This is a note to let you know that I've just added the patch titled

x86/speculation, objtool: Annotate indirect calls/jumps for objtool

to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: x86-speculation-objtool-annotate-indirect-calls-jumps-for-objtool.patch and it can be found in the queue-4.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From 9e0e3c5130e949c389caabc8033e9799b129e429 Mon Sep 17 00:00:00 2001

From: Peter Zijlstra peterz@infradead.org Date: Wed, 17 Jan 2018 22:34:34 +0100 Subject: x86/speculation, objtool: Annotate indirect calls/jumps for objtool

From: Peter Zijlstra peterz@infradead.org

commit 9e0e3c5130e949c389caabc8033e9799b129e429 upstream.

Annotate the indirect calls/jumps in the CALL_NOSPEC/JUMP_NOSPEC alternatives.

Signed-off-by: Peter Zijlstra (Intel) peterz@infradead.org Reviewed-by: David Woodhouse dwmw@amazon.co.uk 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: 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 Signed-off-by: Ingo Molnar mingo@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

--- arch/x86/include/asm/nospec-branch.h | 27 +++++++++++++++++++++++---- 1 file changed, 23 insertions(+), 4 deletions(-)

--- a/arch/x86/include/asm/nospec-branch.h +++ b/arch/x86/include/asm/nospec-branch.h @@ -68,6 +68,18 @@ .endm

/* + * This should be used immediately before an indirect jump/call. It tells + * objtool the subsequent indirect jump/call is vouched safe for retpoline + * builds. + */ +.macro ANNOTATE_RETPOLINE_SAFE + .Lannotate_@: + .pushsection .discard.retpoline_safe + _ASM_PTR .Lannotate_@ + .popsection +.endm + +/* * These are the bare retpoline primitives for indirect jmp and call. * Do not use these directly; they only exist to make the ALTERNATIVE * invocation below less ugly. @@ -103,9 +115,9 @@ .macro JMP_NOSPEC reg:req #ifdef CONFIG_RETPOLINE ANNOTATE_NOSPEC_ALTERNATIVE - ALTERNATIVE_2 __stringify(jmp *\reg), \ + ALTERNATIVE_2 __stringify(ANNOTATE_RETPOLINE_SAFE; jmp *\reg), \ __stringify(RETPOLINE_JMP \reg), X86_FEATURE_RETPOLINE, \ - __stringify(lfence; jmp *\reg), X86_FEATURE_RETPOLINE_AMD + __stringify(lfence; ANNOTATE_RETPOLINE_SAFE; jmp *\reg), X86_FEATURE_RETPOLINE_AMD #else jmp *\reg #endif @@ -114,9 +126,9 @@ .macro CALL_NOSPEC reg:req #ifdef CONFIG_RETPOLINE ANNOTATE_NOSPEC_ALTERNATIVE - ALTERNATIVE_2 __stringify(call *\reg), \ + ALTERNATIVE_2 __stringify(ANNOTATE_RETPOLINE_SAFE; call *\reg), \ __stringify(RETPOLINE_CALL \reg), X86_FEATURE_RETPOLINE,\ - __stringify(lfence; call *\reg), X86_FEATURE_RETPOLINE_AMD + __stringify(lfence; ANNOTATE_RETPOLINE_SAFE; call *\reg), X86_FEATURE_RETPOLINE_AMD #else call *\reg #endif @@ -144,6 +156,12 @@ ".long 999b - .\n\t" \ ".popsection\n\t"

+#define ANNOTATE_RETPOLINE_SAFE \ + "999:\n\t" \ + ".pushsection .discard.retpoline_safe\n\t" \ + _ASM_PTR " 999b\n\t" \ + ".popsection\n\t" + #if defined(CONFIG_X86_64) && defined(RETPOLINE)

/* @@ -153,6 +171,7 @@ # define CALL_NOSPEC \ ANNOTATE_NOSPEC_ALTERNATIVE \ ALTERNATIVE( \ + ANNOTATE_RETPOLINE_SAFE \ "call *%[thunk_target]\n", \ "call __x86_indirect_thunk_%V[thunk_target]\n", \ X86_FEATURE_RETPOLINE)

Patches currently in stable-queue which might be from peterz@infradead.org are

queue-4.14/x86-retpoline-support-retpoline-builds-with-clang.patch queue-4.14/x86-ldt-avoid-warning-in-32-bit-builds-with-older-gcc.patch queue-4.14/x86-entry-reduce-the-code-footprint-of-the-idtentry-macro.patch queue-4.14/bug-use-pb-in-bug-and-stack-protector-failure.patch queue-4.14/revert-x86-retpoline-simplify-vmexit_fill_rsb.patch queue-4.14/nospec-include-asm-barrier.h-dependency.patch queue-4.14/x86-mm-remove-stale-comment-about-kmemcheck.patch queue-4.14/x86-speculation-use-ibrs-if-available-before-calling-into-firmware.patch queue-4.14/x86-asm-improve-how-gen_-_suffixed_rmwcc-specify-clobbers.patch queue-4.14/x86-64-realmode-add-instruction-suffix.patch queue-4.14/x86-speculation-objtool-annotate-indirect-calls-jumps-for-objtool.patch queue-4.14/x86-entry-64-use-xorl-for-faster-register-clearing.patch queue-4.14/nospec-kill-array_index_nospec_mask_check.patch queue-4.14/lib-bug.c-exclude-non-bug-warn-exceptions-from-report_bug.patch