From: Theo Buehler <tb@openbsd.org>
Subject: Re: gnustep/libobjc2 and BTI (was:  Re: x11/gnustep/libobjc2 failed to build)
To: Jeremie Courreges-Anglas <jca@wxcvbn.org>
Cc: Sebastian Reitenbach <sebastia@l00-bugdead-prods.de>, Mark Kettenis <kettenis@openbsd.org>, Stuart Henderson <stu@spacehopper.org>, Antoine Jacoutot <ajacoutot@bsdfrog.org>, ports@openbsd.org
Date: Wed, 6 Mar 2024 19:27:22 +0100

On Wed, Mar 06, 2024 at 07:02:35PM +0100, Jeremie Courreges-Anglas wrote:
> Le Wed, Mar 06, 2024 at 10:17:32AM +0100, Theo Buehler a écrit :
> > Could you please resend the endbr64 patches with Cc kettenis? They
> > should make release.
> 
> Since I now have a laptop with BTI I figured I was going to give this
> a try.  -current x11/gnustep/zipper was crashing with SIGILL on amd64.
> For the amd64 diff I'm deliberately not caring about the assembly for
> Windows.  I can't test the arm64 part but it looks simple.
> 
> ok?

I had a somewhat different approach:
https://marc.info/?l=openbsd-ports&m=170915116023144&w=2

Since you add the endbr64 before the MSGSEND macro, they now come before
.cfi_startproc. In all other patches I'm aware of, we put them after.
Not sure if that will matter in the future.

I also added landing pads to the trampolines; I'm sure the old libobjc2
warned about these with kettenis's ld.lld diff. Maybe it's no longer
needed.

> 
> Sebastian, feel free to commit this if it matches your previous diff.
> 
> 
> Index: Makefile
> ===================================================================
> RCS file: /home/cvs/ports/x11/gnustep/libobjc2/Makefile,v
> diff -u -p -r1.37 Makefile
> --- Makefile	5 Mar 2024 16:11:15 -0000	1.37
> +++ Makefile	6 Mar 2024 17:26:11 -0000
> @@ -4,7 +4,7 @@ COMMENT =	GNUstep libobjc2 objective-c r
>  
>  # note: this port does not use the gnustep module
>  VERSION =	2.2
> -REVISION =	3
> +REVISION =	4
>  GH_ACCOUNT =	gnustep
>  GH_PROJECT =	libobjc2
>  GH_TAGNAME =	v${VERSION}
> Index: patches/patch-objc_msgSend_aarch64_S
> ===================================================================
> RCS file: patches/patch-objc_msgSend_aarch64_S
> diff -N patches/patch-objc_msgSend_aarch64_S
> --- /dev/null	1 Jan 1970 00:00:00 -0000
> +++ patches/patch-objc_msgSend_aarch64_S	6 Mar 2024 17:19:04 -0000
> @@ -0,0 +1,11 @@
> +Index: objc_msgSend.aarch64.S
> +--- objc_msgSend.aarch64.S.orig
> ++++ objc_msgSend.aarch64.S
> +@@ -73,6 +73,7 @@ CDECL(objc_msgSend):
> + CDECL(objc_msgSend_fpret):
> + CDECL(objc_msgSend_stret):
> + 	EH_START
> ++	bti    c
> + 
> + 	cbz    x0, 4f                   // Skip everything if the receiver is nil
> + 	                                       // Jump to 6: if this is a small object
> Index: patches/patch-objc_msgSend_x86-64_S
> ===================================================================
> RCS file: patches/patch-objc_msgSend_x86-64_S
> diff -N patches/patch-objc_msgSend_x86-64_S
> --- /dev/null	1 Jan 1970 00:00:00 -0000
> +++ patches/patch-objc_msgSend_x86-64_S	6 Mar 2024 17:18:56 -0000
> @@ -0,0 +1,15 @@
> +Index: objc_msgSend.x86-64.S
> +--- objc_msgSend.x86-64.S.orig
> ++++ objc_msgSend.x86-64.S
> +@@ -307,9 +307,11 @@ TYPE_DIRECTIVE(CDECL(objc_msgSend), @function)
> + TYPE_DIRECTIVE(CDECL(objc_msgSend_fpret), @function)
> + CDECL(objc_msgSend_fpret):
> + CDECL(objc_msgSend):
> ++	endbr64
> + 	MSGSEND objc_msgSend, %rdi, %rsi
> + .globl CDECL(objc_msgSend_stret)
> + TYPE_DIRECTIVE(CDECL(objc_msgSend_stret), @function)
> + CDECL(objc_msgSend_stret):
> ++	endbr64
> + 	MSGSEND objc_msgSend_stret, %rsi, %rdx
> + #endif
> 
> 
> -- 
> jca
>