linux/kernel/trace
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
..
blktrace.c blktrace: fix trace mutex deadlock 2017-11-27 12:03:58 -07:00
bpf_trace.c bpf: fix corruption on concurrent perf_event_output calls 2017-12-12 09:51:12 -08:00
ftrace.c Tracing updates for 4.15: 2017-11-17 14:58:01 -08:00
Kconfig tracing: make PREEMPTIRQ_EVENTS depend on TRACING 2017-12-04 06:52:09 -05:00
Makefile Tracing updates for 4.15: 2017-11-17 14:58:01 -08:00
power-traces.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
ring_buffer_benchmark.c ring-buffer: Have ring_buffer_alloc_read_page() return error on offline CPU 2017-08-02 14:23:02 -04:00
ring_buffer.c ring-buffer: Do no reuse reader page if still in use 2017-12-27 14:21:09 -05:00
rpm-traces.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
trace_benchmark.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
trace_benchmark.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
trace_branch.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
trace_clock.c sched/headers: Prepare for new header dependencies before moving code to <linux/sched/clock.h> 2017-03-02 08:42:27 +01:00
trace_entries.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
trace_event_perf.c perf/ftrace: Small cleanup 2017-10-16 18:13:28 -04:00
trace_events_filter_test.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
trace_events_filter.c mm: treewide: remove GFP_TEMPORARY allocation flag 2017-09-13 18:53:16 -07:00
trace_events_hist.c tracing: Reimplement log2 2017-10-04 13:10:39 -04:00
trace_events_trigger.c sched/headers: Prepare to use <linux/rcuupdate.h> instead of <linux/rculist.h> in <linux/sched.h> 2017-03-02 08:42:38 +01:00
trace_events.c tracing: Reverse the order of trace_types_lock and event_mutex 2017-10-04 11:36:56 -04:00
trace_export.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
trace_functions_graph.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
trace_functions.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
trace_hwlat.c trace: make trace_hwlat timestamp y2038 safe 2017-05-08 17:15:15 -07:00
trace_irqsoff.c tracing: Add support for preempt and irq enable/disable events 2017-10-10 18:58:43 -04:00
trace_kdb.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
trace_kprobe.c Tracing updates for 4.15: 2017-11-17 14:58:01 -08:00
trace_mmiotrace.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
trace_nop.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
trace_output.c sched/debug: Rename task-state printing helpers 2017-10-10 11:43:29 +02:00
trace_output.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
trace_printk.c tracing: Handle NULL formats in hold_module_trace_bprintk_format() 2016-06-20 09:46:12 -04:00
trace_probe.c tracing: Make traceprobe parsing code reusable 2017-10-04 13:06:44 -04:00
trace_probe.h bpf: Revert bpf_overrid_function() helper changes. 2017-11-11 18:24:55 +09:00
trace_sched_switch.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
trace_sched_wakeup.c Merge branch 'linus' into sched/core, to pick up fixes 2017-11-08 10:17:15 +01:00
trace_selftest_dynamic.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
trace_selftest.c Tracing updates for 4.15: 2017-11-17 14:58:01 -08:00
trace_seq.c tracing: use %*pb[l] to print bitmaps including cpumasks and nodemasks 2015-02-13 21:21:37 -08:00
trace_stack.c tracing: Have stack trace not record if RCU is not watching 2017-12-14 20:48:22 -05:00
trace_stat.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
trace_stat.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
trace_syscalls.c Tracing updates for 4.15: 2017-11-17 14:58:01 -08:00
trace_uprobe.c Tracing updates for 4.15: 2017-11-17 14:58:01 -08:00
trace.c tracing: Remove extra zeroing out of the ring buffer page 2017-12-27 14:20:59 -05:00
trace.h Tracing updates for 4.15: 2017-11-17 14:58:01 -08:00
tracing_map.c tracing: Remove lookups from tracing_map hitcount 2017-10-04 13:05:42 -04:00
tracing_map.h Tracing updates for 4.15: 2017-11-17 14:58:01 -08:00