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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Evan Quan <evan.quan@amd.com>,
        Alex Deucher <alexander.deucher@amd.com>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.8 111/464] drm/amdgpu/debugfs: fix ref count leak when pm_runtime_get_sync fails
Date:   Mon, 17 Aug 2020 17:11:04 +0200
Message-Id: <20200817143839.121606604@linuxfoundation.org>
In-Reply-To: <20200817143833.737102804@linuxfoundation.org>
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From: Alex Deucher <alexander.deucher@amd.com>

[ Upstream commit 9eee152aab56d374edb9ad21b3db05f5cdda2fe6 ]

The call to pm_runtime_get_sync increments the counter even in case of
failure, leading to incorrect ref count.
In case of failure, decrement the ref count before returning.

Acked-by: Evan Quan <evan.quan@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c | 95 +++++++++++++++------
 1 file changed, 70 insertions(+), 25 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
index a414da22a359c..386b979e08522 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
@@ -223,12 +223,16 @@ static int  amdgpu_debugfs_process_reg_op(bool read, struct file *f,
 	*pos &= (1UL << 22) - 1;
 
 	r = pm_runtime_get_sync(adev->ddev->dev);
-	if (r < 0)
+	if (r < 0) {
+		pm_runtime_put_autosuspend(adev->ddev->dev);
 		return r;
+	}
 
 	r = amdgpu_virt_enable_access_debugfs(adev);
-	if (r < 0)
+	if (r < 0) {
+		pm_runtime_put_autosuspend(adev->ddev->dev);
 		return r;
+	}
 
 	if (use_bank) {
 		if ((sh_bank != 0xFFFFFFFF && sh_bank >= adev->gfx.config.max_sh_per_se) ||
@@ -332,12 +336,16 @@ static ssize_t amdgpu_debugfs_regs_pcie_read(struct file *f, char __user *buf,
 		return -EINVAL;
 
 	r = pm_runtime_get_sync(adev->ddev->dev);
-	if (r < 0)
+	if (r < 0) {
+		pm_runtime_put_autosuspend(adev->ddev->dev);
 		return r;
+	}
 
 	r = amdgpu_virt_enable_access_debugfs(adev);
-	if (r < 0)
+	if (r < 0) {
+		pm_runtime_put_autosuspend(adev->ddev->dev);
 		return r;
+	}
 
 	while (size) {
 		uint32_t value;
@@ -387,12 +395,16 @@ static ssize_t amdgpu_debugfs_regs_pcie_write(struct file *f, const char __user
 		return -EINVAL;
 
 	r = pm_runtime_get_sync(adev->ddev->dev);
-	if (r < 0)
+	if (r < 0) {
+		pm_runtime_put_autosuspend(adev->ddev->dev);
 		return r;
+	}
 
 	r = amdgpu_virt_enable_access_debugfs(adev);
-	if (r < 0)
+	if (r < 0) {
+		pm_runtime_put_autosuspend(adev->ddev->dev);
 		return r;
+	}
 
 	while (size) {
 		uint32_t value;
@@ -443,12 +455,16 @@ static ssize_t amdgpu_debugfs_regs_didt_read(struct file *f, char __user *buf,
 		return -EINVAL;
 
 	r = pm_runtime_get_sync(adev->ddev->dev);
-	if (r < 0)
+	if (r < 0) {
+		pm_runtime_put_autosuspend(adev->ddev->dev);
 		return r;
+	}
 
 	r = amdgpu_virt_enable_access_debugfs(adev);
-	if (r < 0)
+	if (r < 0) {
+		pm_runtime_put_autosuspend(adev->ddev->dev);
 		return r;
+	}
 
 	while (size) {
 		uint32_t value;
@@ -498,12 +514,16 @@ static ssize_t amdgpu_debugfs_regs_didt_write(struct file *f, const char __user
 		return -EINVAL;
 
 	r = pm_runtime_get_sync(adev->ddev->dev);
-	if (r < 0)
+	if (r < 0) {
+		pm_runtime_put_autosuspend(adev->ddev->dev);
 		return r;
+	}
 
 	r = amdgpu_virt_enable_access_debugfs(adev);
-	if (r < 0)
+	if (r < 0) {
+		pm_runtime_put_autosuspend(adev->ddev->dev);
 		return r;
+	}
 
 	while (size) {
 		uint32_t value;
@@ -554,12 +574,16 @@ static ssize_t amdgpu_debugfs_regs_smc_read(struct file *f, char __user *buf,
 		return -EINVAL;
 
 	r = pm_runtime_get_sync(adev->ddev->dev);
-	if (r < 0)
+	if (r < 0) {
+		pm_runtime_put_autosuspend(adev->ddev->dev);
 		return r;
+	}
 
 	r = amdgpu_virt_enable_access_debugfs(adev);
-	if (r < 0)
+	if (r < 0) {
+		pm_runtime_put_autosuspend(adev->ddev->dev);
 		return r;
+	}
 
 	while (size) {
 		uint32_t value;
@@ -609,12 +633,16 @@ static ssize_t amdgpu_debugfs_regs_smc_write(struct file *f, const char __user *
 		return -EINVAL;
 
