Randy Dunlap [Wed, 25 Apr 2012 01:04:57 +0000 (11:04 +1000)]
kconfig: update compression algorithm info
There have been new compression algorithms added without updating nearby
relevant descriptive text that refers to (a) the number of compression
algorithms and (b) the most recent one. Fix these inconsistencies.
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net> Reported-by: <qasdfgtyuiop@gmail.com> Cc: Lasse Collin <lasse.collin@tukaani.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Markus Trippelsdorf <markus@trippelsdorf.de> Cc: Alain Knaff <alain@knaff.lu> Cc: Albin Tonnerre <albin.tonnerre@free-electrons.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Randy Dunlap [Wed, 25 Apr 2012 01:04:57 +0000 (11:04 +1000)]
ramoops: fix printk format warnings
Fix printk format warnings for phys_addr_t type variables:
drivers/char/ramoops.c:246:3: warning: format '%llx' expects type 'long long unsigned int', but argument 3 has type 'phys_addr_t'
drivers/char/ramoops.c:273:2: warning: format '%llx' expects type 'long long unsigned int', but argument 3 has type 'phys_addr_t'
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net> Cc: Kees Cook <keescook@chromium.org> Cc: Greg Kroah-Hartman <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Instead of using /dev/mem directly and forcing userspace to know (or
extract) where the platform has defined persistent memory, how many slots
it has, the sizes, etc, use the common pstore infrastructure to handle
Oops gathering and extraction. This presents a much easier to use
filesystem-based view to the memory region. This also means that any
other tools that are written to understand pstore will automatically be
able to process ramoops too.
Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Tony Luck <tony.luck@intel.com> Cc: Marco Stornelli <marco.stornelli@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Greg Kroah-Hartman <greg@kroah.com> Cc: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
c/r: prctl: update prctl_set_mm_exe_file() after mm->num_exe_file_vmas removal
[ fix for "c-r-prctl-add-ability-to-set-new-mm_struct-exe_file-v2" from mm tree ]
After removing mm->num_exe_file_vmas kernel keeps mm->exe_file until final
mmput(), it never becomes NULL while task is alive.
We can check for other mapped files in mm instead of checking
mm->num_exe_file_vmas, and mark mm with flag MMF_EXE_FILE_CHANGED in order
to forbid second changing of mm->exe_file.
Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org> Reviewed-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Matt Helsley <matthltc@us.ibm.com> Cc: Kees Cook <keescook@chromium.org> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Tejun Heo <tj@kernel.org> Cc: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
c/r: prctl: add ability to set new mm_struct::exe_file
When we do restore we would like to have a way to setup a former
mm_struct::exe_file so that /proc/pid/exe would point to the original
executable file a process had at checkpoint time.
For this the PR_SET_MM_EXE_FILE code is introduced. This option takes a
file descriptor which will be set as a source for new /proc/$pid/exe
symlink.
Note it allows to change /proc/$pid/exe if there are no VM_EXECUTABLE
vmas present for current process, simply because this feature is a special
to C/R and mm::num_exe_file_vmas become meaningless after that.
To minimize the amount of transition the /proc/pid/exe symlink might have,
this feature is implemented in one-shot manner. Thus once changed the
symlink can't be changed again. This should help sysadmins to monitor the
symlinks over all process running in a system.
In particular one could make a snapshot of processes and ring alarm if
there unexpected changes of /proc/pid/exe's in a system.
Note -- this feature is available iif CONFIG_CHECKPOINT_RESTORE is set and
the caller must have CAP_SYS_RESOURCE capability granted, otherwise the
request to change symlink will be rejected.
c/r: prctl: simplify PR_SET_MM on mm::code/data assignment
The mm::start_code, end_code, start_data, end_data members are set during
startup of executable file and are not changed after.
But the program itself might map new executable or/and data areas in time
so the original values written into mm fields mentioned above might not
have correspond VMA area at all, thus if one try to use this prctl codes
without underlied VMA, the error will be returned.
Drop this requirement. This shrinks the code and eliminates redundant
calls to vma_flags_mismatch. The worst thing one can do (if say to write
some bad values here) -- the weird results will be shown in
/proc/$pid/statm or in /proc/pid/stat.
Still, assignement of data on stack (such as command line and environment
variables) requires the underlied VMA to exist.
c/r: prctl: extend PR_SET_MM to set up more mm_struct entries
During checkpoint we dump whole process memory to a file and the dump
includes process stack memory. But among stack data itself, the stack
carries additional parameters such as command line arguments, environment
data and auxiliary vector.
So when we do restore procedure and once we've restored stack data itself
we need to setup mm_struct::arg_start/end, env_start/end, so restored
process would be able to find command line arguments and environment data
it had at checkpoint time. The same applies to auxiliary vector.
