[v3] tests: set MALLOC_PERTURB_ to expose memory bugs

glibc wipes malloc(3) memory when the MALLOC_PERTURB_ environment
variable is set.  The value of the environment variable determines the
bit pattern used to wipe memory.  For more information, see
http://udrepper.livejournal.com/11429.html.

Set MALLOC_PERTURB_ for gtester and qemu-iotests.  Note we pick a random
value from 1 to 255 to expose more bugs.  If you need to reproduce a
crash use 'show environment' in gdb to extract the MALLOC_PERTURB_
value from a core dump.

Both make check and qemu-iotests pass with MALLOC_PERTURB_ enabled.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
v3:
 * Use $ escaping in tests/Makefile [eblake]

v2:
 * Randomize MALLOC_PERTURB_ value [armbru]
 * Preserve existing MALLOC_PERTURB_ variable, if set [danpb]

 tests/Makefile           | 5 ++++-
 tests/qemu-iotests/check | 3 ++-
 2 files changed, 6 insertions(+), 2 deletions(-)

On 22/05/13 05:16 AM, Stefan Hajnoczi wrote:
> glibc wipes malloc(3) memory when the MALLOC_PERTURB_ environment
> variable is set.  The value of the environment variable determines the
> bit pattern used to wipe memory.  For more information, see
> http://udrepper.livejournal.com/11429.html.
>
> Set MALLOC_PERTURB_ for gtester and qemu-iotests.  Note we pick a random
> value from 1 to 255 to expose more bugs.  If you need to reproduce a
> crash use 'show environment' in gdb to extract the MALLOC_PERTURB_
> value from a core dump.
>
> Both make check and qemu-iotests pass with MALLOC_PERTURB_ enabled.

This looks good to me, thanks Stefan!

Acked-by: Lucas Meneghel Rodrigues <lmr@redhat.com>

> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> ---
> v3:
>   * Use $ escaping in tests/Makefile [eblake]
>
> v2:
>   * Randomize MALLOC_PERTURB_ value [armbru]
>   * Preserve existing MALLOC_PERTURB_ variable, if set [danpb]
>
>   tests/Makefile           | 5 ++++-
>   tests/qemu-iotests/check | 3 ++-
>   2 files changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/tests/Makefile b/tests/Makefile
> index a307d5a..7844cd7 100644
> --- a/tests/Makefile
> +++ b/tests/Makefile
> @@ -171,6 +171,7 @@ GCOV_OPTIONS = -n $(if $(V),-f,)
>   $(patsubst %, check-qtest-%, $(QTEST_TARGETS)): check-qtest-%: $(check-qtest-y)
>   	$(if $(CONFIG_GCOV),@rm -f *.gcda */*.gcda */*/*.gcda */*/*/*.gcda,)
>   	$(call quiet-command,QTEST_QEMU_BINARY=$*-softmmu/qemu-system-$* \
> +		MALLOC_PERTURB_=$${MALLOC_PERTURB_:-$$(($$RANDOM % 255 + 1))} \
>   		gtester $(GTESTER_OPTIONS) -m=$(SPEED) $(check-qtest-$*-y),"GTESTER $@")
>   	$(if $(CONFIG_GCOV),@for f in $(gcov-files-$*-y); do \
>   	  echo Gcov report for $$f:;\
> @@ -180,7 +181,9 @@ $(patsubst %, check-qtest-%, $(QTEST_TARGETS)): check-qtest-%: $(check-qtest-y)
>   .PHONY: $(patsubst %, check-%, $(check-unit-y))
>   $(patsubst %, check-%, $(check-unit-y)): check-%: %
>   	$(if $(CONFIG_GCOV),@rm -f *.gcda */*.gcda */*/*.gcda */*/*/*.gcda,)
> -	$(call quiet-command,gtester $(GTESTER_OPTIONS) -m=$(SPEED) $*,"GTESTER $*")
> +	$(call quiet-command, \
> +		MALLOC_PERTURB_=$${MALLOC_PERTURB_:-$$(($$RANDOM % 255 + 1))} \
> +		gtester $(GTESTER_OPTIONS) -m=$(SPEED) $*,"GTESTER $*")
>   	$(if $(CONFIG_GCOV),@for f in $(gcov-files-$(subst tests/,,$*)-y); do \
>   	  echo Gcov report for $$f:;\
>   	  $(GCOV) $(GCOV_OPTIONS) $$f -o `dirname $$f`; \
> diff --git a/tests/qemu-iotests/check b/tests/qemu-iotests/check
> index 432732c..74628ae 100755
> --- a/tests/qemu-iotests/check
> +++ b/tests/qemu-iotests/check
> @@ -214,7 +214,8 @@ do
>   	start=`_wallclock`
>   	$timestamp && echo -n "	["`date "+%T"`"]"
>   	[ ! -x $seq ] && chmod u+x $seq # ensure we can run it
> -	./$seq >$tmp.out 2>&1
> +	MALLOC_PERTURB_=${MALLOC_PERTURB_:-$(($RANDOM % 255 + 1))} \
> +		./$seq >$tmp.out 2>&1
>   	sts=$?
>   	$timestamp && _timestamp
>   	stop=`_wallclock`
>

