pve-edge-kernel/patches/kernel/0052-objtool-Don-t-report-end-of-section-error-after-an-e.patch

From 985d8e62ef5f1b006da5e175858e552c0dbda771 Mon Sep 17 00:00:00 2001
From: Josh Poimboeuf <[email protected]>
Date: Mon, 18 Sep 2017 21:43:30 -0500
Subject: [PATCH 052/231] objtool: Don't report end of section error after an
 empty unwind hint
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CVE-2017-5754

If asm code specifies an UNWIND_HINT_EMPTY hint, don't warn if the
section ends unexpectedly.  This can happen with the xen-head.S code
because the hypercall_page is "text" but it's all zeros.

Signed-off-by: Josh Poimboeuf <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Boris Ostrovsky <[email protected]>
Cc: Jiri Slaby <[email protected]>
Cc: Juergen Gross <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Link: http://lkml.kernel.org/r/ddafe199dd8797e40e3c2777373347eba1d65572.1505764066.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <[email protected]>
(cherry picked from commit 00d96180dc38ef872ac471c2d3e14b067cbd895d)
Signed-off-by: Andy Whitcroft <[email protected]>
Signed-off-by: Kleber Sacilotto de Souza <[email protected]>
(cherry picked from commit 9d22f903bba24f2ac86de8a81dc1788f9957aca8)
Signed-off-by: Fabian Grünbichler <[email protected]>
---
 tools/objtool/check.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 368275de5f23..0a86fd0ac082 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -1652,11 +1652,14 @@ static int validate_branch(struct objtool_file *file, struct instruction *first,
 		if (insn->dead_end)
 			return 0;
 
-		insn = next_insn;
-		if (!insn) {
+		if (!next_insn) {
+			if (state.cfa.base == CFI_UNDEFINED)
+				return 0;
 			WARN("%s: unexpected end of section", sec->name);
 			return 1;
 		}
+
+		insn = next_insn;
 	}
 
 	return 0;
-- 
2.14.2