答案Github库
https://github.com/jzplp/OSTEP-Answers
- 问题 1 答案
[testjz@localhost vm-mechanism]$ ./relocation.py -s 1 -c
ARG seed 1
ARG address space size 1k
ARG phys mem size 16k
Base-and-Bounds register information:
Base : 0x0000363c (decimal 13884)
Limit : 290
Virtual Address Trace
VA 0: 0x0000030e (decimal: 782) --> SEGMENTATION VIOLATION
VA 1: 0x00000105 (decimal: 261) --> VALID: 0x00003741 (decimal: 14145)
VA 2: 0x000001fb (decimal: 507) --> SEGMENTATION VIOLATION
VA 3: 0x000001cc (decimal: 460) --> SEGMENTATION VIOLATION
VA 4: 0x0000029b (decimal: 667) --> SEGMENTATION VIOLATION
[testjz@localhost vm-mechanism]$ ./relocation.py -s 2 -c
ARG seed 2
ARG address space size 1k
ARG phys mem size 16k
Base-and-Bounds register information:
Base : 0x00003ca9 (decimal 15529)
Limit : 500
Virtual Address Trace
VA 0: 0x00000039 (decimal: 57) --> VALID: 0x00003ce2 (decimal: 15586)
VA 1: 0x00000056 (decimal: 86) --> VALID: 0x00003cff (decimal: 15615)
VA 2: 0x00000357 (decimal: 855) --> SEGMENTATION VIOLATION
VA 3: 0x000002f1 (decimal: 753) --> SEGMENTATION VIOLATION
VA 4: 0x000002ad (decimal: 685) --> SEGMENTATION VIOLATION
[testjz@localhost vm-mechanism]$ ./relocation.py -s 3 -c
ARG seed 3
ARG address space size 1k
ARG phys mem size 16k
Base-and-Bounds register information:
Base : 0x000022d4 (decimal 8916)
Limit : 316
Virtual Address Trace
VA 0: 0x0000017a (decimal: 378) --> SEGMENTATION VIOLATION
VA 1: 0x0000026a (decimal: 618) --> SEGMENTATION VIOLATION
VA 2: 0x00000280 (decimal: 640) --> SEGMENTATION VIOLATION
VA 3: 0x00000043 (decimal: 67) --> VALID: 0x00002317 (decimal: 8983)
VA 4: 0x0000000d (decimal: 13) --> VALID: 0x000022e1 (decimal: 8929)
- 问题 2 答案
[testjz@localhost vm-mechanism]$ ./relocation.py -s 0 -n 10 -l 930 -c
ARG seed 0
ARG address space size 1k
ARG phys mem size 16k
Base-and-Bounds register information:
Base : 0x0000360b (decimal 13835)
Limit : 930
Virtual Address Trace
VA 0: 0x00000308 (decimal: 776) --> VALID: 0x00003913 (decimal: 14611)
VA 1: 0x000001ae (decimal: 430) --> VALID: 0x000037b9 (decimal: 14265)
VA 2: 0x00000109 (decimal: 265) --> VALID: 0x00003714 (decimal: 14100)
VA 3: 0x0000020b (decimal: 523) --> VALID: 0x00003816 (decimal: 14358)
VA 4: 0x0000019e (decimal: 414) --> VALID: 0x000037a9 (decimal: 14249)
VA 5: 0x00000322 (decimal: 802) --> VALID: 0x0000392d (decimal: 14637)
VA 6: 0x00000136 (decimal: 310) --> VALID: 0x00003741 (decimal: 14145)
VA 7: 0x000001e8 (decimal: 488) --> VALID: 0x000037f3 (decimal: 14323)
VA 8: 0x00000255 (decimal: 597) --> VALID: 0x00003860 (decimal: 14432)
VA 9: 0x000003a1 (decimal: 929) --> VALID: 0x000039ac (decimal: 14764)
界限寄存器的值最小设置为930.
- 问题 3 答案
题目翻译错误，问题应该是问基址寄存器base的最大值。
[testjz@localhost vm-mechanism]$ ./relocation.py -s 1 -n 10 -l 100 -b 16284 -c
ARG seed 1
ARG address space size 1k
ARG phys mem size 16k
Base-and-Bounds register information:
Base : 0x00003f9c (decimal 16284)
Limit : 100
Virtual Address Trace
VA 0: 0x00000089 (decimal: 137) --> SEGMENTATION VIOLATION
VA 1: 0x00000363 (decimal: 867) --> SEGMENTATION VIOLATION
VA 2: 0x0000030e (decimal: 782) --> SEGMENTATION VIOLATION
VA 3: 0x00000105 (decimal: 261) --> SEGMENTATION VIOLATION
VA 4: 0x000001fb (decimal: 507) --> SEGMENTATION VIOLATION
VA 5: 0x000001cc (decimal: 460) --> SEGMENTATION VIOLATION
VA 6: 0x0000029b (decimal: 667) --> SEGMENTATION VIOLATION
VA 7: 0x00000327 (decimal: 807) --> SEGMENTATION VIOLATION
VA 8: 0x00000060 (decimal: 96) --> VALID: 0x00003ffc (decimal: 16380)
VA 9: 0x0000001d (decimal: 29) --> VALID: 0x00003fb9 (decimal: 16313)
16k-100=16284.
- 问题 4 答案
[testjz@localhost vm-mechanism]$ ./relocation.py -s 1 -n 10 -l 100 -b 499900 -a 500000 -p 500001 -c
ARG seed 1
ARG address space size 500000
ARG phys mem size 500001
Base-and-Bounds register information:
Base : 0x0007a0bc (decimal 499900)
Limit : 100
Virtual Address Trace
VA 0: 0x0001066e (decimal: 67182) --> SEGMENTATION VIOLATION
VA 1: 0x00067724 (decimal: 423716) --> SEGMENTATION VIOLATION
VA 2: 0x0005d3bf (decimal: 381887) --> SEGMENTATION VIOLATION
VA 3: 0x0001f22e (decimal: 127534) --> SEGMENTATION VIOLATION
VA 4: 0x0003c7a5 (decimal: 247717) --> SEGMENTATION VIOLATION
VA 5: 0x00036de9 (decimal: 224745) --> SEGMENTATION VIOLATION
VA 6: 0x0004f8a4 (decimal: 325796) --> SEGMENTATION VIOLATION
VA 7: 0x00060479 (decimal: 394361) --> SEGMENTATION VIOLATION
VA 8: 0x0000b751 (decimal: 46929) --> SEGMENTATION VIOLATION
VA 9: 0x0000375d (decimal: 14173) --> SEGMENTATION VIOLATION
这个数字太随机了，看不出效果。
- 问题 5 答案
虚拟地址必须小于界限寄存器，值才是有效的。