On 05/22/2013 02:16 AM, Stefan Hajnoczi wrote:
> glibc wipes malloc(3) memory when the MALLOC_PERTURB_ environment
> variable is set.  The value of the environment variable determines the
> bit pattern used to wipe memory.  For more information, see
> http://udrepper.livejournal.com/11429.html.
> 
> Set MALLOC_PERTURB_ for gtester and qemu-iotests.  Note we pick a random
> value from 1 to 255 to expose more bugs.  If you need to reproduce a
> crash use 'show environment' in gdb to extract the MALLOC_PERTURB_
> value from a core dump.
> 
> Both make check and qemu-iotests pass with MALLOC_PERTURB_ enabled.
> 
> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> ---
> v3:
>  * Use $ escaping in tests/Makefile [eblake]

That was one of my comments, but you missed the other:

> +++ b/tests/Makefile
> @@ -171,6 +171,7 @@ GCOV_OPTIONS = -n $(if $(V),-f,)
>  $(patsubst %, check-qtest-%, $(QTEST_TARGETS)): check-qtest-%: $(check-qtest-y)
>  	$(if $(CONFIG_GCOV),@rm -f *.gcda */*.gcda */*/*.gcda */*/*/*.gcda,)
>  	$(call quiet-command,QTEST_QEMU_BINARY=$*-softmmu/qemu-system-$* \
> +		MALLOC_PERTURB_=$${MALLOC_PERTURB_:-$$(($$RANDOM % 255 + 1))} \

This is broken if /bin/sh is dash.  s/\$\$RANDOM/RANDOM/

>  		gtester $(GTESTER_OPTIONS) -m=$(SPEED) $(check-qtest-$*-y),"GTESTER $@")
>  	$(if $(CONFIG_GCOV),@for f in $(gcov-files-$*-y); do \
>  	  echo Gcov report for $$f:;\
> @@ -180,7 +181,9 @@ $(patsubst %, check-qtest-%, $(QTEST_TARGETS)): check-qtest-%: $(check-qtest-y)
>  .PHONY: $(patsubst %, check-%, $(check-unit-y))
>  $(patsubst %, check-%, $(check-unit-y)): check-%: %
>  	$(if $(CONFIG_GCOV),@rm -f *.gcda */*.gcda */*/*.gcda */*/*/*.gcda,)
> -	$(call quiet-command,gtester $(GTESTER_OPTIONS) -m=$(SPEED) $*,"GTESTER $*")
> +	$(call quiet-command, \
> +		MALLOC_PERTURB_=$${MALLOC_PERTURB_:-$$(($$RANDOM % 255 + 1))} \

Same problem on dash, same fix is needed.