Re: [PATCH 08/14] add thread creation helper to tests

[Samuel Thibault]

Luca Dariz, le jeu. 28 déc. 2023 20:42:55 +0100, a ecrit:
> diff --git a/tests/testlib.c b/tests/testlib.c
> index 6abe8c4d..e6be46ee 100644
> --- a/tests/testlib.c
> +++ b/tests/testlib.c
> @@ -95,3 +95,56 @@ void _start()
>    printf("%s: test %s exit code %x\n", TEST_SUCCESS_MARKER, argv[0], ret);
>    halt();
>  }
> +
> +// started from 
> https://github.com/dwarfmaster/mach-ipc/blob/master/minimal_threads/main.c

So this *has* to reproduce the MIT license header of that repository.
Better put it in a separate file.

> +static uint32_t stack_top[PAGE_SIZE]  __attribute__ ((aligned (PAGE_SIZE)));
> +thread_t test_thread_start(task_t task, void(*routine)(void*), void* arg) {
> +  const vm_size_t stack_size = PAGE_SIZE * 16;
> +  kern_return_t ret;
> +  vm_address_t stack;
> +
> +  ret = vm_allocate(task, &stack, stack_size, TRUE);
> +  ASSERT_RET(ret, "can't allocate the stack for a new thread");
> +
> +  ret = vm_protect(task, stack, PAGE_SIZE, FALSE, VM_PROT_NONE);
> +  ASSERT_RET(ret, "can't protect the stack from overflows");
> +
> +  long *top = (long*)((vm_offset_t)stack_top + PAGE_SIZE) - 2;

> +  *top = 0;        /* The return address */
> +#ifndef __x86_64__
> +  *(top + 1) = (long)arg; /* The argument is passed on the stack on x86_32 */
> +#endif
> +  ret = vm_write(task, stack + stack_size - PAGE_SIZE, 
> (vm_offset_t)stack_top, PAGE_SIZE);
> +  ASSERT_RET(ret, "can't initialize the stack for the new thread");
> +
> +  thread_t thread;
> +  ret = thread_create(task, &thread);
> +  ASSERT_RET(ret, "thread_create()");
> +
> +  struct i386_thread_state state;
> +  unsigned int count;
> +  count = i386_THREAD_STATE_COUNT;
> +  ret = thread_get_state(thread, i386_REGS_SEGS_STATE,
> +                         (thread_state_t) &state, &count);
> +  ASSERT_RET(ret, "thread_get_state()");
> +
> +#ifdef __x86_64__
> +  state.rip = (long) routine;
> +  state.ursp = (long) (stack + stack_size - 16);

Rather use sizeof(long)*2.

> +  state.rbp = 0;
> +  state.rdi = (long)arg;
> +#else
> +  state.eip = (long) routine;
> +  state.uesp = (long) (stack + stack_size - 8);

And here as well.

> +  state.ebp = 0;
> +#endif
> +  ret = thread_set_state(thread, i386_REGS_SEGS_STATE,
> +                         (thread_state_t) &state, i386_THREAD_STATE_COUNT);
> +  ASSERT_RET(ret, "thread_set_state");
> +
> +  ret = thread_resume(thread);
> +  ASSERT_RET(ret, "thread_resume");
> +
> +  return thread;
> +}
> -- 
> 2.39.2