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492a74f421
linux/kernel
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Steven Rostedt 492a74f421 ring-buffer: Check if ring buffer iterator has stale data 
Usually reads of the ring buffer is performed by a single task.
There are two types of reads from the ring buffer.

One is a consuming read which will consume the entry that was read
and the next read will be the entry that follows.

The other is an iterator that will let the user read the contents of
the ring buffer without modifying it. When an iterator is allocated,
writes to the ring buffer are disabled to protect the iterator.

The problem exists when consuming reads happen while an iterator is
allocated. Specifically, the kind of read that swaps out an entire
page (used by splice) and replaces it with a new read. If the iterator
is on the page that is swapped out, then the next read may read
from this swapped out page and return garbage.

This patch adds a check when reading the iterator to make sure that
the iterator contents are still valid. If a consuming read has taken
place, the iterator is reset.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-01-26 16:09:30 -05:00
..
gcov microblaze: Enable GCOV_PROFILE_ALL 2009-09-21 14:29:21 +02:00
irq genirq: Convert irq_desc.lock to raw_spinlock 2009-12-14 23:55:33 +01:00
power vt: introduce and use vt_kmsg_redirect() function 2009-12-15 08:53:28 -08:00
time clockevent: Don't remove broadcast device when cpu is dead 2010-01-18 14:44:50 +01:00
trace ring-buffer: Check if ring buffer iterator has stale data 2010-01-26 16:09:30 -05:00
.gitignore
acct.c bsdacct: fix uid/gid misreporting 2009-12-15 08:53:10 -08:00
async.c
audit_tree.c fix more leaks in audit_tree.c tag_chunk() 2009-12-19 09:27:43 -08:00
audit_watch.c Audit: reorganize struct audit_watch to save 8 bytes 2009-09-24 03:50:25 -04:00
audit.c Audit: send signal info if selinux is disabled 2009-09-24 03:50:26 -04:00
audit.h
auditfilter.c
auditsc.c Sanitize f_flags helpers 2009-12-22 12:27:34 -05:00
backtracetest.c
bounds.c kbuild: move bounds.h to include/generated 2009-12-12 13:08:14 +01:00
capability.c remove CONFIG_SECURITY_FILE_CAPABILITIES compile option 2009-11-24 15:06:47 +11:00
cgroup_freezer.c cgroups: let ss->can_attach and ss->attach do whole threadgroups at a time 2009-09-24 07:20:58 -07:00
cgroup.c cgroups: fix 2.6.32 regression causing BUG_ON() in cgroup_diput() 2010-01-11 09:34:05 -08:00
compat.c
configs.c
cpu.c sched: Fix set_cpu_active() in cpu_down() 2009-12-16 19:01:53 +01:00
cpuset.c sched: Fix balance vs hotplug race 2009-12-06 21:10:56 +01:00
cred-internals.h
cred.c creds_are_invalid() needs to be exported for use by modules: 2009-09-23 11:02:26 -07:00
delayacct.c headers: taskstats_kern.h trim 2009-09-18 09:48:52 -07:00
dma.c
exec_domain.c
exit.c do_wait() optimization: do not place sub-threads on task_struct->children list 2009-12-17 15:45:31 -08:00
extable.c
fork.c do_wait() optimization: do not place sub-threads on task_struct->children list 2009-12-17 15:45:31 -08:00
freezer.c
futex_compat.c
futex.c futexes: Remove rw parameter from get_futex_key() 2010-01-13 09:17:36 +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 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-12-31 11:52:01 -08:00
itimer.c itimers: Fix racy writes to cpu_itimer fields 2009-11-18 16:32:12 +01:00
kallsyms.c hw-breakpoints: Fix broken hw-breakpoint sample module 2009-11-10 11:23:29 +01:00
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 Merge git://git.infradead.org/~dwmw2/mtd-2.6.33 2010-01-24 10:31:34 -08:00
kfifo.c kfifo: document everywhere that size has to be power of two 2010-01-16 12:15:38 -08:00
kgdb.c kgdb: Always process the whole breakpoint list on activate or deactivate 2009-12-11 08:43:20 -06:00
kmod.c kmod: fix resource leak in call_usermodehelper_pipe() 2010-01-11 09:34:04 -08:00
kprobes.c kprobes: Fix distinct type warning 2009-12-28 10:25:31 +01:00
ksysfs.c kexec: premit reduction of the reserved memory size 2009-12-16 07:20:13 -08:00
kthread.c sched: Move kthread_bind() back to kthread.c 2009-12-16 19:01:57 +01:00
latencytop.c
lockdep_internals.h
lockdep_proc.c seq_file: constify seq_operations 2009-09-23 07:39:29 -07:00
lockdep_states.h
lockdep.c locking: Convert __raw_spin* functions to arch_spin* 2009-12-14 23:55:32 +01:00
Makefile Merge branch 'kvm-updates/2.6.33' of git://git.kernel.org/pub/scm/virt/kvm/kvm 2009-12-08 08:02:38 -08:00
module.c modules: Skip empty sections when exporting section notes 2010-01-06 01:11:29 -08:00
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 kprobes: Fix to add __kprobes to notify_die 2009-08-30 03:08:26 +02:00
