On 26/03/2019 12:31, Geert Uytterhoeven wrote:
Hi John,
CC robh
On Tue, Mar 26, 2019 at 12:42 PM John Garry <john.garry@xxxxxxxxxx> wrote:
Memory is incorrectly freed using the direct ops, as dma_map_ops = NULL.
Oops...
After reversing the order of the calls to arch_teardown_dma_ops() and
devres_release_all(), dma_map_ops is still valid, and the DMA memory is
now released using __iommu_free_attrs():
+sata_rcar ee300000.sata: dmam_release:32: size 2048 vaddr ffffff8012145000 dma_handle 0x0x00000000fffff000 attrs 0x0
+sata_rcar ee300000.sata: dma_free_attrs:289: size 2048, ops = iommu_dma_ops
+sata_rcar ee300000.sata: dma_free_attrs:311: calling __iommu_free_attrs()
---
drivers/base/dd.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index 8ac10af17c0043a3..d62487d024559620 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -968,9 +968,9 @@ static void __device_release_driver(struct device *dev, struct device *parent)
drv->remove(dev);
device_links_driver_cleanup(dev);
- arch_teardown_dma_ops(dev);
devres_release_all(dev);
+ arch_teardown_dma_ops(dev);
dev->driver = NULL;
Hi guys,
Could there still be the same problem in the error path of really_probe():
static int really_probe(struct device *dev, struct device_driver *drv)
{
[...]
goto done;
probe_failed:
arch_teardown_dma_ops(dev);
dma_failed:
if (dev->bus)
blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
BUS_NOTIFY_DRIVER_NOT_BOUND, dev);
pinctrl_bind_failed:
device_links_no_driver(dev);
devres_release_all(dev);
driver_sysfs_remove(dev);
dev->driver = NULL;
dev_set_drvdata(dev, NULL);
We seem to be able to call arch_teardown_dma_ops() prior to
devres_release_all() if we reach probe_failed label.
Yes, this looks like another instance of the same problem.
And test_remove doesn't expose this, as it doesn't exercise the full cycle.
Hi Geert,
OK, thanks.
There is another devres_release_all() call in device_release(). Not sure
if there is another potential problem there also...
As for this issue, I'll look to fix unless anyone else doing it.
Cheers,
John
Gr{oetje,eeting}s,
Geert
