only used as a compile-time stub [0].
[0] immediately shows some new bug as DTRACE-derived support for debug
in sfxge is broken and it was never really tested. As it was not
including correctly opt_kdtrace.h before it was never enabled so it
was kept broken for a while. Fix this by using a protection stub,
leaving sfxge driver authors the responsibility for fixing it
appropriately [1].
Sponsored by: EMC / Isilon storage division
Discussed with: rstone
[0] Reported by: rstone
[1] Discussed with: philip
Per POSIX, si_status should contain the value passed to exit() for
si_code==CLD_EXITED and the signal number for other si_code. This was
incorrect for CLD_EXITED and CLD_DUMPED.
This is still not fully POSIX-compliant (Austin group issue #594 says that
the full value passed to exit() shall be returned via si_status, not just
the low 8 bits) but is sufficient for a si_status-related test in libnih
(upstart, Debian/kFreeBSD).
PR: kern/184002
Reported by: Dmitrijs Ledkovs
Tested by: Dmitrijs Ledkovs
using SDT_PROBE_ARGTYPE(). This will make it easy to extend the SDT(9) API
to allow probes with dynamically-translated types.
There is no functional change.
MFC after: 2 weeks
- Capability is no longer separate descriptor type. Now every descriptor
has set of its own capability rights.
- The cap_new(2) system call is left, but it is no longer documented and
should not be used in new code.
- The new syscall cap_rights_limit(2) should be used instead of
cap_new(2), which limits capability rights of the given descriptor
without creating a new one.
- The cap_getrights(2) syscall is renamed to cap_rights_get(2).
- If CAP_IOCTL capability right is present we can further reduce allowed
ioctls list with the new cap_ioctls_limit(2) syscall. List of allowed
ioctls can be retrived with cap_ioctls_get(2) syscall.
- If CAP_FCNTL capability right is present we can further reduce fcntls
that can be used with the new cap_fcntls_limit(2) syscall and retrive
them with cap_fcntls_get(2).
- To support ioctl and fcntl white-listing the filedesc structure was
heavly modified.
- The audit subsystem, kdump and procstat tools were updated to
recognize new syscalls.
- Capability rights were revised and eventhough I tried hard to provide
backward API and ABI compatibility there are some incompatible changes
that are described in detail below:
CAP_CREATE old behaviour:
- Allow for openat(2)+O_CREAT.
- Allow for linkat(2).
- Allow for symlinkat(2).
CAP_CREATE new behaviour:
- Allow for openat(2)+O_CREAT.
Added CAP_LINKAT:
- Allow for linkat(2). ABI: Reuses CAP_RMDIR bit.
- Allow to be target for renameat(2).
Added CAP_SYMLINKAT:
- Allow for symlinkat(2).
Removed CAP_DELETE. Old behaviour:
- Allow for unlinkat(2) when removing non-directory object.
- Allow to be source for renameat(2).
Removed CAP_RMDIR. Old behaviour:
- Allow for unlinkat(2) when removing directory.
Added CAP_RENAMEAT:
- Required for source directory for the renameat(2) syscall.
Added CAP_UNLINKAT (effectively it replaces CAP_DELETE and CAP_RMDIR):
- Allow for unlinkat(2) on any object.
- Required if target of renameat(2) exists and will be removed by this
call.
Removed CAP_MAPEXEC.
CAP_MMAP old behaviour:
- Allow for mmap(2) with any combination of PROT_NONE, PROT_READ and
PROT_WRITE.
CAP_MMAP new behaviour:
- Allow for mmap(2)+PROT_NONE.
Added CAP_MMAP_R:
- Allow for mmap(PROT_READ).
Added CAP_MMAP_W:
- Allow for mmap(PROT_WRITE).
Added CAP_MMAP_X:
- Allow for mmap(PROT_EXEC).
Added CAP_MMAP_RW:
- Allow for mmap(PROT_READ | PROT_WRITE).
Added CAP_MMAP_RX:
- Allow for mmap(PROT_READ | PROT_EXEC).
Added CAP_MMAP_WX:
- Allow for mmap(PROT_WRITE | PROT_EXEC).
Added CAP_MMAP_RWX:
- Allow for mmap(PROT_READ | PROT_WRITE | PROT_EXEC).
Renamed CAP_MKDIR to CAP_MKDIRAT.
Renamed CAP_MKFIFO to CAP_MKFIFOAT.
