Add a security hook call to enable security modules to control the ability
to attach a task to a cpuset. While limited control over this operation is
possible via permission checks on the pseudo fs interface, those checks are
not sufficient to control access to the target task, which is looked up in
this function. The existing task_setscheduler hook is re-used for this
operation since this falls under the same class of operations.
Signed-off-by: David Quigley <dpquigl@tycho.nsa.gov>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
Acked-by: Paul Jackson <pj@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch adds LSM hooks into the setaffinity and getaffinity functions to
enable security modules to control these operations between tasks with
task_setscheduler and task_getscheduler LSM hooks.
Signed-off-by: David Quigley <dpquigl@tycho.nsa.gov>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The definition of the third parameter is a pointer to an array of virtual
addresses which give us some trouble. The existing code calculated the
wrong address in the array since I used void to avoid having to specify a
type.
I now use the correct type "compat_uptr_t __user *" in the definition of
the function in kernel/compat.c.
However, I used __u32 in syscalls.h. Would have to include compat.h there
in order to provide the same definition which would generate an ugly
include situation.
On both ia64 and x86_64 compat_uptr_t is u32. So this works although
parameter declarations differ.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
sys_move_pages() support for 32bit (i386 plus x86_64 compat layer)
Add support for move_pages() on i386 and also add the compat functions
necessary to run 32 bit binaries on x86_64.
Add compat_sys_move_pages to the x86_64 32bit binary layer. Note that it is
not up to date so I added the missing pieces. Not sure if this is done the
right way.
[akpm@osdl.org: compile fix]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
move_pages() is used to move individual pages of a process. The function can
be used to determine the location of pages and to move them onto the desired
node. move_pages() returns status information for each page.
long move_pages(pid, number_of_pages_to_move,
addresses_of_pages[],
nodes[] or NULL,
status[],
flags);
The addresses of pages is an array of void * pointing to the
pages to be moved.
The nodes array contains the node numbers that the pages should be moved
to. If a NULL is passed instead of an array then no pages are moved but
the status array is updated. The status request may be used to determine
the page state before issuing another move_pages() to move pages.
The status array will contain the state of all individual page migration
attempts when the function terminates. The status array is only valid if
move_pages() completed successfullly.
Possible page states in status[]:
0..MAX_NUMNODES The page is now on the indicated node.
-ENOENT Page is not present
-EACCES Page is mapped by multiple processes and can only
be moved if MPOL_MF_MOVE_ALL is specified.
-EPERM The page has been mlocked by a process/driver and
cannot be moved.
-EBUSY Page is busy and cannot be moved. Try again later.
-EFAULT Invalid address (no VMA or zero page).
-ENOMEM Unable to allocate memory on target node.
-EIO Unable to write back page. The page must be written
back in order to move it since the page is dirty and the
filesystem does not provide a migration function that
would allow the moving of dirty pages.
-EINVAL A dirty page cannot be moved. The filesystem does not provide
a migration function and has no ability to write back pages.
The flags parameter indicates what types of pages to move:
MPOL_MF_MOVE Move pages that are only mapped by the process.
MPOL_MF_MOVE_ALL Also move pages that are mapped by multiple processes.
Requires sufficient capabilities.
Possible return codes from move_pages()
-ENOENT No pages found that would require moving. All pages
are either already on the target node, not present, had an
invalid address or could not be moved because they were
mapped by multiple processes.
-EINVAL Flags other than MPOL_MF_MOVE(_ALL) specified or an attempt
to migrate pages in a kernel thread.
-EPERM MPOL_MF_MOVE_ALL specified without sufficient priviledges.
or an attempt to move a process belonging to another user.
-EACCES One of the target nodes is not allowed by the current cpuset.
-ENODEV One of the target nodes is not online.
-ESRCH Process does not exist.
-E2BIG Too many pages to move.
-ENOMEM Not enough memory to allocate control array.
-EFAULT Parameters could not be accessed.
A test program for move_pages() may be found with the patches
on ftp.kernel.org:/pub/linux/kernel/people/christoph/pmig/patches-2.6.17-rc4-mm3
From: Christoph Lameter <clameter@sgi.com>
Detailed results for sys_move_pages()
Pass a pointer to an integer to get_new_page() that may be used to
indicate where the completion status of a migration operation should be
placed. This allows sys_move_pags() to report back exactly what happened to
each page.
