sktt

(gdb) b *0x1fafde147e00
Breakpoint 2 at 0x1fafde147e00
(gdb) cont
Continuing.

Thread 1 "d8" hit Breakpoint 2, 0x00001fafde147e00 in LazyCompile:*myfunc test.js:144 ()
=> 0x00001fafde147e00 <LazyCompile:*myfunc test.js:144+0>:  48 8d 1d f9 ff ff ff    lea    -0x7(%rip),%rbx        # 0x1fafde147e00 <LazyCompile:*myfunc test.js:144>
(gdb) i r rbx rcx
rbx            0x5      5
rcx            0x1fafde147e00   34840205622784

sktt

Instructions (size = 868)
0x1fafde147e00     0  cc             int3l
0x1fafde147e01     1  8d1df9ffffff   leal rbx,[rip+0xfffffff9]
0x1fafde147e07     7  483bd9         REX.W cmpq rbx,rcx
0x1fafde147e0a     a  7418           jz 0x1fafde147e24  <+0x24>
0x1fafde147e0c     c  48ba0000000036000000 REX.W movq rdx,0x3600000000
0x1fafde147e16    16  cc             int3l
0x1fafde147e17    17  ba4022c4b5     movl rdx,0xb5c42240     ;; off heap target
0x1fafde147e1c    1c  317f00         xorl [rdi+0x0],rdi
0x1fafde147e1f    1f  0041ff         addb [rcx-0x1],al

sktt

jnes:src/ (9c8138f7b0✗) $ xxd -s0x1fafde147e00 -g1 -e -len 64 /proc/`pidof d8`/mem 
de147e00: 48 8d 1d f9 ff ff ff 48 3b d9 74 18 48 ba 00 00  H......H;.t.H...
de147e10: 00 00 36 00 00 00 49 ba 40 22 c4 b5 31 7f 00 00  ..6...I.@"..1...
de147e20: 41 ff d2 cc 48 8b 59 e0 f6 43 0f 01 0f 85 ae 31  A...H.Y..C.....1
de147e30: f4 ff 55 48 89 e5 56 57 48 83 ec 30 48 89 75 e0  ..UH..VWH..0H.u.