Renamed CAP_MKNODE to CAP_MKNODEAT.
CAP_READ old behaviour:
- Allow pread(2).
- Disallow read(2), readv(2) (if there is no CAP_SEEK).
CAP_READ new behaviour:
- Allow read(2), readv(2).
- Disallow pread(2) (CAP_SEEK was also required).
CAP_WRITE old behaviour:
- Allow pwrite(2).
- Disallow write(2), writev(2) (if there is no CAP_SEEK).
CAP_WRITE new behaviour:
- Allow write(2), writev(2).
- Disallow pwrite(2) (CAP_SEEK was also required).
Added convinient defines:
#define CAP_PREAD (CAP_SEEK | CAP_READ)
#define CAP_PWRITE (CAP_SEEK | CAP_WRITE)
#define CAP_MMAP_R (CAP_MMAP | CAP_SEEK | CAP_READ)
#define CAP_MMAP_W (CAP_MMAP | CAP_SEEK | CAP_WRITE)
#define CAP_MMAP_X (CAP_MMAP | CAP_SEEK | 0x0000000000000008ULL)
#define CAP_MMAP_RW (CAP_MMAP_R | CAP_MMAP_W)
#define CAP_MMAP_RX (CAP_MMAP_R | CAP_MMAP_X)
#define CAP_MMAP_WX (CAP_MMAP_W | CAP_MMAP_X)
#define CAP_MMAP_RWX (CAP_MMAP_R | CAP_MMAP_W | CAP_MMAP_X)
#define CAP_RECV CAP_READ
#define CAP_SEND CAP_WRITE
#define CAP_SOCK_CLIENT \
(CAP_CONNECT | CAP_GETPEERNAME | CAP_GETSOCKNAME | CAP_GETSOCKOPT | \
CAP_PEELOFF | CAP_RECV | CAP_SEND | CAP_SETSOCKOPT | CAP_SHUTDOWN)
#define CAP_SOCK_SERVER \
(CAP_ACCEPT | CAP_BIND | CAP_GETPEERNAME | CAP_GETSOCKNAME | \
CAP_GETSOCKOPT | CAP_LISTEN | CAP_PEELOFF | CAP_RECV | CAP_SEND | \
CAP_SETSOCKOPT | CAP_SHUTDOWN)
Added defines for backward API compatibility:
#define CAP_MAPEXEC CAP_MMAP_X
#define CAP_DELETE CAP_UNLINKAT
#define CAP_MKDIR CAP_MKDIRAT
#define CAP_RMDIR CAP_UNLINKAT
#define CAP_MKFIFO CAP_MKFIFOAT
#define CAP_MKNOD CAP_MKNODAT
#define CAP_SOCK_ALL (CAP_SOCK_CLIENT | CAP_SOCK_SERVER)
Sponsored by: The FreeBSD Foundation
Reviewed by: Christoph Mallon <christoph.mallon@gmx.de>
Many aspects discussed with: rwatson, benl, jonathan
ABI compatibility discussed with: kib
until child performs exec(). The behaviour is reasonable when a
debugger is the real parent, because the parent is stopped until
exec(), and sending a debugging event to the debugger would deadlock
both parent and child.
On the other hand, when debugger is not the parent of the vforked
child, not sending debugging signals makes it impossible to debug
across vfork.
Fix the issue by declining generating debug signals only when vfork()
was done and child called ptrace(PT_TRACEME). Set a new process flag
P_PPTRACE from the attach code for PT_TRACEME, if P_PPWAIT flag is
set, which indicates that the process was created with vfork() and
still did not execed. Check P_PPTRACE from issignal(), instead of
refusing the trace outright for the P_PPWAIT case. The scope of
P_PPTRACE is exactly contained in the scope of P_PPWAIT.
Found and tested by: zont
Reviewed by: pluknet
MFC after: 2 weeks
in kern_wait6(), which is called by kern_wait(). Remove the redundand
check, introduced in r243136, and add a comment noting this, to make
the code less confusing.
The blank lines are added to properly delineate the scope of the
preceeding comments.
Noted by: "Jukka A. Ukkonen" <jau@iki.fi>
MFC after: 1 week
designator to select a process which is waited for. The system call
optionally returns siginfo_t which would be otherwise provided to
SIGCHLD handler, as well as extended structure accounting for child
and cumulative grandchild resource usage.
