Here is the next installment of static-pie support. This time it is for aarch64 (arm64). It uses the same relocation methods as i386, x86_64, and arm.
The only other major difference is the disabling of stack protectors in reloc_static_pie.c since it can lead to access of dynamic memory prior to relocation.
From b55075957b6a95e120095fb5d5dcc96bd500749e Mon Sep 17 00:00:00 2001
From: linted <
linted@users.noreply.github.com>
Date: Sat, 16 Jul 2022 16:23:45 -0400
Subject: [PATCH] Added support for creation of Static Position-Independent
Executables (PIE) on aarch64
Updated config to allow compilation of rcrt1.o for aarch64 and modified it's crt1.S to relocate dynamic section prior to __uClibc_main.
Disabled stack protector when compiling reloc_static_pie.c to avoid TLS access prior to it being setup.
Signed-off-by: linted <
linted@users.noreply.github.com>
---
extra/Configs/Config.in | 2 +-
libc/misc/internals/Makefile.in | 2 +-
libc/sysdeps/linux/aarch64/crt1.S | 14 ++++++++++++++
3 files changed, 16 insertions(+), 2 deletions(-)
diff --git a/extra/Configs/Config.in b/extra/Configs/Config.in
index a49278b30..7d7d374c3 100644
--- a/extra/Configs/Config.in
+++ b/extra/Configs/Config.in
@@ -304,7 +304,7 @@ config DOPIC
config STATIC_PIE
bool "Add support for Static Position Independent Executables (PIE)"
default n
- depends on DOPIC && !UCLIBC_FORMAT_FDPIC_ELF && (TARGET_arm || TARGET_i386 || TARGET_x86_64)
+ depends on DOPIC && !UCLIBC_FORMAT_FDPIC_ELF && (TARGET_arm || TARGET_i386 || TARGET_x86_64 || TARGET_aarch64)
config ARCH_HAS_NO_SHARED
bool
diff --git a/libc/misc/internals/Makefile.in b/libc/misc/internals/Makefile.in
index 4a6e73d2d..69af8b76e 100644
--- a/libc/misc/internals/Makefile.in
+++ b/libc/misc/internals/Makefile.in
@@ -17,7 +17,7 @@ MISC_INTERNALS_SRC := $(patsubst %.c,$(MISC_INTERNALS_DIR)/%.c,$(CSRC-y))
MISC_INTERNALS_OBJ := $(patsubst %.c,$(MISC_INTERNALS_OUT)/%.o,$(CSRC-y))
CFLAGS-__uClibc_main.c := $(SSP_DISABLE_FLAGS)
-
+CFLAGS-reloc_static_pie.c := $(SSP_DISABLE_FLAGS)
libc-y += $(MISC_INTERNALS_OBJ)
ifneq ($(UCLIBC_FORMAT_SHARED_FLAT),y)
diff --git a/libc/sysdeps/linux/aarch64/crt1.S b/libc/sysdeps/linux/aarch64/crt1.S
index 09d0327ac..e9f946894 100644
--- a/libc/sysdeps/linux/aarch64/crt1.S
+++ b/libc/sysdeps/linux/aarch64/crt1.S
@@ -48,6 +48,20 @@ _start:
mov x29, #0
mov x30, #0
+#ifdef L_rcrt1
+ /* Save off the atexit pointer */
+ mov x19, x0
+
+ /* Calculate load address... idk how this works, but it does */
+ adrp x0, _start
+
+ /* Do relocations */
+ bl reloc_static_pie
+
+ /* restore atexit pointer */
+ mov x0, x19
+#endif
+
/* Setup _fini in argument register */
mov x5, x0
--
2.34.1