[PATCH 7.2.y 2/2] drm/amdgpu: free the userptr ranges when a CS fails after parser_bos

[Sasha Levin <sashal@kernel.org>]

From: Jesse Zhang <Jesse.Zhang@amd.com>

[ Upstream commit 1b4da805a0ba354a549ce07459c871c17dd94fe0 ]

amdgpu_cs_parser_bos() allocates an HMM range for every userptr entry of
the BO list and looks up the user pages. Those ranges are only freed when
amdgpu_cs_parser_bos() itself fails or when amdgpu_cs_submit() checks
them under the notifier lock. If amdgpu_cs_patch_jobs(),
amdgpu_cs_vm_handling(), amdgpu_cs_sync_rings() or the early part of
amdgpu_cs_submit() fails, nothing frees them: neither
amdgpu_cs_parser_fini() nor amdgpu_bo_list_free() touch e->range.

Each such CS then leaks the range, its hmm_pfns array (8 bytes per page
of the userptr BO) and the BO reference the range holds. An IB on a ring
that patches the CS in place (e.g. VCN) with an unmapped va_start fails
in amdgpu_cs_patch_ibs() and takes this path.

Free the ranges on those error paths. Ranges amdgpu_cs_submit() already
dropped are NULL, so freeing them again is a no-op.

Fixes: fec8fdb54e8f ("drm/amdgpu: fix userptr HMM range handling v2")
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Jesse Zhang <Jesse.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit c52a9542ed7cfd527feb938bd0accada2ac8d267)
Cc: stable@vger.kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
index 2c1c540808109..75b39a41fb923 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
@@ -1434,6 +1434,7 @@ static void amdgpu_cs_parser_fini(struct amdgpu_cs_parser *parser)
 int amdgpu_cs_ioctl(struct drm_device *dev, void *data, struct drm_file *filp)
 {
 	struct amdgpu_device *adev = drm_to_adev(dev);
+	struct amdgpu_bo_list_entry *e;
 	struct amdgpu_cs_parser parser;
 	int r;
 
@@ -1468,25 +1469,31 @@ int amdgpu_cs_ioctl(struct drm_device *dev, void *data, struct drm_file *filp)
 
 	r = amdgpu_cs_patch_jobs(&parser);
 	if (r)
-		goto error_fini;
+		goto error_free_user_pages;
 
 	r = amdgpu_cs_vm_handling(&parser);
 	if (r)
-		goto error_fini;
+		goto error_free_user_pages;
 
 	r = amdgpu_cs_sync_rings(&parser);
 	if (r)
-		goto error_fini;
+		goto error_free_user_pages;
 
 	trace_amdgpu_cs_ibs(&parser);
 
 	r = amdgpu_cs_submit(&parser, data);
 	if (r)
-		goto error_fini;
+		goto error_free_user_pages;
 
 	amdgpu_cs_parser_fini(&parser);
 	return 0;
 
+error_free_user_pages:
+	/* amdgpu_cs_submit() only drops the ranges once it got that far. */
+	amdgpu_bo_list_for_each_userptr_entry(e, parser.bo_list) {
+		amdgpu_hmm_range_free(e->range);
+		e->range = NULL;
+	}
 error_fini:
 	amdgpu_cs_parser_fini(&parser);
 	return r;
-- 
2.53.0