Allow to get the current rusage information for non-exited processes
as well, similar to Solaris.
The explicit WEXITED flag is required to wait for exited processes,
allowing for more fine-grained control of the events the waiter is
interested in.
Fix the handling of siginfo for WNOWAIT option for all wait*(2)
family, by not removing the queued signal state.
PR: standards/170346
Submitted by: "Jukka A. Ukkonen" <jau@iki.fi>
MFC after: 1 month
In particular, do not lock Giant conditionally when calling into the
filesystem module, remove the VFS_LOCK_GIANT() and related
macros. Stop handling buffers belonging to non-mpsafe filesystems.
The VFS_VERSION is bumped to indicate the interface change which does
not result in the interface signatures changes.
Conducted and reviewed by: attilio
Tested by: pho
set p_xstat to the signal that triggered the stop, but p_xstat is also
used to hold the exit status of an exiting process. Without this change,
a stop signal that arrived after a process was marked P_WEXIT but before
it was marked a zombie would overwrite the exit status with the stop signal
number.
Reviewed by: kib
MFC after: 1 week
to the debugger. When reparenting for debugging, keep the child in
the new orphan list of old parent. When looping over the children in
kern_wait(), iterate over both children list and orphan list to search
for the process by pid.
Submitted by: Dmitry Mikulin <dmitrym juniper.net>
MFC after: 2 weeks
we were accounting the newly created process to its parent instead
of the child itself. This caused problems later, when the child
changed its credentials - the per-uid, per-jail etc counters were
not properly updated, because the maxproc counter in the child
process was 0.
Approved by: re (kib)
patch modifies makesyscalls.sh to prefix all of the non-compatibility
calls (e.g. not linux_, freebsd32_) with sys_ and updates the kernel
entry points and all places in the code that use them. It also
fixes an additional name space collision between the kernel function
psignal and the libc function of the same name by renaming the kernel
psignal kern_psignal(). By introducing this change now we will ease future
MFCs that change syscalls.
Reviewed by: rwatson
Approved by: re (bz)
A "process descriptor" file descriptor is used to manage processes
without using the PID namespace. This is required for Capsicum's
Capability Mode, where the PID namespace is unavailable.
New system calls pdfork(2) and pdkill(2) offer the functional equivalents
of fork(2) and kill(2). pdgetpid(2) allows querying the PID of the remote
process for debugging purposes. The currently-unimplemented pdwait(2) will,
in the future, allow querying rusage/exit status. In the interim, poll(2)
may be used to check (and wait for) process termination.
When a process is referenced by a process descriptor, it does not issue
SIGCHLD to the parent, making it suitable for use in libraries---a common
scenario when using library compartmentalisation from within large
applications (such as web browsers). Some observers may note a similarity
to Mach task ports; process descriptors provide a subset of this behaviour,
but in a UNIX style.
This feature is enabled by "options PROCDESC", but as with several other
Capsicum kernel features, is not enabled by default in GENERIC 9.0.
Reviewed by: jhb, kib
Approved by: re (kib), mentor (rwatson)
Sponsored by: Google Inc
won't happen before 9.0. This commit adds "#ifdef RACCT" around all the
"PROC_LOCK(p); racct_whatever(p, ...); PROC_UNLOCK(p)" instances, in order
to avoid useless locking/unlocking in kernels built without "options RACCT".
and per-loginclass resource accounting information, to be used by the new
resource limits code. It's connected to the build, but the code that
actually calls the new functions will come later.
Sponsored by: The FreeBSD Foundation
Reviewed by: kib (earlier version)
on FreeBSD (amd64), invocations of "javac" (or "java") eventually
end with the output of "Killed" and exit code 137.
This is caused by:
1. After calling exec() in multithreaded linux program threads are not
destroyed and continue running. They get killed after program being
executed finishes.
2. linux_exit_group doesn't return correct exit code when called not
from group leader. Which happens regularly using sun jvm.
The submitters fix this in a similar way to how NetBSD handles this.
I took the PRs away from dchagin, who seems to be out of touch of
this since a while (no response from him).
The patches committed here are from [2], with some little modifications
from me to the style.
