[Nasm-bugs] [Bug 3392468] NASM 2.13.02 breaks macho64 .data fixups

[no-reply at bugzilla-nasm.gorcunov.org]

https://bugzilla.nasm.us/show_bug.cgi?id=3392468

ig <glucksmann at avast.com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |glucksmann at avast.com

--- Comment #3 from ig <glucksmann at avast.com> ---
We had a similar problem (mach-o code jumping to weird locations when using
jump tables) even with 2.13.03, downgrading to 2.13.01 fixed it.

I can't provide a simple working PoC (don't even have a Mac to try it on), but
in general the code looked like this (multiple subsequent versions of the same
function generated with a macro):


%macro FUNCTION 1    ; parameter is SSE/AVX version to use
    ; ...
    lea  r9, [%%_JumpTable]
    mov  rdx, [r9 + 8*rbp]
    jmp  rdx
    ; ...

%%_Label1:
    ; ...
%%_Label2:
    ; ...
%%_Label3:
    ; ...
%%_Label4:
    ; ...

SECTION .rodata align=64
align 8, db 0

%%_JumpTable:
dq  %%_Label1
dq  %%_Label2
dq  %%_Label3
dq  %%_Label4

SECTION .text align=64

%endmacro

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