- Hold the proc lock while changing the state from PRS_NEW to PRS_NORMAL
in fork to honor the locking requirements. While here, expand the scope
of the PROC_LOCK() on the new process (p2) to avoid some LORs. Previously
the code was locking the new child process (p2) after it had locked the
parent process (p1). However, when locking two processes, the safe order
is to lock the child first, then the parent.
- Fix various places that were checking p_state against PRS_NEW without
having the process locked to use PROC_LOCK(). Every place was already
locking the process, just after the PRS_NEW check.
- Remove or reduce the use of PROC_SLOCK() for places that were checking
p_state against PRS_NEW. The PROC_LOCK() alone is sufficient for reading
the current state.
- Reorder fill_kinfo_proc() slightly so it only acquires PROC_SLOCK() once.
MFC after: 1 week
compiled conditionally on options CAPABILITIES:
Add a new credential flag, CRED_FLAG_CAPMODE, which indicates that a
subject (typically a process) is in capability mode.
Add two new system calls, cap_enter(2) and cap_getmode(2), which allow
setting and querying (but never clearing) the flag.
Export the capability mode flag via process information sysctls.
Sponsored by: Google, Inc.
Reviewed by: anderson
Discussed with: benl, kris, pjd
Obtained from: Capsicum Project
MFC after: 3 months
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]
of p_traceflag that is stored in the kinfo_proc structure. It is still
racey even with the lock and the code will read a consistent snapshot of
the flag without the lock.
mostly work on 64bit host.
The work is based on an original patch submitted by emaste, obtained
from Sandvine's source tree.
Reviewed by: jhb
MFC after: 1 week
in the process queue when gathering information for the process, and set
of signals pending for the thread, when gathering information for the
thread. Previously, the sysctl returned a union of the process and some
arbitrary thread pending set for the process, and union of the process
and the thread pending set for the thread.
MFC after: 1 week
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
if it is empty. Otherwise the previous thread's name would remain in the
struct and then be reported for this thread.
Submitted by: Ryan Stone
MFC after: 1 week
Remove the altkstacks, instead instantiate threads with kernel stack
allocated with the right size from the start. For the thread that has
kernel stack cached, verify that requested stack size is equial to the
actual, and reallocate the stack if sizes differ [1].
This fixes the bug introduced by r173361 that was committed several days
after r173004 and consisted of kthread_add(9) ignoring the non-default
kernel stack size.
Also, r173361 removed the caching of the kernel stacks for a non-first
thread in the process. Introduce separate kernel stack cache that keeps
some limited amount of preallocated kernel stacks to lower the latency
of thread allocation. Add vm_lowmem handler to prune the cache on
low memory condition. This way, system with reasonable amount of the
threads get lower latency of thread creation, while still not exhausting
significant portion of KVA for unused kstacks.
Submitted by: peter [1]
Discussed with: jhb, julian, peter
Reviewed by: jhb
Tested by: pho (and retested according to new test scenarious)
MFC after: 1 week
allocated with the right size from the start. For the thread that has
kernel stack cached, verify that requested stack size is equial to the
actual, and reallocate the stack if sizes differ [1].
This fixes the bug introduced by r173361 that was committed several days
after r173004 and consisted of kthread_add(9) ignoring the non-default
kernel stack size.
Also, r173361 removed the caching of the kernel stacks for a non-first
thread in the process. Introduce separate kernel stack cache that keeps
some limited amount of preallocated kernel stacks to lower the latency
of thread allocation. Add vm_lowmem handler to prune the cache on
low memory condition. This way, system with reasonable amount of the
threads get lower latency of thread creation, while still not exhausting
significant portion of KVA for unused kstacks.
Submitted by: peter [1]
Discussed with: jhb, julian, peter
Reviewed by: jhb
Tested by: pho
MFC after: 1 week
ability to retrieve the group list of each process.
Modify procstat's -s option to query this mib when the kinfo_proc
reports that the field has been truncated. If the mib does not exist,
fall back to the truncated list.
Reviewed by: rwatson
Approved by: re (kib)
MFC after: 2 weeks
in up to 16 (KI_NGROUPS) values and steal a bit from ki_cr_flags
(all bits currently unused) to indicate overflow with the new flag
KI_CRF_GRP_OVERFLOW.
This fixes procstat -s.
Approved by: re (kib)
a device pager (OBJT_DEVICE) object in that it uses fictitious pages to
provide aliases to other memory addresses. The primary difference is that
it uses an sglist(9) to determine the physical addresses for a given offset
into the object instead of invoking the d_mmap() method in a device driver.
Reviewed by: alc
Approved by: re (kensmith)
MFC after: 2 weeks
NGROUPS_MAX, eliminate ABI dependencies on them, and raise the to 1024
and 1023 respectively. (Previously they were equal, but under a close
reading of POSIX, NGROUPS_MAX was defined to be too large by 1 since it
is the number of supplemental groups, not total number of groups.)
The bulk of the change consists of converting the struct ucred member
cr_groups from a static array to a pointer. Do the equivalent in
kinfo_proc.
Introduce new interfaces crcopysafe() and crsetgroups() for duplicating
a process credential before modifying it and for setting group lists
respectively. Both interfaces take care for the details of allocating
groups array. crsetgroups() takes care of truncating the group list
to the current maximum (NGROUPS) if necessary. In the future,
crsetgroups() may be responsible for insuring invariants such as sorting
the supplemental groups to allow groupmember() to be implemented as a
binary search.