PR: 141439 [1], 144194 [2]
Submitted by: Stefan Schmidt <stefan.schmidt@stadtbuch.de>, gk
Reviewed by: rdivacky (in april 2010)
MFC after: 5 days
may be left. This fixes a memory leak that can occur when tracing is
disabled on a process via disabling tracing of a specific file (or if
an I/O error occurs with the tracefile) if the process's next system
call is exit(). The trace disabling code clears p_traceflag, so exit1()
doesn't do any KTRACE-related cleanup leading to the leak. I chose to
make the free'ing of pending records synchronous rather than patching
exit1().
- Move KTRACE-specific logic out of kern_(exec|exit|fork).c and into
kern_ktrace.c instead. Make ktrace_mtx private to kern_ktrace.c as a
result.
MFC after: 1 month
rwlock to protect the table. In old code, thread lookup is done with
process lock held, to find a thread, kernel has to iterate through
process and thread list, this is quite inefficient.
With this change, test shows in extreme case performance is
dramatically improved.
Earlier patch was reviewed by: jhb, julian
use '-' in probe names, matching the probe names in Solaris.[1]
Add userland SDT probes definitions to sys/sdt.h.
Sponsored by: The FreeBSD Foundation
Discussed with: rwaston [1]
- Rename tdsignal() to tdsendsignal() and make it private to kern_sig.c.
- Add tdsignal() and tdksignal() routines that mirror psignal() and
pksignal() except that they accept a thread as an argument instead of
a process. They send a signal to a specific thread rather than to an
individual process.
Reviewed by: kib
Basically this commit changes two things, which improves access to TTYs
in exceptional conditions. Basically the problem was that when you ran
jexec(8) to attach to a jail, you couldn't use /dev/tty (well, also the
node of the actual TTY, e.g. /dev/pts/X). This is very inconvenient if
you want to attach to screens quickly, use ssh(1), etc.
The fixes:
- Cache the cdev_priv of the controlling TTY in struct session. Change
devfs_access() to compare against the cdev_priv instead of the vnode.
This allows you to bypass UNIX permissions, even across different
mounts of devfs.
- Extend devfs_prison_check() to unconditionally expose the device node
of the controlling TTY, even if normal prison nesting rules normally
don't allow this. This actually allows you to interact with this
device node.
To be honest, I'm not really happy with this solution. We now have to
store three pointers to a controlling TTY (s_ttyp, s_ttyvp, s_ttydp).
In an ideal world, we should just get rid of the latter two and only use
s_ttyp, but this makes certian pieces of code very impractical (e.g.
devfs, kern_exit.c).
Reported by: Many people
set quite late in the revocation path, properly verify that vnode is
not doomed before calling VOP.
Reported and tested by: Harald Schmalzbauer <h.schmalzbauer omnilan de>
MFC after: 3 days
causing a panic if it is killed due to a unsolved stack overflow
seen very late during shutdown on sparc64 when the gmirror worker
process exists, which is a regression introduced in 8.0.
Reviewed by: kib
MFC after: 3 days
correctly checks for reclaimed vnode, possibly calling VOP_REVOKE for
such vnode. If the terminal is already revoked, or devfs mount was
forcibly unmounted, the revocation of doomed ctty vnode causes panic.
Reported and tested by: lstewart
Approved by: re (kensmith)
MFC after: 2 weeks
specific macros for each audit argument type. This makes it easier to
follow call-graphs, especially for automated analysis tools (such as
fxr).
In MFC, we should leave the existing AUDIT_ARG() macros as they may be
used by third-party kernel modules.
Suggested by: brooks
Approved by: re (kib)
Obtained from: TrustedBSD Project
MFC after: 1 week
The code that was in place in exit1() was mainly based on code from the
old TTY layer. The main reason behind this, was because at one moment I
ran a system that had two TTY layers in place at the same time. It is
now sufficient to do the following:
- Remove references from the session structure to the TTY vnode and the
session leader.
- If we have a controlling TTY and the session used by the TTY is equal
to our session, send the SIGHUP.
- If we have a vnode to the controlling TTY which has not been revoked,
revoke it.
While there, change sys/kern/tty.c to use s_ttyp in the comparison
instead of s_ttyvp. It should not make any difference, because s_ttyvp
can only become null when the session leader already left, but it's
nicer to compare against the proper value.
Right now the only way to make tcsetsid(3)/TIOCSCTTY work, is by
ensuring the session leader is dead. This means that an application that
catches SIGHUPs and performs a sleep prevents us from assigning a new
session leader.
