Anthony Liguori <aligu...@us.ibm.com> writes:
> qemu_malloc() does not allow size=0 to be passed in and aborts on this
> behavior.
>
> Unfortunately, there is good reason to believe that within qemu, there are a
> number of, so far, undetected places that assume size=0 can be safely passed.
> Since we do not want to abort unnecessarily in production builds, return
> qemu_malloc(1) whenever the version file indicates that this is a production
> build.
>
> Also introduce --enable-zero-malloc/--disable-zero-malloc to make this
> behavior
> overridable.
>
> Signed-off-by: Anthony Liguori <aligu...@us.ibm.com>
> ---
> configure | 24 +++++++++++++++++++++++-
> qemu-malloc.c | 17 +++++++++++++----
> 2 files changed, 36 insertions(+), 5 deletions(-)
>
[...]
> diff --git a/qemu-malloc.c b/qemu-malloc.c
> index 295d185..e82af26 100644
> --- a/qemu-malloc.c
> +++ b/qemu-malloc.c
> @@ -42,21 +42,30 @@ void qemu_free(void *ptr)
> free(ptr);
> }
>
> +static int allow_zero_malloc(void)
> +{
> +#if defined(CONFIG_ZERO_MALLOC)
> + return 1;
> +#else
> + return 0;
> +#endif
> +}
> +
> void *qemu_malloc(size_t size)
> {
> - if (!size) {
> + if (!size && !allow_zero_malloc()) {
> abort();
> }
> - return oom_check(malloc(size));
> + return oom_check(malloc(size ? size : 1));
> }
>
> void *qemu_realloc(void *ptr, size_t size)
> {
> if (size) {
> return oom_check(realloc(ptr, size));
> - } else {
> + } else if (allow_zero_malloc()) {
> if (ptr) {
> - return realloc(ptr, size);
> + return realloc(ptr, size ? size : 1);
> }
> }
> abort();
This still aborts on qemu_realloc(NULL, 0), even with
CONFIG_ZERO_MALLOC. Intentional?
