From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: Tue, 7 Jan 2020 09:33:56 +0000 (+0100)
Subject: 4.9-stable patches
X-Git-Tag: v4.14.163~31
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=c51a35a8d29a8ba0d75cb744dae739091bca4d5e;p=thirdparty%2Fkernel%2Fstable-queue.git

4.9-stable patches

added patches:
	ftrace-avoid-potential-division-by-zero-in-function-profiler.patch
---

diff --git a/queue-4.9/ftrace-avoid-potential-division-by-zero-in-function-profiler.patch b/queue-4.9/ftrace-avoid-potential-division-by-zero-in-function-profiler.patch
new file mode 100644
index 00000000000..4b8456107a4
--- /dev/null
+++ b/queue-4.9/ftrace-avoid-potential-division-by-zero-in-function-profiler.patch
@@ -0,0 +1,49 @@
+From e31f7939c1c27faa5d0e3f14519eaf7c89e8a69d Mon Sep 17 00:00:00 2001
+From: Wen Yang <wenyang@linux.alibaba.com>
+Date: Fri, 3 Jan 2020 11:02:48 +0800
+Subject: ftrace: Avoid potential division by zero in function profiler
+
+From: Wen Yang <wenyang@linux.alibaba.com>
+
+commit e31f7939c1c27faa5d0e3f14519eaf7c89e8a69d upstream.
+
+The ftrace_profile->counter is unsigned long and
+do_div truncates it to 32 bits, which means it can test
+non-zero and be truncated to zero for division.
+Fix this issue by using div64_ul() instead.
+
+Link: http://lkml.kernel.org/r/20200103030248.14516-1-wenyang@linux.alibaba.com
+
+Cc: stable@vger.kernel.org
+Fixes: e330b3bcd8319 ("tracing: Show sample std dev in function profiling")
+Fixes: 34886c8bc590f ("tracing: add average time in function to function profiler")
+Signed-off-by: Wen Yang <wenyang@linux.alibaba.com>
+Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ kernel/trace/ftrace.c |    6 +++---
+ 1 file changed, 3 insertions(+), 3 deletions(-)
+
+--- a/kernel/trace/ftrace.c
++++ b/kernel/trace/ftrace.c
+@@ -609,8 +609,7 @@ static int function_stat_show(struct seq
+ 	}
+ 
+ #ifdef CONFIG_FUNCTION_GRAPH_TRACER
+-	avg = rec->time;
+-	do_div(avg, rec->counter);
++	avg = div64_ul(rec->time, rec->counter);
+ 	if (tracing_thresh && (avg < tracing_thresh))
+ 		goto out;
+ #endif
+@@ -636,7 +635,8 @@ static int function_stat_show(struct seq
+ 		 * Divide only 1000 for ns^2 -> us^2 conversion.
+ 		 * trace_print_graph_duration will divide 1000 again.
+ 		 */
+-		do_div(stddev, rec->counter * (rec->counter - 1) * 1000);
++		stddev = div64_ul(stddev,
++				  rec->counter * (rec->counter - 1) * 1000);
+ 	}
+ 
+ 	trace_seq_init(&s);
diff --git a/queue-4.9/series b/queue-4.9/series
index 5113cc575de..cae3ad2b5dc 100644
--- a/queue-4.9/series
+++ b/queue-4.9/series
@@ -28,3 +28,4 @@ ata-ahci_brcm-fix-ahci-resources-management.patch
 gpiolib-fix-up-emulated-open-drain-outputs.patch
 tracing-have-the-histogram-compare-functions-convert-to-u64-first.patch
 alsa-cs4236-fix-error-return-comparison-of-an-unsigned-integer.patch
+ftrace-avoid-potential-division-by-zero-in-function-profiler.patch