From: John Groves <[email protected]> Convert the WARN_ON to a fatal error when pgmap_phys > phys. This condition means the remapped region starts after the device's data region, which is an impossible state. Previously the probe continued with data_offset=0, leaving virt_addr silently misaligned. Now probe returns -EINVAL with a diagnostic message. Fixes: 759455848df0b ("dax: Save the kva from memremap") Reviewed-by: Dave Jiang <[email protected]> Reviewed-by: Alison Schofield <[email protected]> Signed-off-by: John Groves <[email protected]>
Reviewed-by: Pankaj Gupta <[email protected]>
--- drivers/dax/fsdev.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/dax/fsdev.c b/drivers/dax/fsdev.c index 07de6bfbbf673..71d2bee1e2805 100644 --- a/drivers/dax/fsdev.c +++ b/drivers/dax/fsdev.c @@ -320,8 +320,12 @@ static int fsdev_dax_probe(struct dev_dax *dev_dax) u64 phys = dev_dax->ranges[0].range.start; u64 pgmap_phys = pgmap[0].range.start;- if (!WARN_ON(pgmap_phys > phys))- data_offset = phys - pgmap_phys; + if (pgmap_phys > phys) { + dev_err(dev, "pgmap start %#llx exceeds data start %#llx\n", + pgmap_phys, phys); + return -EINVAL; + } + data_offset = phys - pgmap_phys;pr_debug("%s: offset detected phys=%llx pgmap_phys=%llx offset=%llx\n",__func__, phys, pgmap_phys, data_offset);
