This removes the need for manually changing this flag for Google Chrome
users. It also improves compatibility with Linux applications running under
Linuxulator compatibility layer, and possibly also helps in porting software
from Linux.
Generally speaking, the flag allows applications to create the shared memory
segment, attach it, remove it, and then continue to use it and to reattach it
later. This means that the kernel will automatically "clean up" after the
application exits.
It could be argued that it's against POSIX. However, SUSv3 says this
about IPC_RMID: "Remove the shared memory identifier specified by shmid from
the system and destroy the shared memory segment and shmid_ds data structure
associated with it." From my reading, we break it in any case by deferring
removal of the segment until it's detached; we won't break it any more
by also deferring removal of the identifier.
This is the behaviour exhibited by Linux since... probably always, and
also by OpenBSD since the following commit:
revision 1.54
date: 2011/10/27 07:56:28; author: robert; state: Exp; lines: +3 -8;
Allow segments to be used even after they were marked for deletion with
the IPC_RMID flag.
This is permitted as an extension beyond the standards and this is similar
to what other operating systems like linux do.
MFC after: 1 month
Relnotes: yes
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D3603
Use the same scheme implemented to manage credentials.
Code needing to look at process's credentials (as opposed to thred's) is
provided with *_proc variants of relevant functions.
Places which possibly had to take the proc lock anyway still use the proc
pointer to access limits.
The point of this is to be able to add RACCT (with RACCT_DISABLED)
to GENERIC, to avoid having to rebuild the kernel to use rctl(8).
Differential Revision: https://reviews.freebsd.org/D2369
Reviewed by: kib@
MFC after: 1 month
Relnotes: yes
Sponsored by: The FreeBSD Foundation
- Use real locking, replace Giant with global sx protecting the
subsystem. Since the subsystem' lock is no longer dropped during
the sleepsk, remove not needed SHMSEG_WANTED segment flag, and
revert r278963.
- To do proper code simplification possible after the change of the
lock, restructure several functions into _locked body and
originally-named wrapper which calls into _locked variant. This
allows to eliminate the 'goto done2' spread over the code.
- Merge shm_find_segment_by_shmid() and shm_find_segment_by_shmidx().
- Consistently change all function prototypes to ANSI C.
Reviewed by: mjg (who has earlier version of the similar patch to
introduce real locking)
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
The kernel tracks syscall users so that modules can safely unregister them.
But if the module is not unloadable or was compiled into the kernel, there is
no need to do this.
Achieve this by adding SY_THR_STATIC_KLD macro which expands to SY_THR_STATIC
during kernel build and 0 otherwise.
Reviewed by: kib (previous version)
MFC after: 2 weeks
These changes prevent sysctl(8) from returning proper output,
such as:
1) no output from sysctl(8)
2) erroneously returning ENOMEM with tools like truss(1)
or uname(1)
truss: can not get etype: Cannot allocate memory
there is an environment variable which shall initialize the SYSCTL
during early boot. This works for all SYSCTL types both statically and
dynamically created ones, except for the SYSCTL NODE type and SYSCTLs
which belong to VNETs. A new flag, CTLFLAG_NOFETCH, has been added to
be used in the case a tunable sysctl has a custom initialisation
function allowing the sysctl to still be marked as a tunable. The
kernel SYSCTL API is mostly the same, with a few exceptions for some
special operations like iterating childrens of a static/extern SYSCTL
node. This operation should probably be made into a factored out
common macro, hence some device drivers use this. The reason for
changing the SYSCTL API was the need for a SYSCTL parent OID pointer
and not only the SYSCTL parent OID list pointer in order to quickly
generate the sysctl path. The motivation behind this patch is to avoid
parameter loading cludges inside the OFED driver subsystem. Instead of
adding special code to the OFED driver subsystem to post-load tunables
into dynamically created sysctls, we generalize this in the kernel.
Other changes:
- Corrected a possibly incorrect sysctl name from "hw.cbb.intr_mask"
to "hw.pcic.intr_mask".
- Removed redundant TUNABLE statements throughout the kernel.
- Some minor code rewrites in connection to removing not needed
TUNABLE statements.
- Added a missing SYSCTL_DECL().
- Wrapped two very long lines.
- Avoid malloc()/free() inside sysctl string handling, in case it is
called to initialize a sysctl from a tunable, hence malloc()/free() is
not ready when sysctls from the sysctl dataset are registered.
