From 1fa29c42bb742a5f31926b7a4eb61b6164734d00 Mon Sep 17 00:00:00 2001
From: Michal Meloun <mmel@FreeBSD.org>
Date: Mon, 16 Dec 2019 14:08:49 +0000
Subject: [PATCH] Fix LLVM libunwnwind _Unwind_Backtrace symbol version for
 ARM. In original  GNU libgcc, _Unwind_Backtrace is published with GCC_3.3
 version for all architectures but ARM. For ARM should be publishes with
 GCC_4.3.0 version. This was originally omitted in r255095, fixed in r318024
 and omitted aging in LLVM libunwind implementation in r354347.

For ARM _Unwind_Backtrace should be published as default with GCC_4.3.0
version , (because this is right original version) and again as
normal(not-default) with GCC_3.3 version (to maintain ABI compatibility
compiled/linked with wrong pre r318024 libgcc)

PR:	233664
---
 contrib/libunwind/src/UnwindLevel1-gcc-ext.c | 4 ++--
 lib/libgcc_s/Makefile                        | 2 ++
 lib/libgcc_s/Symbol.map                      | 1 -
 lib/libgcc_s/SymbolDefault.map               | 7 +++++++
 lib/libgcc_s/arm/Symbol.map                  | 4 ++++
 5 files changed, 15 insertions(+), 3 deletions(-)
 create mode 100644 lib/libgcc_s/SymbolDefault.map

diff --git a/contrib/libunwind/src/UnwindLevel1-gcc-ext.c b/contrib/libunwind/src/UnwindLevel1-gcc-ext.c
index 2afa6c69d4d..00cfd243d47 100644
--- a/contrib/libunwind/src/UnwindLevel1-gcc-ext.c
+++ b/contrib/libunwind/src/UnwindLevel1-gcc-ext.c
@@ -182,8 +182,8 @@ _Unwind_Backtrace(_Unwind_Trace_Fn callback, void *ref) {
   }
 }
 #ifdef __arm__
-/* Preserve legacy libgcc ARM ABI mistake. */
-__sym_compat(_Unwind_Backtrace, _Unwind_Backtrace, GCC_4.3.0);
+/* Preserve legacy libgcc (pre r318024) ARM ABI mistake */
+__sym_compat(_Unwind_Backtrace, _Unwind_Backtrace, GCC_3.3);
 #endif
 
 
diff --git a/lib/libgcc_s/Makefile b/lib/libgcc_s/Makefile
index ef309421032..0b9bbf257c5 100644
--- a/lib/libgcc_s/Makefile
+++ b/lib/libgcc_s/Makefile
@@ -18,6 +18,8 @@ SYMBOL_MAPS=	${.CURDIR}/Symbol.map
 # Export ARM AEABI unwind routines needed by libc and libthr.
 .if exists(${.CURDIR}/${MACHINE_CPUARCH}/Symbol.map)
 SYMBOL_MAPS+=	${.CURDIR}/${MACHINE_CPUARCH}/Symbol.map
+.else
+SYMBOL_MAPS+=	${.CURDIR}/SymbolDefault.map
 .endif
 .endif
 
diff --git a/lib/libgcc_s/Symbol.map b/lib/libgcc_s/Symbol.map
index 065629d44cd..695f6189336 100644
--- a/lib/libgcc_s/Symbol.map
+++ b/lib/libgcc_s/Symbol.map
@@ -86,7 +86,6 @@ GCC_3.0 {
 };
 
 GCC_3.3 {
-	_Unwind_Backtrace;
 	_Unwind_FindEnclosingFunction;
 	_Unwind_GetCFA;
 	_Unwind_Resume_or_Rethrow;
diff --git a/lib/libgcc_s/SymbolDefault.map b/lib/libgcc_s/SymbolDefault.map
new file mode 100644
index 00000000000..b3da3a8688b
--- /dev/null
+++ b/lib/libgcc_s/SymbolDefault.map
@@ -0,0 +1,7 @@
+/*
+ * $FreeBSD$
+ */
+/* _Unwind_Backtrace should be exported with different version on ARM */
+GCC_3.3 {
+	_Unwind_Backtrace;
+};
diff --git a/lib/libgcc_s/arm/Symbol.map b/lib/libgcc_s/arm/Symbol.map
index 447ba923ccb..fd48eab4d60 100644
--- a/lib/libgcc_s/arm/Symbol.map
+++ b/lib/libgcc_s/arm/Symbol.map
@@ -10,3 +10,7 @@ GCC_3.5 {
 	__aeabi_unwind_cpp_pr2;
 	__gnu_unwind_frame;
 };
+
+GCC_4.3.0 {
+	_Unwind_Backtrace;
+};