[PATCH 3.18 25/54] drm/ast: Fix incorrect free on ioregs

From: Greg Kroah-Hartman
Date: Tue Dec 11 2018 - 10:43:14 EST

3.18-stable review patch. If anyone has any objections, please let me know.


From: Sam Bobroff <sbobroff@xxxxxxxxxxxxx>

commit dc25ab067645eabd037f1a23d49a666f9e0b8c68 upstream.

If the platform has no IO space, ioregs is placed next to the already
allocated regs. In this case, it should not be separately freed.

This prevents a kernel warning from __vunmap "Trying to vfree()
nonexistent vm area" when unloading the driver.

Fixes: 0dd68309b9c5 ("drm/ast: Try to use MMIO registers when PIO isn't supported")

Signed-off-by: Sam Bobroff <sbobroff@xxxxxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Dave Airlie <airlied@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

drivers/gpu/drm/ast/ast_main.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- a/drivers/gpu/drm/ast/ast_main.c
+++ b/drivers/gpu/drm/ast/ast_main.c
@@ -489,7 +489,8 @@ int ast_driver_unload(struct drm_device

- pci_iounmap(dev->pdev, ast->ioregs);
+ if (ast->ioregs != ast->regs + AST_IO_MM_OFFSET)
+ pci_iounmap(dev->pdev, ast->ioregs);
pci_iounmap(dev->pdev, ast->regs);
return 0;