[Intel-gfx] [PATCH] drm/i915/userptr: restore probe_range behaviour

[Matthew Auld <matthew.auld@intel.com>]

The conversion looks harmless, however the addr value is updated inside
the loop with the previous vm_end, which then incorrectly leads to
for_each_vma_range() iterating over stuff outside the range we care
about. Fix this by storing the end value separately.

Testcase: igt@gem_userptr_blits@probe
Fixes: f683b9d61319 ("i915: use the VMA iterator")
Reported-by: kernel test robot <oliver.sang@intel.com>
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yu Zhao <yuzhao@google.com>
---
 drivers/gpu/drm/i915/gem/i915_gem_userptr.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c
index b7e24476a0fd..dadb3e3fa9c8 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c
@@ -427,9 +427,10 @@ probe_range(struct mm_struct *mm, unsigned long addr, unsigned long len)
 {
 	VMA_ITERATOR(vmi, mm, addr);
 	struct vm_area_struct *vma;
+	unsigned long end = addr + len;
 
 	mmap_read_lock(mm);
-	for_each_vma_range(vmi, vma, addr + len) {
+	for_each_vma_range(vmi, vma, end) {
 		/* Check for holes, note that we also update the addr below */
 		if (vma->vm_start > addr)
 			break;
-- 
2.37.3