Patch "retpoline: Introduce start/end markers of indirect thunk" has been added to the 4.9-stable tree

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

retpoline: Introduce start/end markers of indirect thunk

to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
retpoline-introduce-start-end-markers-of-indirect-thunk.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Masami Hiramatsu <[email protected]>
Date: Fri, 19 Jan 2018 01:14:21 +0900
Subject: retpoline: Introduce start/end markers of indirect thunk

From: Masami Hiramatsu <[email protected]>

commit 736e80a4213e9bbce40a7c050337047128b472ac upstream.

Introduce start/end markers of __x86_indirect_thunk_* functions. To make it easy, consolidate .text.__x86.indirect_thunk.* sections to one .text.__x86.indirect_thunk section and put it in the end of kernel text section and adds __indirect_thunk_start/end so that other subsystem (e.g. kprobes) can identify it.

---
 arch/x86/include/asm/nospec-branch.h |    3 +++
 arch/x86/kernel/vmlinux.lds.S        |    7 +++++++
 arch/x86/lib/retpoline.S             |    2 +-
 3 files changed, 11 insertions(+), 1 deletion(-)

@@ -194,6 +194,9 @@ enum spectre_v2_mitigation {
 	SPECTRE_V2_IBRS,
 };
 
+extern char __indirect_thunk_start[];
+extern char __indirect_thunk_end[];
+
 /*
  * On VMEXIT we must ensure that no RSB predictions learned in the guest
  * can be followed in the host, by overwriting the RSB completely. Both

@@ -105,6 +105,13 @@ SECTIONS
 		SOFTIRQENTRY_TEXT
 		*(.fixup)
 		*(.gnu.warning)
+
+#ifdef CONFIG_RETPOLINE
+		__indirect_thunk_start = .;
+		*(.text.__x86.indirect_thunk)
+		__indirect_thunk_end = .;
+#endif
+
 		/* End of text section */
 		_etext = .;
 	} :text = 0x9090

@@ -9,7 +9,7 @@
 #include <asm/nospec-branch.h>
 
 .macro THUNK reg
-	.section .text.__x86.indirect_thunk.\reg
+	.section .text.__x86.indirect_thunk
 
 ENTRY(__x86_indirect_thunk_\reg)
 	CFI_STARTPROC

Patches currently in stable-queue which might be from [email protected] are

queue-4.9/perf-tools-fix-build-with-arch-x86_64.patch queue-4.9/kprobes-x86-disable-optimizing-on-the-function-jumps-to-indirect-thunk.patch queue-4.9/kprobes-x86-blacklist-indirect-thunk-functions-for-kprobes.patch queue-4.9/retpoline-introduce-start-end-markers-of-indirect-thunk.patch