[PATCH 07/11] add thread creation helper to tests

[Luca Dariz]

---
 tests/include/testlib.h      |  1 +
 tests/testlib_thread_start.c | 86 ++++++++++++++++++++++++++++++++++++
 tests/user-qemu.mk           |  1 +
 3 files changed, 88 insertions(+)
 create mode 100644 tests/testlib_thread_start.c

diff --git a/tests/include/testlib.h b/tests/include/testlib.h
index e492f2f6..a3f3a6a8 100644
--- a/tests/include/testlib.h
+++ b/tests/include/testlib.h
@@ -65,6 +65,7 @@ const char* e2s(int err);
 const char* e2s_gnumach(int err);
 void halt();
 int msleep(uint32_t timeout);
+thread_t test_thread_start(task_t task, void(*routine)(void*), void* arg);
 
 mach_port_t host_priv(void);
 mach_port_t device_priv(void);
diff --git a/tests/testlib_thread_start.c b/tests/testlib_thread_start.c
new file mode 100644
index 00000000..c52694ca
--- /dev/null
+++ b/tests/testlib_thread_start.c
@@ -0,0 +1,86 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2017 Luc Chabassier
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to 
deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included in 
all
+ * copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 
FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 
THE
+ * SOFTWARE.
+ */
+
+/* This small helper was started from 
+ * https://github.com/dwarfmaster/mach-ipc/blob/master/minimal_threads/main.c
+ * and then reworked. */
+
+#include <testlib.h>
+#include <mach/vm_param.h>
+#include <mach.user.h>
+
+/* This is just a temporary mapping to set up the stack */
+static long stack_top[PAGE_SIZE/sizeof(long)] __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) - 1;
+#ifdef __i386__
+  *top = (long)arg; /* The argument is passed on the stack on x86_32 */
+  *(top - 1) = 0;   /* The return address */
+#elif defined(__x86_64__)
+  *top = 0;         /* The return address */
+#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 __i386__
+  state.eip = (long) routine;
+  state.uesp = (long) (stack + stack_size - sizeof(long) * 2);
+  state.ebp = 0;
+#elif defined(__x86_64__)
+  state.rip = (long) routine;
+  state.ursp = (long) (stack + stack_size - sizeof(long) * 1);
+  state.rbp = 0;
+  state.rdi = (long)arg;
+#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;
+}
diff --git a/tests/user-qemu.mk b/tests/user-qemu.mk
index 1ab7cb8c..8f10ba36 100644
--- a/tests/user-qemu.mk
+++ b/tests/user-qemu.mk
@@ -125,6 +125,7 @@ SRC_TESTLIB= \
        $(srcdir)/tests/syscalls.S \
        $(srcdir)/tests/start.S \
        $(srcdir)/tests/testlib.c \
+       $(srcdir)/tests/testlib_thread_start.c \
        $(builddir)/tests/errlist.c \
        $(MIG_GEN_CC)
 
-- 
2.39.2