Re: freshly built wx86cl64.exe crashes on start

The feature is known as ASLR in both Windows and Linux

https://learn.microsoft.com/en-us/windows/security/threat-protection/overview-of-threat-mitigations-in-windows-10#address-space-layout-randomization

On Thu, Dec 29, 2022 at 12:43 PM Tim McNerney <[email protected]> wrote:

> I wonder if you need to *turn off* Windows 10’s new-ish, nondeterministic
> memory allocation policy. We have run into this with other Lisps. I don’t
> remember the correct terminology for this malware countermeasure or the
> name of the configuration flag. Sorry. Can someone else chime in?
>
> --Tim
>
> On Dec 29, 2022, at 13:49, Bharat Shetty <[email protected]> wrote:
>
> 
> Hi,
>
> I built ccl (downloaded the 1.12.1 zip file from github)on
>
>    - Windows 10 (cygwin)
>    - gcc version 11.3.0
>    - ld/binutils version 2.39
>    - debug flag changed to -g3 in Makefile
>    - code optimisation level set to -O0 (zero) also in Makefile
>
>
> When the exe was built i got a message that section /1, /8 and /32 are
> before text. I altered the pei-x86-64.x to include the new debug
> sections(upto dwarf 5). For this i generated the default script running ld
> --verbose. retained .Copied .spfoo from the original, removed KEEP() and
> most of the SORT() unless it was present in the original file. Besides this
> I had to add *-no-pie and -Wl,--allow-multiple-definition* to the build
> rule for wx86cl64.exe target. I have not made any changes to the source
> code. This got an exe that starts.
>
> However every time I run this, it crashes at calculate_relocation in
> x86-gc.c. The back trace is as follows:
> #0  0x0000000000031d56 in calculate_relocation () at ../x86-gc.c:1571
> #1  0x000000000002ea15 in gc (tcr=0x5acebc0, param=0) at
> ../gc-common.c:1821
> #2  0x000000000003a170 in gc_from_tcr (tcr=0x5acebc0, param=0) at
> ../x86-exceptions.c:3014
> #3  0x000000000003a06b in gc_like_from_xp (xp=0x25f6f570, fun=0x3a126
> <gc_from_tcr>, param=0) at ../x86-exceptions.c:2970
> #4  0x000000000003a1ce in gc_from_xp (xp=0x25f6f570, param=0) at
> ../x86-exceptions.c:3026
> #5  0x0000000000035c0f in allocate_object (xp=0x25f6f570, bytes_needed=16,
> disp_from_allocptr=13, tcr=0x5acebc0, crossed_threshold=0x25f6f1ec) at
> ../x86-exceptions.c:171
> #6  0x0000000000036f26 in handle_alloc_trap (xp=0x25f6f570, tcr=0x5acebc0,
> notify=0x25f6f1ec) at ../x86-exceptions.c:665
> #7  0x0000000000037f15 in handle_exception (signum=11, info=0x25f6f4d8,
> context=0x25f6f570, tcr=0x5acebc0, old_valence=0) at
> ../x86-exceptions.c:1215
> #8  0x0000000000038cf3 in windows_exception_handler
> (exception_pointers=0x25f6f4c0, tcr=0x5acebc0, signal_number=11) at
> ../x86-exceptions.c:2150
> #9  0x00000000000438dd in windows_switch_to_foreign_stack () at
> ../x86-asmutils64.s:263
> #10 0x0000000025f6f4c0 in ?? ()
>
> This happens after start_lisp is called. By the time the code reaches gc.c
> global_reloctab is reset (set to 0x7cfe000000 before entering start_lisp).
> Due to this GCrelocptr is also set to 0x0 in gc-common.c. This results in
> relocptr being set to 0x0 in calculate_relocation.
> Also GCndynamic_dnodes_in_area is also 0 at this point(in the downloaded
> version it is 2048 at this point).
>
> Does anyone know why these global variables are reset ? And how can I fix
> this? I suspect this is because of the newer versions of gcc and ld.
>
> Regards,
> Bharat
>
>