lkl: Remove gettid from host_ops

host_ops.gettid is not called anywhere except in a boot test. The boot
test just checks to see if gettid returns a non-zero tid, which makes no
sense.

I suspect host_ops.gettid was added for some historical reason, but it
can now be safely removed. This commit removes it as well as the silly
test.

Signed-off-by: Ruihan Li <lrh2000@pku.edu.cn>

Author: lrh2000

arch/lkl/include/uapi/asm/host_ops.h

@@ -110,9 +110,6 @@ enum lkl_prot {
  * @iomem_acess - reads or writes to and I/O memory region; addr must be in the
  * range returned by ioremap
  *
- * @gettid - returns the host thread id of the caller, which need not
- * be the same as the handle returned by thread_create
- *
  * @jmp_buf_set - runs the give function and setups a jump back point by saving
  * the context in the jump buffer; jmp_buf_longjmp can be called from the give
  * function or any callee in that function to return back to the jump back
@@ -177,8 +174,6 @@ struct lkl_host_operations {
 	int (*iomem_access)(const volatile void *addr, void *val, int size,
 			    int write);
 
-	long (*gettid)(void);
-
 	void (*jmp_buf_set)(struct lkl_jmp_buf *jmpb, void (*f)(void));
 	void (*jmp_buf_longjmp)(struct lkl_jmp_buf *jmpb, int val);
 

tools/lkl/lib/nt-host.c

@@ -241,11 +241,6 @@ static void print(const char *str, int len)
 	write(1, str, len);
 }
 
-static long gettid(void)
-{
-	return GetCurrentThreadId();
-}
-
 static void *mem_alloc(unsigned long size)
 {
 	return malloc(size);
@@ -281,7 +276,6 @@ struct lkl_host_operations lkl_host_ops = {
 	.ioremap = lkl_ioremap,
 	.iomem_access = lkl_iomem_access,
 	.virtio_devices = lkl_virtio_devs,
-	.gettid = gettid,
 	.jmp_buf_set = jmp_buf_set,
 	.jmp_buf_longjmp = jmp_buf_longjmp,
 };

tools/lkl/lib/posix-host.c

@@ -448,15 +448,6 @@ static void panic(void)
 	assert(0);
 }
 
-static long _gettid(void)
-{
-#ifdef	__FreeBSD__
-	return (long)pthread_self();
-#else
-	return syscall(SYS_gettid);
-#endif
-}
-
 static void *page_alloc(unsigned long size)
 {
 	void *addr;
@@ -607,7 +598,6 @@ struct lkl_host_operations lkl_host_ops = {
 	.ioremap = lkl_ioremap,
 	.iomem_access = lkl_iomem_access,
 	.virtio_devices = lkl_virtio_devs,
-	.gettid = _gettid,
 	.jmp_buf_set = jmp_buf_set,
 	.jmp_buf_longjmp = jmp_buf_longjmp,
 	.memcpy = posix_memcpy,

tools/lkl/tests/boot.c

@@ -385,20 +385,6 @@ static int lkl_test_semaphore(void)
 	return ret;
 }
 
-static int lkl_test_gettid(void)
-{
-	long tid = lkl_host_ops.gettid();
-	lkl_test_logf("%ld", tid);
-
-	/* As far as I know, thread IDs are non-zero on all reasonable
-	 * systems. */
-	if (tid) {
-		return TEST_SUCCESS;
-	} else {
-		return TEST_FAILURE;
-	}
-}
-
 static void test_thread(void *data)
 {
 	int *pipe_fds = (int*) data;
@@ -753,7 +739,6 @@ struct lkl_test tests[] = {
 	LKL_TEST(chdir_root),
 	LKL_TEST(umount_fs_proc),
 	LKL_TEST(lo_ifup),
-	LKL_TEST(gettid),
 	LKL_TEST(syscall_thread),
 	/*
 	 * Wine has an issue where the FlsCallback is not called when