For this reason additional PR_SET_MM_(ARG_START | ARG_END | ENV_START |
ENV_END | AUXV) codes are introduced.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Acked-by: Kees Cook <keescook@chromium.org> Cc: Tejun Heo <tj@kernel.org> Cc: Andrew Vagin <avagin@openvz.org> Cc: Serge Hallyn <serge.hallyn@canonical.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Vasiliy Kulikov <segoon@openwall.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
c/r: procfs: add arg_start/end, env_start/end and exit_code members to /proc/$pid/stat
We would like to have an ability to restore command line arguments and
program environment pointers but first we need to obtain them somehow.
Thus we put these values into /proc/$pid/stat. The exit_code is needed to
restore zombie tasks.
While doing the checkpoint-restore in the user space one need to determine
whether various kernel objects (like mm_struct-s of file_struct-s) are
shared between tasks and restore this state.
The 2nd step can be solved by using appropriate CLONE_ flags and the
unshare syscall, while there's currently no ways for solving the 1st one.
One of the ways for checking whether two tasks share e.g. mm_struct is to
provide some mm_struct ID of a task to its proc file, but showing such
info considered to be not that good for security reasons.
Thus after some debates we end up in conclusion that using that named
'comparison' syscall might be the best candidate. So here is it --
__NR_kcmp.
It takes up to 5 arguments - the pids of the two tasks (which
characteristics should be compared), the comparison type and (in case of
comparison of files) two file descriptors.
Lookups for pids are done in the caller's PID namespace only.
At moment only x86 is supported and tested.
[akpm@linux-foundation.org: fix up selftests, warnings]
[akpm@linux-foundation.org: include errno.h] Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Andrey Vagin <avagin@openvz.org> Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Glauber Costa <glommer@parallels.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Tejun Heo <tj@kernel.org> Cc: Matt Helsley <matthltc@us.ibm.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Vasiliy Kulikov <segoon@openwall.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Valdis.Kletnieks@vt.edu Cc: Michal Marek <mmarek@suse.cz> Cc: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
When we do checkpoint of a task we need to know the list of children the
task, has but there is no easy and fast way to generate reverse
parent->children chain from arbitrary <pid> (while a parent pid is
provided in "PPid" field of /proc/<pid>/status).
So instead of walking over all pids in the system (creating one big
process tree in memory, just to figure out which children a task has) --
we add explicit /proc/<pid>/task/<tid>/children entry, because the kernel
already has this kind of information but it is not yet exported.
This is a first level children, not the whole process tree.
Christopher Yeoh [Wed, 25 Apr 2012 01:04:51 +0000 (11:04 +1000)]
aio/vfs: cleanup of rw_copy_check_uvector() and compat_rw_copy_check_uvector()
A cleanup of rw_copy_check_uvector and compat_rw_copy_check_uvector after
changes made to support CMA in an earlier patch.
Rather than having an additional check_access parameter to these
functions, the first paramater type is overloaded to allow the caller to
specify CHECK_IOVEC_ONLY which means check that the contents of the iovec
are valid, but do not check the memory that they point to. This is used
by process_vm_readv/writev where we need to validate that a iovec passed
to the syscall is valid but do not want to check the memory that it points
to at this point because it refers to an address space in another process.
Signed-off-by: Chris Yeoh <yeohc@au1.ibm.com> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
eventfd_ctx->count is an __u64 counter which is allowed to reach
ULLONG_MAX. eventfd_write() adds a __u64 value to "count", but the kernel
side eventfd_signal() only adds an int value to it. Make them consistent.
Adds support for DMA Engine API into Tsi721 mport driver.
Includes following changes for Tsi721 driver:
- Modifies BDMA register offset definitions to support per-channel handling
- Separates BDMA channel reserved for RIO Maintenance requests
- Adds DMA Engine callback routines
Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Vinod Koul <vinod.koul@intel.com> Cc: Li Yang <leoli@freescale.com> Cc: Matt Porter <mporter@kernel.crashing.org> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
rapidio: add DMA engine support for RIO data transfers
Adds DMA Engine framework support into RapidIO subsystem.
Uses DMA Engine DMA_SLAVE interface to generate data transfers to/from
remote RapidIO target devices.
Introduces RapidIO-specific wrapper for prep_slave_sg() interface with an
extra parameter to pass target specific information.
Uses scatterlist to describe local data buffer. Address flat data buffer
on a remote side.
Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com> Cc: Dan Williams <dan.j.williams@intel.com> Acked-by: Vinod Koul <vinod.koul@linux.intel.com> Cc: Li Yang <leoli@freescale.com> Cc: Matt Porter <mporter@kernel.crashing.org> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Add a directory to house POSIX message queue subsystem specific tests.
Add first test which checks the operation of mq_open() under various
corner conditions.