Wish there would be a better way to do this. Looks a bit hacky.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Jes Sorensen <jes@trained-monkey.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Andi Kleen <ak@muc.de>
Cc: Michael Kerrisk <mtk-manpages@gmx.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Rework the swsusp's memory shrinker in the following way:
- Simplify balance_pgdat() by removing all of the swsusp-related code
from it.
- Make shrink_all_memory() use shrink_slab() and a new function
shrink_all_zones() which calls shrink_active_list() and
shrink_inactive_list() directly for each zone in a way that's optimized
for suspend.
In shrink_all_memory() we try to free exactly as many pages as the caller
asks for, preferably in one shot, starting from easier targets. If slab
caches are huge, they are most likely to have enough pages to reclaim.
The inactive lists are next (the zones with more inactive pages go first)
etc.
Each time shrink_all_memory() attempts to shrink the active and inactive
lists for each zone in 5 passes. In the first pass, only the inactive
lists are taken into consideration. In the next two passes the active
lists are also shrunk, but mapped pages are not reclaimed. In the last
two passes the active and inactive lists are shrunk and mapped pages are
reclaimed as well. The aim of this is to alter the reclaim logic to choose
the best pages to keep on resume and improve the responsiveness of the
resumed system.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Con Kolivas <kernel@kolivas.org>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch adds panic_on_oom sysctl under sys.vm.
When sysctl vm.panic_on_oom = 1, the kernel panics intead of killing rogue
processes. And if vm.panic_on_oom is 0 the kernel will do oom_kill() in
the same way as it does today. Of course, the default value is 0 and only
root can modifies it.
In general, oom_killer works well and kill rogue processes. So the whole
system can survive. But there are environments where panic is preferable
rather than kill some processes.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Give the statfs superblock operation a dentry pointer rather than a superblock
pointer.
This complements the get_sb() patch. That reduced the significance of
sb->s_root, allowing NFS to place a fake root there. However, NFS does
require a dentry to use as a target for the statfs operation. This permits
the root in the vfsmount to be used instead.
linux/mount.h has been added where necessary to make allyesconfig build
successfully.
Interest has also been expressed for use with the FUSE and XFS filesystems.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: Nathan Scott <nathans@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Extend the get_sb() filesystem operation to take an extra argument that
permits the VFS to pass in the target vfsmount that defines the mountpoint.
The filesystem is then required to manually set the superblock and root dentry
pointers. For most filesystems, this should be done with simple_set_mnt()
which will set the superblock pointer and then set the root dentry to the
superblock's s_root (as per the old default behaviour).
The get_sb() op now returns an integer as there's now no need to return the
superblock pointer.
This patch permits a superblock to be implicitly shared amongst several mount
points, such as can be done with NFS to avoid potential inode aliasing. In
such a case, simple_set_mnt() would not be called, and instead the mnt_root
and mnt_sb would be set directly.
The patch also makes the following changes:
(*) the get_sb_*() convenience functions in the core kernel now take a vfsmount
pointer argument and return an integer, so most filesystems have to change
very little.
(*) If one of the convenience function is not used, then get_sb() should
normally call simple_set_mnt() to instantiate the vfsmount. This will
always return 0, and so can be tail-called from get_sb().
(*) generic_shutdown_super() now calls shrink_dcache_sb() to clean up the
dcache upon superblock destruction rather than shrink_dcache_anon().
This is required because the superblock may now have multiple trees that
aren't actually bound to s_root, but that still need to be cleaned up. The
currently called functions assume that the whole tree is rooted at s_root,
and that anonymous dentries are not the roots of trees which results in
dentries being left unculled.
However, with the way NFS superblock sharing are currently set to be
implemented, these assumptions are violated: the root of the filesystem is
simply a dummy dentry and inode (the real inode for '/' may well be
inaccessible), and all the vfsmounts are rooted on anonymous[*] dentries
with child trees.
[*] Anonymous until discovered from another tree.
(*) The documentation has been adjusted, including the additional bit of
changing ext2_* into foo_* in the documentation.
