[PATCH AUTOSEL 6.6 19/31] drm/amdkfd: Fix lock dependency warning

[PATCH AUTOSEL 6.6 19/31] drm/amdkfd: Fix lock dependency warning

[Sasha Levin]

From: Felix Kuehling <felix.kuehling@amd.com>

[ Upstream commit 47bf0f83fc86df1bf42b385a91aadb910137c5c9 ]

======================================================
WARNING: possible circular locking dependency detected
6.5.0-kfd-fkuehlin #276 Not tainted
------------------------------------------------------
kworker/8:2/2676 is trying to acquire lock:
ffff9435aae95c88 ((work_completion)(&svm_bo->eviction_work)){+.+.}-{0:0}, at: __flush_work+0x52/0x550

but task is already holding lock:
ffff9435cd8e1720 (&svms->lock){+.+.}-{3:3}, at: svm_range_deferred_list_work+0xe8/0x340 [amdgpu]

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #2 (&svms->lock){+.+.}-{3:3}:
       __mutex_lock+0x97/0xd30
       kfd_ioctl_alloc_memory_of_gpu+0x6d/0x3c0 [amdgpu]
       kfd_ioctl+0x1b2/0x5d0 [amdgpu]
       __x64_sys_ioctl+0x86/0xc0
       do_syscall_64+0x39/0x80
       entry_SYSCALL_64_after_hwframe+0x63/0xcd

-> #1 (&mm->mmap_lock){++++}-{3:3}:
       down_read+0x42/0x160
       svm_range_evict_svm_bo_worker+0x8b/0x340 [amdgpu]
       process_one_work+0x27a/0x540
       worker_thread+0x53/0x3e0
       kthread+0xeb/0x120
       ret_from_fork+0x31/0x50
       ret_from_fork_asm+0x11/0x20

-> #0 ((work_completion)(&svm_bo->eviction_work)){+.+.}-{0:0}:
       __lock_acquire+0x1426/0x2200
       lock_acquire+0xc1/0x2b0
       __flush_work+0x80/0x550
       __cancel_work_timer+0x109/0x190
       svm_range_bo_release+0xdc/0x1c0 [amdgpu]
       svm_range_free+0x175/0x180 [amdgpu]
       svm_range_deferred_list_work+0x15d/0x340 [amdgpu]
       process_one_work+0x27a/0x540
       worker_thread+0x53/0x3e0
       kthread+0xeb/0x120
       ret_from_fork+0x31/0x50
       ret_from_fork_asm+0x11/0x20

other info that might help us debug this:

Chain exists of:
  (work_completion)(&svm_bo->eviction_work) --> &mm->mmap_lock --> &svms->lock

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&svms->lock);
                               lock(&mm->mmap_lock);
                               lock(&svms->lock);
  lock((work_completion)(&svm_bo->eviction_work));

I believe this cannot really lead to a deadlock in practice, because
svm_range_evict_svm_bo_worker only takes the mmap_read_lock if the BO
refcount is non-0. That means it's impossible that svm_range_bo_release
is running concurrently. However, there is no good way to annotate this.

To avoid the problem, take a BO reference in
svm_range_schedule_evict_svm_bo instead of in the worker. That way it's
impossible for a BO to get freed while eviction work is pending and the
cancel_work_sync call in svm_range_bo_release can be eliminated.

v2: Use svm_bo_ref_unless_zero and explained why that's safe. Also
removed redundant checks that are already done in
amdkfd_fence_enable_signaling.

Signed-off-by: Felix Kuehling <felix.kuehling@amd.com>
Reviewed-by: Philip Yang <philip.yang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/gpu/drm/amd/amdkfd/kfd_svm.c | 26 ++++++++++----------------
 1 file changed, 10 insertions(+), 16 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
index 8e368e4659fd..a4c911fa1675 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
@@ -391,14 +391,9 @@ static void svm_range_bo_release(struct kref *kref)
 		spin_lock(&svm_bo->list_lock);
 	}
 	spin_unlock(&svm_bo->list_lock);
-	if (!dma_fence_is_signaled(&svm_bo->eviction_fence->base)) {
-		/* We're not in the eviction worker.
-		 * Signal the fence and synchronize with any
-		 * pending eviction work.
-		 */
+	if (!dma_fence_is_signaled(&svm_bo->eviction_fence->base))
+		/* We're not in the eviction worker. Signal the fence. */
 		dma_fence_signal(&svm_bo->eviction_fence->base);
-		cancel_work_sync(&svm_bo->eviction_work);
-	}
 	dma_fence_put(&svm_bo->eviction_fence->base);
 	amdgpu_bo_unref(&svm_bo->bo);
 	kfree(svm_bo);
@@ -3424,13 +3419,14 @@ svm_range_trigger_migration(struct mm_struct *mm, struct svm_range *prange,
 
