linux-bl808/kernel
Steven Rostedt (VMware) ae415fa4c5 ring-buffer: Do no reuse reader page if still in use
To free the reader page that is allocated with ring_buffer_alloc_read_page(),
ring_buffer_free_read_page() must be called. For faster performance, this
page can be reused by the ring buffer to avoid having to free and allocate
new pages.

The issue arises when the page is used with a splice pipe into the
networking code. The networking code may up the page counter for the page,
and keep it active while sending it is queued to go to the network. The
incrementing of the page ref does not prevent it from being reused in the
ring buffer, and this can cause the page that is being sent out to the
network to be modified before it is sent by reading new data.

Add a check to the page ref counter, and only reuse the page if it is not
being used anywhere else.

Cc: stable@vger.kernel.org
Fixes: 73a757e631 ("ring-buffer: Return reader page back into existing ring buffer")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-12-27 14:21:09 -05:00
..
bpf bpf: add schedule points to map alloc/free 2017-12-12 15:27:22 -08:00
cgroup Revert "cgroup/cpuset: remove circular dependency deadlock" 2017-12-04 14:55:59 -08:00
configs
debug kdb: Fix handling of kallsyms_symbol_next() return value 2017-12-06 16:12:43 -06:00
events Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-12-08 13:32:44 -08:00
gcov
irq genirq/matrix: Fix the precedence fix for real 2017-12-04 20:50:35 +01:00
livepatch
locking locking/lockdep: Remove the cross-release locking checks 2017-12-12 12:38:51 +01:00
power Revert "cpuset: Make cpuset hotplug synchronous" 2017-12-04 14:41:11 -08:00
printk remove task and stack pointer printout from oops dump 2017-12-05 08:23:20 -08:00
rcu
sched sched/rt: Do not pull from current CPU if only one CPU to pull 2017-12-15 16:28:02 +01:00
time posix-timer: Properly check sigevent->sigev_notify 2017-12-15 11:08:40 +01:00
trace ring-buffer: Do no reuse reader page if still in use 2017-12-27 14:21:09 -05:00
.gitignore
acct.c
async.c
audit.c
audit.h
audit_fsnotify.c
audit_tree.c
audit_watch.c
auditfilter.c
auditsc.c
backtracetest.c
bounds.c
capability.c
compat.c
configs.c
context_tracking.c
cpu.c Merge branch 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-12-06 17:45:36 -08:00
cpu_pm.c
crash_core.c
crash_dump.c
cred.c
delayacct.c
dma.c
elfcore.c
exec_domain.c
exit.c arch: define weak abort() 2017-12-14 16:00:49 -08:00
extable.c
fork.c
freezer.c
futex.c futex: futex_wake_op, fix sign_extend32 sign bits 2017-12-10 12:50:57 -08:00
futex_compat.c
groups.c kernel: make groups_sort calling a responsibility group_info allocators 2017-12-14 16:00:49 -08:00
hung_task.c
irq_work.c
jump_label.c
kallsyms.c kallsyms: take advantage of the new '%px' format 2017-11-29 10:30:13 -08:00
kcmp.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kcov.c kcov: fix comparison callback signature 2017-12-14 16:00:48 -08:00
kexec.c
kexec_core.c
kexec_file.c
kexec_internal.h
kmod.c
kprobes.c
ksysfs.c
kthread.c
latencytop.c
Makefile
memremap.c
module-internal.h
module.c kallsyms: take advantage of the new '%px' format 2017-11-29 10:30:13 -08:00
module_signing.c
notifier.c
nsproxy.c
padata.c
panic.c
params.c
pid.c
pid_namespace.c
profile.c
ptrace.c
range.c
reboot.c
relay.c
resource.c
seccomp.c
signal.c
smp.c
smpboot.c
smpboot.h
softirq.c
stacktrace.c
stop_machine.c
sys.c
sys_ni.c
sysctl.c
sysctl_binary.c
task_work.c
taskstats.c
test_kprobes.c
torture.c
tracepoint.c
tsacct.c
ucount.c
uid16.c kernel: make groups_sort calling a responsibility group_info allocators 2017-12-14 16:00:49 -08:00
umh.c
up.c
user-return-notifier.c
user.c
user_namespace.c
utsname.c
utsname_sysctl.c
watchdog.c
watchdog_hld.c
workqueue.c workqueue: remove unneeded kallsyms include 2017-12-11 07:15:43 -08:00
workqueue_internal.h