Paolo Bonzini <pbonz...@redhat.com> writes:
> There is a data race if the variable is written concurrently to the
> read. In C11 this has undefined behavior. Use atomic_read. The
> write side does not need atomic_set, because it is protected by a
> mutex.
>
> Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
Reviewed-by: Alex Bennée <alex.ben...@linaro.org>
> ---
> cpus.c | 9 +++++----
> 1 file changed, 5 insertions(+), 4 deletions(-)
>
> diff --git a/cpus.c b/cpus.c
> index b2fbe33..3fc2f6e 100644
> --- a/cpus.c
> +++ b/cpus.c
> @@ -170,7 +170,8 @@ int64_t cpu_get_icount_raw(void)
> static int64_t cpu_get_icount_locked(void)
> {
> int64_t icount = cpu_get_icount_raw();
> - return timers_state.qemu_icount_bias + cpu_icount_to_ns(icount);
> + int64_t ns = cpu_icount_to_ns(icount);
> + return atomic_read(&timers_state.qemu_icount_bias) + ns;
> }
>
> int64_t cpu_get_icount(void)
> @@ -206,7 +207,7 @@ int64_t cpu_get_ticks(void)
> }
>
> ticks = timers_state.cpu_ticks_offset;
> - if (timers_state.cpu_ticks_enabled) {
> + if (atomic_read(&timers_state.cpu_ticks_enabled)) {
> ticks += cpu_get_host_ticks();
> }
>
> @@ -225,8 +226,8 @@ static int64_t cpu_get_clock_locked(void)
> {
> int64_t time;
>
> - time = timers_state.cpu_clock_offset;
> - if (timers_state.cpu_ticks_enabled) {
> + time = atomic_read(&timers_state.cpu_clock_offset);
> + if (atomic_read(&timers_state.cpu_ticks_enabled)) {
> time += get_clock();
> }
--
Alex Bennée