 int svm_range_schedule_evict_svm_bo(struct amdgpu_amdkfd_fence *fence)
 {
-	if (!fence)
-		return -EINVAL;
-
-	if (dma_fence_is_signaled(&fence->base))
-		return 0;
-
-	if (fence->svm_bo) {
+	/* Dereferencing fence->svm_bo is safe here because the fence hasn't
+	 * signaled yet and we're under the protection of the fence->lock.
+	 * After the fence is signaled in svm_range_bo_release, we cannot get
+	 * here any more.
+	 *
+	 * Reference is dropped in svm_range_evict_svm_bo_worker.
+	 */
+	if (svm_bo_ref_unless_zero(fence->svm_bo)) {
 		WRITE_ONCE(fence->svm_bo->evicting, 1);
 		schedule_work(&fence->svm_bo->eviction_work);
 	}
@@ -3445,8 +3441,6 @@ static void svm_range_evict_svm_bo_worker(struct work_struct *work)
 	int r = 0;
 
 	svm_bo = container_of(work, struct svm_range_bo, eviction_work);
-	if (!svm_bo_ref_unless_zero(svm_bo))
-		return; /* svm_bo was freed while eviction was pending */
 
 	if (mmget_not_zero(svm_bo->eviction_fence->mm)) {
 		mm = svm_bo->eviction_fence->mm;
-- 
2.43.0

[PATCH AUTOSEL 6.6 20/31] drm/amdkfd: Fix lock dependency warning with srcu

[Sasha Levin]

From: Philip Yang <Philip.Yang@amd.com>

[ Upstream commit 2a9de42e8d3c82c6990d226198602be44f43f340 ]

======================================================
WARNING: possible circular locking dependency detected
6.5.0-kfd-yangp #2289 Not tainted
------------------------------------------------------
kworker/0:2/996 is trying to acquire lock:
        (srcu){.+.+}-{0:0}, at: __synchronize_srcu+0x5/0x1a0

but task is already holding lock:
        ((work_completion)(&svms->deferred_list_work)){+.+.}-{0:0}, at:
	process_one_work+0x211/0x560

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #3 ((work_completion)(&svms->deferred_list_work)){+.+.}-{0:0}:
        __flush_work+0x88/0x4f0
        svm_range_list_lock_and_flush_work+0x3d/0x110 [amdgpu]
        svm_range_set_attr+0xd6/0x14c0 [amdgpu]
        kfd_ioctl+0x1d1/0x630 [amdgpu]
        __x64_sys_ioctl+0x88/0xc0

-> #2 (&info->lock#2){+.+.}-{3:3}:
        __mutex_lock+0x99/0xc70
        amdgpu_amdkfd_gpuvm_restore_process_bos+0x54/0x740 [amdgpu]
        restore_process_helper+0x22/0x80 [amdgpu]
        restore_process_worker+0x2d/0xa0 [amdgpu]
        process_one_work+0x29b/0x560
        worker_thread+0x3d/0x3d0

-> #1 ((work_completion)(&(&process->restore_work)->work)){+.+.}-{0:0}:
        __flush_work+0x88/0x4f0
        __cancel_work_timer+0x12c/0x1c0
        kfd_process_notifier_release_internal+0x37/0x1f0 [amdgpu]
        __mmu_notifier_release+0xad/0x240
        exit_mmap+0x6a/0x3a0
        mmput+0x6a/0x120
        do_exit+0x322/0xb90
        do_group_exit+0x37/0xa0
        __x64_sys_exit_group+0x18/0x20
        do_syscall_64+0x38/0x80