Change the code to make it work on revoked TTYs as well. This allows us
to change init(8) to make the shutdown script run in a more clean
environment.
and used in a large number of files, but also because an increasing number
of incorrect uses of MAC calls were sneaking in due to copy-and-paste of
MAC-aware code without the associated opt_mac.h include.
Discussed with: pjd
by creating a child jail, which is visible to that jail and to any
parent jails. Child jails may be restricted more than their parents,
but never less. Jail names reflect this hierarchy, being MIB-style
dot-separated strings.
Every thread now points to a jail, the default being prison0, which
contains information about the physical system. Prison0's root
directory is the same as rootvnode; its hostname is the same as the
global hostname, and its securelevel replaces the global securelevel.
Note that the variable "securelevel" has actually gone away, which
should not cause any problems for code that properly uses
securelevel_gt() and securelevel_ge().
Some jail-related permissions that were kept in global variables and
set via sysctls are now per-jail settings. The sysctls still exist for
backward compatibility, used only by the now-deprecated jail(2) system
call.
Approved by: bz (mentor)
virtualized instances of hostname and domainname, as well as a new top-level
virtualization struct vimage, which holds pointers to struct vnet and struct
vprocg. Struct vprocg is likely to become replaced in the near future with
a new jail management API import.
As a consequence of this change, change struct ucred to point to a struct
vimage, instead of directly pointing to a vnet.
Merge vnet / vimage / ucred refcounting infrastructure from p4 / vimage
branch.
Permit kldload / kldunload operations to be executed only from the default
vimage context.
This change should have no functional impact on nooptions VIMAGE kernel
builds.
Reviewed by: bz
Approved by: julian (mentor)
or ignored SIGCHLD, unconditionally wake up the parent instead of doing
this only when the child is a last child.
This brings us in line with other U**xes that support SA_NOCLDWAIT. If
the parent called waitpid(childpid), then exit of the child should wake
up the parent immediately instead of forcing it to wait for all children
to exit.
Reported by: Alan Ferrency <alan pair com>
Submitted by: Jilles Tjoelker <jilles stack nl>
PR: 108390
MFC after: 2 weeks
kern_time.c:
- Unused variable `p'.
kern_thr.c:
- Variable `error' is always caught immediately, so no reason to
initialize it. There is no way that error != 0 at the end of
create_thread().
kern_sig.c:
- Unused variable `code'.
kern_synch.c:
- `rval' is always assigned in all different cases.
kern_rwlock.c:
- `v' is always overwritten with RW_UNLOCKED further on.
kern_malloc.c:
- `size' is always initialized with the proper value before being used.
kern_exit.c:
- `error' is always caught and returned immediately. abort2() never
returns a non-zero value.
kern_exec.c:
- `len' is always assigned inside the if-statement right below it.
tty_info.c:
- `td' is always overwritten by FOREACH_THREAD_IN_PROC().
Found by: LLVM's scan-build
parent threads sleep on the parent' struct proc until corresponding
child releases the vmspace. Each sleep is interlocked with proc mutex of
the child, that triggers assertion in the sleepq_add(). The assertion
requires that at any time, all simultaneous sleepers for the channel use
the same interlock.
Silent the assertion by using conditional variable allocated in the
child. Broadcast the variable event on exec() and exit().
Since struct proc * sleep wait channel is overloaded for several
unrelated events, I was unable to remove wakeups from the places where
cv_broadcast() is added, except exec().
Reported and tested by: ganbold
Suggested and reviewed by: jhb
MFC after: 2 week
Bring in updated jail support from bz_jail branch.
This enhances the current jail implementation to permit multiple
addresses per jail. In addtion to IPv4, IPv6 is supported as well.
Due to updated checks it is even possible to have jails without
an IP address at all, which basically gives one a chroot with
restricted process view, no networking,..
SCTP support was updated and supports IPv6 in jails as well.
Cpuset support permits jails to be bound to specific processor
sets after creation.
Jails can have an unrestricted (no duplicate protection, etc.) name
in addition to the hostname. The jail name cannot be changed from
within a jail and is considered to be used for management purposes
or as audit-token in the future.
DDB 'show jails' command was added to aid debugging.
Proper compat support permits 32bit jail binaries to be used on 64bit
systems to manage jails. Also backward compatibility was preserved where
possible: for jail v1 syscalls, as well as with user space management
utilities.
Both jail as well as prison version were updated for the new features.
