23 lines
606 B
Nim
23 lines
606 B
Nim
import posix
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let MAP_ANONYMOUS {.importc: "MAP_ANONYMOUS", header: "<sys/mman.h>".}: cint
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proc test(a, b: cint): cint =
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# mov EAX, [ESP+4]
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# add EAX, [ESP+8]
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# ret
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var code = [0x8B'u8, 0x44, 0x24, 0x4, 0x3, 0x44, 0x24, 0x8, 0xC3]
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# create an executable buffer
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var buf = mmap(nil, sizeof(code), PROT_READ or PROT_WRITE or PROT_EXEC,
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MAP_PRIVATE or MAP_ANONYMOUS, -1, 0)
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# copy code to the buffer
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copyMem(buf, addr code[0], sizeof(code))
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# run code
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result = cast[proc(a, b: cint): cint {.nimcall.}](buf)(a, b)
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# free buffer
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discard munmap(buf, sizeof(code))
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echo test(7, 12)
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