On 24/10/2022 18:21, Matthew Auld wrote:
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@xxxxxxxxx> Signed-off-by: Matthew Auld <matthew.auld@xxxxxxxxx> Cc: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxxxxxxxx> Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> Cc: Vlastimil Babka <vbabka@xxxxxxx> Cc: Yu Zhao <yuzhao@xxxxxxxxxx> --- 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;
I am unsure of the for_each_vma_range() behaviour regarding holes. If it just skips overs them and continues to next VMA in the range then patch looks good to me. Could someone confirm?
Regards, Tvrtko