- Bumped FreeBSD version to indicate SYSCTL API change.
MFC after: 2 weeks
Sponsored by: Mellanox Technologies
an address in the first 2GB of the process's address space. This flag should
have the same semantics as the same flag on Linux.
To facilitate this, add a new parameter to vm_map_find() that specifies an
optional maximum virtual address. While here, fix several callers of
vm_map_find() to use a VMFS_* constant for the findspace argument instead of
TRUE and FALSE.
Reviewed by: alc
Approved by: re (kib)
- Add a new address space allocation method (VMFS_OPTIMAL_SPACE) for
vm_map_find() that will try to alter the alignment of a mapping to match
any existing superpage mappings of the object being mapped. If no
suitable address range is found with the necessary alignment,
vm_map_find() will fall back to using the simple first-fit strategy
(VMFS_ANY_SPACE).
- Change mmap() without MAP_FIXED, shmat(), and the GEM mapping ioctl to
use VMFS_OPTIMAL_SPACE instead of VMFS_ANY_SPACE.
Reviewed by: alc (earlier version)
MFC after: 2 weeks
future further optimizations where the vm_object lock will be held
in read mode most of the time the page cache resident pool of pages
are accessed for reading purposes.
The change is mostly mechanical but few notes are reported:
* The KPI changes as follow:
- VM_OBJECT_LOCK() -> VM_OBJECT_WLOCK()
- VM_OBJECT_TRYLOCK() -> VM_OBJECT_TRYWLOCK()
- VM_OBJECT_UNLOCK() -> VM_OBJECT_WUNLOCK()
- VM_OBJECT_LOCK_ASSERT(MA_OWNED) -> VM_OBJECT_ASSERT_WLOCKED()
(in order to avoid visibility of implementation details)
- The read-mode operations are added:
VM_OBJECT_RLOCK(), VM_OBJECT_TRYRLOCK(), VM_OBJECT_RUNLOCK(),
VM_OBJECT_ASSERT_RLOCKED(), VM_OBJECT_ASSERT_LOCKED()
* The vm/vm_pager.h namespace pollution avoidance (forcing requiring
sys/mutex.h in consumers directly to cater its inlining functions
using VM_OBJECT_LOCK()) imposes that all the vm/vm_pager.h
consumers now must include also sys/rwlock.h.
* zfs requires a quite convoluted fix to include FreeBSD rwlocks into
the compat layer because the name clash between FreeBSD and solaris
versions must be avoided.
At this purpose zfs redefines the vm_object locking functions
directly, isolating the FreeBSD components in specific compat stubs.
The KPI results heavilly broken by this commit. Thirdy part ports must
be updated accordingly (I can think off-hand of VirtualBox, for example).
Sponsored by: EMC / Isilon storage division
Reviewed by: jeff
Reviewed by: pjd (ZFS specific review)
Discussed with: alc
Tested by: pho
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)
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".
for racct.
Note that after this commit, ipcs(1) needs to be rebuilt. Otherwise, it will
fail with "ipcs: sysctlbyname: kern.ipc.msqids: Cannot allocate memory".
Sponsored by: The FreeBSD Foundation
Reviewed by: kib (earlier version)
PMC/SYSV/...).
No FreeBSD version bump, the userland application to query the features will
be committed last and can serve as an indication of the availablility if
needed.
Sponsored by: Google Summer of Code 2010
Submitted by: kibab
Reviewed by: arch@ (parts by rwatson, trasz, jhb)
X-MFC after: to be determined in last commit with code from this project
shm syscalls, and initial check for the number of allocated segments
in the module deinitialization code, the following might happen:
after the check for active segment, while waiting for threads to
leave some other syscall, shmget(2) is called. Then, we can end
up with the shared segment that cannot be detached since sysvshm
module is unloaded.
Prevent the leak by rechecking and disclaiming a reference to the vm
object owned by sysvshm module, that might have grown during the drain.
Tested by: pho
Reviewed by: jhb
MFC after: 1 month
shared resources defaults beyond absolute minimums.
The new values are chosen mostly by magic. They are still fairly
small and will need increasing for large installations (especially
SHMMAX). However, they are now enough to e.g. start PostgreSQL
installations with ~~300 users and nearly 512 MB of shared buffers.
Reviewed by: A short discussion on hackers@
sysv_{msg,sem,shm}.c files.
