From 33f90c87190830f23c52531322268cd97e28d71e Mon Sep 17 00:00:00 2001 From: Borislav Petkov Date: Sat, 14 Jul 2018 02:27:19 -0700 Subject: x86/alternatives: Add an auxilary section commit 337e4cc84021212a87b04b77b65cccc49304909e upstream Add .altinstr_aux for additional instructions which will be used before and/or during patching. All stuff which needs more sophisticated patching should go there. See next patch. Signed-off-by: Borislav Petkov Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/1453842730-28463-8-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar Signed-off-by: Srivatsa S. Bhat Reviewed-by: Matt Helsley (VMware) Reviewed-by: Alexey Makhalov Reviewed-by: Bo Gan Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/vmlinux.lds.S | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'arch') diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S index e065065a4dfb..a703842b54de 100644 --- a/arch/x86/kernel/vmlinux.lds.S +++ b/arch/x86/kernel/vmlinux.lds.S @@ -202,6 +202,17 @@ SECTIONS :init #endif + /* + * Section for code used exclusively before alternatives are run. All + * references to such code must be patched out by alternatives, normally + * by using X86_FEATURE_ALWAYS CPU feature bit. + * + * See static_cpu_has() for an example. + */ + .altinstr_aux : AT(ADDR(.altinstr_aux) - LOAD_OFFSET) { + *(.altinstr_aux) + } + INIT_DATA_SECTION(16) .x86_cpu_dev.init : AT(ADDR(.x86_cpu_dev.init) - LOAD_OFFSET) { -- cgit v1.2.3