| include macamd64.inc |
| |
| _TEXT SEGMENT |
| sample PROC FRAME |
| db 048h; emit a REX prefix, to enable hot-patching |
| push rbp |
| .pushreg rbp |
| sub rsp, 040h |
| .allocstack 040h |
| lea rbp, [rsp+020h] |
| .setframe rbp, 020h |
| movdqa [rbp], xmm7 |
| .savexmm128 xmm7, 020h;the offset is from the base of the frame |
| ;not the scaled offset of the frame |
| mov [rbp+018h], rsi |
| .savereg rsi, 018h |
| mov [rsp+010h], rdi |
| .savereg rdi, 010h; you can still use RSP as the base of the frame |
| ; or any other register you choose |
| .endprolog |
| |
| ; you can modify the stack pointer outside of the prologue (similar to alloca) |
| ; because we have a frame pointer. |
| ; if we didn't have a frame pointer, this would be illegal |
| ; if we didn't make this modification, |
| ; there would be no need for a frame pointer |
| |
| sub rsp, 060h |
| |
| ; we can unwind from the following AV because of the frame pointer |
| |
| mov rax, 0 |
| mov rax, [rax] ; AV! |
| |
| ; restore the registers that weren't saved with a push |
| ; this isn't part of the official epilog, as described in section 2.5 |
| |
| movdqa xmm7, [rbp] |
| mov rsi, [rbp+018h] |
| mov rdi, [rbp-010h] |
| |
| ; Here's the official epilog |
| |
| lea rsp, [rbp-020h] |
| pop rbp |
| ret |
| sample ENDP |
| |
| |
| sampleFrame struct |
| Fill dq ? ; fill to 8 mod 16 |
| SavedRdi dq ? ; Saved Register RDI |
| SavedRsi dq ? ; Saved Register RSI |
| sampleFrame ends |
| |
| sample2 PROC FRAME |
| alloc_stack(sizeof sampleFrame) |
| save_reg rdi, sampleFrame.SavedRdi |
| save_reg rsi, sampleFrame.SavedRsi |
| .endprolog |
| |
| ; function body |
| |
| mov rsi, sampleFrame.SavedRsi[rsp] |
| mov rdi, sampleFrame.SavedRdi[rsp] |
| |
| ; Here's the official epilog |
| |
| add rsp, (sizeof sampleFrame) |
| ret |
| sample2 ENDP |
| |
| _TEXT ENDS |
| end |
