mirror of git://sourceware.org/git/glibc.git
149 lines
4.2 KiB
ArmAsm
149 lines
4.2 KiB
ArmAsm
/* Copyright (C) 2001-2025 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>
|
|
#include <pointer_guard.h>
|
|
#include <jmpbuf-offsets.h>
|
|
#include <jmp_buf-ssp.h>
|
|
#include <asm-syntax.h>
|
|
#include <stap-probe.h>
|
|
|
|
/* Don't restore shadow stack register if shadow stack isn't enabled. */
|
|
#if !SHSTK_ENABLED || defined DO_NOT_RESTORE_SHADOW_STACK
|
|
# undef SHADOW_STACK_POINTER_OFFSET
|
|
#endif
|
|
|
|
#ifndef CHECK_INVALID_LONGJMP
|
|
# define CHECK_INVALID_LONGJMP
|
|
#endif
|
|
|
|
/* Jump to the position specified by ENV, causing the
|
|
setjmp call there to return VAL, or 1 if VAL is 0.
|
|
void __longjmp (__jmp_buf env, int val). */
|
|
.text
|
|
ENTRY(__longjmp)
|
|
/* Restore registers. */
|
|
mov (JB_RSP*8)(%rdi),%R8_LP
|
|
mov (JB_RBP*8)(%rdi),%R9_LP
|
|
mov (JB_PC*8)(%rdi),%RDX_LP
|
|
#ifdef PTR_DEMANGLE
|
|
PTR_DEMANGLE (%R8_LP)
|
|
PTR_DEMANGLE (%R9_LP)
|
|
PTR_DEMANGLE (%RDX_LP)
|
|
# ifdef __ILP32__
|
|
/* We ignored the high bits of the %rbp value because only the low
|
|
bits are mangled. But we cannot presume that %rbp is being used
|
|
as a pointer and truncate it, so recover the high bits. */
|
|
movl (JB_RBP*8 + 4)(%rdi), %eax
|
|
shlq $32, %rax
|
|
orq %rax, %r9
|
|
# endif
|
|
#endif
|
|
|
|
CHECK_INVALID_LONGJMP
|
|
|
|
#ifdef SHADOW_STACK_POINTER_OFFSET
|
|
# if IS_IN (libc) && defined SHARED && defined FEATURE_1_OFFSET
|
|
/* Check if Shadow Stack is enabled. */
|
|
testl $X86_FEATURE_1_SHSTK, %fs:FEATURE_1_OFFSET
|
|
jz L(skip_ssp)
|
|
# else
|
|
xorl %eax, %eax
|
|
# endif
|
|
/* Check and adjust the Shadow-Stack-Pointer. */
|
|
/* Get the current ssp. */
|
|
rdsspq %rax
|
|
/* Save the current ssp. */
|
|
movq %rax, %r10
|
|
/* And compare it with the saved ssp value. */
|
|
movq SHADOW_STACK_POINTER_OFFSET(%rdi), %rcx
|
|
subq %rcx, %rax
|
|
je L(skip_ssp)
|
|
|
|
/* Save the target ssp. */
|
|
movq %rcx, %r11
|
|
|
|
L(find_restore_token_loop):
|
|
/* Look for a restore token. */
|
|
movq -8(%rcx), %rbx
|
|
andq $-8, %rbx
|
|
cmpq %rcx, %rbx
|
|
/* Find the restore token. */
|
|
je L(restore_shadow_stack)
|
|
|
|
/* Try the next slot. */
|
|
subq $8, %rcx
|
|
/* Stop if the current ssp is found. */
|
|
cmpq %rcx, %r10
|
|
jne L(find_restore_token_loop)
|
|
jmp L(no_shadow_stack_token)
|
|
|
|
L(restore_shadow_stack):
|
|
/* Restore the target shadow stack. */
|
|
rstorssp -8(%rcx)
|
|
/* Save the restore token on the old shadow stack. */
|
|
saveprevssp
|
|
rdsspq %rax
|
|
subq %r11, %rax
|
|
|
|
L(no_shadow_stack_token):
|
|
/* Count the number of frames to adjust and adjust it
|
|
with incssp instruction. The instruction can adjust
|
|
the ssp by [0..255] value only thus use a loop if
|
|
the number of frames is bigger than 255. */
|
|
negq %rax
|
|
shrq $3, %rax
|
|
/* NB: We saved Shadow-Stack-Pointer of setjmp. Since we are
|
|
restoring Shadow-Stack-Pointer of setjmp's caller, we
|
|
need to unwind shadow stack by one more frame. */
|
|
addq $1, %rax
|
|
|
|
movl $255, %ebx
|
|
L(loop):
|
|
cmpq %rbx, %rax
|
|
cmovb %rax, %rbx
|
|
incsspq %rbx
|
|
subq %rbx, %rax
|
|
ja L(loop)
|
|
|
|
L(skip_ssp):
|
|
#endif
|
|
LIBC_PROBE (longjmp, 3, LP_SIZE@%RDI_LP, -4@%esi, LP_SIZE@%RDX_LP)
|
|
/* We add unwind information for the target here. */
|
|
cfi_def_cfa(%rdi, 0)
|
|
cfi_register(%rsp,%r8)
|
|
cfi_register(%rbp,%r9)
|
|
cfi_register(%rip,%rdx)
|
|
cfi_offset(%rbx,JB_RBX*8)
|
|
cfi_offset(%r12,JB_R12*8)
|
|
cfi_offset(%r13,JB_R13*8)
|
|
cfi_offset(%r14,JB_R14*8)
|
|
cfi_offset(%r15,JB_R15*8)
|
|
movq (JB_RBX*8)(%rdi),%rbx
|
|
movq (JB_R12*8)(%rdi),%r12
|
|
movq (JB_R13*8)(%rdi),%r13
|
|
movq (JB_R14*8)(%rdi),%r14
|
|
movq (JB_R15*8)(%rdi),%r15
|
|
/* Set return value for setjmp. */
|
|
mov %esi, %eax
|
|
mov %R8_LP,%RSP_LP
|
|
movq %r9,%rbp
|
|
LIBC_PROBE (longjmp_target, 3,
|
|
LP_SIZE@%RDI_LP, -4@%eax, LP_SIZE@%RDX_LP)
|
|
jmpq *%rdx
|
|
END (__longjmp)
|