madvise(2) except that it operates on a file descriptor instead of a
memory region. It is currently only supported on regular files.
Just as with madvise(2), the advice given to posix_fadvise(2) can be
divided into two types. The first type provide hints about data access
patterns and are used in the file read and write routines to modify the
I/O flags passed down to VOP_READ() and VOP_WRITE(). These modes are
thus filesystem independent. Note that to ease implementation (and
since this API is only advisory anyway), only a single non-normal
range is allowed per file descriptor.
The second type of hints are used to hint to the OS that data will or
will not be used. These hints are implemented via a new VOP_ADVISE().
A default implementation is provided which does nothing for the WILLNEED
request and attempts to move any clean pages to the cache page queue for
the DONTNEED request. This latter case required two other changes.
First, a new V_CLEANONLY flag was added to vinvalbuf(). This requests
vinvalbuf() to only flush clean buffers for the vnode from the buffer
cache and to not remove any backing pages from the vnode. This is
used to ensure clean pages are not wired into the buffer cache before
attempting to move them to the cache page queue. The second change adds
a new vm_object_page_cache() method. This method is somewhat similar to
vm_object_page_remove() except that instead of freeing each page in the
specified range, it attempts to move clean pages to the cache queue if
possible.
To preserve the ABI of struct file, the f_cdevpriv pointer is now reused
in a union to point to the currently active advice region if one is
present for regular files.
Reviewed by: jilles, kib, arch@
Approved by: re (kib)
MFC after: 1 month
exposed by the security fix in FreeBSD-SA-11:05.unix.
Approved by: so (cperciva)
Approved by: re (kib)
Security: Related to FreeBSD-SA-11:05.unix, but not actually
a security fix.
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
kernel for FreeBSD 9.0:
Add a new capability mask argument to fget(9) and friends, allowing system
call code to declare what capabilities are required when an integer file
descriptor is converted into an in-kernel struct file *. With options
CAPABILITIES compiled into the kernel, this enforces capability
protection; without, this change is effectively a no-op.
Some cases require special handling, such as mmap(2), which must preserve
information about the maximum rights at the time of mapping in the memory
map so that they can later be enforced in mprotect(2) -- this is done by
narrowing the rights in the existing max_protection field used for similar
purposes with file permissions.
In namei(9), we assert that the code is not reached from within capability
mode, as we're not yet ready to enforce namespace capabilities there.
This will follow in a later commit.
Update two capability names: CAP_EVENT and CAP_KEVENT become
CAP_POST_KEVENT and CAP_POLL_KEVENT to more accurately indicate what they
represent.
Approved by: re (bz)
Submitted by: jonathan
Sponsored by: Google Inc
configured swap devices in the Linux-compatible format.
Based on the submission by: Robert Millan <rmh debian org>
PR: kern/159281
Reviewed by: bde
Approved by: re (kensmith)
MFC after: 2 weeks
Implement two previously-reserved Capsicum system calls:
- cap_new() creates a capability to wrap an existing file descriptor
- cap_getrights() queries the rights mask of a capability.
Approved by: mentor (rwatson), re (Capsicum blanket)
Sponsored by: Google Inc
option that is highly recommended to be adjusted in too much
documentation while doing nothing in FreeBSD since r2729 (rev 1.1).
ipcs(1) needs to be recompiled as it is accessing _KERNEL private
variables.
Reviewed by: jhb (before comment change on linux code)
Sponsored by: Sandvine Incorporated
space. This is consistent with the behavior in linux.
PR: kern/157871
Reported by: Petr Salinger <Petr Salinger att seznam cz>
Verified on: GNU/kFreeBSD debian 8.2-1-amd64 (by reporter)
Reviewed by: kib (some time ago)
MFC after: 2 weeks
native devices which support the v4l2 API from processes running within
the linuxulator, e.g. skype or flash can access the multimedia/pwcbsd
or multimedia/webcamd supplied drivers.
Submitted by: nox
MFC after: 1 month
vop_stdallocate() is filesystem agnostic and will run as slow as a
read/write loop in userspace; however, it serves to correctly
implement the functionality for filesystems that do not implement a
VOP_ALLOCATE.
Note that __FreeBSD_version was already bumped today to 900036 for any
ports which would like to use this function.
Also reserve space in the syscall table for posix_fadvise(2).
Reviewed by: -arch (previous version)
safer for i386 because it can be easily over 4 GHz now. More worse, it can
be easily changed by user with 'machdep.tsc_freq' tunable (directly) or
cpufreq(4) (indirectly). Note it is intentionally not used in performance
critical paths to avoid performance regression (but we should, in theory).
Alternatively, we may add "virtual TSC" with lower frequency if maximum
frequency overflows 32 bits (and ignore possible incoherency as we do now).
