Libguestfs - Aug 2021 - [PATCH nbdkit v2 2/2] wrapper: Remove GLIBC_TUNABLES when running under valgrind

On Sun, Aug 22, 2021 at 01:57:16PM +0100, Richard W.M. Jones
wrote:
> ---
>  wrapper.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/wrapper.c b/wrapper.c
> index ed77a0a1..42a0cd88 100644
> --- a/wrapper.c
> +++ b/wrapper.c
> @@ -220,6 +220,15 @@ main (int argc, char *argv[])
>       * https://lists.fedoraproject.org/archives/list/devel at
lists.fedoraproject.org/thread/57EYTAFQJVVG4APOV6AMM7C26H77IQEC/
>       */
>      unsetenv ("DEBUGINFOD_URLS");
> +
> +    /* Temporary(?) workaround for:
> +     * https://sourceware.org/bugzilla/show_bug.cgi?id=28256
> +     *
> +     * But should we actually use malloc checking etc when we are
> +     * valgrinding?  It seems to duplicate work done by valgrind and
> +     * might even hide issues.
> +     */
> +    unsetenv ("GLIBC_TUNABLES");
Good point about reducing the cross-interference between glibc and
what valgrind wants to prove.  I'm fine if we permanently disable
glibc's malloc checking when we know we are running under valgrind.

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org

Thanks for the review.  This is what I pushed which I think should
incorporate all the suggestions you made.  I have also checked it
works with older glibc now.

https://gitlab.com/nbdkit/nbdkit/-/commit/362e0fdcae37db876e13b944102a5c152e6bc563
https://gitlab.com/nbdkit/nbdkit/-/commit/ae8c815e54e66ac7b421e0a6929c39d9ce3834dc

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
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