Re: [PATCH] target/arm: Check if debug is already initialized

[Peter Maydell]

On Wed, 5 Apr 2023 at 08:02, Akihiko Odaki <akihiko.odaki@daynix.com> wrote:
>
> When virtualizing SMP system, kvm_arm_init_debug() will be called
> multiple times. Check if the debug feature is already initialized when the
> function is called; otherwise it will overwrite pointers to memory
> allocated with the previous call and leak it.
>
> Fixes: e4482ab7e3 ("target-arm: kvm - add support for HW assisted debug")
> Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
> ---
>  target/arm/kvm64.c | 23 +++++++++++++++++------
>  1 file changed, 17 insertions(+), 6 deletions(-)

I think I agree with Philippe that the better fix is to call
kvm_arm_init_debug() from kvm_arch_init() -- if we avoid
calling this for each vcpu then we don't have to carefully arrange
to ignore all but the first call. We never actually care about
the CPUState we're passed in, so we could instead pass in the
KVMState directly, which kvm_arch_init() has.

thanks
-- PMM