Signed-off-by: Doug Ledford <dledford@redhat.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Doug Ledford <dledford@redhat.com> Cc: Joe Korty <joe.korty@ccur.com> Cc: Amerigo Wang <amwang@redhat.com> Cc: Serge E. Hallyn <serue@us.ibm.com> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mqueue: separate mqueue default value from maximum value
commit b231cca438 ("message queues: increase range limits") changed mqueue
default value when attr parameter is specified NULL from hard coded value
to fs.mqueue.{msg,msgsize}_max sysctl value.
This made large side effect. When user need to use two mqueue
applications 1) using !NULL attr parameter and it require big message size
and 2) using NULL attr parameter and only need small size message, app (1)
require to raise fs.mqueue.msgsize_max and app (2) consume large memory
size even though it doesn't need.
Doug Ledford propsed to switch back it to static hard coded value.
However it also has a compatibility problem. Some applications might
started depend on the default value is tunable.
The solution is to separate default value from maximum value.
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Doug Ledford <dledford@redhat.com> Acked-by: Doug Ledford <dledford@redhat.com> Acked-by: Joe Korty <joe.korty@ccur.com> Cc: Amerigo Wang <amwang@redhat.com> Acked-by: Serge E. Hallyn <serue@us.ibm.com> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
KMALLOC_MAX_SIZE is not a good threshold. It is extremely high and
problematic. Unfortunately, some silly drivers depend on this and we
can't change it. But any new code needn't use such extreme ugly high
order allocations. It brings us awful fragmentation issues and system
slowdown.
Signed-off-by: KOSAKI Motohiro <mkosaki@jp.fujitsu.com> Acked-by: Doug Ledford <dledford@redhat.com> Acked-by: Joe Korty <joe.korty@ccur.com> Cc: Amerigo Wang <amwang@redhat.com> Cc: Serge E. Hallyn <serue@us.ibm.com> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Joe Korty <joe.korty@ccur.com> Cc: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Mqueue limitation is slightly naieve parameter likes other ipcs because
unprivileged user can consume kernel memory by using ipcs.
Thus, too aggressive raise bring us security issue. Example, current
setting allow evil unprivileged user use 256GB (= 256 * 1024 * 1024*1024)
and it's enough large to system will belome unresponsive. Don't do that.
Instead, every admin should adjust the knobs for their own systems.
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Acked-by: Doug Ledford <dledford@redhat.com> Acked-by: Joe Korty <joe.korty@ccur.com> Cc: Amerigo Wang <amwang@redhat.com> Acked-by: Serge E. Hallyn <serue@us.ibm.com> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Manfred Spraul <manfred@colorfullife.com> Cc: Dave Hansen <haveblue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
ipc/mqueue: update maximums for the mqueue subsystem
Commit b231cca4381e ("message queues: increase range limits") changed the
maximum size of a message in a message queue from INT_MAX to 8192*128.
Unfortunately, we had customers that relied on a size much larger than
8192*128 on their production systems. After reviewing POSIX, we found
that it is silent on the maximum message size. We did find a couple other
areas in which it was not silent. Fix up the mqueue maximums so that the
customer's system can continue to work, and document both the POSIX and
real world requirements in ipc_namespace.h so that we don't have this
issue crop back up.
Also, commit 9cf18e1dd74cd0 ("ipc: HARD_MSGMAX should be higher not lower
on 64bit") fiddled with HARD_MSGMAX without realizing that the number was
intentionally in place to limit the msg queue depth to one that was small
enough to kmalloc an array of pointers (hence why we divided 128k by
sizeof(long)). If we wish to meet POSIX requirements, we have no choice
but to change our allocation to a vmalloc instead (at least for the large
queue size case). With that, it's possible to increase our allowed
maximum to the POSIX requirements (or more if we choose).
Signed-off-by: Doug Ledford <dledford@redhat.com> Cc: Serge E. Hallyn <serue@us.ibm.com> Cc: Amerigo Wang <amwang@redhat.com> Cc: Joe Korty <joe.korty@ccur.com> Cc: Jiri Slaby <jslaby@suse.cz> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
In two places we don't enforce the hard limits for CAP_SYS_RESOURCE apps.
In preparation for making more reasonable hard limits, start enforcing
them even on CAP_SYS_RESOURCE.
Signed-off-by: Doug Ledford <dledford@redhat.com> Cc: Serge E. Hallyn <serue@us.ibm.com> Cc: Amerigo Wang <amwang@redhat.com> Cc: Joe Korty <joe.korty@ccur.com> Cc: Jiri Slaby <jslaby@suse.cz> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
ipc/mqueue: switch back to using non-max values on create
Commit b231cca4381 ("message queues: increase range limits") changed how
we create a queue that does not include an attr struct passed to open so
that it creates the queue with whatever the maximum values are. However,
if the admin has set the maximums to allow flexibility in creating a queue
(aka, both a large size and large queue are allowed, but combined they
create a queue too large for the RLIMIT_MSGQUEUE of the user), then
attempts to create a queue without an attr struct will fail. Switch back
to using acceptable defaults regardless of what the maximums are.
