- We weren't zeroing p->rss_stat[] at fork()
- Consequently sync_mm_rss() was dereferencing tsk->mm for kernel
threads and was oopsing.
- Make __sync_task_rss_stat() static, too.
Addresses https://bugzilla.kernel.org/show_bug.cgi?id=15648
[akpm@linux-foundation.org: remove the BUG_ON(!mm->rss)]
Reported-by: Troels Liebe Bentsen <tlb@rapanden.dk>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
"Michael S. Tsirkin" <mst@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
genirq: Force MSI irq handlers to run with interrupts disabled
Module refcounting is implemented with a per-cpu counter for speed.
However there is a race when tallying the counter where a reference may
be taken by one CPU and released by another. Reference count summation
may then see the decrement without having seen the previous increment,
leading to lower than expected count. A module which never has its
actual reference drop below 1 may return a reference count of 0 due to
this race.
Module removal generally runs under stop_machine, which prevents this
race causing bugs due to removal of in-use modules. However there are
other real bugs in module.c code and driver code (module_refcount is
exported) where the callers do not run under stop_machine.
Fix this by maintaining running per-cpu counters for the number of
module refcount increments and the number of refcount decrements. The
increments are tallied after the decrements, so any decrement seen will
always have its corresponding increment counted. The final refcount is
the difference of the total increments and decrements, preventing a
low-refcount from being returned.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There have been a number of reports of people seeing the message:
"name_count maxed, losing inode data: dev=00:05, inode=3185"
in dmesg. These usually lead to people reporting problems to the filesystem
group who are in turn clueless what they mean.
Eventually someone finds me and I explain what is going on and that
these come from the audit system. The basics of the problem is that the
audit subsystem never expects a single syscall to 'interact' (for some
wish washy meaning of interact) with more than 20 inodes. But in fact
some operations like loading kernel modules can cause changes to lots of
inodes in debugfs.
There are a couple real fixes being bandied about including removing the
fixed compile time limit of 20 or not auditing changes in debugfs (or
both) but neither are small and obvious so I am not sending them for
immediate inclusion (I hope Al forwards a real solution next devel
window).
In the meantime this patch simply adds 'audit' to the beginning of the
crap message so if a user sees it, they come blame me first and we can
talk about what it means and make sure we understand all of the reasons
it can happen and make sure this gets solved correctly in the long run.
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'slabh' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/misc:
eeepc-wmi: include slab.h
staging/otus: include slab.h from usbdrv.h
percpu: don't implicitly include slab.h from percpu.h
kmemcheck: Fix build errors due to missing slab.h
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
iwlwifi: don't include iwl-dev.h from iwl-devtrace.h
x86: don't include slab.h from arch/x86/include/asm/pgtable_32.h
Fix up trivial conflicts in include/linux/percpu.h due to
is_kernel_percpu_address() having been introduced since the slab.h
cleanup with the percpu_up.c splitup.
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu:
module: add stub for is_module_percpu_address
percpu, module: implement and use is_kernel/module_percpu_address()
module: encapsulate percpu handling better and record percpu_size
* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
perf: Always build the powerpc perf_arch_fetch_caller_regs version
perf: Always build the stub perf_arch_fetch_caller_regs version
perf, probe-finder: Build fix on Debian
perf/scripts: Tuple was set from long in both branches in python_process_event()
perf: Fix 'perf sched record' deadlock
perf, x86: Fix callgraphs of 32-bit processes on 64-bit kernels
perf, x86: Fix AMD hotplug & constraint initialization
x86: Move notify_cpu_starting() callback to a later stage
x86,kgdb: Always initialize the hw breakpoint attribute
perf: Use hot regs with software sched switch/migrate events
perf: Correctly align perf event tracing buffer
* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
sched: set_cpus_allowed_ptr(): Don't use rq->migration_thread after unlock
sched: Fix proc_sched_set_task()
Perf_event does not need seeking, so prevent it in order to
get rid of default_llseek, which uses the BKL.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@elte.hu>
[drop the nonseekable_open, not needed for anon inodes]
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Now that software events use perf_arch_fetch_caller_regs() too, we
need the stub version to be always built in for archs that don't
implement it.
Fixes the following build error in PARISC:
kernel/built-in.o: In function `perf_event_task_sched_out':
(.text.perf_event_task_sched_out+0x54): undefined reference to `perf_arch_fetch_caller_regs'
Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
* 'kgdb-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb:
kgdb: Turn off tracing while in the debugger
kgdb: use atomic_inc and atomic_dec instead of atomic_set
kgdb: eliminate kgdb_wait(), all cpus enter the same way
kgdbts,sh: Add in breakpoint pc offset for superh
kgdb: have ebin2mem call probe_kernel_write once
* 'pm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6:
Freezer: Fix buggy resume test for tasks frozen with cgroup freezer
Freezer: Only show the state of tasks refusing to freeze
The kernel debugger should turn off kernel tracing any time the
debugger is active and restore it on resume.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Memory barriers should be used for the kgdb cpu synchronization. The
atomic_set() does not imply a memory barrier.
Reported-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
This is a kgdb architectural change to have all the cpus (master or
slave) enter the same function.
A cpu that hits an exception (wants to be the master cpu) will call
kgdb_handle_exception() from the trap handler and then invoke a
kgdb_roundup_cpu() to synchronize the other cpus and bring them into
the kgdb_handle_exception() as well.
A slave cpu will enter kgdb_handle_exception() from the
kgdb_nmicallback() and set the exception state to note that the
processor is a slave.
Previously the salve cpu would have called kgdb_wait(). This change
allows the debug core to change cpus without resuming the system in
order to inspect arch specific cpu information.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Rather than call probe_kernel_write() one byte at a time, process the
whole buffer locally and pass the entire result in one go. This way,
architectures that need to do special handling based on the length can
do so, or we only end up calling memcpy() once.
[sonic.zhang@analog.com: Reported original problem and preliminary patch]
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
perf sched record can deadlock a box should the holder of
handle->data->lock take an interrupt, and then attempt to
acquire an rq lock held by a CPU trying to acquire the
same lock. Disable interrupts.
CPU0 CPU1
sched event with rq->lock held
grab handle->data->lock
spin on handle->data->lock
interrupt
try to grab rq->lock
Reported-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Tested-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <1269598293.6174.8.camel@marge.simson.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
