Nick Piggin 5fbfb18d7a Fix up possibly racy module refcounting ... 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>		2010-04-05 19:50:02 -07:00
..
gcov
irq	include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h	2010-03-30 22:02:32 +09:00
power	Merge branch 'master' into export-slabh	2010-04-05 11:37:28 +09:00
time	include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h	2010-03-30 22:02:32 +09:00
trace	Merge branch 'master' into export-slabh	2010-04-05 11:37:28 +09:00
.gitignore
acct.c	copy_signal() cleanup: kill taskstats_tgid_init() and acct_init_pacct()	2010-03-12 15:52:39 -08:00
async.c	include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h	2010-03-30 22:02:32 +09:00
audit.c	include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h	2010-03-30 22:02:32 +09:00
audit.h
audit_tree.c	include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h	2010-03-30 22:02:32 +09:00
audit_watch.c	include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h	2010-03-30 22:02:32 +09:00
auditfilter.c	include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h	2010-03-30 22:02:32 +09:00
auditsc.c	audit: preface audit printk with audit	2010-04-05 13:19:45 -07:00
backtracetest.c
bounds.c	kbuild: move bounds.h to include/generated	2009-12-12 13:08:14 +01:00
capability.c	capabilities: Use RCU to protect task lookup in sys_capget	2009-12-10 09:42:48 +11:00
cgroup.c	cgroups: remove duplicate include	2010-03-24 16:31:19 -07:00
cgroup_freezer.c	Merge branch 'master' into export-slabh	2010-04-05 11:37:28 +09:00
compat.c	include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h	2010-03-30 22:02:32 +09:00
configs.c
cpu.c	include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h	2010-03-30 22:02:32 +09:00
cpuset.c	cpuset: alloc nodemask_t on the heap rather than the stack	2010-03-24 16:31:21 -07:00
cred-internals.h
cred.c	Merge branch 'master' into export-slabh	2010-04-05 11:37:28 +09:00
delayacct.c
dma.c
early_res.c	x86: Do not free zero sized per cpu areas	2010-03-29 18:55:40 +02:00
elfcore.c	elf coredump: add extended numbering support	2010-03-06 11:26:46 -08:00
exec_domain.c
exit.c	Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2010-03-13 14:43:01 -08:00
extable.c
fork.c	Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2010-03-13 14:43:01 -08:00
freezer.c
futex.c	futex: Handle futex value corruption gracefully	2010-02-03 15:13:22 +01:00
futex_compat.c	futex: Protect pid lookup in compat code with RCU	2009-12-09 14:22:14 +01:00
groups.c
hrtimer.c	hrtimers: Convert to raw_spinlocks	2009-12-14 23:55:34 +01:00
hung_task.c	softlockup: Fix hung_task_check_count sysctl	2009-11-27 06:21:57 +01:00
hw_breakpoint.c	Merge branch 'perf/core' into perf/urgent	2010-03-04 11:47:52 +01:00
itimer.c	itimers: Fix racy writes to cpu_itimer fields	2009-11-18 16:32:12 +01:00
kallsyms.c	include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h	2010-03-30 22:02:32 +09:00
Kconfig.freezer
Kconfig.hz
Kconfig.locks	mutex: Better control mutex adaptive spinning config	2009-12-03 11:50:11 +01:00
Kconfig.preempt
kexec.c	percpu: add __percpu sparse annotations to core kernel subsystems	2010-02-17 11:17:38 +09:00
kfifo.c	kfifo: Don't use integer as NULL pointer	2010-02-16 15:11:08 -08:00
kgdb.c	kgdb: Turn off tracing while in the debugger	2010-04-02 14:58:19 -05:00
kmod.c	kmod: fix resource leak in call_usermodehelper_pipe()	2010-01-11 09:34:04 -08:00
kprobes.c	kprobes: Calculate the index correctly when freeing the out-of-line execution slot	2010-03-11 14:06:16 +01:00
ksysfs.c	Merge branch 'for-next' into for-linus	2010-03-08 16:55:37 +01:00
kthread.c	cpuset: fix the problem that cpuset_mem_spread_node() returns an offline node	2010-03-24 16:31:21 -07:00
latencytop.c	include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h	2010-03-30 22:02:32 +09:00
lockdep.c	Merge branch 'slabh' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/misc	2010-04-05 09:39:11 -07:00
lockdep_internals.h
lockdep_proc.c
lockdep_states.h
Makefile	elf coredump: replace ELF_CORE_EXTRA_* macros by functions	2010-03-06 11:26:45 -08:00
module.c	Fix up possibly racy module refcounting	2010-04-05 19:50:02 -07:00
mutex-debug.c	headers: remove sched.h from interrupt.h	2009-10-11 11:20:58 -07:00
mutex-debug.h	locking: Implement new raw_spinlock	2009-12-14 23:55:32 +01:00
mutex.c	mutex: Better control mutex adaptive spinning config	2009-12-03 11:50:11 +01:00
mutex.h
notifier.c	sched: Use lockdep-based checking on rcu_dereference()	2010-02-25 10:34:26 +01:00
ns_cgroup.c
nsproxy.c	include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h	2010-03-30 22:02:32 +09:00
padata.c	include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h	2010-03-30 22:02:32 +09:00
panic.c	panic: fix panic_timeout accuracy when running on a hypervisor	2010-03-06 11:26:33 -08:00
params.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial	2010-03-12 16:04:50 -08:00
perf_event.c	Merge branch 'master' into export-slabh	2010-04-05 11:37:28 +09:00
