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Diffstat (limited to 'drivers/comedi/comedi_fops.c')
-rw-r--r--drivers/comedi/comedi_fops.c12
1 files changed, 12 insertions, 0 deletions
diff --git a/drivers/comedi/comedi_fops.c b/drivers/comedi/comedi_fops.c
index 1b481731df96..b9df9b19d4bd 100644
--- a/drivers/comedi/comedi_fops.c
+++ b/drivers/comedi/comedi_fops.c
@@ -2407,6 +2407,18 @@ static int comedi_mmap(struct file *file, struct vm_area_struct *vma)
start += PAGE_SIZE;
}
+
+#ifdef CONFIG_MMU
+ /*
+ * Leaving behind a partial mapping of a buffer we're about to
+ * drop is unsafe, see remap_pfn_range_notrack().
+ * We need to zap the range here ourselves instead of relying
+ * on the automatic zapping in remap_pfn_range() because we call
+ * remap_pfn_range() in a loop.
+ */
+ if (retval)
+ zap_vma_ptes(vma, vma->vm_start, size);
+#endif
}
if (retval == 0) {