-> #0 (srcu){.+.+}-{0:0}:
        __lock_acquire+0x1521/0x2510
        lock_sync+0x5f/0x90
        __synchronize_srcu+0x4f/0x1a0
        __mmu_notifier_release+0x128/0x240
        exit_mmap+0x6a/0x3a0
        mmput+0x6a/0x120
        svm_range_deferred_list_work+0x19f/0x350 [amdgpu]
        process_one_work+0x29b/0x560
        worker_thread+0x3d/0x3d0

other info that might help us debug this:
Chain exists of:
  srcu --> &info->lock#2 --> (work_completion)(&svms->deferred_list_work)

Possible unsafe locking scenario:

        CPU0                    CPU1
        ----                    ----
        lock((work_completion)(&svms->deferred_list_work));
                        lock(&info->lock#2);
			lock((work_completion)(&svms->deferred_list_work));
        sync(srcu);

Signed-off-by: Philip Yang <Philip.Yang@amd.com>
Reviewed-by: Felix Kuehling <felix.kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/gpu/drm/amd/amdkfd/kfd_svm.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
index a4c911fa1675..b51224a85a38 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
@@ -2343,8 +2343,10 @@ static void svm_range_deferred_list_work(struct work_struct *work)
 		mutex_unlock(&svms->lock);
 		mmap_write_unlock(mm);
 
-		/* Pairs with mmget in svm_range_add_list_work */
-		mmput(mm);
+		/* Pairs with mmget in svm_range_add_list_work. If dropping the
+		 * last mm refcount, schedule release work to avoid circular locking
+		 */
+		mmput_async(mm);
 
 		spin_lock(&svms->deferred_list_lock);
 	}
-- 
2.43.0

[PATCH AUTOSEL 6.6 26/31] drm/amdgpu: fix avg vs input power reporting on smu7

[Sasha Levin]

From: Alex Deucher <alexander.deucher@amd.com>

[ Upstream commit 25852d4b97572ff62ffee574cb8bb4bc551af23a ]

Hawaii, Bonaire, Fiji, and Tonga support average power, the others
support current power.

Reviewed-by: Yang Wang <kevinyang.wang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 .../gpu/drm/amd/pm/powerplay/hwmgr/smu7_hwmgr.c | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/pm/powerplay/hwmgr/smu7_hwmgr.c b/drivers/gpu/drm/amd/pm/powerplay/hwmgr/smu7_hwmgr.c
index 11372fcc59c8..a2c7b2e111fa 100644
--- a/drivers/gpu/drm/amd/pm/powerplay/hwmgr/smu7_hwmgr.c
+++ b/drivers/gpu/drm/amd/pm/powerplay/hwmgr/smu7_hwmgr.c
@@ -3995,6 +3995,7 @@ static int smu7_read_sensor(struct pp_hwmgr *hwmgr, int idx,
 	uint32_t sclk, mclk, activity_percent;
 	uint32_t offset, val_vid;
 	struct smu7_hwmgr *data = (struct smu7_hwmgr *)(hwmgr->backend);
+	struct amdgpu_device *adev = hwmgr->adev;
 
 	/* size must be at least 4 bytes for all sensors */
 	if (*size < 4)
@@ -4038,7 +4039,21 @@ static int smu7_read_sensor(struct pp_hwmgr *hwmgr, int idx,
 		*size = 4;
 		return 0;
 	case AMDGPU_PP_SENSOR_GPU_INPUT_POWER:
-		return smu7_get_gpu_power(hwmgr, (uint32_t *)value);
+		if ((adev->asic_type != CHIP_HAWAII) &&
+		    (adev->asic_type != CHIP_BONAIRE) &&
+		    (adev->asic_type != CHIP_FIJI) &&
+		    (adev->asic_type != CHIP_TONGA))
+			return smu7_get_gpu_power(hwmgr, (uint32_t *)value);
+		else
+			return -EOPNOTSUPP;
+	case AMDGPU_PP_SENSOR_GPU_AVG_POWER:
+		if ((adev->asic_type != CHIP_HAWAII) &&
+		    (adev->asic_type != CHIP_BONAIRE) &&
+		    (adev->asic_type != CHIP_FIJI) &&
+		    (adev->asic_type != CHIP_TONGA))
+			return -EOPNOTSUPP;
+		else
+			return smu7_get_gpu_power(hwmgr, (uint32_t *)value);
 	case AMDGPU_PP_SENSOR_VDDGFX:
 		if ((data->vr_config & VRCONF_VDDGFX_MASK) ==
 		    (VR_SVI2_PLANE_2 << VRCONF_VDDGFX_SHIFT))
-- 
2.43.0