Note: so far, we only know of a few applications that rely on this
behavior (specifically, set the maximums in /proc, then run the
application which calls mq_open() without passing in an attr struct, and
the application expects the newly created message queue to have the
maximum sizes that were set in /proc used on the mq_open() call, and all
of those applications that we know of are actually part of regression test
suites that were coded to do something like this:
for size in 4096 65536 $((1024 * 1024)) $((16 * 1024 * 1024)); do
echo $size > /proc/sys/fs/mqueue/msgsize_max
mq_open || echo "Error opening mq with size $size"
done
These test suites that depend on any behavior like this are broken. The
concept that programs should rely upon the system wide maximum in order to
get their desired results instead of simply using a attr struct to specify
what they want is fundamentally unfriendly programming practice for any
multi-tasking OS.
Fixing this will break those few apps that we know of (and those app
authors recognize the brokenness of their code and the need to fix it).
However, the following patch "mqueue: separate mqueue default value"
allows a workaround in the form of new knobs for the default msg queue
creation parameters for any software out there that we don't already know
about that might rely on this behavior at the moment.
Signed-off-by: Doug Ledford <dledford@redhat.com> Cc: Serge E. Hallyn <serue@us.ibm.com> Cc: Amerigo Wang <amwang@redhat.com> Cc: Joe Korty <joe.korty@ccur.com> Cc: Jiri Slaby <jslaby@suse.cz> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
ipc/mqueue: cleanup definition names and locations
Since commit b231cca4381 ("message queues: increase range limits") on Oct
18, 2008, calls to mq_open() that did not pass in an attribute struct and
expected to get default values for the size of the queue and the max
message size now get the system wide maximums instead of hardwired
defaults like they used to get.
This was uncovered when one of the earlier patches in this patch set
increased the default system wide maximums at the same time it increased
the hard ceiling on the system wide maximums (a customer specifically
needed the hard ceiling brought back up, the new ceiling that commit b231cca4381 introduced was too low for their production systems). By
increasing the default maximums and not realising they were tied to any
attempt to create a message queue without an attribute struct, I had
inadvertently made it such that all message queue creation attempts
without an attribute struct were failing because the new default maximums
would create a queue that exceeded the default rlimit for message queue
bytes.
As a result, the system wide defaults were brought back down to their
previous levels, and the system wide ceilings on the maximums were raised
to meet the customer's needs. However, the fact that the no attribute
struct behavior of mq_open() could be broken by changing the system wide
maximums for message queues was seen as fundamentally broken itself. So
we hardwired the no attribute case back like it used to be. But, then we
realized that on the very off chance that some piece of software in the
wild depended on that behavior, we could work around that issue by adding
two new knobs to /proc that allowed setting the defaults for message
queues created without an attr struct separately from the system wide
maximums.
What is not an option IMO is to leave the current behavior in place. No
piece of software should ever rely on setting the system wide maximums in
order to get a desired message queue. Such a reliance would be so
fundamentally multitasking OS unfriendly as to not really be tolerable.
Fortunately, we don't know of any software in the wild that uses this
except for a regression test program that caught the issue in the first
place. If there is though, we have made accommodations with the two new
/proc knobs (and that's all the accommodations such fundamentally broken
software can be allowed)..
This patch:
The various defines for minimums and maximums of the sysctl controllable
mqueue values are scattered amongst different files and named
inconsistently. Move them all into ipc_namespace.h and make them have
consistent names. Additionally, make the number of queues per namespace
also have a minimum and maximum and use the same sysctl function as the
other two settable variables.
Signed-off-by: Doug Ledford <dledford@redhat.com> Acked-by: Serge E. Hallyn <serue@us.ibm.com> Cc: Amerigo Wang <amwang@redhat.com> Cc: Joe Korty <joe.korty@ccur.com> Cc: Jiri Slaby <jslaby@suse.cz> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
ipc/sem.c uses a custom wakeup scheme that relies on preempt_disable().
On -RT, this causes increased latencies and debug warnings.
The patch adds two additional schemes:
- one built around a completion - could be better for -RT kernels
- one built around a spinlock - unfortunately it's broken
- and the current one
My preferred solution would be the spinlock implementation: RT would use
premptible spinlocks, mainline normal spinlocks. Thus both get the
optimal implementation without any special code in ipc/sem.c.
Unfortunately, I don't see how it could be fixed.
Signed-off-by: Manfred Spraul <manfred@colorfullife.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Mike Galbraith <efault@gmx.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
fork: call complete_vfork_done() after clearing child_tid and flushing rss-counters
Child should wake up the parent from vfork() only after finishing all
operations with shared mm. There is no sense in using
CLONE_CHILD_CLEARTID together with CLONE_VFORK, but it looks more accurate
now.
Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Konstantin Khlebnikov <khlebnikov@openvz.org> Cc: Markus Trippelsdorf <markus@trippelsdorf.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tim Bird [Wed, 25 Apr 2012 01:04:42 +0000 (11:04 +1000)]
stack usage: add pid to warning printk in check_stack_usage
In embedded systems, sometimes the same program (busybox) is the cause of
multiple warnings. Outputting the pid with the program name in the
warning printk helps distinguish which instances of a program are using
the stack most.
This is a small patch, but useful.
Signed-off-by: Tim Bird <tim.bird@am.sony.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
cred: remove task_is_dead() from __task_cred() validation
commit 8f92054e ("CRED: Fix __task_cred()'s lockdep check and banner
comment"):
add the following validation condition:
task->exit_state >= 0
to permit the access if the target task is dead and therefore
unable to change its own credentials.
OK, but afaics currently this can only help wait_task_zombie() which calls
__task_cred() without rcu lock.
Remove this validation and change wait_task_zombie() to use task_uid()
instead. This means we do rcu_read_lock() only to shut up the lockdep,
but we already do the same in, say, wait_task_stopped().
task_is_dead() should die, task->exit_state != 0 means that this task has
passed exit_notify(), only do_wait-like code paths should use this.
Unfortunately, we can't kill task_is_dead() right now, it has already
acquired buggy users in drivers/staging. The fix already exists.
Signed-off-by: Oleg Nesterov <oleg@redhat.com> Reviewed-by: "Eric W. Biederman" <ebiederm@xmission.com> Acked-by: David Howells <dhowells@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: James Morris <jmorris@namei.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The system deadlocks (at least since 2.6.10) when
call_usermodehelper(UMH_WAIT_EXEC) request triggered
call_usermodehelper(UMH_WAIT_PROC) request.
This is because "khelper thread is waiting for the worker thread at
wait_for_completion() in do_fork() since the worker thread was created
with CLONE_VFORK flag" and "the worker thread cannot call complete()
because do_execve() is blocked at UMH_WAIT_PROC request" and "the khelper
thread cannot start processing UMH_WAIT_PROC request because the khelper
thread is waiting for the worker thread at wait_for_completion() in
do_fork()".
In order to avoid deadlock, do not try to call wait_for_completion() in
call_usermodehelper_exec() if the worker thread was created by khelper
thread with CLONE_VFORK flag.
The easiest example to observe this deadlock is to use a corrupted
/sbin/hotplug binary (like shown below).
call_usermodehelper("/tmp/dummy", UMH_WAIT_EXEC) is called from
kobject_uevent_env() in lib/kobject_uevent.c upon loading/unloading a
module. do_execve("/tmp/dummy") triggers a call to
request_module("binfmt-0000") from search_binary_handler() which in turn
calls call_usermodehelper(UMH_WAIT_PROC).
There are various hooks called during do_execve() operation (e.g.
security_bprm_check(), audit_bprm(), "struct
linux_binfmt"->load_binary()). If one of such hooks triggers
UMH_WAIT_EXEC, this deadlock will happen even if /sbin/hotplug is not
corrupted.
[akpm@linux-foundation.org: add comment to kmod_thread_locker] Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
kmod: move call_usermodehelper_fns() to .c file and unexport all it's helpers
If we move call_usermodehelper_fns() to kmod.c file and EXPORT_SYMBOL it
we can avoid exporting all it's helper functions:
call_usermodehelper_setup
call_usermodehelper_setfns
call_usermodehelper_exec
And make all of them static to kmod.c
Since the optimizer will see all these as a single call site it will
inline them inside call_usermodehelper_fns(). So we loose the call to
_fns but gain 3 calls to the helpers. (Not that it matters)
kmod: convert two call sites to call_usermodehelper_fns()
Both kernel/sys.c && security/keys/request_key.c where inlining the exact
same code as call_usermodehelper_fns(); So simply convert these sites to
directly use call_usermodehelper_fns().
drivers/rtc/rtc-m41t93.c: don't let get_time() reset M41T93_FLAG_OF
If the rtc reports the time might be invalid due to oscillator failure,
M41T93_FLAG_OF flag must not be reset by get_time() as the read operation
doesn't make the time valid.
Without this patch, only the first get_time() reported an invalid time,
the second get_time() reported a valid time althought the reported time is
probably wrong due to oscillator failure.
Instead of resetting in get_time(), with this patch M41T93_FLAG_OF is
reset in set_time() when a valid time is to be written.
Signed-off-by: Nikolaus Voss <n.voss@weinmann.de> Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: Grant Likely <grant.likely@secretlab.ca> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Wolfram Sang [Wed, 25 Apr 2012 01:04:39 +0000 (11:04 +1000)]
rtc: ds1307: add trickle charger support
Some DS13XX devices have "trickle chargers". Its configuration register
is at different locations, the setup is the same, though. Since the
configuration is board specific, introduce a platform_data to this driver.
Tested with a DS1339 on a custom board.
