blob: f1cf32dec9f05ca24d50d3a67550c29e58eb1028 [file] [log] [blame]
# x86/x86_64 support for -fsplit-stack.
# Copyright (C) 2009-2022 Free Software Foundation, Inc.
# Contributed by Ian Lance Taylor <iant@google.com>.
# This file is part of GCC.
# GCC is free software; you can redistribute it and/or modify it under
# the terms of the GNU General Public License as published by the Free
# Software Foundation; either version 3, or (at your option) any later
# version.
# GCC 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 General Public License
# for more details.
# Under Section 7 of GPL version 3, you are granted additional
# permissions described in the GCC Runtime Library Exception, version
# 3.1, as published by the Free Software Foundation.
# You should have received a copy of the GNU General Public License and
# a copy of the GCC Runtime Library Exception along with this program;
# see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
# <http://www.gnu.org/licenses/>.
#include "auto-host.h"
# Support for allocating more stack space when using -fsplit-stack.
# When a function discovers that it needs more stack space, it will
# call __morestack with the size of the stack frame and the size of
# the parameters to copy from the old stack frame to the new one.
# The __morestack function preserves the parameter registers and
# calls __generic_morestack to actually allocate the stack space.
# When this is called stack space is very low, but we ensure that
# there is enough space to push the parameter registers and to call
# __generic_morestack.
# When calling __generic_morestack, FRAME_SIZE points to the size of
# the desired frame when the function is called, and the function
# sets it to the size of the allocated stack. OLD_STACK points to
# the parameters on the old stack and PARAM_SIZE is the number of
# bytes of parameters to copy to the new stack. These are the
# parameters of the function that called __morestack. The
# __generic_morestack function returns the new stack pointer,
# pointing to the address of the first copied parameter. The return
# value minus the returned *FRAME_SIZE will be the first address on
# the stack which we should not use.
# void *__generic_morestack (size_t *frame_size, void *old_stack,
# size_t param_size);
# The __morestack routine has to arrange for the caller to return to a
# stub on the new stack. The stub is responsible for restoring the
# old stack pointer and returning to the caller's caller. This calls
# __generic_releasestack to retrieve the old stack pointer and release
# the newly allocated stack.
# void *__generic_releasestack (size_t *available);
# We do a little dance so that the processor's call/return return
# address prediction works out. The compiler arranges for the caller
# to look like this:
# call __generic_morestack
# ret
# L:
# // carry on with function
# After we allocate more stack, we call L, which is in our caller.
# When that returns (to the predicted instruction), we release the
# stack segment and reset the stack pointer. We then return to the
# predicted instruction, namely the ret instruction immediately after
# the call to __generic_morestack. That then returns to the caller of
# the original caller.
# The amount of extra space we ask for. In general this has to be
# enough for the dynamic loader to find a symbol and for a signal
# handler to run.
#ifndef __x86_64__
#define BACKOFF (1024)
#else
#define BACKOFF (3584)
#endif
# The amount of space we ask for when calling non-split-stack code.
#define NON_SPLIT_STACK 0x100000
# This entry point is for split-stack code which calls non-split-stack
# code. When the linker sees this case, it converts the call to
# __morestack to call __morestack_non_split instead. We just bump the
# requested stack space by 16K.
#include <cet.h>
.global __morestack_non_split
.hidden __morestack_non_split
#ifdef __ELF__
.type __morestack_non_split,@function
#endif
__morestack_non_split:
.cfi_startproc
#ifndef __x86_64__
# See below for an extended explanation of this.
.cfi_def_cfa %esp,16
pushl %eax # Save %eax in case it is a parameter.
.cfi_adjust_cfa_offset 4 # Account for pushed register.
movl %esp,%eax # Current stack,
subl 8(%esp),%eax # less required stack frame size,
subl $NON_SPLIT_STACK,%eax # less space for non-split code.
cmpl %gs:0x30,%eax # See if we have enough space.
jb 2f # Get more space if we need it.
