diff options
Diffstat (limited to 'util/coroutine-ucontext.c')
| -rw-r--r-- | util/coroutine-ucontext.c | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/util/coroutine-ucontext.c b/util/coroutine-ucontext.c index 613f4c118e..f0b66320e1 100644 --- a/util/coroutine-ucontext.c +++ b/util/coroutine-ucontext.c @@ -45,6 +45,11 @@ typedef struct { Coroutine base; void *stack; size_t stack_size; +#ifdef CONFIG_SAFESTACK + /* Need an unsafe stack for each coroutine */ + void *unsafe_stack; + size_t unsafe_stack_size; +#endif sigjmp_buf env; void *tsan_co_fiber; @@ -179,6 +184,10 @@ Coroutine *qemu_coroutine_new(void) co = g_malloc0(sizeof(*co)); co->stack_size = COROUTINE_STACK_SIZE; co->stack = qemu_alloc_stack(&co->stack_size); +#ifdef CONFIG_SAFESTACK + co->unsafe_stack_size = COROUTINE_STACK_SIZE; + co->unsafe_stack = qemu_alloc_stack(&co->unsafe_stack_size); +#endif co->base.entry_arg = &old_env; /* stash away our jmp_buf */ uc.uc_link = &old_uc; @@ -203,6 +212,22 @@ Coroutine *qemu_coroutine_new(void) COROUTINE_YIELD, &fake_stack_save, co->stack, co->stack_size, co->tsan_co_fiber); + +#ifdef CONFIG_SAFESTACK + /* + * Before we swap the context, set the new unsafe stack + * The unsafe stack grows just like the normal stack, so start from + * the last usable location of the memory area. + * NOTE: we don't have to re-set the usp afterwards because we are + * coming back to this context through a siglongjmp. + * The compiler already wrapped the corresponding sigsetjmp call with + * code that saves the usp on the (safe) stack before the call, and + * restores it right after (which is where we return with siglongjmp). + */ + void *usp = co->unsafe_stack + co->unsafe_stack_size; + __safestack_unsafe_stack_ptr = usp; +#endif + swapcontext(&old_uc, &uc); } @@ -235,6 +260,9 @@ void qemu_coroutine_delete(Coroutine *co_) #endif qemu_free_stack(co->stack, co->stack_size); +#ifdef CONFIG_SAFESTACK + qemu_free_stack(co->unsafe_stack, co->unsafe_stack_size); +#endif g_free(co); } |