From: John Groves <[email protected]>
Use __va(phys) instead of virt_addr + linear_offset for the kaddr
return in __fsdev_dax_direct_access(). The previous code added a
device-linear byte offset to virt_addr (which is __va of ranges[0]),
but for multi-range devices with physical gaps between ranges, this
linear arithmetic crosses the gap and produces a wrong kernel virtual
address. Using __va(phys) where phys comes from dax_pgoff_to_phys()
is correct for any range layout because the direct map translates
each physical address independently.
Fixes: 759455848df0b ("dax: Save the kva from memremap")
Signed-off-by: John Groves <[email protected]>
---
drivers/dax/fsdev.c | 7 ++-----
1 file changed, 2 insertions(+), 5 deletions(-)
diff --git a/drivers/dax/fsdev.c b/drivers/dax/fsdev.c
index 42aac7e952516..a2d2eb20fb4d0 100644
--- a/drivers/dax/fsdev.c
+++ b/drivers/dax/fsdev.c
@@ -51,9 +51,7 @@ static long __fsdev_dax_direct_access(struct dax_device
*dax_dev, pgoff_t pgoff,
struct dev_dax *dev_dax = dax_get_private(dax_dev);
size_t size = nr_pages << PAGE_SHIFT;
size_t offset = pgoff << PAGE_SHIFT;
- void *virt_addr = dev_dax->virt_addr + offset;
phys_addr_t phys;
- unsigned long local_pfn;
phys = dax_pgoff_to_phys(dev_dax, pgoff, size);
if (phys == -1) {
@@ -63,11 +61,10 @@ static long __fsdev_dax_direct_access(struct dax_device
*dax_dev, pgoff_t pgoff,
}
if (kaddr)
- *kaddr = virt_addr;
+ *kaddr = __va(phys);
- local_pfn = PHYS_PFN(phys);
if (pfn)
- *pfn = local_pfn;
+ *pfn = PHYS_PFN(phys);
/*
* Use cached_size which was computed at probe time. The size cannot
--
2.53.0
