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Commit | Line | Data |
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1da177e4 | 1 | |
1da177e4 LT |
2 | Virtual memory map with 4 level page tables: |
3 | ||
57d30772 | 4 | 0000000000000000 - 00007fffffffffff (=47 bits) user space, different per mm |
4c7c4483 | 5 | hole caused by [47:63] sign extension |
beb9147e | 6 | ffff800000000000 - ffff87ffffffffff (=43 bits) guard hole, reserved for hypervisor |
2feceeff | 7 | ffff880000000000 - ffffc7ffffffffff (=64 TB) direct mapping of all phys. memory |
c898faf9 RR |
8 | ffffc80000000000 - ffffc8ffffffffff (=40 bits) hole |
9 | ffffc90000000000 - ffffe8ffffffffff (=45 bits) vmalloc/ioremap space | |
10 | ffffe90000000000 - ffffe9ffffffffff (=40 bits) hole | |
11 | ffffea0000000000 - ffffeaffffffffff (=40 bits) virtual memory map (1TB) | |
ef7f0d6a | 12 | ... unused hole ... |
9d9cce7f | 13 | ffffec0000000000 - fffffbffffffffff (=44 bits) kasan shadow memory (16TB) |
1da177e4 | 14 | ... unused hole ... |
9376ab43 TG |
15 | fffffe0000000000 - fffffe7fffffffff (=39 bits) cpu_entry_area mapping |
16 | fffffe8000000000 - fffffeffffffffff (=39 bits) LDT remap for PTI | |
3891a04a PA |
17 | ffffff0000000000 - ffffff7fffffffff (=39 bits) %esp fixup stacks |
18 | ... unused hole ... | |
9d9cce7f | 19 | ffffffef00000000 - fffffffeffffffff (=64 GB) EFI region mapping space |
ff3d0a12 | 20 | ... unused hole ... |
9d9cce7f | 21 | ffffffff80000000 - ffffffff9fffffff (=512 MB) kernel text mapping, from phys 0 |
d6948986 AL |
22 | ffffffffa0000000 - [fixmap start] (~1526 MB) module mapping space (variable) |
23 | [fixmap start] - ffffffffff5fffff kernel-internal fixmap range | |
24 | ffffffffff600000 - ffffffffff600fff (=4 kB) legacy vsyscall ABI | |
aca91bfc | 25 | ffffffffffe00000 - ffffffffffffffff (=2 MB) unused hole |
1da177e4 | 26 | |
4c7c4483 KS |
27 | Virtual memory map with 5 level page tables: |
28 | ||
29 | 0000000000000000 - 00ffffffffffffff (=56 bits) user space, different per mm | |
30 | hole caused by [56:63] sign extension | |
31 | ff00000000000000 - ff0fffffffffffff (=52 bits) guard hole, reserved for hypervisor | |
32 | ff10000000000000 - ff8fffffffffffff (=55 bits) direct mapping of all phys. memory | |
c2506438 | 33 | ff90000000000000 - ff9fffffffffffff (=52 bits) LDT remap for PTI |
29b1c137 | 34 | ffa0000000000000 - ffd1ffffffffffff (=54 bits) vmalloc/ioremap space (12800 TB) |
4c7c4483 KS |
35 | ffd2000000000000 - ffd3ffffffffffff (=49 bits) hole |
36 | ffd4000000000000 - ffd5ffffffffffff (=49 bits) virtual memory map (512TB) | |
37 | ... unused hole ... | |
2ce42815 | 38 | ffdf000000000000 - fffffc0000000000 (=53 bits) kasan shadow memory (8PB) |
4c7c4483 | 39 | ... unused hole ... |
9376ab43 TG |
40 | fffffe0000000000 - fffffe7fffffffff (=39 bits) cpu_entry_area mapping |
41 | ... unused hole ... | |
4c7c4483 KS |
42 | ffffff0000000000 - ffffff7fffffffff (=39 bits) %esp fixup stacks |
43 | ... unused hole ... | |
44 | ffffffef00000000 - fffffffeffffffff (=64 GB) EFI region mapping space | |
45 | ... unused hole ... | |
46 | ffffffff80000000 - ffffffff9fffffff (=512 MB) kernel text mapping, from phys 0 | |
1b1ff152 | 47 | ffffffffa0000000 - fffffffffeffffff (1520 MB) module mapping space |
d6948986 AL |
48 | [fixmap start] - ffffffffff5fffff kernel-internal fixmap range |
49 | ffffffffff600000 - ffffffffff600fff (=4 kB) legacy vsyscall ABI | |
4c7c4483 KS |
50 | ffffffffffe00000 - ffffffffffffffff (=2 MB) unused hole |
51 | ||
52 | Architecture defines a 64-bit virtual address. Implementations can support | |
53 | less. Currently supported are 48- and 57-bit virtual addresses. Bits 63 | |
d9012133 PZ |
54 | through to the most-significant implemented bit are sign extended. |
55 | This causes hole between user space and kernel addresses if you interpret them | |
56 | as unsigned. | |
4c7c4483 | 57 | |
57d30772 | 58 | The direct mapping covers all memory in the system up to the highest |
8315eca2 | 59 | memory address (this means in some cases it can also include PCI memory |
57d30772 | 60 | holes). |
8315eca2 | 61 | |
4c7c4483 KS |
62 | vmalloc space is lazily synchronized into the different PML4/PML5 pages of |
63 | the processes using the page fault handler, with init_top_pgt as | |
1da177e4 LT |
64 | reference. |
65 | ||
ff3d0a12 MF |
66 | We map EFI runtime services in the 'efi_pgd' PGD in a 64Gb large virtual |
67 | memory window (this size is arbitrary, it can be raised later if needed). | |
68 | The mappings are not part of any other kernel PGD and are only available | |
69 | during EFI runtime calls. | |
d2f7cbe7 | 70 | |
0483e1fa TG |
71 | Note that if CONFIG_RANDOMIZE_MEMORY is enabled, the direct mapping of all |
72 | physical memory, vmalloc/ioremap space and virtual memory map are randomized. | |
73 | Their order is preserved but their base will be offset early at boot time. |