Because we can not change struct xucred without breaking application
ABIs, we leave it alone and introduce a new XU_NGROUPS value which is
always 16 and is to be used or NGRPS as appropriate for things such as
NFS which need to use no more than 16 groups. When feasible, truncate
the group list rather than generating an error.
Minor changes:
- Reduce the number of hand rolled versions of groupmember().
- Do not assign to both cr_gid and cr_groups[0].
- Modify ipfw to cache ucreds instead of part of their contents since
they are immutable once referenced by more than one entity.
Submitted by: Isilon Systems (initial implementation)
X-MFC after: never
PR: bin/113398 kern/133867
consuming one of its spare fields. The cr_flags field is currently
unused, but will be used for features, including capability mode and
pay-as-you-go audit.
Discussed with: jhb, sson
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)
members for a kinfo entry on a process-wide system.
- Use the newly introduced function in order to fix cases like
KERN_PROC_PROC where aggregating stats are broken because they just
consider the first thread in the pool for each process.
(Note, additively, that KERN_PROC_PROC is rather inaccurate on
thread-wide informations like the 'state' of the process. Such
informations should maybe be invalidated and being forceably discarded
by the consumers?).
- Simplify the logic of sysctl_out_proc() and adjust the
fill_kinfo_thread() accordingly.
- Remove checks on the FIRST_THREAD_IN_PROC() being NULL but add
assertives.
This patch should fix aggregate statistics for KERN_PROC_PROC.
This is one of the reasons why top doesn't use this option and now it
can be use it safely.
ps, when launched in order to display just processes, now should report
correct cpu utilization percentages and times (as opposed by the old
code).
Reviewed by: jhb, emaste
Sponsored by: Sandvine Incorporated
compare map->timestamp with saved timestamp after map read lock is
reacquired, not with saved timestamp + 1. The only consequence of the +1
was unconditional lookup of the next map entry, though.
Tested by: pho
Approved by: des
MFC after: 2 weeks
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
This changes struct kinfo_filedesc and kinfo_vmentry such that they are
same on both 32 and 64 bit platforms like i386/amd64 and won't require
sysctl wrapping.
Two new OIDs are assigned. The old ones are available under
COMPAT_FREEBSD7 - but it isn't that simple. The superceded interface
was never actually released on 7.x.
The other main change is to pack the data passed to userland via the
sysctl. kf_structsize and kve_structsize are reduced for the copyout.
If you have a process with 100,000+ sockets open, the unpacked records
require a 132MB+ copyout. With packing, it is "only" ~35MB. (Still
seriously unpleasant, but not quite as devastating). A similar problem
exists for the vmentry structure - have lots and lots of shared libraries
and small mmaps and its copyout gets expensive too.
My immediate problem is valgrind. It traditionally achieves this
functionality by parsing procfs output, in a packed format. Secondly, when
tracing 32 bit binaries on amd64 under valgrind, it uses a cross compiled
32 bit binary which ran directly into the differing data structures in 32
vs 64 bit mode. (valgrind uses this to track file descriptor operations
and this therefore affected every single 32 bit binary)
I've added two utility functions to libutil to unpack the structures into
a fixed record length and to make it a little more convenient to use.
This bring huge amount of changes, I'll enumerate only user-visible changes:
- Delegated Administration
Allows regular users to perform ZFS operations, like file system
creation, snapshot creation, etc.
- L2ARC
Level 2 cache for ZFS - allows to use additional disks for cache.
Huge performance improvements mostly for random read of mostly
static content.
- slog
Allow to use additional disks for ZFS Intent Log to speed up
operations like fsync(2).
- vfs.zfs.super_owner
Allows regular users to perform privileged operations on files stored
on ZFS file systems owned by him. Very careful with this one.
- chflags(2)
Not all the flags are supported. This still needs work.
- ZFSBoot
Support to boot off of ZFS pool. Not finished, AFAIK.
Submitted by: dfr
- Snapshot properties
- New failure modes
Before if write requested failed, system paniced. Now one
can select from one of three failure modes:
- panic - panic on write error
- wait - wait for disk to reappear
- continue - serve read requests if possible, block write requests
- Refquota, refreservation properties
Just quota and reservation properties, but don't count space consumed
by children file systems, clones and snapshots.
- Sparse volumes
ZVOLs that don't reserve space in the pool.
- External attributes
Compatible with extattr(2).
- NFSv4-ACLs
Not sure about the status, might not be complete yet.
Submitted by: trasz
- Creation-time properties
- Regression tests for zpool(8) command.
Obtained from: OpenSolaris
vnode in question does not need to be held. All the data structures used
during the name lookup are protected by the global name cache lock.
Instead, the caller merely needs to ensure a reference is held on the
vnode (such as vhold()) to keep it from being freed.
In the case of procfs' <pid>/file entry, grab the process lock while we
gain a new reference (via vhold()) on p_textvp to fully close races with
execve(2).
For the kern.proc.vmmap sysctl handler, use a shared vnode lock around
the call to VOP_GETATTR() rather than an exclusive lock.
MFC after: 1 month
within an object that a mapping refers to. fileid and fsid are inode/dev
for vnodes. (Linux procfs has these and valgrind is really unhappy
without them.) I believe I didn't change the size of the struct.
Unlike tty_rel_gone() and tty_rel_sess(), the tty_rel_pgrp() routine
does not unlock the TTY. I once had the idea to make the code call
tty_rel_pgrp() and tty_rel_sess(), picking up the TTY lock once. This
turned out a little harder than I expected, so this is how it works now.
It's a lot easier if we just let tty_rel_pgrp() unlock the TTY, because
the other routines do this anyway.
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.
