memfd: Avoid Coverity warning about integer overflow

Coverity complains about qemu_memfd_create() (CID 1385858) because
we calculate a bit position htsize which could be up to 63, but
then use it in "1 << htsize" which is a 32-bit integer calculation
and could push the 1 off the top of the value.

Silence the complaint bu using "1ULL"; this isn't a bug in
practice since a hugetlbsize of 4GB is not very plausible.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20180515172729.24564-1-peter.maydell@linaro.org>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Peter Maydell 2018-05-15 18:27:29 +01:00 committed by Paolo Bonzini
parent eeaa671505
commit 4f938cbd90

View file

@ -66,7 +66,7 @@ int qemu_memfd_create(const char *name, size_t size, bool hugetlb,
{
int htsize = hugetlbsize ? ctz64(hugetlbsize) : 0;
if (htsize && 1 << htsize != hugetlbsize) {
if (htsize && 1ULL << htsize != hugetlbsize) {
error_setg(errp, "Hugepage size must be a power of 2");
return -1;
}