msys2-runtime-3.3 binaries no longer work

[jeremyd2019]

From msys2/MSYS2-packages#4421, it was discovered that msys2-runtime-3.3-3.3.6-7 does not work, while -6 does, both on x86_64 and i686. On i686 at least, I found that downgrading to binutils-2.40-1 resulted in a working dll while any later version I tried did not.

Again on i686, I found that it crashed early on when the dll was loaded, in a memset call. It appears that the memory at _cygheap_start is not writable anymore.

[jeremyd2019]

OK, check this out:

$ objdump -h /usr/bin/msys-2.0.dll

/usr/bin/msys-2.0.dll:     file format pei-i386

Sections:
Idx Name          Size      VMA       LMA       File off  Algn
...
 11 .rsrc         00000408  612e6000  612e6000  002a6a00  2**2
                  CONTENTS, ALLOC, LOAD, DATA
 12 .cygheap      00209000  612e7000  612e7000  00000000  2**2
                  ALLOC

$ nm -B /usr/bin/msys-2.0.dll | grep cygheap_start
612e6408 D __cygheap_start

$ objdump -h usr/bin/msys-2.0.dll

usr/bin/msys-2.0.dll:     file format pei-i386

Sections:
Idx Name          Size      VMA       LMA       File off  Algn
...
 11 .rsrc         00000408  612e5000  612e5000  002a6200  2**2
                  CONTENTS, ALLOC, LOAD, READONLY, DATA
 12 .cygheap      0020a000  612e6000  612e6000  00000000  2**2
                  ALLOC

$ nm -B usr/bin/msys-2.0.dll | grep cygheap_start
612e5408 R __cygheap_start

So _cygheap_start is actually in the .rsrc section, and that section seems to have changed to be READONLY. That actually makes some sense, due to:

msys2-runtime/winsup/cygwin/cygwin.sc.in

Lines 141 to 156 in 3cba82a

	.rsrc BLOCK(__section_alignment__) :
	{
	*(.rsrc)
	*(SORT(.rsrc$*))
	_SYM (_cygheap_start) = .;
	}
	.cygheap ALIGN(__section_alignment__) :
	{
	#ifdef __x86_64__
	. = . + (3072 * 1024);
	#else
	. = . + (2048 * 1024);
	#endif
	. = ALIGN(0x10000);
	_SYM (_cygheap_end) = .;
	}

Maybe the solution is to figure out how to make the .rsrc section writable again? I have to imagine there's some good reason why _cygheap_start was put in the .rsrc instead of .cygheap section to begin with...

[lazka]

bminor/binutils-gdb@c53c618 / https://sourceware.org/bugzilla/show_bug.cgi?id=30142 ?

[jeremyd2019]

I saw that, but I don't yet see a way to force the section to be writable. I've been playing with objcopy but I'm not getting --set-section-flags to do what I want.