From 0e42f65d72d188dc0535f5ba70192cae632d5be3 Mon Sep 17 00:00:00 2001
From: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Date: Tue, 30 Jun 2009 11:41:20 -0700
Subject: [PATCH] --- yaml --- r: 154583 b: refs/heads/master c:
 972c71a3183ab41c0b1a9e50842be7e3e980954f h: refs/heads/master i:   154581:
 0b313dbe8d994dcb70ac7dc7fa6059fa50409312   154579:
 d2ed18d78918fb93faac734b1e8d5ab1550fa497   154575:
 cfed10814c0649be502932d230a965bea9a5a5bb v: v3

---
 [refs]                       |  2 +-
 trunk/Documentation/gcov.txt | 25 ++++++++++++++++---------
 2 files changed, 17 insertions(+), 10 deletions(-)

diff --git a/[refs] b/[refs]
index bbb156e6b86d..5ba0379921a8 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: b01e8dc34379f4ba2f454390e340a025edbaaa7e
+refs/heads/master: 972c71a3183ab41c0b1a9e50842be7e3e980954f
diff --git a/trunk/Documentation/gcov.txt b/trunk/Documentation/gcov.txt
index e716aadb3a33..40ec63352760 100644
--- a/trunk/Documentation/gcov.txt
+++ b/trunk/Documentation/gcov.txt
@@ -188,13 +188,18 @@ Solution: Exclude affected source files from profiling by specifying
           GCOV_PROFILE := n or GCOV_PROFILE_basename.o := n in the
           corresponding Makefile.
 
+Problem:  Files copied from sysfs appear empty or incomplete.
+Cause:    Due to the way seq_file works, some tools such as cp or tar
+          may not correctly copy files from sysfs.
+Solution: Use 'cat' to read .gcda files and 'cp -d' to copy links.
+          Alternatively use the mechanism shown in Appendix B.
+
 
 Appendix A: gather_on_build.sh
 ==============================
 
 Sample script to gather coverage meta files on the build machine
 (see 6a):
-
 #!/bin/bash
 
 KSRC=$1
@@ -226,7 +231,7 @@ Appendix B: gather_on_test.sh
 Sample script to gather coverage data files on the test machine
 (see 6b):
 
-#!/bin/bash
+#!/bin/bash -e
 
 DEST=$1
 GCDA=/sys/kernel/debug/gcov
@@ -236,11 +241,13 @@ if [ -z "$DEST" ] ; then
   exit 1
 fi
 
-find $GCDA -name '*.gcno' -o -name '*.gcda' | tar cfz $DEST -T -
+TEMPDIR=$(mktemp -d)
+echo Collecting data..
+find $GCDA -type d -exec mkdir -p $TEMPDIR/\{\} \;
+find $GCDA -name '*.gcda' -exec sh -c 'cat < $0 > '$TEMPDIR'/$0' {} \;
+find $GCDA -name '*.gcno' -exec sh -c 'cp -d $0 '$TEMPDIR'/$0' {} \;
+tar czf $DEST -C $TEMPDIR sys
+rm -rf $TEMPDIR
 
-if [ $? -eq 0 ] ; then
-  echo "$DEST successfully created, copy to build system and unpack with:"
-  echo "  tar xfz $DEST"
-else
-  echo "Could not create file $DEST"
-fi
+echo "$DEST successfully created, copy to build system and unpack with:"
+echo "  tar xfz $DEST"