A gap was intentionally left as the intermediate versions had been
used by various patches floating around the last years.
Bump __FreeBSD_version for the afore mentioned and in kernel changes.
Special thanks to:
- Pawel Jakub Dawidek (pjd) for his multi-IPv4 patches
and Olivier Houchard (cognet) for initial single-IPv6 patches.
- Jeff Roberson (jeff) and Randall Stewart (rrs) for their
help, ideas and review on cpuset and SCTP support.
- Robert Watson (rwatson) for lots and lots of help, discussions,
suggestions and review of most of the patch at various stages.
- John Baldwin (jhb) for his help.
- Simon L. Nielsen (simon) as early adopter testing changes
on cluster machines as well as all the testers and people
who provided feedback the last months on freebsd-jail and
other channels.
- My employer, CK Software GmbH, for the support so I could work on this.
Reviewed by: (see above)
MFC after: 3 months (this is just so that I get the mail)
X-MFC Before: 7.2-RELEASE if possible
this eliminates some problems of locking, e.g, a thread lock is needed
but can not be used at that time. Only the process lock is needed now
for new field.
is returned shall be kept in the waitable state.
Add WSTOPPED as an alias for WUNTRACED.
Submitted by: Jukka Ukkonen <jau at iki fi>
PR: standards/116221
MFC after: 2 weeks
The last half year I've been working on a replacement TTY layer for the
FreeBSD kernel. The new TTY layer was designed to improve the following:
- Improved driver model:
The old TTY layer has a driver model that is not abstract enough to
make it friendly to use. A good example is the output path, where the
device drivers directly access the output buffers. This means that an
in-kernel PPP implementation must always convert network buffers into
TTY buffers.
If a PPP implementation would be built on top of the new TTY layer
(still needs a hooks layer, though), it would allow the PPP
implementation to directly hand the data to the TTY driver.
- Improved hotplugging:
With the old TTY layer, it isn't entirely safe to destroy TTY's from
the system. This implementation has a two-step destructing design,
where the driver first abandons the TTY. After all threads have left
the TTY, the TTY layer calls a routine in the driver, which can be
used to free resources (unit numbers, etc).
The pts(4) driver also implements this feature, which means
posix_openpt() will now return PTY's that are created on the fly.
- Improved performance:
One of the major improvements is the per-TTY mutex, which is expected
to improve scalability when compared to the old Giant locking.
Another change is the unbuffered copying to userspace, which is both
used on TTY device nodes and PTY masters.
Upgrading should be quite straightforward. Unlike previous versions,
existing kernel configuration files do not need to be changed, except
when they reference device drivers that are listed in UPDATING.
Obtained from: //depot/projects/mpsafetty/...
Approved by: philip (ex-mentor)
Discussed: on the lists, at BSDCan, at the DevSummit
Sponsored by: Snow B.V., the Netherlands
dcons(4) fixed by: kan
requiring the per-process spinlock to only requiring the process lock.
- Reflect these changes in the proc.h documentation and consumers throughout
the kernel. This is a substantial reduction in locking cost for these
fields and was made possible by recent changes to threading support.
conjuction with 'thread' argument passing which is always curthread.
Remove the unuseful extra-argument and pass explicitly curthread to lower
layer functions, when necessary.
KPI results broken by this change, which should affect several ports, so
version bumping and manpage update will be further committed.
Tested by: kris, pho, Diego Sardina <siarodx at gmail dot com>
kthread_add() takes the same parameters as the old kthread_create()
plus a pointer to a process structure, and adds a kernel thread
to that process.
kproc_kthread_add() takes the parameters for kthread_add,
plus a process name and a pointer to a pointer to a process instead of just
a pointer, and if the proc * is NULL, it creates the process to the
specifications required, before adding the thread to it.
All other old kthread_xxx() calls return, but act on (struct thread *)
instead of (struct proc *). One reason to change the name is so that
any old kernel modules that are lying around and expect kthread_create()
to make a process will not just accidentally link.
fix top to show kernel threads by their thread name in -SH mode
add a tdnam formatting option to ps to show thread names.
make all idle threads actual kthreads and put them into their own idled process.
make all interrupt threads kthreads and put them in an interd process
(mainly for aesthetic and accounting reasons)
rename proc 0 to be 'kernel' and it's swapper thread is now 'swapper'
man page fixes to follow.
from Mac OS X Leopard--rationalize naming for entry points to
the following general forms:
mac_<object>_<method/action>
mac_<object>_check_<method/action>
The previous naming scheme was inconsistent and mostly
reversed from the new scheme. Also, make object types more
consistent and remove spaces from object types that contain
multiple parts ("posix_sem" -> "posixsem") to make mechanical
parsing easier. Introduce a new "netinet" object type for
certain IPv4/IPv6-related methods. Also simplify, slightly,
some entry point names.