ns_cgroup.c cgroups: let ss->can_attach and ss->attach do whole threadgroups at a time 2009-09-24 07:20:58 -07:00
nsproxy.c
panic.c kmsg_dump: Dump on crash_kexec as well 2009-12-31 19:45:04 +00:00
params.c tree-wide: convert open calls to remove spaces to skip_spaces() lib function 2009-12-15 08:53:32 -08:00
perf_event.c perf: Honour event state for aux stream data 2010-01-21 13:40:40 +01:00
pid_namespace.c pidns: deny CLONE_PARENT|CLONE_NEWPID combination 2009-09-24 07:21:04 -07:00
pid.c pid: reduce code size by using a pointer to iterate over array 2009-12-16 07:20:12 -08:00
pm_qos_params.c pm_qos: clean up racy global "name" variable 2009-10-14 15:31:10 +02:00
posix-cpu-timers.c posix-cpu-timers: optimize and document timer_create callback 2009-11-18 12:36:05 +01:00
posix-timers.c time: Introduce CLOCK_REALTIME_COARSE 2009-08-21 21:43:46 +02:00
printk.c Merge git://git.infradead.org/~dwmw2/mtd-2.6.33 2010-01-24 10:31:34 -08:00
profile.c kernel/profile.c: Switch /proc/irq/prof_cpu_mask to seq_file 2009-09-20 20:15:40 +02:00
ptrace.c ptrace: __ptrace_detach: do __wake_up_parent() if we reap the tracee 2009-09-24 07:20:59 -07:00
rcupdate.c rcu: Re-arrange code to reduce #ifdef pain 2009-11-22 18:58:16 +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 2009-12-14 09:58:24 -08:00
rcutree_plugin.h rcu: Add expedited grace-period support for preemptible RCU 2009-12-03 11:35:25 +01:00
rcutree_trace.c rcu: Add expedited grace-period support for preemptible RCU 2009-12-03 11:35:25 +01:00
rcutree.c rcu: Add expedited grace-period support for preemptible RCU 2009-12-03 11:35:25 +01:00
rcutree.h rcu: Add expedited grace-period support for preemptible RCU 2009-12-03 11:35:25 +01:00
relay.c const: constify remaining pipe_buf_operations 2009-12-16 07:20:05 -08:00
res_counter.c memcg: some modification to softlimit under hierarchical memory reclaim. 2009-10-01 16:11:13 -07:00
resource.c resources: fix call to alignf() in allocate_resource() 2009-12-21 10:42:29 -08:00
rtmutex_common.h
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
rwsem.c
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 sched: Convert cpupri lock to raw_spinlock 2009-12-14 23:55:33 +01:00
sched_cpupri.h sched: Convert cpupri lock to raw_spinlock 2009-12-14 23:55:33 +01:00
sched_debug.c sched: Convert rq->lock to raw_spinlock 2009-12-14 23:55:33 +01:00
sched_fair.c sched: Fix vmark regression on big machines 2010-01-21 13:39:03 +01:00
sched_features.h sched: Discard some old bits 2009-12-09 10:03:07 +01:00
sched_idletask.c sched: Restore printk sanity 2009-12-20 19:05:02 +01:00
sched_rt.c sched: Add pre and post wakeup hooks 2009-12-16 19:01:58 +01:00
sched_stats.h
sched.c sched: Reassign prev and switch_count when reacquire_kernel_lock() fail 2010-01-21 13:39:04 +01:00
seccomp.c
semaphore.c
signal.c kernel/signal.c: fix kernel information leak with print-fatal-signals=1 2010-01-11 09:34:05 -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 Merge git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/sysctl-2.6 2009-12-08 07:38:50 -08:00
slow-work.h SLOW_WORK: Move slow_work's proc file to debugfs 2009-12-01 08:20:31 -08:00
smp.c smp_call_function_any(): pass the node value to cpumask_of_node() 2010-01-16 12:15:39 -08:00
softirq.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu 2009-12-14 09:58:24 -08:00
softlockup.c percpu: make percpu symbols under kernel/ and mm/ unique 2009-10-29 22:34:13 +09:00
spinlock.c locking: Cleanup the name space completely 2009-12-14 23:55:33 +01:00
srcu.c rcu: Add synchronize_srcu_expedited() 2009-10-26 09:40:30 +01:00
stacktrace.c
stop_machine.c
sys_ni.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6 2009-12-08 07:55:01 -08:00
sys.c Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-12-19 09:47:34 -08:00
sysctl_binary.c SYSCTL: Print binary sysctl warnings (nearly) only once 2009-12-23 21:00:20 +01:00
sysctl_check.c ipv4 05/05: add sysctl to accept packets with local source addresses 2009-12-03 12:14:38 -08:00
sysctl.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6 2009-12-17 16:58:26 -08:00
taskstats.c
test_kprobes.c
time.c Revert "time: Remove xtime_cache" 2009-12-22 14:10:37 -08:00
timeconst.pl
timer.c perf: Fix perf_event_do_pending() fallback callsite 2010-01-21 13:40:39 +01:00
tracepoint.c trivial: fix typo "to to" in multiple files 2009-09-21 15:14:55 +02:00
tsacct.c
uid16.c headers: utsname.h redux 2009-09-23 18:13:10 -07:00
up.c
user_namespace.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 uids: Prevent tear down race 2009-11-02 16:02:39 +01:00
utsname_sysctl.c sysctl kernel: Remove binary sysctl logic 2009-11-12 02:04:55 -08:00
utsname.c
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