There is a generic problem with the shims for ioctls that receive
pointers to the usermode data areas in the data argument. We either have
to modify the handler to accept UIO_USERSPACE/UIO_SYSSPACE indicator, or
allocate and fill a usermode memory for data buffer in the host format.
The change goes the second route, in particular because we do not need
to modify the handler.
Submitted by: John Wehle <john feith com>
MFC after: 2 weeks
In particular:
- implement compat shims for old stat(2) variants and ogetdirentries(2);
- implement delivery of signals with ancient stack frame layout and
corresponding sigreturn(2);
- implement old getpagesize(2);
- provide a user-mode trampoline and LDT call gate for lcall $7,$0;
- port a.out image activator and connect it to the build as a module
on amd64.
The changes are hidden under COMPAT_43.
MFC after: 1 month
I have not properly thought through the commit. After r220031 (linux
compat: improve and fix sendmsg/recvmsg compatibility) the basic
handling for SO_PASSCRED is not sufficient as it breaks recvmsg
functionality for SCM_CREDS messages because now we would need to handle
sockcred data in addition to cmsgcred. And that is not implemented yet.
Pointyhat to: avg
on the set of rules it maintains and the current resource usage. It also
privides userland API to manage that ruleset.
Sponsored by: The FreeBSD Foundation
Reviewed by: kib (earlier version)
This seems to have been a part of a bigger patch by dchagin that either
haven't been committed or committed partially.
Submitted by: dchagin, nox
MFC after: 2 weeks
- implement baseic stubs for capget, capset, prctl PR_GET_KEEPCAPS
and prctl PR_SET_KEEPCAPS.
- add SCM_CREDS support to sendmsg and recvmsg
- modify sendmsg to ignore control messages if not using UNIX
domain sockets
This should allow linux pulse audio daemon and client work on FreeBSD
and interoperate with native counter-parts modulo the differences in
pulseaudio versions.
PR: kern/149168
Submitted by: John Wehle <john@feith.com>
Reviewed by: netchild
MFC after: 2 weeks
Code inspection shows freebsd32_ioctl calls fget for a fd and calls
a subroutine to handle each specific ioctl. It is expected that the
subroutine will call fdrop when done. However many of the subroutines
will exit out early if copyin encounters an error resulting in fdrop
never being called.
Submitted by: John Wehle <john feith com>
MFC after: 3 days
- 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
explicit process at fork trampoline path instead of eventhadler(schedtail)
invocation for each child process.
Remove eventhandler(schedtail) code and change linux ABI to use newly added
sysvec method.
While here replace explicit comparing of module sysentvec structure with the
newly created process sysentvec to detect the linux ABI.
Discussed with: kib
MFC after: 2 Week
it possible for the kernel to track login class the process is assigned to,
which is required for RCTL. This change also make setusercontext(3) call
setloginclass(2) and makes it possible to retrieve current login class using
id(1).
Reviewed by: kib (as part of a larger patch)
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
resource - the layout of cprd_port is identical but using cprd_mem
makes the code easier to understand.
PR: kern/118493
Submitted by: Weongyo Jeong <weongyo.jeong at gmail.com>
MFC after: 3 days
different processes that happen to use the same user address in the
separate processes will now be treated as distinct futexes rather than the
same futex. We can now honor shared futexes properly by mapping them to a
PROCESS_SHARED umtx_key. Private futexes use THREAD_SHARED umtx_key
objects.
In conjunction with: dchagin
Reviewed by: kib
MFC after: 1 week
1) Translate the native signal number in the appropriate Linux signal.
2) Remove bogus code, which can lead to a panic as it calls
kern_sigtimedwait with same ksiginfo.
3) Return the corresponding signal number.
to construct the full pathname. It starts to search at the default
mountpoint which is /dev/shm. If this fails it runs through fstab
and searches for shmfs and tmpfs. Whatever it finds will be
statfs()'ed to be checked for Linux' fs magic for shmfs (0x01021994).
Ideally our tmpfs should deliver this fs magic to Linux processes, but
as our tmpfs is considered to be an experimental feature we can not
assume that there is always a tmpfs available.
To make shared memory work in the Linuxulator, force the fs type of
/dev/shm (which can be a symlink) to match what Linux expects. The user
is responsible (info has to be added to the linux base ports and the docs)
to setup a suitable link for /dev/shm.
Noticed by: Andre Albsmeier <Andre.Albsmeier@siemens.com>
Submitted by: Andre Albsmeier <Andre.Albsmeier@siemens.com>
MFC after: 1 month
try to export as much information as we can match.
Requested on: Debian GNU/kFreeBSD list (debian-bsd lists.debian.org) 2010-12
Tested by: Mats Erik Andersson (mats.andersson gisladisker.se)
MFC after: 10 days
be used by linuxolator itself.
Move linux_wait4() to MD path as it requires native struct
rusage translation to struct l_rusage on linux32/amd64.
MFC after: 1 Month.
