C++ (Cpp) __clear_user_std Examples

Example #1

File: uaccess_with_memcpy.c Project: klothius/htc_pyramid_kernel_30

unsigned long __clear_user(void __user *addr, unsigned long n)
{
	/* See rational for this in __copy_to_user() above. */
	if (n < 64)
		return __clear_user_std(addr, n);
	return __clear_user_memset(addr, n);
}

Example #2

File: uaccess_with_memcpy.c Project: bongbongco/linux-rpi

unsigned long arm_clear_user(void __user *addr, unsigned long n)
{
	/* See rational for this in __copy_to_user() above. */
	if (n < 64) {
		unsigned long ua_flags = uaccess_save_and_enable();
		n = __clear_user_std(addr, n);
		uaccess_restore(ua_flags);
	} else {
		n = __clear_user_memset(addr, n);
	}
	return n;
}

Example #3

File: uaccess_with_memcpy.c Project: bongbongco/linux-rpi

static int __init test_size_treshold(void)
{
	struct page *src_page, *dst_page;
	void *user_ptr, *kernel_ptr;
	unsigned long long t0, t1, t2;
	int size, ret;

	ret = -ENOMEM;
	src_page = alloc_page(GFP_KERNEL);
	if (!src_page)
		goto no_src;
	dst_page = alloc_page(GFP_KERNEL);
	if (!dst_page)
		goto no_dst;
	kernel_ptr = page_address(src_page);
	user_ptr = vmap(&dst_page, 1, VM_IOREMAP, __pgprot(__P010));
	if (!user_ptr)
		goto no_vmap;

	/* warm up the src page dcache */
	ret = __copy_to_user_memcpy(user_ptr, kernel_ptr, PAGE_SIZE);

	for (size = PAGE_SIZE; size >= 4; size /= 2) {
		t0 = sched_clock();
		ret |= __copy_to_user_memcpy(user_ptr, kernel_ptr, size);
		t1 = sched_clock();
		ret |= __copy_to_user_std(user_ptr, kernel_ptr, size);
		t2 = sched_clock();
		printk("copy_to_user: %d %llu %llu\n", size, t1 - t0, t2 - t1);
	}

	for (size = PAGE_SIZE; size >= 4; size /= 2) {
		t0 = sched_clock();
		ret |= __clear_user_memset(user_ptr, size);
		t1 = sched_clock();
		ret |= __clear_user_std(user_ptr, size);
		t2 = sched_clock();
		printk("clear_user: %d %llu %llu\n", size, t1 - t0, t2 - t1);
	}

	if (ret)
		ret = -EFAULT;

	vunmap(user_ptr);
no_vmap:
	put_page(dst_page);
no_dst:
	put_page(src_page);
no_src:
	return ret;
}