linux-kernel - [PATCH] drm/bochs: replace ioremap with devm

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Date:   Tue, 21 Mar 2023 17:52:16 +0800
From:   Gencen Gan <gangecen@...t.edu.cn>
To:     Gerd Hoffmann <kraxel@...hat.com>,
        David Airlie <airlied@...il.com>,
        Daniel Vetter <daniel@...ll.ch>
Cc:     Gan Gecen <gangecen@...t.edu.cn>, Dongliang Mu <dzm91@...t.edu.cn>,
        virtualization@...ts.linux-foundation.org,
        dri-devel@...ts.freedesktop.org, linux-kernel@...r.kernel.org
Subject: [PATCH] drm/bochs: replace ioremap with devm_ioremap to avoid immo leak

From: Gan Gecen <gangecen@...t.edu.cn>

Smatch reports:

	drivers/gpu/drm/tiny/bochs.c:290 bochs_hw_init()
	warn: 'bochs->mmio' from ioremap() not released on
	lines: 246,250,254.

In the function bochs_load() that calls bochs_hw_init()
only, if bochs_hw_init(dev) returns -ENODEV(-19), it
will jumps to err_free_dev instead of err_hw_fini, so
bochs->immo won't be freed.

We would prefer to replace ioremap with devm_ioremap
to avoid adding lengthy error handling. The function 
`devm_ioremap` will automatically release the allocated
resources after use.

Signed-off-by: Gan Gecen <gangecen@...t.edu.cn>
Reviewed-by: Dongliang Mu <dzm91@...t.edu.cn>
---
 drivers/gpu/drm/tiny/bochs.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/tiny/bochs.c b/drivers/gpu/drm/tiny/bochs.c
index 024346054c70..0d7e119a732f 100644
--- a/drivers/gpu/drm/tiny/bochs.c
+++ b/drivers/gpu/drm/tiny/bochs.c
@@ -223,7 +223,7 @@ static int bochs_hw_init(struct drm_device *dev)
 		}
 		ioaddr = pci_resource_start(pdev, 2);
 		iosize = pci_resource_len(pdev, 2);
-		bochs->mmio = ioremap(ioaddr, iosize);
+		bochs->mmio = devm_ioremap(&pdev->dev, ioaddr, iosize);
 		if (bochs->mmio == NULL) {
 			DRM_ERROR("Cannot map mmio region\n");
 			return -ENOMEM;
-- 
2.34.1