diff options
Diffstat (limited to 'aarch64-Move-ld.so-_start-to-separate-file-and-drop-.patch')
| -rw-r--r-- | aarch64-Move-ld.so-_start-to-separate-file-and-drop-.patch | 188 |
1 files changed, 188 insertions, 0 deletions
diff --git a/aarch64-Move-ld.so-_start-to-separate-file-and-drop-.patch b/aarch64-Move-ld.so-_start-to-separate-file-and-drop-.patch new file mode 100644 index 0000000..15738b9 --- /dev/null +++ b/aarch64-Move-ld.so-_start-to-separate-file-and-drop-.patch @@ -0,0 +1,188 @@ +From 1da064c015dce624cb19fcdc0bace7af2bd8caec Mon Sep 17 00:00:00 2001 +From: Szabolcs Nagy <szabolcs.nagy@arm.com> +Date: Thu, 30 Dec 2021 17:08:36 +0000 +Subject: [PATCH 4/4] aarch64: Move ld.so _start to separate file and drop + _dl_skip_args + +Conflict:NA +Reference:https://sourceware.org/git/?p=glibc.git;a=commitdiff;h=1da064c015dce624cb19fcdc0bace7af2bd8caec + +A separate asm file is easier to maintain than a macro that expands to +inline asm. + +The RTLD_START macro is only needed now because _dl_start is local in +rtld.c, but _start has to call it, if _dl_start was made hidden then it +could be empty. + +_dl_skip_args is no longer needed. + +Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org> +--- + sysdeps/aarch64/Makefile | 1 + + sysdeps/aarch64/dl-machine.h | 77 +----------------------------------- + sysdeps/aarch64/dl-start.S | 53 +++++++++++++++++++++++++ + 3 files changed, 56 insertions(+), 75 deletions(-) + create mode 100644 sysdeps/aarch64/dl-start.S + +diff --git a/sysdeps/aarch64/Makefile b/sysdeps/aarch64/Makefile +index 7183895d04..17fb1c5b72 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 b40050a981..fe120bb507 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 0000000000..a3a57bd5a1 +--- /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) +-- +2.27.0 + |