linux-kernel - [PATCH] drm/amdgpu: Fix resource leak on probe error path

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Date:   Thu, 24 Jun 2021 13:20:21 +0200 (CEST)
From:   Jiri Kosina <jikos@...nel.org>
To:     Alex Deucher <alexander.deucher@....com>,
        Christian König <christian.koenig@....com>,
        David Airlie <airlied@...ux.ie>
cc:     amd-gfx@...ts.freedesktop.org, dri-devel@...ts.freedesktop.org,
        linux-kernel@...r.kernel.org, Vojtech Pavlik <vojtech@....cz>
Subject: [PATCH] drm/amdgpu: Fix resource leak on probe error path

From: Jiri Kosina <jkosina@...e.cz>

This reverts commit 4192f7b5768912ceda82be2f83c87ea7181f9980.

It is not true (as stated in the reverted commit changelog) that we never 
unmap the BAR on failure; it actually does happen properly on 
amdgpu_driver_load_kms() -> amdgpu_driver_unload_kms() -> 
amdgpu_device_fini() error path.

What's worse, this commit actually completely breaks resource freeing on 
probe failure (like e.g. failure to load microcode), as 
amdgpu_driver_unload_kms() notices adev->rmmio being NULL and bails too 
early, leaving all the resources that'd normally be freed in 
amdgpu_acpi_fini() and amdgpu_device_fini() still hanging around, leading 
to all sorts of oopses when someone tries to, for example, access the 
sysfs and procfs resources which are still around while the driver is 
gone.

Fixes: 4192f7b57689 ("drm/amdgpu: unmap register bar on device init failure")
Reported-by: Vojtech Pavlik <vojtech@....cz>
Signed-off-by: Jiri Kosina <jkosina@...e.cz>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
index 57ec108b5972..0f1c0e17a587 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
@@ -3414,13 +3414,13 @@ int amdgpu_device_init(struct amdgpu_device *adev,
 	r = amdgpu_device_get_job_timeout_settings(adev);
 	if (r) {
 		dev_err(adev->dev, "invalid lockup_timeout parameter syntax\n");
-		goto failed_unmap;
+		return r;
 	}

 	/* early init functions */
 	r = amdgpu_device_ip_early_init(adev);
 	if (r)
-		goto failed_unmap;
+		return r;

 	/* doorbell bar mapping and doorbell index init*/
 	amdgpu_device_doorbell_init(adev);
@@ -3646,10 +3646,6 @@ int amdgpu_device_init(struct amdgpu_device *adev,
 failed:
 	amdgpu_vf_error_trans_all(adev);

-failed_unmap:
-	iounmap(adev->rmmio);
-	adev->rmmio = NULL;
-
 	return r;
 }

-- 
2.12.3