All MAC policy modules will need to be recompiled, and modules
not updates as part of this commit will need to be modified to
conform to the new KPI.
Sponsored by: SPARTA (original patches against Mac OS X)
Obtained from: TrustedBSD Project, Apple Computer
- Depessimize userret() in kernels where KTRACE is enabled by doing an
unlocked check of the per-process queue of pending events before
acquiring any locks. Previously ktr_userret() unconditionally acquired
the global ktrace_sx lock on every return to userland for every thread,
even if ktrace wasn't enabled for the thread.
- Optimize the locking in exit() to first perform an unlocked read of
p_traceflag to see if ktrace is enabled and only acquire locks and
teardown ktrace if the test succeeds. Also, explicitly disable tracing
before draining any pending events so the pending events actually get
written out. The unlocked read is safe because proc lock is acquired
earlier after single-threading so p_traceflag can't change between then
and this check (well, it can currently due to a bug in ktrace I will fix
next, but that race existed prior to this change as well).
Reviewed by: rwatson
This patch fixes places where they should be called atomically changing
their locking requirements (both assume per-proc spinlock held) and
introducing rufetchcalc which wrappers both calls to be performed in
atomic way.
Reviewed by: jeff
Approved by: jeff (mentor)
- Unsafeness on ruadd() in thread_exit()
- Unatomicity of thread_exiit() in the exit1() operations
This patch addresses these problems allocating p_fd as part of the
process and modifying the way it is accessed.
A small chunk of this patch, resolves a race about p_state in kern_wait(),
since we have to be sure about the zombif-ing process.
Submitted by: jeff
Approved by: jeff (mentor)
embedded storage in struct ucred. This allows audit state to be cached
with the thread, avoiding locking operations with each system call, and
makes it available in asynchronous execution contexts, such as deep in
the network stack or VFS.
Reviewed by: csjp
Approved by: re (kensmith)
Obtained from: TrustedBSD Project
- Use thread_lock() rather than sched_lock for per-thread scheduling
sychronization.
- Use the per-process spinlock rather than the sched_lock for per-process
scheduling synchronization.
Tested by: kris, current@
Tested on: i386, amd64, ULE, 4BSD, libthr, libkse, PREEMPTION, etc.
Discussed with: kris, attilio, kmacy, jhb, julian, bde (small parts each)
td_ru. This removes the requirement for per-process synchronization in
statclock() and mi_switch(). This was previously supported by
sched_lock which is going away. All modifications to rusage are now
done in the context of the owning thread. reads proceed without locks.
- Aggregate exiting threads rusage in thread_exit() such that the exiting
thread's rusage is not lost.
- Provide a new routine, rufetch() to fetch an aggregate of all rusage
structures from all threads in a process. This routine must be used
in any place requiring a rusage from a process prior to it's exit. The
exited process's rusage is still available via p_ru.
- Aggregate tick statistics only on demand via rufetch() or when a thread
exits. Tick statistics are kept in the thread and protected by sched_lock
until it exits.
Initial patch by: attilio
Reviewed by: attilio, bde (some objections), arch (mostly silent)
SIGCHLD/kevent(2) notification of process termination and wait(). Now
we no longer drop locks between sending the notification and marking
the process as a zombie. Previously, if another process attempted to do
a wait() with W_NOHANG after receiving a SIGCHLD or kevent and locked
the process while the exiting thread was in cpu_exit(), then wait() would
fail to find the process, which is quite astonishing to the process
calling wait().
MFC after: 3 days
- Remove also "MP SAFE" after prior "MPSAFE" pass. (suggested by bde)
- Remove extra blank lines in some cases.
- Add extra blank lines in some cases.
- Remove no-op comments consisting solely of the function name, the word
"syscall", or the system call name.
- Add punctuation.
- Re-wrap some comments.
system calls now enter without Giant held, and then in some cases, acquire
Giant explicitly.