Mark SysV IPC freebsd32 syscalls as NOSTD and add required
SYSCALL_INIT_HELPER/SYSCALL32_INIT_HELPERs to provide auto
register/unregister on module load.
This makes COMPAT_FREEBSD32 functional with SysV IPC compiled and loaded
as modules.
Reviewed by: jhb
MFC after: 2 weeks
- The uid/cuid members of struct ipc_perm are now uid_t instead of unsigned
short.
- The gid/cgid members of struct ipc_perm are now gid_t instead of unsigned
short.
- The mode member of struct ipc_perm is now mode_t instead of unsigned short
(this is merely a style bug).
- The rather dubious padding fields for ABI compat with SV/I386 have been
removed from struct msqid_ds and struct semid_ds.
- The shm_segsz member of struct shmid_ds is now a size_t instead of an
int. This removes the need for the shm_bsegsz member in struct
shmid_kernel and should allow for complete support of SYSV SHM regions
>= 2GB.
- The shm_nattch member of struct shmid_ds is now an int instead of a
short.
- The shm_internal member of struct shmid_ds is now gone. The internal
VM object pointer for SHM regions has been moved into struct
shmid_kernel.
- The existing __semctl(), msgctl(), and shmctl() system call entries are
now marked COMPAT7 and new versions of those system calls which support
the new ABI are now present.
- The new system calls are assigned to the FBSD-1.1 version in libc. The
FBSD-1.0 symbols in libc now refer to the old COMPAT7 system calls.
- A simplistic framework for tagging system calls with compatibility
symbol versions has been added to libc. Version tags are added to
system calls by adding an appropriate __sym_compat() entry to
src/lib/libc/incldue/compat.h. [1]
PR: kern/16195 kern/113218 bin/129855
Reviewed by: arch@, rwatson
Discussed with: kan, kib [1]
them under COMPAT_FREEBSD[4567]. Starting with FreeBSD 5.0 the SYSV IPC
API was implemented via direct system calls (e.g. msgctl(), msgget(), etc.)
rather than indirecting through the var-args *sys() system calls. The
shmsys() system call was already effectively deprecated for all but
COMPAT_FREEBSD4 already as its implementation for the !COMPAT_FREEBSD4 case
was to simply invoke nosys().
rlimit RLIMIT_SWAP that limits the amount of swap that may be reserved
for the uid.
The accounting information (charge) is associated with either map entry,
or vm object backing the entry, assuming the object is the first one
in the shadow chain and entry does not require COW. Charge is moved
from entry to object on allocation of the object, e.g. during the mmap,
assuming the object is allocated, or on the first page fault on the
entry. It moves back to the entry on forks due to COW setup.
The per-entry granularity of accounting makes the charge process fair
for processes that change uid during lifetime, and decrements charge
for proper uid when region is unmapped.
The interface of vm_pager_allocate(9) is extended by adding struct ucred *,
that is used to charge appropriate uid when allocation if performed by
kernel, e.g. md(4).
Several syscalls, among them is fork(2), may now return ENOMEM when
global or per-uid limits are enforced.
In collaboration with: pho
Reviewed by: alc
Approved by: re (kensmith)
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)
Do not overload the local variable size in kern_shmat() due to vm_size_t
change.
Fix style bug by adding explicit comparision with 0.
Discussed with: bde
MFC after: 1 week
memory from int to size_t. Implement a workaround for current ABI not
allowing to properly save size for and report more then 2Gb sized segment
of shared memory.
This makes it possible to use > 2 Gb shared memory segments on 64bit
architectures. Please note the new BUGS section in shmctl(2) and
UPDATING note for limitations of this temporal solution.
Reviewed by: csjp
Tested by: Nikolay Dzham <i levsha org ua>
MFC after: 2 weeks
through the FreeBSD ABI. IPC_INFO, SHM_INFO, SHM_STAT were added
specifically for Linux binary support. They are not documented
as being a part of the FreeBSD ABI, also, the structures necessary
for them have been hidden away from the users for a long time.
Also, the Linux ABI layer uses it's own structures to populate the
responses back to the user to ensure that the ABI is consistent.
I think there is a bit more separation work that needs to happen.
Reviewed by: jhb
Discussed with: jhb
Discussed on: freebsd-arch@ (very briefly)
MFC after: 1 month
