Add linker support for PIE
Modify the dynamic linker so that executables can be loaded
at locations other than 0x00000000.
Modify crtbegin* so that non-PIC compilant "thumb interwork
veneers" are not created by the linker.
Bug: 5323301
Change-Id: Iece0272e2b708c79034f302c20160e1fe9029588
diff --git a/libc/arch-arm/bionic/crtbegin_dynamic.S b/libc/arch-arm/bionic/crtbegin_dynamic.S
index 0999084..6ca0845 100644
--- a/libc/arch-arm/bionic/crtbegin_dynamic.S
+++ b/libc/arch-arm/bionic/crtbegin_dynamic.S
@@ -43,21 +43,17 @@
# - address of an "onexit" function, not used on any
# platform supported by Bionic
#
-# - address of the "main" function of the program. We
-# can't hard-code it in the adr pseudo instruction
-# so we use a tiny trampoline that will get relocated
-# by the dynamic linker before this code runs
+# - address of the "main" function of the program.
#
# - address of the constructor list
#
_start:
mov r0, sp
mov r1, #0
- adr r2, 0f
- adr r3, 1f
- b __libc_init
-
-0: b main
+ ldr r2, =main
+ adr r3, 1f
+ ldr r4, =__libc_init
+ bx r4
1: .long __PREINIT_ARRAY__
.long __INIT_ARRAY__
diff --git a/libc/arch-arm/bionic/crtbegin_static.S b/libc/arch-arm/bionic/crtbegin_static.S
index 13b05b2..e62ac1d 100644
--- a/libc/arch-arm/bionic/crtbegin_static.S
+++ b/libc/arch-arm/bionic/crtbegin_static.S
@@ -43,21 +43,17 @@
# - address of an "onexit" function, not used on any
# platform supported by Bionic
#
-# - address of the "main" function of the program. We
-# can't hard-code it in the adr pseudo instruction
-# so we use a tiny trampoline that will get relocated
-# by the dynamic linker before this code runs
+# - address of the "main" function of the program.
#
# - address of the constructor list
#
_start:
mov r0, sp
mov r1, #0
- adr r2, 0f
- adr r3, 1f
- b __libc_init
-
-0: b main
+ ldr r2, =main
+ adr r3, 1f
+ ldr r4, =__libc_init
+ bx r4
1: .long __PREINIT_ARRAY__
.long __INIT_ARRAY__