Remove a number of other MPSAFE annotations in the credential code and
tweak one or two other adjacent comments.
begun with a repo-copy of mac.h to mac_framework.h. sys/mac.h now
contains the userspace and user<->kernel API and definitions, with all
in-kernel interfaces moved to mac_framework.h, which is now included
across most of the kernel instead.
This change is the first step in a larger cleanup and sweep of MAC
Framework interfaces in the kernel, and will not be MFC'd.
Obtained from: TrustedBSD Project
Sponsored by: SPARTA
protect the vnode, it was present to synchronize access to TTY session
information between exit(2) and the TTY code. While we are here, note that
Giant is required for TTY protection.
Clue from: bde
Discussed with: jhb
MFC after: 1 week
vmspace_exitfree() and vmspace_free() which could result in the same
vmspace being freed twice.
Factor out part of exit1() into new function vmspace_exit(). Attach
to vmspace0 to allow old vmspace to be freed earlier.
Add new function, vmspace_acquire_ref(), for obtaining a vmspace
reference for a vmspace belonging to another process. Avoid changing
vmspace refcount from 0 to 1 since that could also lead to the same
vmspace being freed twice.
Change vmtotal() and swapout_procs() to use vmspace_acquire_ref().
Reviewed by: alc
doesn't appear to be protecting anything. Most of consumers funsetownlst(9)
do not appear to be picking up Giant anywhere. This was originally a part
of my Giant exit(2) clean up revision 1.272 but I thought it was a good idea
to leave it out until we were able to analyze it better.
Tested by: kris
MFC after: 3 weeks
- Reorder the events in exit(2) slightly so that we trigger the S_EXIT
stop event earlier. After we have signalled that, we set P_WEXIT and
then wait for any processes with a hold on the vmspace via PHOLD to
release it. PHOLD now KASSERT()'s that P_WEXIT is clear when it is
invoked, and PRELE now does a wakeup if P_WEXIT is set and p_lock drops
to zero.
- Change proc_rwmem() to require that the processing read from has its
vmspace held via PHOLD by the caller and get rid of all the junk to
screw around with the vmspace reference count as we no longer need it.
- In ptrace() and pseudofs(), treat a process with P_WEXIT set as if it
doesn't exist.
- Only do one PHOLD in kern_ptrace() now, and do it earlier so it covers
FIX_SSTEP() (since on alpha at least this can end up calling proc_rwmem()
to clear an earlier single-step simualted via a breakpoint). We only
do one to avoid races. Also, by making the EINVAL error for unknown
requests be part of the default: case in the switch, the various
switch cases can now just break out to return which removes a _lot_ of
duplicated PRELE and proc unlocks, etc. Also, it fixes at least one bug
where a LWP ptrace command could return EINVAL with the proc lock still
held.
- Changed the locking for ptrace_single_step(), ptrace_set_pc(), and
ptrace_clear_single_step() to always be called with the proc lock
held (it was a mixed bag previously). Alpha and arm have to drop
the lock while the mess around with breakpoints, but other archs
avoid extra lock release/acquires in ptrace(). I did have to fix a
couple of other consumers in kern_kse and a few other places to
hold the proc lock and PHOLD.
Tested by: ps (1 mostly, but some bits of 2-4 as well)
MFC after: 1 week
Keep accounting time (in per-cpu) cputicks and the statistics counts
in the thread and summarize into struct proc when at context switch.
Don't reach across CPUs in calcru().
Add code to calibrate the top speed of cpu_tickrate() for variable
cpu_tick hardware (like TSC on power managed machines).
Don't enforce monotonicity (at least for now) in calcru. While the
calibrated cpu_tickrate ramps up it may not be true.
Use 27MHz counter on i386/Geode.
Use TSC on amd64 & i386 if present.
Use tick counter on sparc64
Keep track of time spent by the cpu in various contexts in units of
"cputicks" and scale to real-world microsec^H^H^H^H^H^H^H^Hclock_t
only when somebody wants to inspect the numbers.
For now "cputicks" are still derived from the current timecounter
and therefore things should by definition remain sensible also on
SMP machines. (The main reason for this first milestone commit is
to verify that hypothesis.)
On slower machines, the avoided multiplications to normalize timestams
at every context switch, comes out as a 5-7% better score on the
unixbench/context1 microbenchmark. On more modern hardware no change
in performance is seen.