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From:   Xin Xiong <xiongx18@fudan.edu.cn>
To:     Alex Deucher <alexander.deucher@amd.com>,
        =?UTF-8?q?Christian=20K=C3=B6nig?= <christian.koenig@amd.com>,
        "Pan, Xinhui" <Xinhui.Pan@amd.com>,
        David Airlie <airlied@linux.ie>,
        Daniel Vetter <daniel@ffwll.ch>,
        Matthew Dawson <matthew@mjdsystems.ca>,
        amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org,
        linux-kernel@vger.kernel.org
Cc:     yuanxzhang@fudan.edu.cn, Xin Xiong <xiongx18@fudan.edu.cn>,
        Xin Tan <tanxin.ctf@gmail.com>
Subject: [PATCH v2] drm/radeon: fix potential memory leaks in two ib test functions
Date:   Sat, 25 Jun 2022 20:56:48 +0800
Message-Id: <20220625125647.1782-1-xiongx18@fudan.edu.cn>
MIME-Version: 1.0
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Precedence: bulk

The issue takes place in several error handling paths in both
cik_sdma_ib_test() and r600_dma_ib_test(). Take cik_sdma_ib_test()
for an example. When radeon_fence_wait_timeout() returns a value equal
or less than zero, the function simply returns an error code,
forgetting to free the object "ib", which is requested by calling
radeon_ib_get() earlier. This may result in memory leaks.

Fix it by freeing "ib" in specific error handling paths.

Fixes: 04db4caf5c83 ("drm/radeon: Avoid double gpu reset by adding a timeout on IB ring tests.")
Signed-off-by: Xin Xiong <xiongx18@fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
---
V1 -> V2: Fix another function of similar pattern
---
 drivers/gpu/drm/radeon/cik_sdma.c | 9 +++++----
 drivers/gpu/drm/radeon/r600_dma.c | 9 +++++----
 2 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/radeon/cik_sdma.c b/drivers/gpu/drm/radeon/cik_sdma.c
index 919b14845c3c..d0e7323cdd42 100644
--- a/drivers/gpu/drm/radeon/cik_sdma.c
+++ b/drivers/gpu/drm/radeon/cik_sdma.c
@@ -732,18 +732,18 @@ int cik_sdma_ib_test(struct radeon_device *rdev, struct radeon_ring *ring)
 
 	r = radeon_ib_schedule(rdev, &ib, NULL, false);
 	if (r) {
-		radeon_ib_free(rdev, &ib);
 		DRM_ERROR("radeon: failed to schedule ib (%d).\n", r);
-		return r;
+		goto out;
 	}
 	r = radeon_fence_wait_timeout(ib.fence, false, usecs_to_jiffies(
 		RADEON_USEC_IB_TEST_TIMEOUT));
 	if (r < 0) {
 		DRM_ERROR("radeon: fence wait failed (%d).\n", r);
-		return r;
+		goto out;
 	} else if (r == 0) {
 		DRM_ERROR("radeon: fence wait timed out.\n");
-		return -ETIMEDOUT;
+		r = -ETIMEDOUT;
+		goto out;
 	}
 	r = 0;
 	for (i = 0; i < rdev->usec_timeout; i++) {
@@ -758,6 +758,7 @@ int cik_sdma_ib_test(struct radeon_device *rdev, struct radeon_ring *ring)
 		DRM_ERROR("radeon: ib test failed (0x%08X)\n", tmp);
 		r = -EINVAL;
 	}
+out:
 	radeon_ib_free(rdev, &ib);
 	return r;
 }
diff --git a/drivers/gpu/drm/radeon/r600_dma.c b/drivers/gpu/drm/radeon/r600_dma.c
index 89ca2738c5d4..75ed03886fc2 100644
--- a/drivers/gpu/drm/radeon/r600_dma.c
+++ b/drivers/gpu/drm/radeon/r600_dma.c
@@ -363,18 +363,18 @@ int r600_dma_ib_test(struct radeon_device *rdev, struct radeon_ring *ring)
 
 	r = radeon_ib_schedule(rdev, &ib, NULL, false);
 	if (r) {
-		radeon_ib_free(rdev, &ib);
 		DRM_ERROR("radeon: failed to schedule ib (%d).\n", r);
-		return r;
+		goto out;
 	}
 	r = radeon_fence_wait_timeout(ib.fence, false, usecs_to_jiffies(
 		RADEON_USEC_IB_TEST_TIMEOUT));
 	if (r < 0) {
 		DRM_ERROR("radeon: fence wait failed (%d).\n", r);
-		return r;
+		goto out;
 	} else if (r == 0) {
 		DRM_ERROR("radeon: fence wait timed out.\n");
-		return -ETIMEDOUT;
+		r = -ETIMEDOUT;
+		goto out;
 	}
 	r = 0;
 	for (i = 0; i < rdev->usec_timeout; i++) {
@@ -389,6 +389,7 @@ int r600_dma_ib_test(struct radeon_device *rdev, struct radeon_ring *ring)
 		DRM_ERROR("radeon: ib test failed (0x%08X)\n", tmp);
 		r = -EINVAL;
 	}
+out:
 	radeon_ib_free(rdev, &ib);
 	return r;
 }
-- 
2.25.1