[akpm@osdl.org: convert ipath_fs, do other stuff]
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: Nathan Scott <nathans@sgi.com>
Cc: Roland Dreier <rolandd@cisco.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc: (139 commits)
[POWERPC] re-enable OProfile for iSeries, using timer interrupt
[POWERPC] support ibm,extended-*-frequency properties
[POWERPC] Extra sanity check in EEH code
[POWERPC] Dont look for class-code in pci children
[POWERPC] Fix mdelay badness on shared processor partitions
[POWERPC] disable floating point exceptions for init
[POWERPC] Unify ppc syscall tables
[POWERPC] mpic: add support for serial mode interrupts
[POWERPC] pseries: Print PCI slot location code on failure
[POWERPC] spufs: one more fix for 64k pages
[POWERPC] spufs: fail spu_create with invalid flags
[POWERPC] spufs: clear class2 interrupt status before wakeup
[POWERPC] spufs: fix Makefile for "make clean"
[POWERPC] spufs: remove stop_code from struct spu
[POWERPC] spufs: fix spu irq affinity setting
[POWERPC] spufs: further abstract priv1 register access
[POWERPC] spufs: split the Cell BE support into generic and platform dependant parts
[POWERPC] spufs: dont try to access SPE channel 1 count
[POWERPC] spufs: use kzalloc in create_spu
[POWERPC] spufs: fix initial state of wbox file
...
Manually resolved conflicts in:
drivers/net/phy/Makefile
include/asm-powerpc/spu.h
Avoid taking tasklist_lock for at getrusage for the multithreaded case too.
We don't need to take the tasklist lock for thread traversal of a process
since Oleg's do-__unhash_process-under-siglock.patch and related work.
Signed-off-by: Ravikiran Thirumalai <kiran@scalex86.org>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
kernel/power/main.c: In function 'suspend_prepare':
kernel/power/main.c:89: warning: implicit declaration of function 'suspend_console'
kernel/power/main.c: In function 'suspend_finish':
kernel/power/main.c:137: warning: implicit declaration of function 'resume_console'
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Introduce SELinux hooks to support the access key retention subsystem
within the kernel. Incorporate new flask headers from a modified version
of the SELinux reference policy, with support for the new security class
representing retained keys. Extend the "key_alloc" security hook with a
task parameter representing the intended ownership context for the key
being allocated. Attach security information to root's default keyrings
within the SELinux initialization routine.
Has passed David's testsuite.
Signed-off-by: Michael LeMay <mdlemay@epoch.ncsc.mil>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
Acked-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* git://git.infradead.org/~dwmw2/rbtree-2.6:
[RBTREE] Switch rb_colour() et al to en_US spelling of 'color' for consistency
Update UML kernel/physmem.c to use rb_parent() accessor macro
[RBTREE] Update hrtimers to use rb_parent() accessor macro.
[RBTREE] Add explicit alignment to sizeof(long) for struct rb_node.
[RBTREE] Merge colour and parent fields of struct rb_node.
[RBTREE] Remove dead code in rb_erase()
[RBTREE] Update JFFS2 to use rb_parent() accessor macro.
[RBTREE] Update eventpoll.c to use rb_parent() accessor macro.
[RBTREE] Update key.c to use rb_parent() accessor macro.
[RBTREE] Update ext3 to use rb_parent() accessor macro.
[RBTREE] Change rbtree off-tree marking in I/O schedulers.
[RBTREE] Add accessor macros for colour and parent fields of rb_node
* git://git.infradead.org/mtd-2.6: (199 commits)
[MTD] NAND: Fix breakage all over the place
[PATCH] NAND: fix remaining OOB length calculation
[MTD] NAND Fixup NDFC merge brokeness
[MTD NAND] S3C2410 driver cleanup
[MTD NAND] s3c24x0 board: Fix clock handling, ensure proper initialisation.
[JFFS2] Check CRC32 on dirent and data nodes each time they're read
[JFFS2] When retiring nextblock, allocate a node_ref for the wasted space
[JFFS2] Mark XATTR support as experimental, for now
[JFFS2] Don't trust node headers before the CRC is checked.
[MTD] Restore MTD_ROM and MTD_RAM types
[MTD] assume mtd->writesize is 1 for NOR flashes
[MTD NAND] Fix s3c2410 NAND driver so it at least _looks_ like it compiles
[MTD] Prepare physmap for 64-bit-resources
[JFFS2] Fix more breakage caused by janitorial meddling.
[JFFS2] Remove stray __exit from jffs2_compressors_exit()
[MTD] Allow alternate JFFS2 mount variant for root filesystem.
[MTD] Disconnect struct mtd_info from ABI
[MTD] replace MTD_RAM with MTD_GENERIC_TYPE
[MTD] replace MTD_ROM with MTD_GENERIC_TYPE
[MTD] remove a forgotten MTD_XIP
...
