[PATCH 4.14 18/55] drm/ast: Fix incorrect free on ioregs

Greg Kroah-Hartman
2018-12-06T14:57:48Z

From: Sam Bobroff <sbobroff@linux.ibm.com>

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@linux.ibm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
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
@@ -583,7 +583,8 @@ void ast_driver_unload(struct drm_device
drm_mode_config_cleanup(dev);

ast_mm_fini(ast);
- 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);
kfree(ast);
}