diff options
| -rw-r--r-- | sysdeps/aarch64/Makefile | 1 | ||||
| -rw-r--r-- | sysdeps/aarch64/dl-machine.h | 77 | ||||
| -rw-r--r-- | sysdeps/aarch64/dl-start.S | 53 |
3 files changed, 56 insertions, 75 deletions
diff --git a/sysdeps/aarch64/Makefile b/sysdeps/aarch64/Makefile index 7183895..17fb1c5 100644 --- a/sysdeps/aarch64/Makefile +++ b/sysdeps/aarch64/Makefile @@ -33,6 +33,7 @@ tst-audit27-ENV = LD_AUDIT=$(objpfx)tst-auditmod27.so endif ifeq ($(subdir),elf) +sysdep-rtld-routines += dl-start sysdep-dl-routines += tlsdesc dl-tlsdesc gen-as-const-headers += dl-link.sym diff --git a/sysdeps/aarch64/dl-machine.h b/sysdeps/aarch64/dl-machine.h index b40050a..fe120bb 100644 --- a/sysdeps/aarch64/dl-machine.h +++ b/sysdeps/aarch64/dl-machine.h @@ -105,81 +105,8 @@ elf_machine_runtime_setup (struct link_map *l, struct r_scope_elem *scope[], return lazy; } -/* Initial entry point for the dynamic linker. The C function - _dl_start is the real entry point, its return value is the user - program's entry point */ -#ifdef __LP64__ -# define RTLD_START RTLD_START_1 ("x", "3", "sp") -#else -# define RTLD_START RTLD_START_1 ("w", "2", "wsp") -#endif - - -#define RTLD_START_1(PTR, PTR_SIZE_LOG, PTR_SP) asm ("\ -.text \n\ -.globl _start \n\ -.type _start, %function \n\ -.globl _dl_start_user \n\ -.type _dl_start_user, %function \n\ -_start: \n\ - // bti c \n\ - hint 34 \n\ - mov " PTR "0, " PTR_SP " \n\ - bl _dl_start \n\ - // returns user entry point in x0 \n\ - mov x21, x0 \n\ -_dl_start_user: \n\ - // get the original arg count \n\ - ldr " PTR "1, [sp] \n\ - // get the argv address \n\ - add " PTR "2, " PTR_SP ", #(1<<" PTR_SIZE_LOG ") \n\ - // get _dl_skip_args to see if we were \n\ - // invoked as an executable \n\ - adrp x4, _dl_skip_args \n\ - ldr w4, [x4, #:lo12:_dl_skip_args] \n\ - // do we need to adjust argc/argv \n\ - cmp w4, 0 \n\ - beq .L_done_stack_adjust \n\ - // subtract _dl_skip_args from original arg count \n\ - sub " PTR "1, " PTR "1, " PTR "4 \n\ - // store adjusted argc back to stack \n\ - str " PTR "1, [sp] \n\ - // find the first unskipped argument \n\ - mov " PTR "3, " PTR "2 \n\ - add " PTR "4, " PTR "2, " PTR "4, lsl #" PTR_SIZE_LOG " \n\ - // shuffle argv down \n\ -1: ldr " PTR "5, [x4], #(1<<" PTR_SIZE_LOG ") \n\ - str " PTR "5, [x3], #(1<<" PTR_SIZE_LOG ") \n\ - cmp " PTR "5, #0 \n\ - bne 1b \n\ - // shuffle envp down \n\ -1: ldr " PTR "5, [x4], #(1<<" PTR_SIZE_LOG ") \n\ - str " PTR "5, [x3], #(1<<" PTR_SIZE_LOG ") \n\ - cmp " PTR "5, #0 \n\ - bne 1b \n\ - // shuffle auxv down \n\ -1: ldp " PTR "0, " PTR "5, [x4, #(2<<" PTR_SIZE_LOG ")]! \n\ - stp " PTR "0, " PTR "5, [x3], #(2<<" PTR_SIZE_LOG ") \n\ - cmp " PTR "0, #0 \n\ - bne 1b \n\ - // Update _dl_argv \n\ - adrp x3, __GI__dl_argv \n\ - str " PTR "2, [x3, #:lo12:__GI__dl_argv] \n\ -.L_done_stack_adjust: \n\ - // compute envp \n\ - add " PTR "3, " PTR "2, " PTR "1, lsl #" PTR_SIZE_LOG " \n\ - add " PTR "3, " PTR "3, #(1<<" PTR_SIZE_LOG ") \n\ - adrp x16, _rtld_local \n\ - add " PTR "16, " PTR "16, #:lo12:_rtld_local \n\ - ldr " PTR "0, [x16] \n\ - bl _dl_init \n\ - // load the finalizer function \n\ - adrp x0, _dl_fini \n\ - add " PTR "0, " PTR "0, #:lo12:_dl_fini \n\ - // jump to the user_s entry point \n\ - mov x16, x21 \n\ - br x16 \n\ -"); +/* In elf/rtld.c _dl_start should be global so dl-start.S can reference it. */ +#define RTLD_START asm (".globl _dl_start"); #define elf_machine_type_class(type) \ ((((type) == AARCH64_R(JUMP_SLOT) \ diff --git a/sysdeps/aarch64/dl-start.S b/sysdeps/aarch64/dl-start.S new file mode 100644 index 0000000..a3a57bd --- /dev/null +++ b/sysdeps/aarch64/dl-start.S @@ -0,0 +1,53 @@ +/* ld.so _start code. + Copyright (C) 2022 Free Software Foundation, Inc. + + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <https://www.gnu.org/licenses/>. */ + +#include <sysdep.h> + +ENTRY (_start) + /* Create an initial frame with 0 LR and FP */ + cfi_undefined (x30) + mov x29, #0 + mov x30, #0 + + mov x0, sp + PTR_ARG (0) + bl _dl_start + /* Returns user entry point in x0. */ + mov PTR_REG (21), PTR_REG (0) +.globl _dl_start_user +.type _dl_start_user, %function +_dl_start_user: + /* Get argc. */ + ldr PTR_REG (1), [sp] + /* Get argv. */ + add x2, sp, PTR_SIZE + /* Compute envp. */ + add PTR_REG (3), PTR_REG (2), PTR_REG (1), lsl PTR_LOG_SIZE + add PTR_REG (3), PTR_REG (3), PTR_SIZE + adrp x16, _rtld_local + add PTR_REG (16), PTR_REG (16), :lo12:_rtld_local + ldr PTR_REG (0), [x16] + bl _dl_init + /* Load the finalizer function. */ + adrp x0, _dl_fini + add PTR_REG (0), PTR_REG (0), :lo12:_dl_fini + /* Jump to the user's entry point. */ + mov x16, x21 + br x16 +END (_start) |