Hi,
I was doing some testing and noticed that when the audit system was disabled,
I was still getting messages about the loginuid being set. The following patch
makes audit_set_loginuid look at in_syscall to determine if it should create
an audit event. The loginuid will continue to be set as long as there is a context.
Signed-off-by: Steve Grubb <sgrubb@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Clear AUDIT_FILTER_PREPEND flag after adding rule to list. This
fixes three problems when a rule is added with the -A syntax:
- auditctl displays filter list as "(null)"
- the rule cannot be removed using -d
- a duplicate rule can be added with -a
Signed-off-by: Amy Griffis <amy.griffis@hp.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
In this implementation, audit registers inotify watches on the parent
directories of paths specified in audit rules. When audit's inotify
event handler is called, it updates any affected rules based on the
filesystem event. If the parent directory is renamed, removed, or its
filesystem is unmounted, audit removes all rules referencing that
inotify watch.
To keep things simple, this implementation limits location-based
auditing to the directory entries in an existing directory. Given
a path-based rule for /foo/bar/passwd, the following table applies:
passwd modified -- audit event logged
passwd replaced -- audit event logged, rules list updated
bar renamed -- rule removed
foo renamed -- untracked, meaning that the rule now applies to
the new location
Audit users typically want to have many rules referencing filesystem
objects, which can significantly impact filtering performance. This
patch also adds an inode-number-based rule hash to mitigate this
situation.
The patch is relative to the audit git tree:
http://kernel.org/git/?p=linux/kernel/git/viro/audit-current.git;a=summary
and uses the inotify kernel API:
http://lkml.org/lkml/2006/6/1/145
Signed-off-by: Amy Griffis <amy.griffis@hp.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This patch adds audit support to POSIX message queues. It applies cleanly to
the lspp.b15 branch of Al Viro's git tree. There are new auxiliary data
structures, and collection and emission routines in kernel/auditsc.c. New hooks
in ipc/mqueue.c collect arguments from the syscalls.
I tested the patch by building the examples from the POSIX MQ library tarball.
Build them -lrt, not against the old MQ library in the tarball. Here's the URL:
http://www.geocities.com/wronski12/posix_ipc/libmqueue-4.41.tar.gz
Do auditctl -a exit,always -S for mq_open, mq_timedsend, mq_timedreceive,
mq_notify, mq_getsetattr. mq_unlink has no new hooks. Please see the
corresponding userspace patch to get correct output from auditd for the new
record types.
[fixes folded]
Signed-off-by: George Wilson <ltcgcw@us.ibm.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The following patch addresses most of the issues with the IPC_SET_PERM
records as described in:
https://www.redhat.com/archives/linux-audit/2006-May/msg00010.html
and addresses the comments I received on the record field names.
To summarize, I made the following changes:
1. Changed sys_msgctl() and semctl_down() so that an IPC_SET_PERM
record is emitted in the failure case as well as the success case.
This matches the behavior in sys_shmctl(). I could simplify the
code in sys_msgctl() and semctl_down() slightly but it would mean
that in some error cases we could get an IPC_SET_PERM record
without an IPC record and that seemed odd.
2. No change to the IPC record type, given no feedback on the backward
compatibility question.
3. Removed the qbytes field from the IPC record. It wasn't being
set and when audit_ipc_obj() is called from ipcperms(), the
information isn't available. If we want the information in the IPC
record, more extensive changes will be necessary. Since it only
applies to message queues and it isn't really permission related, it
doesn't seem worth it.
4. Removed the obj field from the IPC_SET_PERM record. This means that
the kern_ipc_perm argument is no longer needed.
5. Removed the spaces and renamed the IPC_SET_PERM field names. Replaced iuid and
igid fields with ouid and ogid in the IPC record.
I tested this with the lspp.22 kernel on an x86_64 box. I believe it
applies cleanly on the latest kernel.
-- ljk
Signed-off-by: Linda Knippers <linda.knippers@hp.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Just a few minor proposed updates. Only the last one will
actually affect behavior. The rest are just misleading
code.
Several AUDIT_SET functions return 'old' value, but only
return value <0 is checked for. So just return 0.
propagate audit_set_rate_limit and audit_set_backlog_limit
error values
In audit_buffer_free, the audit_freelist_count was being
incremented even when we discard the return buffer, so
audit_freelist_count can end up wrong. This could cause
the actual freelist to shrink over time, eventually
threatening to degrate audit performance.
Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Don't return -ENOMEM when callers of these functions are checking for
a NULL return. Bug noticed by Serge Hallyn.
Signed-off-by: Amy Griffis <amy.griffis@hp.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
We should not send a pile of replies while holding audit_netlink_mutex
since we hold the same mutex when we receive commands. As the result,
we can get blocked while sending and sit there holding the mutex while
auditctl is unable to send the next command and get around to receiving
what we'd sent.
Solution: create skb and put them into a queue instead of sending;
once we are done, send what we've got on the list. The former can
be done synchronously while we are handling AUDIT_LIST or AUDIT_LIST_RULES;
we are holding audit_netlink_mutex at that point. The latter is done
asynchronously and without messing with audit_netlink_mutex.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The following series of patches introduces a kernel API for inotify,
making it possible for kernel modules to benefit from inotify's
mechanism for watching inodes. With these patches, inotify will
maintain for each caller a list of watches (via an embedded struct
inotify_watch), where each inotify_watch is associated with a
corresponding struct inode. The caller registers an event handler and
specifies for which filesystem events their event handler should be
called per inotify_watch.
Signed-off-by: Amy Griffis <amy.griffis@hp.com>
Acked-by: Robert Love <rml@novell.com>
Acked-by: John McCutchan <john@johnmccutchan.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Trying to suspend/resume with console messages flying all around is
doomed to failure, when the devices that the messages are trying to
go to are being shut down.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
arm_timer() checks PF_EXITING to prevent BUG_ON(->exit_state)
in run_posix_cpu_timers().
However, for some reason it does so only for CPUCLOCK_PERTHREAD
case (which is imho wrong).
Also, this check is not reliable, PF_EXITING could be set on
another cpu without any locks/barriers just after the check,
so it can't prevent from attaching the timer to the exiting
task.
The previous patch makes this check unneeded.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
do_exit() clears ->it_##clock##_expires, but nothing prevents
another cpu to attach the timer to exiting process after that.
arm_timer() tries to protect against this race, but the check
is racy.
After exit_notify() does 'write_unlock_irq(&tasklist_lock)' and
before do_exit() calls 'schedule() local timer interrupt can find
tsk->exit_state != 0. If that state was EXIT_DEAD (or another cpu
does sys_wait4) interrupted task has ->signal == NULL.
At this moment exiting task has no pending cpu timers, they were
cleanuped in __exit_signal()->posix_cpu_timers_exit{,_group}(),
so we can just return from irq.
John Stultz recently confirmed this bug, see
http://marc.theaimsgroup.com/?l=linux-kernel&m=115015841413687
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
If the local timer interrupt happens just after do_exit() sets PF_EXITING
(and before it clears ->it_xxx_expires) run_posix_cpu_timers() will call
check_process_timers() with tasklist_lock + ->siglock held and
check_process_timers:
t = tsk;
do {
....
do {
t = next_thread(t);
} while (unlikely(t->flags & PF_EXITING));
} while (t != tsk);
the outer loop will never stop.
Actually, the window is bigger. Another process can attach the timer
after ->it_xxx_expires was cleared (see the next commit) and the 'if
(PF_EXITING)' check in arm_timer() is racy (see the one after that).
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This new prctl is intended for changing the execution mode of the
processor, on processors that support both a little-endian mode and a
big-endian mode. It is intended for use by programs such as
instruction set emulators (for example an x86 emulator on PowerPC),
which may find it convenient to use the processor in an alternate
endianness mode when executing translated instructions.
Note that this does not imply the existence of a fully-fledged ABI for
both endiannesses, or of compatibility code for converting system
calls done in the non-native endianness mode. The program is expected
to arrange for all of its system call arguments to be presented in the
native endianness.
Switching between big and little-endian mode will require some care in
constructing the instruction sequence for the switch. Generally the
instructions up to the instruction that invokes the prctl system call
will have to be in the old endianness, and subsequent instructions
will have to be in the new endianness.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
From: Stephen Hemminger <shemminger@osdl.org>
I want to use the hrtimer's in the netem (Network Emulator) qdisc. But the
necessary symbols aren't exported for module use.
Also needed by SystemTap.
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "Stone, Joshua I" <joshua.i.stone@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This reverts commit 5ce74abe78 (and its
dependent commit 8a5bc075b8), because of
audio underruns.
Reported by Rene Herman <rene.herman@keyaccess.nl>, who also pinpointed
the exact cause of the underruns:
"Audio underruns galore, with only ogg123 and firefox (browsing the
GIT tree online is also a nice trigger by the way).
