From: Borislav Petkov <bp@xxxxxxx> 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 <bp@xxxxxxx> Cc: Andy Lutomirski <luto@xxxxxxxxxxxxxx> Cc: Borislav Petkov <bp@xxxxxxxxx> Cc: Brian Gerst <brgerst@xxxxxxxxx> Cc: Denys Vlasenko <dvlasenk@xxxxxxxxxx> Cc: H. Peter Anvin <hpa@xxxxxxxxx> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Link: http://lkml.kernel.org/r/1453842730-28463-8-git-send-email-bp@xxxxxxxxx Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> Signed-off-by: Srivatsa S. Bhat <srivatsa@xxxxxxxxxxxxx> Reviewed-by: Matt Helsley (VMware) <matt.helsley@xxxxxxxxx> Reviewed-by: Alexey Makhalov <amakhalov@xxxxxxxxxx> Reviewed-by: Bo Gan <ganb@xxxxxxxxxx> --- arch/x86/kernel/vmlinux.lds.S | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S index e065065..a703842 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) {
