[uclibc-ng-devel] [PATCH] Added support for creation of Static Position-Independent Executable (PIE) on aarch64

Hello, 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(a)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(a)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