# Here the stack is
# %esp + 20: stack pointer after two returns
# %esp + 16: return address of morestack caller's caller
# %esp + 12: size of parameters
# %esp + 8: new stack frame size
# %esp + 4: return address of this function
# %esp: saved %eax
#
# Since we aren't doing a full split stack, we don't need to
# do anything when our caller returns. So we return to our
# caller rather than calling it, and let it return as usual.
# To make that work we adjust the return address.
# This breaks call/return address prediction for the call to
# this function. I can't figure out a way to make it work
# short of copying the parameters down the stack, which will
# probably take more clock cycles than we will lose breaking
# call/return address prediction. We will only break
# prediction for this call, not for our caller.
movl 4(%esp),%eax # Increment the return address
cmpb $0xc3,(%eax) # to skip the ret instruction;
je 1f # see above.
addl $2,%eax
1: inc %eax
# If the instruction that we return to is
# leal 20(%ebp),{%eax,%ecx,%edx}
# then we have been called by a varargs function that expects
# %ebp to hold a real value. That can only work if we do the
# full stack split routine. FIXME: This is fragile.
cmpb $0x8d,(%eax)
jne 3f
cmpb $0x14,2(%eax)
jne 3f
cmpb $0x45,1(%eax)
je 2f
cmpb $0x4d,1(%eax)
je 2f
cmpb $0x55,1(%eax)
je 2f
3:
movl %eax,4(%esp) # Update return address.
popl %eax # Restore %eax and stack.
.cfi_adjust_cfa_offset -4 # Account for popped register.
ret $8 # Return to caller, popping args.
2:
.cfi_adjust_cfa_offset 4 # Back to where we were.
popl %eax # Restore %eax and stack.
.cfi_adjust_cfa_offset -4 # Account for popped register.
# Increment space we request.
addl $NON_SPLIT_STACK+0x1000+BACKOFF,4(%esp)
# Fall through into morestack.
#else
# See below for an extended explanation of this.
.cfi_def_cfa %rsp,16
pushq %rax # Save %rax in case caller is using
# it to preserve original %r10.
.cfi_adjust_cfa_offset 8 # Adjust for pushed register.
movq %rsp,%rax # Current stack,
subq %r10,%rax # less required stack frame size,
subq $NON_SPLIT_STACK,%rax # less space for non-split code.
#ifdef __LP64__
cmpq %fs:0x70,%rax # See if we have enough space.
#else
cmpl %fs:0x40,%eax
#endif
jb 2f # Get more space if we need it.
# If the instruction that we return to is
# leaq 24(%rbp), %r11n
# then we have been called by a varargs function that expects
# %ebp to hold a real value. That can only work if we do the
# full stack split routine. FIXME: This is fragile.
movq 8(%rsp),%rax
incq %rax # Skip ret instruction in caller.
cmpl $0x185d8d4c,(%rax)
je 2f
# This breaks call/return prediction, as described above.
incq 8(%rsp) # Increment the return address.
popq %rax # Restore register.
.cfi_adjust_cfa_offset -8 # Adjust for popped register.
ret # Return to caller.
2:
popq %rax # Restore register.
.cfi_adjust_cfa_offset -8 # Adjust for popped register.
# Increment space we request.
addq $NON_SPLIT_STACK+0x1000+BACKOFF,%r10
# Fall through into morestack.
#endif
.cfi_endproc
#ifdef __ELF__
.size __morestack_non_split, . - __morestack_non_split
#endif
# __morestack_non_split falls through into __morestack.
# The __morestack function.
.global __morestack
.hidden __morestack
#ifdef __ELF__
.type __morestack,@function
#endif
__morestack:
.LFB1:
.cfi_startproc
#ifndef __x86_64__
# The 32-bit __morestack function.
# We use a cleanup to restore the stack guard if an exception
# is thrown through this code.
#ifndef __PIC__
.cfi_personality 0,__gcc_personality_v0
.cfi_lsda 0,.LLSDA1
#else
.cfi_personality 0x9b,DW.ref.__gcc_personality_v0
.cfi_lsda 0x1b,.LLSDA1
#endif
# We return below with a ret $8. We will return to a single
# return instruction, which will return to the caller of our
# caller. We let the unwinder skip that single return
# instruction, and just return to the real caller.
# Here CFA points just past the return address on the stack,
# e.g., on function entry it is %esp + 4. The stack looks
# like this:
# CFA + 12: stack pointer after two returns
# CFA + 8: return address of morestack caller's caller
# CFA + 4: size of parameters
# CFA: new stack frame size
# CFA - 4: return address of this function
# CFA - 8: previous value of %ebp; %ebp points here
# Setting the new CFA to be the current CFA + 12 (i.e., %esp +
# 16) will make the unwinder pick up the right return address.
.cfi_def_cfa %esp,16
pushl %ebp
.cfi_adjust_cfa_offset 4
.cfi_offset %ebp, -20
movl %esp,%ebp
.cfi_def_cfa_register %ebp
# In 32-bit mode the parameters are pushed on the stack. The
# argument size is pushed then the new stack frame size is
# pushed.
# In the body of a non-leaf function, the stack pointer will
# be aligned to a 16-byte boundary. That is CFA + 12 in the
# stack picture above: (CFA + 12) % 16 == 0. At this point we
# have %esp == CFA - 8, so %esp % 16 == 12. We need some
# space for saving registers and passing parameters, and we
# need to wind up with %esp % 16 == 0.
subl $44,%esp
# Because our cleanup code may need to clobber %ebx, we need
# to save it here so the unwinder can restore the value used
# by the caller. Note that we don't have to restore the
# register, since we don't change it, we just have to save it
# for the unwinder.
movl %ebx,-4(%ebp)
.cfi_offset %ebx, -24
# In 32-bit mode the registers %eax, %edx, and %ecx may be
# used for parameters, depending on the regparm and fastcall
# attributes.
movl %eax,-8(%ebp)
movl %edx,-12(%ebp)
movl %ecx,-16(%ebp)
call __morestack_block_signals
movl 12(%ebp),%eax # The size of the parameters.
movl %eax,8(%esp)
leal 20(%ebp),%eax # Address of caller's parameters.
movl %eax,4(%esp)
addl $BACKOFF,8(%ebp) # Ask for backoff bytes.
leal 8(%ebp),%eax # The address of the new frame size.
movl %eax,(%esp)
call __generic_morestack
movl %eax,%esp # Switch to the new stack.
subl 8(%ebp),%eax # The end of the stack space.
addl $BACKOFF,%eax # Back off 512 bytes.
.LEHB0:
# FIXME: The offset must match
# TARGET_THREAD_SPLIT_STACK_OFFSET in
# gcc/config/i386/linux.h.
movl %eax,%gs:0x30 # Save the new stack boundary.
call __morestack_unblock_signals
movl -12(%ebp),%edx # Restore registers.
movl -16(%ebp),%ecx
movl 4(%ebp),%eax # Increment the return address
cmpb $0xc3,(%eax) # to skip the ret instruction;
je 1f # see above.
addl $2,%eax
1: inc %eax
movl %eax,-12(%ebp) # Store return address in an
# unused slot.
movl -8(%ebp),%eax # Restore the last register.
call *-12(%ebp) # Call our caller!
# The caller will return here, as predicted.
# Save the registers which may hold a return value. We
# assume that __generic_releasestack does not touch any
# floating point or vector registers.
pushl %eax
pushl %edx
# Push the arguments to __generic_releasestack now so that the
# stack is at a 16-byte boundary for
# __morestack_block_signals.
pushl $0 # Where the available space is returned.
leal 0(%esp),%eax # Push its address.
push %eax
call __morestack_block_signals
call __generic_releasestack
subl 4(%esp),%eax # Subtract available space.
addl $BACKOFF,%eax # Back off 512 bytes.
.LEHE0:
movl %eax,%gs:0x30 # Save the new stack boundary.
addl $8,%esp # Remove values from stack.
# We need to restore the old stack pointer, which is in %rbp,
# before we unblock signals. We also need to restore %eax and
# %edx after we unblock signals but before we return. Do this
# by moving %eax and %edx from the current stack to the old
# stack.
popl %edx # Pop return value from current stack.
popl %eax
movl %ebp,%esp # Restore stack pointer.
# As before, we now have %esp % 16 == 12.
pushl %eax # Push return value on old stack.
pushl %edx
subl $4,%esp # Align stack to 16-byte boundary.
call __morestack_unblock_signals
addl $4,%esp
popl %edx # Restore return value.
popl %eax
.cfi_remember_state
# We never changed %ebx, so we don't have to actually restore it.
.cfi_restore %ebx
popl %ebp
.cfi_restore %ebp
.cfi_def_cfa %esp, 16
ret $8 # Return to caller, which will
# immediately return. Pop
# arguments as we go.
# This is the cleanup code called by the stack unwinder when unwinding
# through the code between .LEHB0 and .LEHE0 above.
.L1:
.cfi_restore_state
subl $16,%esp # Maintain 16 byte alignment.
