x86/vsyscall: Remove CONFIG_LEGACY_VSYSCALL_EMULATE
authorAndy Lutomirski <luto@kernel.org>
Wed, 11 May 2022 17:38:53 +0000 (10:38 -0700)
committerBorislav Petkov <bp@suse.de>
Wed, 11 May 2022 18:39:31 +0000 (20:39 +0200)
commitbf00745e7791fe2ba7941aeead8528075a158bbe
treec21f5fa4ccdc9310110c6ac7407de694041a1e20
parentc5eb0a61238dd6faf37f58c9ce61c9980aaffd7a
x86/vsyscall: Remove CONFIG_LEGACY_VSYSCALL_EMULATE

CONFIG_LEGACY_VSYSCALL_EMULATE is, as far as I know, only needed for the
combined use of exotic and outdated debugging mechanisms with outdated
binaries. At this point, no one should be using it. Eventually, dynamic
switching of vsyscalls will be implemented, but this is much more
complicated to support in EMULATE mode than XONLY mode.

So let's force all the distros off of EMULATE mode. If anyone actually
needs it, they can set vsyscall=emulate, and the kernel can then get
away with refusing to support newer security models if that option is
set.

  [ bp: Remove "we"s. ]

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Florian Weimer <fweimer@redhat.com>
Link: https://lore.kernel.org/r/898932fe61db6a9d61bc2458fa2f6049f1ca9f5c.1652290558.git.luto@kernel.org
arch/x86/Kconfig
arch/x86/entry/vsyscall/vsyscall_64.c