Re: [Qemu-devel] [PATCH] tcg: Reload local variables after return from longjmp

[Blue Swirl]

Thanks, applied.

On Sat, Jul 2, 2011 at 10:50 AM, Jan Kiszka <address@hidden> wrote:
> From: Jan Kiszka <address@hidden>
>
> Recent compilers look deep into cpu_exec, find longjmp as a noreturn
> function and decide to smash some stack variables as they won't be used
> again. This may lead to env becoming invalid after return from setjmp,
> causing crashes. Fix it by reloading env from cpu_single_env in that
> case.
>
> Signed-off-by: Jan Kiszka <address@hidden>
> ---
>  cpu-exec.c |    4 ++++
>  1 files changed, 4 insertions(+), 0 deletions(-)
>
> diff --git a/cpu-exec.c b/cpu-exec.c
> index 20e3ec4..de0d716 100644
> --- a/cpu-exec.c
> +++ b/cpu-exec.c
> @@ -587,6 +587,10 @@ int cpu_exec(CPUState *env)
>                 /* reset soft MMU for next block (it can currently
>                    only be set by a memory fault) */
>             } /* for(;;) */
> +        } else {
> +            /* Reload env after longjmp - the compiler may have smashed all
> +             * local variables as longjmp is marked 'noreturn'. */
> +            env = cpu_single_env;
>         }
>     } /* for(;;) */
>
>