movl %eax,4(%esp) # Save exception header.
movl %ebp,(%esp) # Stack pointer after resume.
call __generic_findstack
movl %ebp,%ecx # Get the stack pointer.
subl %eax,%ecx # Subtract available space.
addl $BACKOFF,%ecx # Back off 512 bytes.
movl %ecx,%gs:0x30 # Save new stack boundary.
movl 4(%esp),%eax # Function argument.
movl %eax,(%esp)
#ifdef __PIC__
call __x86.get_pc_thunk.bx # %ebx may not be set up for us.
addl $_GLOBAL_OFFSET_TABLE_, %ebx
call _Unwind_Resume@PLT # Resume unwinding.
#else
call _Unwind_Resume
#endif
#else /* defined(__x86_64__) */
# The 64-bit __morestack function.
# We use a cleanup to restore the stack guard if an exception
# is thrown through this code.
#ifndef __PIC__
.cfi_personality 0x3,__gcc_personality_v0
.cfi_lsda 0x3,.LLSDA1
#else
.cfi_personality 0x9b,DW.ref.__gcc_personality_v0
.cfi_lsda 0x1b,.LLSDA1
#endif
# We will return a single return instruction, which will
# return to the caller of our caller. Let the unwinder skip
# that single return instruction, and just return to the real
# caller.
.cfi_def_cfa %rsp,16
# Set up a normal backtrace.
pushq %rbp
.cfi_adjust_cfa_offset 8
.cfi_offset %rbp, -24
movq %rsp, %rbp
.cfi_def_cfa_register %rbp
# In 64-bit mode the new stack frame size is passed in r10
# and the argument size is passed in r11.
addq $BACKOFF,%r10 # Ask for backoff bytes.
pushq %r10 # Save new frame size.
# In 64-bit mode the registers %rdi, %rsi, %rdx, %rcx, %r8,
# and %r9 may be used for parameters. We also preserve %rax
# which the caller may use to hold %r10.
pushq %rax
pushq %rdi
pushq %rsi
pushq %rdx
pushq %rcx
pushq %r8
pushq %r9
pushq %r11
# We entered morestack with the stack pointer aligned to a
# 16-byte boundary (the call to morestack's caller used 8
# bytes, and the call to morestack used 8 bytes). We have now
# pushed 10 registers, so we are still aligned to a 16-byte
# boundary.
call __morestack_block_signals
leaq -8(%rbp),%rdi # Address of new frame size.
leaq 24(%rbp),%rsi # The caller's parameters.
popq %rdx # The size of the parameters.
subq $8,%rsp # Align stack.
call __generic_morestack
movq -8(%rbp),%r10 # Reload modified frame size
movq %rax,%rsp # Switch to the new stack.
subq %r10,%rax # The end of the stack space.
addq $BACKOFF,%rax # Back off 1024 bytes.
.LEHB0:
# FIXME: The offset must match
# TARGET_THREAD_SPLIT_STACK_OFFSET in
# gcc/config/i386/linux64.h.
# Macro to save the new stack boundary.
#ifdef __LP64__
#define X86_64_SAVE_NEW_STACK_BOUNDARY(reg) movq %r##reg,%fs:0x70
#else
#define X86_64_SAVE_NEW_STACK_BOUNDARY(reg) movl %e##reg,%fs:0x40
#endif
X86_64_SAVE_NEW_STACK_BOUNDARY (ax)
call __morestack_unblock_signals
movq -24(%rbp),%rdi # Restore registers.
movq -32(%rbp),%rsi
movq -40(%rbp),%rdx
movq -48(%rbp),%rcx
movq -56(%rbp),%r8
movq -64(%rbp),%r9
movq 8(%rbp),%r10 # Increment the return address
incq %r10 # to skip the ret instruction;
# see above.
movq -16(%rbp),%rax # Restore caller's %rax.
call *%r10 # Call our caller!
# The caller will return here, as predicted.
# Save the registers which may hold a return value. We
# assume that __generic_releasestack does not touch any
# floating point or vector registers.
pushq %rax
pushq %rdx
call __morestack_block_signals
pushq $0 # For alignment.
pushq $0 # Where the available space is returned.
leaq 0(%rsp),%rdi # Pass its address.
call __generic_releasestack
subq 0(%rsp),%rax # Subtract available space.
addq $BACKOFF,%rax # Back off 1024 bytes.