pid.c	Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2010-03-13 14:43:01 -08:00
pid_namespace.c	include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h	2010-03-30 22:02:32 +09:00
pm_qos_params.c	pm_qos: clean up racy global "name" variable	2009-10-14 15:31:10 +02:00
posix-cpu-timers.c	Merge branch 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2010-03-26 15:10:38 -07:00
posix-timers.c	posix-timers.c: Don't export local functions	2010-02-05 14:54:10 +01:00
printk.c	printk: avoid warning when CONFIG_PRINTK is disabled	2010-03-06 11:26:33 -08:00
profile.c
ptrace.c	ptrace: Fix ptrace_regset() comments and diagnose errors specifically	2010-02-23 13:45:26 -08:00
range.c	x86: Change range end to start+size	2010-02-10 17:47:17 -08:00
rcupdate.c	rcu: Make rcu_read_lock_bh_held() allow for disabled BH	2010-03-16 09:57:49 +01:00
rcutiny.c	rcu: Eliminate unneeded function wrapping	2009-11-22 18:58:16 +01:00
rcutorture.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu	2010-03-03 07:34:18 -08:00
rcutree.c	rcu: Fix accelerated grace periods for last non-dynticked CPU	2010-02-27 09:53:52 +01:00
rcutree.h	rcu: Increase RCU CPU stall timeouts if PROVE_RCU	2010-03-11 13:38:01 +01:00
rcutree_plugin.h	rcu: Fix holdoff for accelerated GPs for last non-dynticked CPU	2010-02-28 09:17:42 +01:00
rcutree_trace.c	rcu: Stop overflowing signed integers	2010-02-25 10:34:57 +01:00
relay.c	splice: comparing unsigned int < 0	2010-03-06 11:26:32 -08:00
res_counter.c	include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h	2010-03-30 22:02:32 +09:00
resource.c	resources: add interfaces that return conflict information	2010-03-23 13:33:50 -07:00
rtmutex-debug.c	sched: Convert pi_lock to raw_spinlock	2009-12-14 23:55:33 +01:00
rtmutex-debug.h
rtmutex-tester.c
rtmutex.c	rtmutes: Convert rtmutex.lock to raw_spinlock	2009-12-14 23:55:33 +01:00
rtmutex.h
rtmutex_common.h
rwsem.c
sched.c	Merge branch 'master' into export-slabh	2010-04-05 11:37:28 +09:00
sched_clock.c	sched: Fix cpu_clock() in NMIs, on !CONFIG_HAVE_UNSTABLE_SCHED_CLOCK	2009-12-15 09:04:36 +01:00
sched_cpupri.c	include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h	2010-03-30 22:02:32 +09:00
sched_cpupri.h	sched: Convert cpupri lock to raw_spinlock	2009-12-14 23:55:33 +01:00
sched_debug.c	sched: Fix proc_sched_set_task()	2010-04-02 20:06:40 +02:00
sched_fair.c	sched, rcu: Fix rcu_dereference() for RCU-lockdep	2010-03-01 09:29:58 +01:00
sched_features.h	sched: Discard some old bits	2009-12-09 10:03:07 +01:00
sched_idletask.c	sched: Remove the sched_class load_balance methods	2010-01-21 13:40:09 +01:00
sched_rt.c	Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2010-03-13 14:46:18 -08:00
sched_stats.h
seccomp.c
semaphore.c
signal.c	kernel core: use helpers for rlimits	2010-03-06 11:26:33 -08:00
slow-work-debugfs.c	SLOW_WORK: Move slow_work's proc file to debugfs	2009-12-01 08:20:31 -08:00
slow-work.c	slow-work: use get_ref wrapper instead of directly calling get_ref	2010-03-29 09:13:30 -07:00
slow-work.h	SLOW_WORK: CONFIG_SLOW_WORK_PROC should be CONFIG_SLOW_WORK_DEBUG	2010-03-29 09:14:47 -07:00
smp.c	include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h	2010-03-30 22:02:32 +09:00
softirq.c	hrtimer, softirq: Fix hrtimer->softirq trampoline	2010-02-03 18:17:40 +01:00
softlockup.c	softlockup: Stop spurious softlockup messages due to overflow	2010-03-21 19:30:13 +01:00
spinlock.c	locking: Cleanup the name space completely	2009-12-14 23:55:33 +01:00
srcu.c	include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h	2010-03-30 22:02:32 +09:00
stacktrace.c
stop_machine.c	percpu: add __percpu sparse annotations to core kernel subsystems	2010-02-17 11:17:38 +09:00
sys.c	include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h	2010-03-30 22:02:32 +09:00
sys_ni.c	Add generic sys_ipc wrapper	2010-03-12 15:52:32 -08:00
sysctl.c	sysctl extern cleanup: lockdep	2010-03-12 15:53:10 -08:00
sysctl_binary.c	include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h	2010-03-30 22:02:32 +09:00
sysctl_check.c	ipv4 05/05: add sysctl to accept packets with local source addresses	2009-12-03 12:14:38 -08:00
taskstats.c	include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h	2010-03-30 22:02:32 +09:00
test_kprobes.c
time.c	include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h	2010-03-30 22:02:32 +09:00
timeconst.pl
timer.c	include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h	2010-03-30 22:02:32 +09:00
tracepoint.c
tsacct.c	mm: clean up mm_counter	2010-03-06 11:26:23 -08:00
uid16.c
up.c
user-return-notifier.c	core: Clean up user return notifers use of per_cpu	2009-12-02 10:22:59 +01:00
user.c	sched: Remove USER_SCHED	2010-01-21 13:40:18 +01:00
user_namespace.c
utsname.c
utsname_sysctl.c	sysctl kernel: Remove binary sysctl logic	2009-11-12 02:04:55 -08:00
wait.c
workqueue.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq	2009-12-10 09:35:44 -08:00