 	r = pm_runtime_get_sync(adev->ddev->dev);
-	if (r < 0)
+	if (r < 0) {
+		pm_runtime_put_autosuspend(adev->ddev->dev);
 		return r;
+	}
 
 	r = amdgpu_virt_enable_access_debugfs(adev);
-	if (r < 0)
+	if (r < 0) {
+		pm_runtime_put_autosuspend(adev->ddev->dev);
 		return r;
+	}
 
 	while (size) {
 		uint32_t value;
@@ -764,12 +792,16 @@ static ssize_t amdgpu_debugfs_sensor_read(struct file *f, char __user *buf,
 	valuesize = sizeof(values);
 
 	r = pm_runtime_get_sync(adev->ddev->dev);
-	if (r < 0)
+	if (r < 0) {
+		pm_runtime_put_autosuspend(adev->ddev->dev);
 		return r;
+	}
 
 	r = amdgpu_virt_enable_access_debugfs(adev);
-	if (r < 0)
+	if (r < 0) {
+		pm_runtime_put_autosuspend(adev->ddev->dev);
 		return r;
+	}
 
 	r = amdgpu_dpm_read_sensor(adev, idx, &values[0], &valuesize);
 
@@ -842,12 +874,16 @@ static ssize_t amdgpu_debugfs_wave_read(struct file *f, char __user *buf,
 	simd = (*pos & GENMASK_ULL(44, 37)) >> 37;
 
 	r = pm_runtime_get_sync(adev->ddev->dev);
-	if (r < 0)
+	if (r < 0) {
+		pm_runtime_put_autosuspend(adev->ddev->dev);
 		return r;
+	}
 
 	r = amdgpu_virt_enable_access_debugfs(adev);
-	if (r < 0)
+	if (r < 0) {
+		pm_runtime_put_autosuspend(adev->ddev->dev);
 		return r;
+	}
 
 	/* switch to the specific se/sh/cu */
 	mutex_lock(&adev->grbm_idx_mutex);
@@ -977,6 +1013,7 @@ static ssize_t amdgpu_debugfs_gpr_read(struct file *f, char __user *buf,
 	}
 
 err:
+	pm_runtime_put_autosuspend(adev->ddev->dev);
 	kfree(data);
 	amdgpu_virt_disable_access_debugfs(adev);
 	return result;
@@ -1003,8 +1040,10 @@ static ssize_t amdgpu_debugfs_gfxoff_write(struct file *f, const char __user *bu
 		return -EINVAL;
 
 	r = pm_runtime_get_sync(adev->ddev->dev);
-	if (r < 0)
+	if (r < 0) {
+		pm_runtime_put_autosuspend(adev->ddev->dev);
 		return r;
+	}
 
 	while (size) {
 		uint32_t value;
@@ -1140,8 +1179,10 @@ static int amdgpu_debugfs_test_ib(struct seq_file *m, void *data)
 	int r = 0, i;
 
 	r = pm_runtime_get_sync(dev->dev);
-	if (r < 0)
+	if (r < 0) {
+		pm_runtime_put_autosuspend(adev->ddev->dev);
 		return r;
+	}
 
 	/* Avoid accidently unparking the sched thread during GPU reset */
 	mutex_lock(&adev->lock_reset);
@@ -1197,8 +1238,10 @@ static int amdgpu_debugfs_evict_vram(struct seq_file *m, void *data)
 	int r;
 
 	r = pm_runtime_get_sync(dev->dev);
-	if (r < 0)
+	if (r < 0) {
+		pm_runtime_put_autosuspend(adev->ddev->dev);
 		return r;
+	}
 
 	seq_printf(m, "(%d)\n", amdgpu_bo_evict_vram(adev));
 
@@ -1216,8 +1259,10 @@ static int amdgpu_debugfs_evict_gtt(struct seq_file *m, void *data)
 	int r;
 
 	r = pm_runtime_get_sync(dev->dev);
-	if (r < 0)
+	if (r < 0) {
+		pm_runtime_put_autosuspend(adev->ddev->dev);
 		return r;
+	}
 
 	seq_printf(m, "(%d)\n", ttm_bo_evict_mm(&adev->mman.bdev, TTM_PL_TT));
 
@@ -1417,16 +1462,16 @@ static int amdgpu_debugfs_sclk_set(void *data, u64 val)
 		return -EINVAL;
 
 	ret = pm_runtime_get_sync(adev->ddev->dev);
-	if (ret < 0)
+	if (ret < 0) {
+		pm_runtime_put_autosuspend(adev->ddev->dev);
 		return ret;
+	}
 
 	if (is_support_sw_smu(adev)) {
 		ret = smu_get_dpm_freq_range(&adev->smu, SMU_SCLK, &min_freq, &max_freq, true);
 		if (ret || val > max_freq || val < min_freq)
 			return -EINVAL;
 		ret = smu_set_soft_freq_range(&adev->smu, SMU_SCLK, (uint32_t)val, (uint32_t)val, true);
-	} else {
-		return 0;
 	}
 
 	pm_runtime_mark_last_busy(adev->ddev->dev);
-- 
2.25.1