4.14-stable review patch. If anyone has any objections, please let me know.
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From: Peter Zijlstra peterz@infradead.org
commit 531bb52a869a9c6e08c8d17ba955fcbfc18037ad upstream.
This is boot code and thus Spectre-safe: we run this _way_ before userspace comes along to have a chance to poison our branch predictor.
Signed-off-by: Peter Zijlstra (Intel) peterz@infradead.org Acked-by: Thomas Gleixner tglx@linutronix.de Acked-by: Josh Poimboeuf jpoimboe@redhat.com Cc: Andy Lutomirski luto@kernel.org Cc: Arjan van de Ven arjan@linux.intel.com Cc: Borislav Petkov bp@alien8.de Cc: Borislav Petkov bp@suse.de Cc: Dan Williams dan.j.williams@intel.com Cc: Dave Hansen dave.hansen@linux.intel.com Cc: David Woodhouse dwmw2@infradead.org Cc: Greg Kroah-Hartman gregkh@linuxfoundation.org Cc: Linus Torvalds torvalds@linux-foundation.org Cc: Peter Zijlstra peterz@infradead.org Cc: Tom Lendacky thomas.lendacky@amd.com Signed-off-by: Ingo Molnar mingo@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/x86/mm/mem_encrypt_boot.S | 2 ++ 1 file changed, 2 insertions(+)
--- a/arch/x86/mm/mem_encrypt_boot.S +++ b/arch/x86/mm/mem_encrypt_boot.S @@ -15,6 +15,7 @@ #include <asm/page.h> #include <asm/processor-flags.h> #include <asm/msr-index.h> +#include <asm/nospec-branch.h>
.text .code64 @@ -59,6 +60,7 @@ ENTRY(sme_encrypt_execute) movq %rax, %r8 /* Workarea encryption routine */ addq $PAGE_SIZE, %r8 /* Workarea intermediate copy buffer */
+ ANNOTATE_RETPOLINE_SAFE call *%rax /* Call the encryption routine */
pop %r12