On 21/02/2024 17.29, Peter Maydell wrote:
On Wed, 21 Feb 2024 at 16:26, Thomas Huth <th...@redhat.com> wrote:To be able to compile QEMU with -Wvla (to prevent potential security issues), we need to get rid of the variable length array in the kvmppc_save_htab() function. Replace it with a heap allocation instead. Signed-off-by: Thomas Huth <th...@redhat.com> --- target/ppc/kvm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/target/ppc/kvm.c b/target/ppc/kvm.c index 26fa9d0575..e7e39c3091 100644 --- a/target/ppc/kvm.c +++ b/target/ppc/kvm.c @@ -2688,7 +2688,7 @@ int kvmppc_get_htab_fd(bool write, uint64_t index, Error **errp) int kvmppc_save_htab(QEMUFile *f, int fd, size_t bufsize, int64_t max_ns) { int64_t starttime = qemu_clock_get_ns(QEMU_CLOCK_REALTIME); - uint8_t buf[bufsize]; + g_autofree uint8_t *buf = g_malloc(bufsize); ssize_t rc;This works, so Reviewed-by: Peter Maydell <peter.mayd...@linaro.org> but you could also drop the bufsize argument, because there are only two callers and they both pass MAX_KVM_BUF_SIZE, and then declare the array as fixed size with "uint8_t buf[MAX_KVM_BUF_SIZE]".
Yes, that's an alternative ... my thinking was that MAX_KVM_BUF_SIZE = 2048 is already a rather big buffer which should maybe rather be allocated on the heap than the stack? But I don't mind too much, so if ppc folks prefer the stack allocation, I can change the patch, too.
Thomas