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de> Cc: Alessandro Zummo <alessandro.zummo@towertech.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Alexander Stein [Wed, 25 Apr 2012 01:04:37 +0000 (11:04 +1000)]
rtc: add ioctl to get/clear battery low voltage status
Currently there is no generic way to get the RTC battery status within an
application. So add an ioctl to read the status bit. The idea is that
the bit is set once a low voltage is detected. It stays there until it is
reset using the RTC_VL_CLR ioctl.
Signed-off-by: Alexander Stein <alexander.stein@systec-electronic.com> Cc: Alessandro Zummo <a.zummo@towertech.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
SPEAr platforms now support DT and so must convert all drivers support DT.
This patch adds DT probing support for rtc and updates its documentation
too.
Signed-off-by: Viresh Kumar <viresh.kumar@st.com> Cc: Stefan Roese <sr@denx.de> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: Rajeev Kumar <rajeev-dlh.kumar@st.com> Cc: Rob Herring <robherring2@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Stephen Boyd [Wed, 25 Apr 2012 01:04:35 +0000 (11:04 +1000)]
spinlock_debug: print kallsyms name for lock
When a spinlock warning is printed we usually get
BUG: spinlock bad magic on CPU#0, modprobe/111
lock: 0xdff09f38, .magic: 00000000, .owner: /0, .owner_cpu: 0
but it's nicer to print the symbol for the lock if we have it so that we
can avoid 'grep dff09f38 /proc/kallsyms' to find out which lock it was.
Use kallsyms to print the symbol name so we get something a bit easier to
read
BUG: spinlock bad magic on CPU#0, modprobe/112
lock: test_lock, .magic: 00000000, .owner: <none>/-1, .owner_cpu: 0
If the lock is not in kallsyms %ps will fall back to printing the address
directly.
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Stephen Boyd [Wed, 25 Apr 2012 01:04:35 +0000 (11:04 +1000)]
vsprintf: fix %ps on non symbols when using kallsyms
Using %ps in a printk format will sometimes fail silently and print the
empty string if the address passed in does not match a symbol that
kallsyms knows about. But using %pS will fall back to printing the full
address if kallsyms can't find the symbol. Make %ps act the same as %pS
by falling back to printing the address.
While we're here also make %ps print the module that a symbol comes from
so that it matches what %pS already does. Take this simple function for
example (in a module):
Andrew Morton [Wed, 25 Apr 2012 01:04:34 +0000 (11:04 +1000)]
lib/bitmap.c: fix documentation for scnprintf() functions
The code comments for bscnl_emit() and bitmap_scnlistprintf() are
describing snprintf() return semantics, but these functions use
scnprintf() return semantics. Fix that, and document the
bitmap_scnprintf() return value as well.
Cc: Ryota Ozaki <ozaki.ryota@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
lib/test-kstrtox.c: mark const init data with __initconst instead of __initdata
As long as there is no other non-const variable marked __initdata in the
same compilation unit it doesn't hurt. If there were one however
compilation would fail with
error: $variablename causes a section type conflict
because a section containing const variables is marked read only and so
cannot contain non-const variables.
Chris Metcalf [Wed, 25 Apr 2012 01:04:33 +0000 (11:04 +1000)]
list_debug: WARN for adding something already in the list
We were bitten by this at one point and added an additional sanity test
for DEBUG_LIST. You can't validly add a list_head to a list where either
prev or next is the same as the thing you're adding.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com> Cc: Andi Kleen <andi@firstfloor.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Change existing timer trigger to use the new ->activated flag to set
activate successful status in activate routine and check it in deactivate
routine to do cleanup.
Signed-off-by: Shuah Khan <shuahkhan@gmail.com> Cc: Richard Purdie <rpurdie@rpsys.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
leds: change existing triggers to use activated flag
Change existing triggers backlight, gpio, and heartbeat to use the new
->activated flag to set activate successful status in their activate
routines and check it in their deactivate routines to do cleanup.
Signed-off-by: Shuah Khan <shuahkhan@gmail.com> Cc: Richard Purdie <rpurdie@rpsys.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
leds: add new field to led_classdev struct to save activation state
Add a new field to led_classdev to save activattion state after activate
routine is successful. This saved state is used in deactivate routine to
do cleanup such as removing device files, and free memory allocated during
activation. Currently trigger_data not being null is used for this
purpose.
Existing triggers will need changes to use this new field.
Signed-off-by: Shuah Khan <shuahkhan@gmail.com> Cc: Richard Purdie <rpurdie@rpsys.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Thomas Meyer [Wed, 25 Apr 2012 01:04:30 +0000 (11:04 +1000)]
leds: Use kcalloc instead of kzalloc to allocate array
The advantage of kcalloc is that will prevent integer overflows which
could result from the multiplication of number of elements and size and it
is also a bit nicer to read.
