Re: [Qemu-devel] [PATCH v3] tests: set MALLOC_PERTURB_ to expose memory bugs

[Eric Blake]

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 <address@hidden>
> ---
> 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.

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org

signature.asc
Description: OpenPGP digital signature