drivers/gpu/drm/amd/amdgpu/amdgpu_object.c:473 amdgpu_bo_validate_size() error: we previously assumed 'man' could be null (see line 458)

[Dan Carpenter]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   1b929c02afd37871d5afb9d498426f83432e71c2
commit: 7554886daa31eacc8e7fac9e15bbce67d10b8f1f drm/amdgpu: Fix size validation for non-exclusive domains (v4)
config: ia64-randconfig-m041-20221229
compiler: ia64-linux-gcc (GCC) 12.1.0

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@xxxxxxxxx>
| Reported-by: Dan Carpenter <error27@xxxxxxxxx>

smatch warnings:
drivers/gpu/drm/amd/amdgpu/amdgpu_object.c:473 amdgpu_bo_validate_size() error: we previously assumed 'man' could be null (see line 458)

vim +/man +473 drivers/gpu/drm/amd/amdgpu/amdgpu_object.c

79c631239a83ae Andrey Grodzovsky 2017-11-10  444  static bool amdgpu_bo_validate_size(struct amdgpu_device *adev,
79c631239a83ae Andrey Grodzovsky 2017-11-10  445  					  unsigned long size, u32 domain)
79c631239a83ae Andrey Grodzovsky 2017-11-10  446  {
9de59bc201496f Dave Airlie       2020-08-04  447  	struct ttm_resource_manager *man = NULL;
79c631239a83ae Andrey Grodzovsky 2017-11-10  448  
79c631239a83ae Andrey Grodzovsky 2017-11-10  449  	/*
79c631239a83ae Andrey Grodzovsky 2017-11-10  450  	 * If GTT is part of requested domains the check must succeed to
7554886daa31ea Luben Tuikov      2022-12-10  451  	 * allow fall back to GTT.
79c631239a83ae Andrey Grodzovsky 2017-11-10  452  	 */
79c631239a83ae Andrey Grodzovsky 2017-11-10  453  	if (domain & AMDGPU_GEM_DOMAIN_GTT) {
6c28aed6e5b7fa Dave Airlie       2020-08-04  454  		man = ttm_manager_type(&adev->mman.bdev, TTM_PL_TT);
79c631239a83ae Andrey Grodzovsky 2017-11-10  455  
7554886daa31ea Luben Tuikov      2022-12-10  456  		if (man && size < man->size)
79c631239a83ae Andrey Grodzovsky 2017-11-10  457  			return true;
7554886daa31ea Luben Tuikov      2022-12-10 @458  		else if (!man)
7554886daa31ea Luben Tuikov      2022-12-10  459  			WARN_ON_ONCE("GTT domain requested but GTT mem manager uninitialized");

WARN()

79c631239a83ae Andrey Grodzovsky 2017-11-10  460  		goto fail;
7554886daa31ea Luben Tuikov      2022-12-10  461  	} else if (domain & AMDGPU_GEM_DOMAIN_VRAM) {
6c28aed6e5b7fa Dave Airlie       2020-08-04  462  		man = ttm_manager_type(&adev->mman.bdev, TTM_PL_VRAM);
79c631239a83ae Andrey Grodzovsky 2017-11-10  463  
7554886daa31ea Luben Tuikov      2022-12-10  464  		if (man && size < man->size)
79c631239a83ae Andrey Grodzovsky 2017-11-10  465  			return true;
79c631239a83ae Andrey Grodzovsky 2017-11-10  466  		goto fail;
79c631239a83ae Andrey Grodzovsky 2017-11-10  467  	}
79c631239a83ae Andrey Grodzovsky 2017-11-10  468  
79c631239a83ae Andrey Grodzovsky 2017-11-10  469  	/* TODO add more domains checks, such as AMDGPU_GEM_DOMAIN_CPU */
79c631239a83ae Andrey Grodzovsky 2017-11-10  470  	return true;
79c631239a83ae Andrey Grodzovsky 2017-11-10  471  
79c631239a83ae Andrey Grodzovsky 2017-11-10  472  fail:
299c776cebb01c Michel Dänzer     2017-11-15 @473  	DRM_DEBUG("BO size %lu > total memory in domain: %llu\n", size,
4499c90e902f39 Christian König   2022-03-11  474  		  man->size);

Followed by crash.

79c631239a83ae Andrey Grodzovsky 2017-11-10  475  	return false;
79c631239a83ae Andrey Grodzovsky 2017-11-10  476  }

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