.LEHE0:
X86_64_SAVE_NEW_STACK_BOUNDARY (ax)
addq $16,%rsp # Remove values from stack.
# We need to restore the old stack pointer, which is in %rbp,
# before we unblock signals. We also need to restore %rax and
# %rdx after we unblock signals but before we return. Do this
# by moving %rax and %rdx from the current stack to the old
# stack.
popq %rdx # Pop return value from current stack.
popq %rax
movq %rbp,%rsp # Restore stack pointer.
# Now (%rsp & 16) == 8.
subq $8,%rsp # For alignment.
pushq %rax # Push return value on old stack.
pushq %rdx
call __morestack_unblock_signals
popq %rdx # Restore return value.
popq %rax
addq $8,%rsp
.cfi_remember_state
popq %rbp
.cfi_restore %rbp
.cfi_def_cfa %rsp, 16
ret # Return to caller, which will
# immediately return.
# This is the cleanup code called by the stack unwinder when unwinding
# through the code between .LEHB0 and .LEHE0 above.
.L1:
.cfi_restore_state
subq $16,%rsp # Maintain 16 byte alignment.
movq %rax,(%rsp) # Save exception header.
movq %rbp,%rdi # Stack pointer after resume.
call __generic_findstack
movq %rbp,%rcx # Get the stack pointer.
subq %rax,%rcx # Subtract available space.
addq $BACKOFF,%rcx # Back off 1024 bytes.
X86_64_SAVE_NEW_STACK_BOUNDARY (cx)
movq (%rsp),%rdi # Restore exception data for call.
#ifdef __PIC__
call _Unwind_Resume@PLT # Resume unwinding.
#else
call _Unwind_Resume # Resume unwinding.
#endif
#endif /* defined(__x86_64__) */
.cfi_endproc
#ifdef __ELF__
.size __morestack, . - __morestack
#endif
#if !defined(__x86_64__) && defined(__PIC__)
# Output the thunk to get PC into bx, since we use it above.
.section .text.__x86.get_pc_thunk.bx,"axG",@progbits,__x86.get_pc_thunk.bx,comdat
.globl __x86.get_pc_thunk.bx
.hidden __x86.get_pc_thunk.bx
#ifdef __ELF__
.type __x86.get_pc_thunk.bx, @function
#endif
__x86.get_pc_thunk.bx:
.cfi_startproc
movl (%esp), %ebx
ret
.cfi_endproc
#ifdef __ELF__
.size __x86.get_pc_thunk.bx, . - __x86.get_pc_thunk.bx
#endif
#endif
# The exception table. This tells the personality routine to execute
# the exception handler.
.section .gcc_except_table,"a",@progbits
.align 4
.LLSDA1:
.byte 0xff # @LPStart format (omit)
.byte 0xff # @TType format (omit)
.byte 0x1 # call-site format (uleb128)
.uleb128 .LLSDACSE1-.LLSDACSB1 # Call-site table length
.LLSDACSB1:
.uleb128 .LEHB0-.LFB1 # region 0 start
.uleb128 .LEHE0-.LEHB0 # length
.uleb128 .L1-.LFB1 # landing pad
.uleb128 0 # action
.LLSDACSE1:
.global __gcc_personality_v0
#ifdef __PIC__
# Build a position independent reference to the basic
# personality function.
.hidden DW.ref.__gcc_personality_v0
.weak DW.ref.__gcc_personality_v0
.section .data.DW.ref.__gcc_personality_v0,"awG",@progbits,DW.ref.__gcc_personality_v0,comdat
.type DW.ref.__gcc_personality_v0, @object
DW.ref.__gcc_personality_v0:
#ifndef __LP64__
.align 4
.size DW.ref.__gcc_personality_v0, 4
.long __gcc_personality_v0
#else
.align 8
.size DW.ref.__gcc_personality_v0, 8
.quad __gcc_personality_v0
#endif
#endif
#if defined __x86_64__ && defined __LP64__
# This entry point is used for the large model. With this entry point
# the upper 32 bits of %r10 hold the argument size and the lower 32
# bits hold the new stack frame size. There doesn't seem to be a way
# to know in the assembler code that we are assembling for the large
# model, and there doesn't seem to be a large model multilib anyhow.
# If one is developed, then the non-PIC code is probably OK since we
# will probably be close to the morestack code, but the PIC code
# almost certainly needs to be changed. FIXME.
.text
.global __morestack_large_model
.hidden __morestack_large_model
#ifdef __ELF__
.type __morestack_large_model,@function
#endif
__morestack_large_model:
.cfi_startproc
_CET_ENDBR
movq %r10, %r11
andl $0xffffffff, %r10d
sarq $32, %r11
jmp __morestack
.cfi_endproc
#ifdef __ELF__
.size __morestack_large_model, . - __morestack_large_model
#endif
#endif /* __x86_64__ && __LP64__ */
# Initialize the stack test value when the program starts or when a
# new thread starts. We don't know how large the main stack is, so we
# guess conservatively. We might be able to use getrlimit here.
.text
.global __stack_split_initialize
.hidden __stack_split_initialize
#ifdef __ELF__
.type __stack_split_initialize, @function
#endif
__stack_split_initialize:
_CET_ENDBR
#ifndef __x86_64__
leal -16000(%esp),%eax # We should have at least 16K.
movl %eax,%gs:0x30
subl $4,%esp # Align stack.
pushl $16000
pushl %esp
#ifdef __PIC__
call __generic_morestack_set_initial_sp@PLT
#else
call __generic_morestack_set_initial_sp
#endif
addl $12,%esp
ret
#else /* defined(__x86_64__) */
leaq -16000(%rsp),%rax # We should have at least 16K.
X86_64_SAVE_NEW_STACK_BOUNDARY (ax)
subq $8,%rsp # Align stack.
movq %rsp,%rdi
movq $16000,%rsi
#ifdef __PIC__
call __generic_morestack_set_initial_sp@PLT
#else
call __generic_morestack_set_initial_sp
#endif
addq $8,%rsp
ret
#endif /* defined(__x86_64__) */
#ifdef __ELF__
.size __stack_split_initialize, . - __stack_split_initialize
#endif
# Routines to get and set the guard, for __splitstack_getcontext,
# __splitstack_setcontext, and __splitstack_makecontext.
# void *__morestack_get_guard (void) returns the current stack guard.
.text
.global __morestack_get_guard
.hidden __morestack_get_guard
#ifdef __ELF__
.type __morestack_get_guard,@function
#endif
__morestack_get_guard:
#ifndef __x86_64__
movl %gs:0x30,%eax
#else
#ifdef __LP64__
movq %fs:0x70,%rax
#else
movl %fs:0x40,%eax
#endif
#endif
ret
#ifdef __ELF__
.size __morestack_get_guard, . - __morestack_get_guard
#endif
# void __morestack_set_guard (void *) sets the stack guard.
.global __morestack_set_guard
.hidden __morestack_set_guard
#ifdef __ELF__
.type __morestack_set_guard,@function
#endif
__morestack_set_guard:
#ifndef __x86_64__
movl 4(%esp),%eax
movl %eax,%gs:0x30
#else
X86_64_SAVE_NEW_STACK_BOUNDARY (di)
#endif
ret
#ifdef __ELF__
.size __morestack_set_guard, . - __morestack_set_guard
#endif
# void *__morestack_make_guard (void *, size_t) returns the stack
# guard value for a stack.
.global __morestack_make_guard
.hidden __morestack_make_guard
#ifdef __ELF__
.type __morestack_make_guard,@function
#endif
__morestack_make_guard:
#ifndef __x86_64__
movl 4(%esp),%eax
subl 8(%esp),%eax
addl $BACKOFF,%eax
#else
subq %rsi,%rdi
addq $BACKOFF,%rdi
movq %rdi,%rax
#endif
ret
#ifdef __ELF__
.size __morestack_make_guard, . - __morestack_make_guard
#endif
# Make __stack_split_initialize a high priority constructor. FIXME:
# This is ELF specific.
#if HAVE_INITFINI_ARRAY_SUPPORT
.section .init_array.00000,"aw",@progbits
#else
.section .ctors.65535,"aw",@progbits
#endif
#ifndef __LP64__
.align 4
.long __stack_split_initialize
.long __morestack_load_mmap
#else
.align 8
.quad __stack_split_initialize
.quad __morestack_load_mmap
#endif
#ifdef __ELF__
.section .note.GNU-stack,"",@progbits
.section .note.GNU-split-stack,"",@progbits
.section .note.GNU-no-split-stack,"",@progbits
#endif