The semantic patch that makes this change is available
in https://lkml.org/lkml/2011/11/25/107
Signed-off-by: Thomas Meyer <thomas@m3y3r.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Axel Lin [Wed, 25 Apr 2012 01:04:15 +0000 (11:04 +1000)]
leds: lm3556: Don't call kfree for the memory allocated by devm_kzalloc
The devm_* functions eliminate the need for manual resource releasing
and simplify error handling. Resources allocated by devm_* are freed
automatically on driver detach.
Thus adding kfree calls here will introduce double free bug.
Signed-off-by: Axel Lin <axel.lin@gmail.com> Cc: Geon Si Jeong <gshark.jeong@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
A simple driver for the Texas Instruments LM3556 chip.
The LM3556 is a 4 MHz fixed-frequency synchronous boost converter plus
1.5A constant current driver for a high-current white LED. Datasheet:
www.national.com/ds/LM/LM3556.pdf
Tested on OMAP4430
Signed-off-by: Geon Si Jeong <gshark.jeong@gmail.com> Cc: Richard Purdie <rpurdie@rpsys.net> Cc: Daniel Jeong <daniel.jeong@ti.com> Cc: Mark Brown <broonie@opensource.wolfsonmicro.com> Cc: Greg KH <greg@kroah.com> Cc: Wolfram Sang <w.sang@pengutronix.de> Cc: Shuah Khan <shuahkhan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Gcc 4.6.2 complains that:
drivers/leds/leds-lp5521.c: In function `lp5521_load_program':
drivers/leds/leds-lp5521.c:214:21: warning: `mode' may be used uninitialized in this function [-Wuninitialized]
drivers/leds/leds-lp5521.c: In function `lp5521_probe':
drivers/leds/leds-lp5521.c:788:5: warning: `buf' may be used uninitialized in this function [-Wuninitialized]
drivers/leds/leds-lp5521.c:740:6: warning: `ret' may be used uninitialized in this function [-Wuninitialized]
These are real problems if lp5521_read() returns an error. When that
happens we should handle it, instead of ignoring it or doing a bitwise OR
with all the other error codes and continuing.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Cc: Milo <Milo.Kim@ti.com> Cc: Richard Purdie <rpurdie@rpsys.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Add FB_EARLY_EVENT_BLANK and FB_R_EARLY_EVENT_BLANK event mode supports.
first, fb_notifier_call_chain() is called with FB_EARLY_EVENT_BLANK and
fb_blank() of specific fb driver is called and then
fb_notifier_call_chain() is called with FB_EVENT_BLANK again at
fb_blank(). and if fb_blank() was failed then fb_nitifier_call_chain()
would be called with FB_R_EARLY_EVENT_BLANK to revert the previous
effects.
Signed-off-by: Inki Dae <inki.dae@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Cc: Lars-Peter Clausen <lars@metafoo.de> Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de> Cc: Richard Purdie <rpurdie@rpsys.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
lcd: add callbacks for early fb event blank support
This patchset adds early fb blank feature that a callback of lcd panel
driver is called prior to specific fb driver's one. In the case of
MIPI-DSI based video mode LCD Panel, for lcd power off, the power off
commands should be transferred to lcd panel with display and mipi-dsi
controller enabled because the commands is set to lcd panel at vsync porch
period. and in opposite case, the callback of fb driver should be called
prior to lcd panel driver's one because of same issue. Also if fb_blank
mode is changed to FB_BLANK_POWERDOWN then display controller would be
off(clock disable) but lcd panel would be still on. at this time, you
could see some issue like sparkling on lcd panel because video clock to be
delivered to ldi module of lcd panel was disabled. this issue could
occurs for all lcd panels.
The callback order is as the following:
at fb_blank function of fbmem.c
-> fb_notifier_call_chain(FB_EARLY_EVENT_BLANK)
-> lcd panel driver's early_set_power()
-> info->fbops->fb_blank()
-> spcefic fb driver's fb_blank()
-> fb_notifier_call_chain(FB_EVENT_BLANK)
-> lcd panel driver's set_power()
-> fb_notifier_call_chain(FB_R_EARLY_EVENT_BLANK) if
info->fops->fb_blank() was failed.
fb_notifier_call_chain(FB_R_EARLY_EVENT_BLANK) would be called to revert
the effects of previous FB_EARLY_EVENT_BLANK call. and note that if
early_set_power() of lcd_ops is NULL then early fb blank callback would be
ignored.
This patch:
Add early_set_power and r_early_set_power callbacks. early_set_power
callback is called prior to fb_blank() of fbmem.c and r_early_set_power
callback is called if fb_blank() was failed to revert the effects of the
early_set_power call of lcd panel driver.
Signed-off-by: Inki Dae <inki.dae@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Cc: Lars-Peter Clausen <lars@metafoo.de> Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de> Cc: Richard Purdie <rpurdie@rpsys.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
blacklight: remove redundant spi driver bus initialization
In ancient times it was necessary to manually initialize the bus field of
an spi_driver to spi_bus_type. These days this is done in
spi_driver_register() so we can drop the manual assignment.
