Hooked Functions (Kernel Space)

This is a variation of Hooked Functions (Volume 1, page 469) pattern for kernel space. In addition to trampoline patching, we also see a modified service table:

0: kd> !chkimg -lo 50 -d !nt -v
Searching for module with expression: !nt
Will apply relocation fixups to file used for comparison
Will ignore NOP/LOCK errors
Will ignore patched instructions
Image specific ignores will be applied
Comparison image path:
c:\symdownstream\ntkrnlmp.exe\4B7A8E62280000\ntkrnlmp.exe
No range specified

Scanning section:    .text
Size: 625257
Range to scan: 80801000-80899a69
    808373e3-808373e9  7 bytes - nt!KeAcquireQueuedSpinLockAtDpcLevel+1b
 [ f7 41 04 01 00 00 00:e9 00 0d b2 76 cc cc ]
    8083e6c8-8083e6cb  4 bytes - nt!KiServiceTable+440 (+0×72e5)
 [ 98 4e 98 80:d0 66 e9 f4 ]
    80840605-8084060a  6 bytes - nt!KxFlushEntireTb+9 (+0×1f3d)
 [ ff 15 1c 10 80 80:e9 a5 7a b1 76 cc ]
Total bytes compared: 625257(100%)
Number of errors: 17

Scanning section: MISYSPTE
Size: 1906
Range to scan: 8089a000-8089a772
Total bytes compared: 1906(100%)
Number of errors: 0

Scanning section:   POOLMI
Size: 7868
Range to scan: 8089b000-8089cebc
Total bytes compared: 7868(100%)
Number of errors: 0

Scanning section: POOLCODE
Size: 7754
Range to scan: 8089d000-8089ee4a
Total bytes compared: 7754(100%)
Number of errors: 0

Scanning section:     PAGE
Size: 1097281
Range to scan: 808bc000-809c7e41
Total bytes compared: 1097281(100%)
Number of errors: 0