Commit 69c90702 authored Jan 22, 2018 by Davidlohr Bueso Committed by Tony Luck Mar 05, 2018

ia64/err-inject: Use get_user_pages_fast()



At the point of sysfs callback, the call to gup is
done without mmap_sem (or any lock for that matter).
This is racy. As such, use the get_user_pages_fast()
alternative and safely avoid taking the lock, if possible.

Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Tony Luck <tony.luck@intel.com>

parent 339d541a

arch/ia64/kernel/err_inject.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -142,7 +142,7 @@ store_virtual_to_phys(struct device dev, struct device_attribute attr,
		u64 virt_addr=simple_strtoull(buf, NULL, 16);
		int ret;

		ret = get_user_pages(virt_addr, 1, FOLL_WRITE, NULL, NULL);
		ret = get_user_pages_fast(virt_addr, 1, FOLL_WRITE, NULL);
		if (ret<=0) {
		#ifdef ERR_INJ_DEBUG
		printk("Virtual address %lx is not existing.\n",virt_addr);