The patch was generated using the following coccinelle semantic patch:
// <smpl>
@@
identifier _driver;
@@
struct spi_driver _driver = {
.driver = {
- .bus = &spi_bus_type,
},
};
// </smpl>
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Cc: Richard Purdie <rpurdie@rpsys.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Here is a new version. I also plugged a hole in num_to_str() -
it was assuming it's safe to call put_dec() for num=0.
(We never tripped over it before because the single caller
of num_to_str() takes care of that case).
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com> Cc: Michal Nazarewicz <mina86@mina86.com> Cc: Douglas W Jones <jones@cs.uiowa.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Previous code was using optimizations which were developed to work well
even on narrow-word CPUs (by today's standards). But Linux runs only on
32-bit and wider CPUs. We can use that.
First: using 32x32->64 multiply and trivial 32-bit shift, we can correctly
divide by 10 much larger numbers, and thus we can print groups of 9 digits
instead of groups of 5 digits.
Next: there are two algorithms to print larger numbers. One is generic:
divide by 1000000000 and repeatedly print groups of (up to) 9 digits.
It's conceptually simple, but requires an (unsigned long long) / 1000000000 division.
Second algorithm splits 64-bit unsigned long long into 16-bit chunks,
manipulates them cleverly and generates groups of 4 decimal digits. It so
happens that it does NOT require long long division.
If long is > 32 bits, division of 64-bit values is relatively easy, and we
will use the first algorithm. If long long is > 64 bits (strange
architecture with VERY large long long), second algorithm can't be used,
and we again use the first one.
Else (if long is 32 bits and long long is 64 bits) we use second one.
And third: there is a simple optimization which takes fast path not only
for zero as was done before, but for all one-digit numbers.
In all tested cases new code is faster than old one, in many cases by 30%,
in few cases by more than 50% (for example, on x86-32, conversion of 12345678). Code growth is ~0 in 32-bit case and ~130 bytes in 64-bit
case.
This patch is based upon an original from Michal Nazarewicz.
Signed-off-by: Michal Nazarewicz <mina86@mina86.com> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com> Cc: Douglas W Jones <jones@cs.uiowa.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
sethostname/setdomainname: notify userspace when there is a change in uts_kern_table
sethostname() and setdomainname() notify userspace on failure (without
modifying uts_kern_table). Change things so that we only notify userspace
on success, when uts_kern_table was actually modified.
Signed-off-by: Sasikantha babu <sasikanth.v19@gmail.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: WANG Cong <amwang@redhat.com> Reviewed-by: Cyrill Gorcunov <gorcunov@openvz.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Xi Wang [Wed, 25 Apr 2012 01:03:54 +0000 (11:03 +1000)]
introduce SIZE_MAX
ULONG_MAX is often used to check for integer overflow when calculating
allocation size. While ULONG_MAX happens to work on most systems, there
is no guarantee that `size_t' must be the same size as `long'.
This patch introduces SIZE_MAX, the maximum value of `size_t', to improve
portability and readability for allocation size validation.
Signed-off-by: Xi Wang <xi.wang@gmail.com> Acked-by: Alex Elder <elder@dreamhost.com> Cc: David Airlie <airlied@linux.ie> Cc: Pekka Enberg <penberg@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Matt Fleming [Wed, 25 Apr 2012 01:03:54 +0000 (11:03 +1000)]
parisc: use set_current_blocked() and block_sigmask()
As described in e6fa16ab ("signal: sigprocmask() should do
retarget_shared_pending()") the modification of current->blocked is
incorrect as we need to check whether the signal we're about to block is
pending in the shared queue.
Also, use the new helper function introduced in commit 5e6292c0f28f
("signal: add block_sigmask() for adding sigmask to current->blocked")
which centralises the code for updating current->blocked after
successfully delivering a signal and reduces the amount of duplicate code
across architectures. In the past some architectures got this code wrong,
so using this helper function should stop that from happening again.
Xi Wang [Wed, 25 Apr 2012 01:03:53 +0000 (11:03 +1000)]
CodingStyle: add kmalloc_array() to memory allocators
Add the new kmalloc_array() to the list of general-purpose memory
allocators in chapter 14.
Signed-off-by: Xi Wang <xi.wang@gmail.com> Acked-by: Jesper Juhl <jj@chaosbits.net> Acked-by: Pekka Enberg <penberg@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
spin_is_locked() is usually misued. In checkpatch.pl:
- warn when it is used at all
- error out when it is asserted on free, because that's usually broken
(e.g. doesn't work on on uni processor builds). Recommend
lockdep_assert_held() instead.
[joe@perches.com: some improvements] Signed-off-by: Andi Kleen <ak@linux.intel.com> Cc: Andy Whitcroft <apw@canonical.com> Cc: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
projects / karo-tx-linux.git / log