If I back it out, everything is fine for me again."
Cc: Rene Herman <rene.herman@keyaccess.nl>
Cc: Mike Galbraith <efault@gmx.de>
Acked-by: Con Kolivas <kernel@kolivas.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Under certain timing conditions, a race during boot occurs where timer
ticks are being processed on remote CPUs. The remote timer ticks can
increment jiffies, and if this happens during a window when a timeout is
very close to expiring but a local tick has not yet been delivered, you can
end up with
1) No softirq pending
2) A local timer wheel which is not synced to jiffies
3) No high resolution timer active
4) A local timer which is supposed to fire before the current jiffies value.
In this circumstance, the comparison in next_timer_interrupt overflows,
because the base of the comparison for high resolution timers is jiffies,
but for the softirq timer wheel, it is relative the the current base of the
wheel (jiffies_base).
Signed-off-by: Zachary Amsden <zach@vmware.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
It's too easy to incorrectly call cpuset_zone_allowed() in an atomic
context without __GFP_HARDWALL set, and when done, it is not noticed until
a tight memory situation forces allocations to be tried outside the current
cpuset.
Add a 'might_sleep_if()' check, to catch this earlier on, instead of
waiting for a similar check in the mutex_lock() code, which is only rarely
invoked.
Signed-off-by: Paul Jackson <pj@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Update the kernel/cpuset.c:cpuset_zone_allowed() comment.
The rule for when mm/page_alloc.c should call cpuset_zone_allowed()
was intended to be:
Don't call cpuset_zone_allowed() if you can't sleep, unless you
pass in the __GFP_HARDWALL flag set in gfp_flag, which disables
the code that might scan up ancestor cpusets and sleep.
The explanation of this rule in the comment above cpuset_zone_allowed() was
stale, as a result of a restructuring of some __alloc_pages() code in
November 2005.
Rewrite that comment ...
Signed-off-by: Paul Jackson <pj@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Even since a previous patch:
Fix race between CONFIG_DEBUG_SLABALLOC and modules
Sun, 27 Jun 2004 17:55:19 +0000 (17:55 +0000)
http://www.kernel.org/git/?p=linux/kernel/git/torvalds/old-2.6-bkcvs.git;a=commit;h=92b3db26d31cf21b70e3c1eadc56c179506d8fbe
The function symbol_put_addr() will deadlock the kernel.
symbol_put_addr() would acquire modlist_lock, then while holding the lock call
two functions kernel_text_address() and module_text_address() which also try
to acquire the same lock. This deadlocks the kernel of course.
This patch changes symbol_put_addr() to not acquire the modlist_lock, it
doesn't need it since it never looks at the module list directly. Also, it
now uses core_kernel_text() instead of kernel_text_address(). The latter has
an additional check for addr inside a module, but we don't need to do that
since we call module_text_address() (the same function kernel_text_address
uses) ourselves.
Signed-off-by: Trent Piepho <xyzzy@speakeasy.org>
Cc: Zwane Mwaikambo <zwane@fsmlabs.com>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
With "Paul E. McKenney" <paulmck@us.ibm.com>
Introduce rcu_needs_cpu() interface. This can be used to tell if there
will be a new rcu batch on a cpu soon by looking at the curlist pointer.
This can be used to avoid to enter a tickless idle state where the cpu
would miss that a new batch is ready when rcu_start_batch would be called
on a different cpu.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Eric Biederman points out that we can't take the task_lock while holding
tasklist_lock for writing, because another CPU that holds the task lock
might take an interrupt that then tries to take tasklist_lock for writing.
Which would be a nasty deadlock, with one CPU spinning forever in an
interrupt handler (although admittedly you need to really work at
triggering it ;)
Since the ptrace_attach() code is special and very unusual, just make it
be extra careful, and use trylock+repeat to avoid the possible deadlock.
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This holds the task lock (and, for ptrace_attach, the tasklist_lock)
over the actual attach event, which closes a race between attacking to a
thread that is either doing a PTRACE_TRACEME or getting de-threaded.
Thanks to Oleg Nesterov for reminding me about this, and Chris Wright
for noticing a lost return value in my first version.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
While testing the watch performance, I noticed that selinux_task_ctxid()
was creeping into the results more than it should. Investigation showed
that the function call was being called whether it was needed or not. The
below patch fixes this.
Signed-off-by: Steve Grubb <sgrubb@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
