From 556182feb40916842b52087f442ebcb4e877dbd7 Mon Sep 17 00:00:00 2001
From: Andrew Hsieh <andrewhsieh@google.com>
Date: Thu, 28 Jun 2012 14:04:36 -0700
Subject: [PATCH] Fix SEGV when unwinding stack pasts __libc_init
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Changed "jump __libc_init" to "call __libc_init" otherwise stack unwinding
past __libc_init may get wrong return address and crash the program or do
wield things.  With "call", return address is pushed on stack and unwinding
stops correctly at _start.  Note that __libc_init never returns, so this
fix wonʼt affect normal program execution.  But just in case it "does"
return, jump to address 0 and halt.

Change-Id: Id194fb32adcbf89ae59939cee33c50b5bbdd36fe
---
 ndk/platforms/android-3/arch-arm/src/crtbegin_dynamic.S  | 4 +++-
 ndk/platforms/android-3/arch-arm/src/crtbegin_static.S   | 4 +++-
 ndk/platforms/android-9/arch-mips/src/crtbegin_dynamic.S | 2 ++
 ndk/platforms/android-9/arch-mips/src/crtbegin_static.S  | 2 ++
 4 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/ndk/platforms/android-3/arch-arm/src/crtbegin_dynamic.S b/ndk/platforms/android-3/arch-arm/src/crtbegin_dynamic.S
index 6ca08458e..ec6d482d8 100644
--- a/ndk/platforms/android-3/arch-arm/src/crtbegin_dynamic.S
+++ b/ndk/platforms/android-3/arch-arm/src/crtbegin_dynamic.S
@@ -53,7 +53,9 @@ _start:
 	ldr	r2, =main
 	adr	r3, 1f
 	ldr	r4, =__libc_init
-	bx	r4
+	blx	r4
+	mov	r0, #0
+	bx	r0
 
 1:  .long   __PREINIT_ARRAY__
     .long   __INIT_ARRAY__
diff --git a/ndk/platforms/android-3/arch-arm/src/crtbegin_static.S b/ndk/platforms/android-3/arch-arm/src/crtbegin_static.S
index ec13351eb..d9d12a786 100644
--- a/ndk/platforms/android-3/arch-arm/src/crtbegin_static.S
+++ b/ndk/platforms/android-3/arch-arm/src/crtbegin_static.S
@@ -53,7 +53,9 @@ _start:
 	ldr	r2, =main
 	adr	r3, 1f
 	ldr	r4, =__libc_init
-	bx	r4
+	blx	r4
+	mov	r0, #0
+	bx	r0
 
 1:  .long   __PREINIT_ARRAY__
     .long   __INIT_ARRAY__
diff --git a/ndk/platforms/android-9/arch-mips/src/crtbegin_dynamic.S b/ndk/platforms/android-9/arch-mips/src/crtbegin_dynamic.S
index 7d1fac740..28f8fd551 100644
--- a/ndk/platforms/android-9/arch-mips/src/crtbegin_dynamic.S
+++ b/ndk/platforms/android-9/arch-mips/src/crtbegin_dynamic.S
@@ -64,6 +64,8 @@ _start:
 	la	$a3, 1f
 	subu	$sp, 32
 	la	$t9, __libc_init
+	jalr	$t9
+	move	$t9, $0
 	j	$t9
 	.end	__start
 
diff --git a/ndk/platforms/android-9/arch-mips/src/crtbegin_static.S b/ndk/platforms/android-9/arch-mips/src/crtbegin_static.S
index 9f00811ea..893863c17 100644
--- a/ndk/platforms/android-9/arch-mips/src/crtbegin_static.S
+++ b/ndk/platforms/android-9/arch-mips/src/crtbegin_static.S
@@ -64,6 +64,8 @@ _start:
 	la	$a3, 1f
 	subu	$sp, 32
 	la	$t9, __libc_init
+	jalr	$t9
+	move	$t9, $0
 	j	$t9
 	.end	__start