tests: avoid false failures with LD_PRELOAD=libasan.so.2

The LD_PRELOAD checks by -fsanitize=address are overly strict:
https://groups.google.com/forum/#!topic/address-sanitizer/jEvOJgkDqQk
A workaround is to first export LD_PRELOAD=libasan.so.2
The tests below are adjusted so that workaround is not discarded.

* tests/cp/no-ctx.sh: Append to $LD_PRELOAD.
* tests/df/no-mtab-status.sh: Likewise.
* tests/df/skip-duplicates.sh: Likewise.
* tests/ls/getxattr-speedup.sh: Likewise.
* tests/rm/r-root.sh: Likewise.
* tests/cp/nfs-removal-race.sh: Likewise.  Also check that
LD_PRELOAD is effective to aid future maintainability
and avoid false failure if libasan.so.2 is not preloaded.

2 files changed, 6 insertions, 6 deletions

diff --git a/tests/df/no-mtab-status.sh b/tests/df/no-mtab-status.sh
index 41d1b521b..c35da6b8c 100755
--- a/tests/df/no-mtab-status.sh
+++ b/tests/df/no-mtab-status.sh
@@ -90,7 +90,7 @@ gcc_shared_ k.c k.so \
 
 cleanup_() { unset LD_PRELOAD; }
 
-export LD_PRELOAD=./k.so
+export LD_PRELOAD=$LD_PRELOAD:./k.so
 
 # Test if LD_PRELOAD works:
 df 2>/dev/null
diff --git a/tests/df/skip-duplicates.sh b/tests/df/skip-duplicates.sh
index c13787665..406960473 100755
--- a/tests/df/skip-duplicates.sh
+++ b/tests/df/skip-duplicates.sh
@@ -146,23 +146,23 @@ gcc_shared_ k.c k.so \
   || framework_failure_ 'failed to build shared library'
 
 # Test if LD_PRELOAD works:
-LD_PRELOAD=./k.so df
+LD_PRELOAD=$LD_PRELOAD:./k.so df
 test -f x || skip_ "internal test failure: maybe LD_PRELOAD doesn't work?"
 
 # The fake mtab file should only contain entries
 # having the same device number; thus the output should
 # consist of a header and unique entries.
-LD_PRELOAD=./k.so df -T >out || fail=1
+LD_PRELOAD=$LD_PRELOAD:./k.so df -T >out || fail=1
 test $(wc -l <out) -eq $(expr 1 + $unique_entries) || { fail=1; cat out; }
 
 # With --total we should suppress the duplicate but separate remote file system
-LD_PRELOAD=./k.so df --total >out || fail=1
+LD_PRELOAD=$LD_PRELOAD:./k.so df --total >out || fail=1
 test "$CU_REMOTE_FS" && elide_remote=1 || elide_remote=0
 test $(wc -l <out) -eq $(expr 2 + $unique_entries - $elide_remote) ||
   { fail=1; cat out; }
 
 # Ensure we don't fail when unable to stat (currently) unavailable entries
-LD_PRELOAD=./k.so CU_TEST_DUPE_INVALID=1 df -T >out || fail=1
+LD_PRELOAD=$LD_PRELOAD:./k.so CU_TEST_DUPE_INVALID=1 df -T >out || fail=1
 test $(wc -l <out) -eq $(expr 1 + $unique_entries) || { fail=1; cat out; }
 
 # df should also prefer "/fsname" over "fsname"
@@ -176,7 +176,7 @@ fi
 test $(grep -c 'virtfs2.*t2' <out) -eq 1 || { fail=1; cat out; }
 
 # Ensure that filtering duplicates does not affect -a processing.
-LD_PRELOAD=./k.so df -a >out || fail=1
+LD_PRELOAD=$LD_PRELOAD:./k.so df -a >out || fail=1
 total_fs=6; test "$CU_REMOTE_FS" && total_fs=$(expr $total_fs + 3)
 test $(wc -l <out) -eq $total_fs || { fail=1; cat out; }
 # Ensure placeholder "-" values used for the eclipsed "virtfs"