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88f4b6929c
This allows us to define a generic no-op version of PTR_MANGLE and PTR_DEMANGLE. In the future, we can use PTR_MANGLE and PTR_DEMANGLE unconditionally in C sources, avoiding an unintended loss of hardening due to missing include files or unlucky header inclusion ordering. In i386 and x86_64, we can avoid a <tls.h> dependency in the C code by using the computed constant from <tcb-offsets.h>. <sysdep.h> no longer includes these definitions, so there is no cyclic dependency anymore when computing the <tcb-offsets.h> constants. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
93 lines
2.8 KiB
ArmAsm
93 lines
2.8 KiB
ArmAsm
/* Copyright (C) 2001-2022 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<https://www.gnu.org/licenses/>. */
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#include <sysdep.h>
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#include <pointer_guard.h>
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#include <jmpbuf-offsets.h>
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#include <tcb-offsets.h>
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#include <asm-syntax.h>
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#include <signal-defines.h>
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/* #include <signal.h> */
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#define SS_ONSTACK 1
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.text
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ENTRY (__longjmp)
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movl 4(%esp), %eax /* User's jmp_buf in %eax. */
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/* Save the return address now. */
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movl (JB_PC*4)(%eax), %edx
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/* Get the stack pointer. */
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movl (JB_SP*4)(%eax), %ecx
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cfi_undefined(%ecx)
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#ifdef PTR_DEMANGLE
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PTR_DEMANGLE (%edx)
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PTR_DEMANGLE (%ecx)
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#endif
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movw %ds, %si
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movw %gs, %di
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cmpw %si, %di
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jz .Lok /* TLS not initialized yet */
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movl %gs:SIGSTATE_OFFSET, %edi
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testl %edi, %edi
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jz .Lok /* sigstate not initialized yet */
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testl $SS_ONSTACK, (HURD_SIGSTATE__SIGALTSTACK__OFFSET + SIGALTSTACK__SS_FLAGS__OFFSET)(%edi)
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jz .Lok
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/* We were on the alternate stack. */
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cmpl (HURD_SIGSTATE__SIGALTSTACK__OFFSET + SIGALTSTACK__SS_SP__OFFSET)(%edi), %ecx
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jb .Loks /* We jump below the alternate stack, switch. */
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movl (HURD_SIGSTATE__SIGALTSTACK__OFFSET + SIGALTSTACK__SS_SP__OFFSET)(%edi), %ebx
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addl (HURD_SIGSTATE__SIGALTSTACK__OFFSET + SIGALTSTACK__SS_SIZE__OFFSET)(%edi), %ebx
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cmpl %ebx, %ecx
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jb .Lok /* We jump inside the alternate stack, do not switch. */
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/* We jump above the alternate stack, switch. */
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.Loks: /* We jump out of the alternate stack, clear SS_ONSTACK flag. */
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andl $~(SS_ONSTACK), (HURD_SIGSTATE__SIGALTSTACK__OFFSET + SIGALTSTACK__SS_FLAGS__OFFSET)(%edi)
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.Lok: /* We add unwind information for the target here. */
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cfi_def_cfa(%eax, 0)
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cfi_register(%eip, %edx)
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cfi_register(%esp, %ecx)
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cfi_offset(%ebx, JB_BX*4)
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cfi_offset(%esi, JB_SI*4)
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cfi_offset(%edi, JB_DI*4)
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cfi_offset(%ebp, JB_BP*4)
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/* Restore registers. */
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movl (JB_BX*4)(%eax), %ebx
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movl (JB_SI*4)(%eax), %esi
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movl (JB_DI*4)(%eax), %edi
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movl (JB_BP*4)(%eax), %ebp
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cfi_restore(%ebx)
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cfi_restore(%esi)
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cfi_restore(%edi)
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cfi_restore(%ebp)
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movl 8(%esp), %eax /* Second argument is return value. */
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movl %ecx, %esp
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/* Jump to saved PC. */
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jmp *%edx
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END (__longjmp)
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