Hello Jerome Glisse,
The patch fb53f8621a3f: "drm/ttm: Print debug information on memory manager when eviction fails" from Dec 9, 2009, leads to the following static checker warning: "drivers/gpu/drm/ttm/ttm_bo.c:1494 ttm_mem_reg_is_pci() warn: buffer overflow 'bdev->man' 8 <= 8"
drivers/gpu/drm/ttm/ttm_bo.c 56 static inline int ttm_mem_type_from_flags(uint32_t flags, uint32_t *mem_type) 57 { 58 int i; 59 60 for (i = 0; i <= TTM_PL_PRIV5; i++) 61 if (flags & (1 << i)) { 62 *mem_type = i; 63 return 0; 64 } 65 return -EINVAL; 66 }
--- [snip] to the ttm_bo_mem_space() function:
869 for (i = 0; i < placement->num_placement; ++i) { 870 ret = ttm_mem_type_from_flags(placement->placement[i], 871 &mem_type); 872 if (ret) 873 return ret; 874 man = &bdev->man[mem_type]; 875
So after ttm_mem_type_from_flags then mem_type can be TTM_PL_PRIV5 (8) but the bdev->man[] array only has TTM_NUM_MEM_TYPES (8) elements so we are one space beyond the end of the array.
regards, dan carpenter