[PATCH AUTOSEL 6.6 27/31] drm/amd/powerplay: Fix kzalloc parameter 'ATOM_Tonga_PPM_Table' in 'get_platform_power_management_table()'

[Sasha Levin]

From: Srinivasan Shanmugam <srinivasan.shanmugam@amd.com>

[ Upstream commit 6616b5e1999146b1304abe78232af810080c67e3 ]

In 'struct phm_ppm_table *ptr' allocation using kzalloc, an incorrect
structure type is passed to sizeof() in kzalloc, larger structure types
were used, thus using correct type 'struct phm_ppm_table' fixes the
below:

drivers/gpu/drm/amd/amdgpu/../pm/powerplay/hwmgr/process_pptables_v1_0.c:203 get_platform_power_management_table() warn: struct type mismatch 'phm_ppm_table vs _ATOM_Tonga_PPM_Table'

Cc: Eric Huang <JinHuiEric.Huang@amd.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/gpu/drm/amd/pm/powerplay/hwmgr/process_pptables_v1_0.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/pm/powerplay/hwmgr/process_pptables_v1_0.c b/drivers/gpu/drm/amd/pm/powerplay/hwmgr/process_pptables_v1_0.c
index f2a55c1413f5..17882f8dfdd3 100644
--- a/drivers/gpu/drm/amd/pm/powerplay/hwmgr/process_pptables_v1_0.c
+++ b/drivers/gpu/drm/amd/pm/powerplay/hwmgr/process_pptables_v1_0.c
@@ -200,7 +200,7 @@ static int get_platform_power_management_table(
 		struct pp_hwmgr *hwmgr,
 		ATOM_Tonga_PPM_Table *atom_ppm_table)
 {
-	struct phm_ppm_table *ptr = kzalloc(sizeof(ATOM_Tonga_PPM_Table), GFP_KERNEL);
+	struct phm_ppm_table *ptr = kzalloc(sizeof(*ptr), GFP_KERNEL);
 	struct phm_ppt_v1_information *pp_table_information =
 		(struct phm_ppt_v1_information *)(hwmgr->pptable);
 
-- 
2.43.0

[PATCH AUTOSEL 6.6 28/31] drm/amdgpu: Fix with right return code '-EIO' in 'amdgpu_gmc_vram_checking()'

[Sasha Levin]

From: Srinivasan Shanmugam <srinivasan.shanmugam@amd.com>

[ Upstream commit fac4ebd79fed60e79cccafdad45a2bb8d3795044 ]

The amdgpu_gmc_vram_checking() function in emulation checks whether
all of the memory range of shared system memory could be accessed by
GPU, from this aspect, -EIO is returned for error scenarios.

Fixes the below:
drivers/gpu/drm/amd/amdgpu/gmc_v6_0.c:919 gmc_v6_0_hw_init() warn: missing error code? 'r'
drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c:1103 gmc_v7_0_hw_init() warn: missing error code? 'r'
drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c:1223 gmc_v8_0_hw_init() warn: missing error code? 'r'
drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c:2344 gmc_v9_0_hw_init() warn: missing error code? 'r'

Cc: Xiaojian Du <Xiaojian.Du@amd.com>
Cc: Lijo Lazar <lijo.lazar@amd.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam@amd.com>
Suggested-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Christian König <christian.koenig@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_gmc.c | 21 ++++++++++++++-------
 1 file changed, 14 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.c
index d78bd9732543..bc0eda1a729c 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.c
@@ -876,21 +876,28 @@ int amdgpu_gmc_vram_checking(struct amdgpu_device *adev)
 	 * seconds, so here, we just pick up three parts for emulation.
 	 */
 	ret = memcmp(vram_ptr, cptr, 10);
-	if (ret)
-		return ret;
+	if (ret) {
+		ret = -EIO;
+		goto release_buffer;
+	}
 
 	ret = memcmp(vram_ptr + (size / 2), cptr, 10);
-	if (ret)
-		return ret;
+	if (ret) {
+		ret = -EIO;
+		goto release_buffer;
+	}
 
 	ret = memcmp(vram_ptr + size - 10, cptr, 10);
-	if (ret)
-		return ret;
+	if (ret) {
+		ret = -EIO;
+		goto release_buffer;
+	}
 
