svn commit: r315522 - in head: contrib/binutils/ld/emulparams sys/conf

[Ian Lepore]

On Sun, 2017-03-19 at 00:22 +0000, Ed Maste wrote:
> Author: emaste
> Date: Sun Mar 19 00:22:13 2017
> New Revision: 315522
> URL: https://svnweb.freebsd.org/changeset/base/315522
> 
> Log:
>   use INT3 instead of NOP for x86 binary padding
>   
>   We should never end up executing the inter-function padding, so we
>   are better off faulting than silently carrying on to whatever
> function
>   happens to be next.
>   
>   Note that LLD will soon do this by default (although it currently
> pads
>   with zeros).
>   
>   Reviewed by:	dim, kib
>   MFC after:	1 month
>   Sponsored by:	The FreeBSD Foundation
>   Differential Revision:	https://reviews.freebsd.org/D10047
> 
> Modified:
>   head/contrib/binutils/ld/emulparams/elf_i386.sh
>   head/contrib/binutils/ld/emulparams/elf_x86_64.sh
>   head/sys/conf/ldscript.amd64
>   head/sys/conf/ldscript.i386
> 
> Modified: head/contrib/binutils/ld/emulparams/elf_i386.sh
> =====================================================================
> =========
> --- head/contrib/binutils/ld/emulparams/elf_i386.sh	Sat Mar 18
> 23:59:50 2017	(r315521)
> +++ head/contrib/binutils/ld/emulparams/elf_i386.sh	Sun Mar 19
> 00:22:13 2017	(r315522)
> @@ -6,7 +6,7 @@ COMMONPAGESIZE="CONSTANT (COMMONPAGESIZE
>  NONPAGED_TEXT_START_ADDR=0x08048000
>  ARCH=i386
>  MACHINE=
> -NOP=0x90909090
> +NOP=0xCCCCCCCC

I have always wondered why the arm ldscript pads with 0x90.  I don't
know if I feel any better now, knowing that it's because that's an x86
nop instruction. :)

-- Ian