From 672f6fc2486745d0cabc3aaeb4e0a3cd13b37b12 Mon Sep 17 00:00:00 2001
From: David Benjamin <davidben@google.com>
Date: Wed, 21 Feb 2018 16:22:34 -0500
Subject: [PATCH] Always use adr with __thumb2__.

Thumb2 addresses are a bit a mess, depending on whether a label is
interpreted as a function pointer value (for use with BX and BLX) or as
a program counter value (for use with PC-relative addressing). Clang's
integrated assembler mis-assembles this code. See
https://crbug.com/124610#c54 for details.

Instead, use the ADR pseudo-instruction which has clear semantics and
should be supported by every assembler that handles the OpenSSL Thumb2
code. (In other files, the ADR vs SUB conditionals are based on
__thumb2__ already. For some reason, this one is based on __APPLE__, I'm
guessing to deal with an older version of clang assembler.)

It's unclear to me which of clang or binutils is "correct" or if this is
even a well-defined notion beyond "whatever binutils does". But I will
note that https://github.com/openssl/openssl/pull/4669 suggests binutils
has also changed behavior around this before.

See also https://github.com/openssl/openssl/pull/5431 in OpenSSL.

Bug: chromium:124610
Change-Id: I5e7a0c8c0f54a3f65cc324ad599a41883675f368
Reviewed-on: https://boringssl-review.googlesource.com/26164
Commit-Queue: Steven Valdez <svaldez@google.com>
Reviewed-by: Steven Valdez <svaldez@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
---

diff --git a/crypto/fipsmodule/aes/asm/aes-armv4.pl b/crypto/fipsmodule/aes/asm/aes-armv4.pl
index 466a4ba..4b507dd 100644
--- a/crypto/fipsmodule/aes/asm/aes-armv4.pl
+++ b/crypto/fipsmodule/aes/asm/aes-armv4.pl
@@ -208,7 +208,7 @@
 	adr	r3,.
 #endif
 	stmdb   sp!,{r1,r4-r12,lr}
-#ifdef	__APPLE__
+#if defined(__thumb2__) || defined(__APPLE__)
 	adr	$tbl,AES_Te
 #else
 	sub	$tbl,r3,#asm_AES_encrypt-AES_Te	@ Te
@@ -486,7 +486,7 @@
 	mov	lr,r1			@ bits
 	mov	$key,r2			@ key
 
-#ifdef	__APPLE__
+#if defined(__thumb2__) || defined(__APPLE__)
 	adr	$tbl,AES_Te+1024				@ Te4
 #else
 	sub	$tbl,r3,#_armv4_AES_set_encrypt_key-AES_Te-1024	@ Te4
@@ -984,7 +984,7 @@
 	adr	r3,.
 #endif
 	stmdb   sp!,{r1,r4-r12,lr}
-#ifdef	__APPLE__
+#if defined(__thumb2__) || defined(__APPLE__)
 	adr	$tbl,AES_Td
 #else
 	sub	$tbl,r3,#asm_AES_decrypt-AES_Td	@ Td
diff --git a/crypto/fipsmodule/aes/asm/bsaes-armv7.pl b/crypto/fipsmodule/aes/asm/bsaes-armv7.pl
index fa1e434..775dbd5 100644
--- a/crypto/fipsmodule/aes/asm/bsaes-armv7.pl
+++ b/crypto/fipsmodule/aes/asm/bsaes-armv7.pl
@@ -742,7 +742,7 @@
 _bsaes_decrypt8:
 	adr	$const,.
 	vldmia	$key!, {@XMM[9]}		@ round 0 key
-#ifdef	__APPLE__
+#if defined(__thumb2__) || defined(__APPLE__)
 	adr	$const,.LM0ISR
 #else
 	add	$const,$const,#.LM0ISR-_bsaes_decrypt8
@@ -841,7 +841,7 @@
 _bsaes_encrypt8:
 	adr	$const,.
 	vldmia	$key!, {@XMM[9]}		@ round 0 key
-#ifdef	__APPLE__
+#if defined(__thumb2__) || defined(__APPLE__)
 	adr	$const,.LM0SR
 #else
 	sub	$const,$const,#_bsaes_encrypt8-.LM0SR
@@ -949,7 +949,7 @@
 _bsaes_key_convert:
 	adr	$const,.
 	vld1.8	{@XMM[7]},  [$inp]!		@ load round 0 key
-#ifdef	__APPLE__
+#if defined(__thumb2__) || defined(__APPLE__)
 	adr	$const,.LM0
 #else
 	sub	$const,$const,#_bsaes_key_convert-.LM0