+release_buffer:
 	amdgpu_bo_free_kernel(&vram_bo, &vram_gpu,
 			&vram_ptr);
 
-	return 0;
+	return ret;
 }
 
 static ssize_t current_memory_partition_show(
-- 
2.43.0

[PATCH AUTOSEL 6.6 29/31] drm/amdgpu: Release 'adev->pm.fw' before return in 'amdgpu_device_need_post()'

[Sasha Levin]

From: Srinivasan Shanmugam <srinivasan.shanmugam@amd.com>

[ Upstream commit 8a44fdd3cf91debbd09b43bd2519ad2b2486ccf4 ]

In function 'amdgpu_device_need_post(struct amdgpu_device *adev)' -
'adev->pm.fw' may not be released before return.

Using the function release_firmware() to release adev->pm.fw.

Thus fixing the below:
drivers/gpu/drm/amd/amdgpu/amdgpu_device.c:1571 amdgpu_device_need_post() warn: 'adev->pm.fw' from request_firmware() not released on lines: 1554.

Cc: Monk Liu <Monk.Liu@amd.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam@amd.com>
Suggested-by: Lijo Lazar <lijo.lazar@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@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_device.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
index 56d99ffbba2e..7791367e7c02 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
@@ -1218,6 +1218,7 @@ bool amdgpu_device_need_post(struct amdgpu_device *adev)
 				return true;
 
 			fw_ver = *((uint32_t *)adev->pm.fw->data + 69);
+			release_firmware(adev->pm.fw);
 			if (fw_ver < 0x00160e00)
 				return true;
 		}
-- 
2.43.0

[PATCH AUTOSEL 6.6 30/31] drm/amdkfd: Fix 'node' NULL check in 'svm_range_get_range_boundaries()'

[Sasha Levin]

From: Srinivasan Shanmugam <srinivasan.shanmugam@amd.com>

[ Upstream commit d7a254fad873775ce6c32b77796c81e81e6b7f2e ]

Range interval [start, last] is ordered by rb_tree, rb_prev, rb_next
return value still needs NULL check, thus modified from "node" to "rb_node".

Fixes the below:
drivers/gpu/drm/amd/amdgpu/../amdkfd/kfd_svm.c:2691 svm_range_get_range_boundaries() warn: can 'node' even be NULL?

Suggested-by: Philip Yang <Philip.Yang@amd.com>
Cc: Felix Kuehling <Felix.Kuehling@amd.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam@amd.com>
Reviewed-by: Felix Kuehling <felix.kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/gpu/drm/amd/amdkfd/kfd_svm.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
index b51224a85a38..87e9ca65e58e 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
@@ -2657,6 +2657,7 @@ svm_range_get_range_boundaries(struct kfd_process *p, int64_t addr,
 {
 	struct vm_area_struct *vma;
 	struct interval_tree_node *node;
+	struct rb_node *rb_node;
 	unsigned long start_limit, end_limit;
 
 	vma = vma_lookup(p->mm, addr << PAGE_SHIFT);
@@ -2676,16 +2677,15 @@ svm_range_get_range_boundaries(struct kfd_process *p, int64_t addr,
 	if (node) {
 		end_limit = min(end_limit, node->start);
 		/* Last range that ends before the fault address */
-		node = container_of(rb_prev(&node->rb),
-				    struct interval_tree_node, rb);
+		rb_node = rb_prev(&node->rb);
 	} else {
 		/* Last range must end before addr because
 		 * there was no range after addr
 		 */
-		node = container_of(rb_last(&p->svms.objects.rb_root),
-				    struct interval_tree_node, rb);
+		rb_node = rb_last(&p->svms.objects.rb_root);
 	}
-	if (node) {
+	if (rb_node) {
+		node = container_of(rb_node, struct interval_tree_node, rb);
 		if (node->last >= addr) {
 			WARN(1, "Overlap with prev node and page fault addr\n");
 			return -EFAULT;
-- 
2.43.0