Lines Matching +full:memory +full:- +full:region

1 // SPDX-License-Identifier: GPL-2.0
3  * This file implements KASLR memory randomization for x86_64. It randomizes
4  * the virtual address space of kernel memory regions (physical memory
11  * The physical memory mapping code was adapted to support P4D/PUD level
13  * 30,000 possible virtual addresses in average for each memory region.
14  * An additional low memory page is used to ensure each CPU can start with
17  * The order of each memory region is not changed. The feature looks at
20  * physical memory mapping is the available physical memory.
44  * Memory regions randomized by KASLR (except modules that use a separate logic
57 /* Get size in bytes used by the memory region */
58 static inline unsigned long get_padding(struct kaslr_memory_region *region)  in get_padding()  argument
60 	return (region->size_tb << TB_SHIFT);  in get_padding()
63 /* Initialize base and padding for each memory region randomized with KASLR */
77 	 * These BUILD_BUG_ON checks ensure the memory layout is consistent  in kernel_randomize_memory()
88 	kaslr_regions[0].size_tb = 1 << (MAX_PHYSMEM_BITS - TB_SHIFT);  in kernel_randomize_memory()
92 	 * Update Physical memory mapping to available and  in kernel_randomize_memory()
93 	 * add padding if needed (especially for memory hotplug support).  in kernel_randomize_memory()
99 	/* Adapt physical memory region size based on available memory */  in kernel_randomize_memory()
104 	 * Calculate the vmemmap region size in TBs, aligned to a TB  in kernel_randomize_memory()
107 	vmemmap_size = (kaslr_regions[0].size_tb << (TB_SHIFT - PAGE_SHIFT)) *  in kernel_randomize_memory()
112 	remain_entropy = vaddr_end - vaddr_start;  in kernel_randomize_memory()
114 		remain_entropy -= get_padding(&kaslr_regions[i]);  in kernel_randomize_memory()
116 	prandom_seed_state(&rand_state, kaslr_get_random_long("Memory"));  in kernel_randomize_memory()
125 		entropy = remain_entropy / (ARRAY_SIZE(kaslr_regions) - i);  in kernel_randomize_memory()
132 		 * Jump the region and add a minimum padding based on  in kernel_randomize_memory()
137 		remain_entropy -= entropy;  in kernel_randomize_memory()