内核配置
确保内核配置选项中启用了debugfs支持(CONFIG_DEBUG_FS=y)并重新编译内核
挂载debugfs文件系统
mount -t debugfs none /sys/kernel/debug
kernel_page_tables
确保内核配置选项中启用了如下配置：
CONFIG_GENERIC_PTDUMP=y
CONFIG_PTDUMP_CORE=y
CONFIG_PTDUMP_DEBUGFS=y
对应的代码文件 arch/arm64/mm/ptdump.c,命令：
#cat /sys/kernel/debug/kernel_page_tables
---[ Linear Mapping start ]---
0xffff000000000000-0xffff6e0000000000 110T PGD
0xffff6e0000000000-0xffff6e77c0000000 479G PUD
0xffff6e77c0000000-0xffff6e77c0210000 2112K PTE RW NX SHD AF UXN MEM/NORMAL-TAGGED
//...
0xffff6e8130000000-0xffff6e8140000000 256M PMD
0xffff6e8140000000-0xffff6f0000000000 507G PUD
0xffff6f0000000000-0xffff800000000000 17T PGD
---[ Linear Mapping end ]---
---[ Modules start ]---
0xffff800000000000-0xffff800008000000 128M PMD
---[ Modules end ]---
---[ vmalloc() area ]---
0xffff800008000000-0xffff800008004000 16K PTE RW NX SHD AF UXN MEM/NORMAL-TAGGED
0xffff800008004000-0xffff800008005000 4K PTE
//...
0xfffffbffeffc4000-0xfffffbffeffd0000 48K PTE RW NX SHD AF UXN MEM/NORMAL
0xfffffbffeffd0000-0xfffffbffeffe2000 72K PTE
0xfffffbffeffe2000-0xfffffbffeffee000 48K PTE RW NX SHD AF UXN MEM/NORMAL
0xfffffbffeffee000-0xfffffbfff0000000 72K PTE
---[ vmalloc() end ]---
0xfffffbfff0000000-0xfffffbfffda00000 218M PMD
0xfffffbfffda00000-0xfffffbfffdbf9000 2020K PTE
---[ Fixmap start ]---
0xfffffbfffdbf9000-0xfffffbfffdbfa000 4K PTE
0xfffffbfffdbfa000-0xfffffbfffdbfd000 12K PTE ro x SHD AF UXN MEM/NORMAL
0xfffffbfffdbfd000-0xfffffbfffdbfe000 4K PTE ro NX SHD AF UXN MEM/NORMAL
0xfffffbfffdbfe000-0xfffffbfffdbff000 4K PTE
0xfffffbfffdbff000-0xfffffbfffdc00000 4K PTE RW NX SHD AF UXN DEVICE/nGnRE
0xfffffbfffdc00000-0xfffffbfffde00000 2M PMD ro NX SHD AF BLK UXN MEM/NORMAL
0xfffffbfffde00000-0xfffffbfffe000000 2M PMD
---[ Fixmap end ]---
0xfffffbfffe000000-0xfffffbfffe800000 8M PMD
---[ PCI I/O start ]---
0xfffffbfffe800000-0xfffffbffff800000 16M PMD
---[ PCI I/O end ]---
0xfffffbffff800000-0xfffffc0000000000 8M PMD
---[ vmemmap start ]---
0xfffffc0000000000-0xfffffd8000000000 1536G PGD
0xfffffd8000000000-0xfffffdb9c0000000 231G PUD
0xfffffdb9c0000000-0xfffffdb9df000000 496M PMD
0xfffffdb9df000000-0xfffffdb9e1000000 32M PMD RW NX SHD AF BLK UXN MEM/NORMAL
0xfffffdb9e1000000-0xfffffdb9ff000000 480M PMD
0xfffffdb9ff000000-0xfffffdba04c00000 92M PMD RW NX SHD AF BLK UXN MEM/NORMAL
0xfffffdba04c00000-0xfffffdba40000000 948M PMD
0xfffffdba40000000-0xfffffe0000000000 279G PUD
---[ vmemmap end ]---
0xfffffe0000000000-0x0000000000000000 2T PGD
memblock
对应的代码文件 mm/memblock.c, 开启CONFIG_DEBUG_FS 就会有命令：
# cat /sys/kernel/debug/memblock/memory
0: 0x0000000080000000..0x00000000f89fffff
1: 0x00000000f8a00000..0x00000000f8dfffff
2: 0x00000000f8e00000..0x00000000f8ffffff
3: 0x0000000880000000..0x00000009efffffff
# cat /sys/kernel/debug/memblock/reserved
0: 0x0000000080210000..0x000000008239efff
1: 0x00000000823a4000..0x00000000823affff
2: 0x0000000087fffa00..0x0000000087ffffcf
3: 0x00000000efb83000..0x00000000efb8607f
4: 0x00000000f4a00000..0x00000000f89fffff
5: 0x00000000f8e00000..0x00000000f8ffffff
6: 0x00000009dba00000..0x00000009e41fffff
7: 0x00000009e4230000..0x00000009e6ffffff
8: 0x00000009e7015500..0x00000009e7015a07
9: 0x00000009e7015a40..0x00000009e7015fc7
10: 0x00000009e7017f80..0x00000009e701b08f
11: 0x00000009e701b0c0..0x00000009e701b11f
12: 0x00000009e701b140..0x00000009e701b34f
13: 0x00000009e701b380..0x00000009e701b49f
14: 0x00000009e701b4c0..0x00000009e701b51f
15: 0x00000009e701b540..0x00000009e701b547
16: 0x00000009e701b580..0x00000009e701b771
17: 0x00000009e701b780..0x00000009e701b971
18: 0x00000009e701b980..0x00000009e701db07
19: 0x00000009e701db28..0x00000009e701db56
20: 0x00000009e701db58..0x00000009e702fffb
21: 0x00000009e7030000..0x00000009efffffff
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