From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: Fri, 27 Jun 2014 23:57:19 +0000 (-0700)
Subject: 3.4-stable patches
X-Git-Tag: v3.4.96~29
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=98585cef03f47ad9fa01c3850b2c06982430ad02;p=thirdparty%2Fkernel%2Fstable-queue.git

3.4-stable patches

added patches:
	arm-stacktrace-avoid-listing-stacktrace-functions-in-stacktrace.patch
---

diff --git a/queue-3.4/arm-stacktrace-avoid-listing-stacktrace-functions-in-stacktrace.patch b/queue-3.4/arm-stacktrace-avoid-listing-stacktrace-functions-in-stacktrace.patch
new file mode 100644
index 00000000000..bb7e6621748
--- /dev/null
+++ b/queue-3.4/arm-stacktrace-avoid-listing-stacktrace-functions-in-stacktrace.patch
@@ -0,0 +1,90 @@
+From 3683f44c42e991d313dc301504ee0fca1aeb8580 Mon Sep 17 00:00:00 2001
+From: Russell King <rmk+kernel@arm.linux.org.uk>
+Date: Sat, 3 May 2014 11:03:28 +0100
+Subject: ARM: stacktrace: avoid listing stacktrace functions in stacktrace
+
+From: Russell King <rmk+kernel@arm.linux.org.uk>
+
+commit 3683f44c42e991d313dc301504ee0fca1aeb8580 upstream.
+
+While debugging the FEC ethernet driver using stacktrace, it was noticed
+that the stacktraces always begin as follows:
+
+ [<c00117b4>] save_stack_trace_tsk+0x0/0x98
+ [<c0011870>] save_stack_trace+0x24/0x28
+ ...
+
+This is because the stack trace code includes the stack frames for itself.
+This is incorrect behaviour, and also leads to "skip" doing the wrong
+thing (which is the number of stack frames to avoid recording.)
+
+Perversely, it does the right thing when passed a non-current thread.  Fix
+this by ensuring that we have a known constant number of frames above the
+main stack trace function, and always skip these.
+
+Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ arch/arm/kernel/stacktrace.c |   18 +++++++++++++-----
+ 1 file changed, 13 insertions(+), 5 deletions(-)
+
+--- a/arch/arm/kernel/stacktrace.c
++++ b/arch/arm/kernel/stacktrace.c
+@@ -83,13 +83,16 @@ static int save_trace(struct stackframe
+ 	return trace->nr_entries >= trace->max_entries;
+ }
+ 
+-void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
++/* This must be noinline to so that our skip calculation works correctly */
++static noinline void __save_stack_trace(struct task_struct *tsk,
++	struct stack_trace *trace, unsigned int nosched)
+ {
+ 	struct stack_trace_data data;
+ 	struct stackframe frame;
+ 
+ 	data.trace = trace;
+ 	data.skip = trace->skip;
++	data.no_sched_functions = nosched;
+ 
+ 	if (tsk != current) {
+ #ifdef CONFIG_SMP
+@@ -102,7 +105,6 @@ void save_stack_trace_tsk(struct task_st
+ 			trace->entries[trace->nr_entries++] = ULONG_MAX;
+ 		return;
+ #else
+-		data.no_sched_functions = 1;
+ 		frame.fp = thread_saved_fp(tsk);
+ 		frame.sp = thread_saved_sp(tsk);
+ 		frame.lr = 0;		/* recovered from the stack */
+@@ -111,11 +113,12 @@ void save_stack_trace_tsk(struct task_st
+ 	} else {
+ 		register unsigned long current_sp asm ("sp");
+ 
+-		data.no_sched_functions = 0;
++		/* We don't want this function nor the caller */
++		data.skip += 2;
+ 		frame.fp = (unsigned long)__builtin_frame_address(0);
+ 		frame.sp = current_sp;
+ 		frame.lr = (unsigned long)__builtin_return_address(0);
+-		frame.pc = (unsigned long)save_stack_trace_tsk;
++		frame.pc = (unsigned long)__save_stack_trace;
+ 	}
+ 
+ 	walk_stackframe(&frame, save_trace, &data);
+@@ -123,9 +126,14 @@ void save_stack_trace_tsk(struct task_st
+ 		trace->entries[trace->nr_entries++] = ULONG_MAX;
+ }
+ 
++void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
++{
++	__save_stack_trace(tsk, trace, 1);
++}
++
+ void save_stack_trace(struct stack_trace *trace)
+ {
+-	save_stack_trace_tsk(current, trace);
++	__save_stack_trace(current, trace, 0);
+ }
+ EXPORT_SYMBOL_GPL(save_stack_trace);
+ #endif
diff --git a/queue-3.4/series b/queue-3.4/series
index b02b0778d0e..a456d1015f8 100644
--- a/queue-3.4/series
+++ b/queue-3.4/series
@@ -27,3 +27,4 @@ usb-sierra-fix-urb-and-memory-leak-in-resume-error-path.patch
 usb-sierra-fix-urb-and-memory-leak-on-disconnect.patch
 usb-sierra-fix-remote-wakeup.patch
 acpi-fix-conflict-between-customized-dsdt-and-dsdt-local-copy.patch
+arm-stacktrace-avoid-listing-stacktrace-functions-in-stacktrace.patch