864 lines
23 KiB
ArmAsm
864 lines
23 KiB
ArmAsm
# x86/x86_64 support for -fsplit-stack.
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# Copyright (C) 2009-2015 Free Software Foundation, Inc.
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# Contributed by Ian Lance Taylor <iant@google.com>.
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# This file is part of GCC.
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# GCC is free software; you can redistribute it and/or modify it under
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# the terms of the GNU General Public License as published by the Free
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# Software Foundation; either version 3, or (at your option) any later
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# version.
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# GCC is distributed in the hope that it will be useful, but WITHOUT ANY
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# WARRANTY; without even the implied warranty of MERCHANTABILITY or
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# FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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# for more details.
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# Under Section 7 of GPL version 3, you are granted additional
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# permissions described in the GCC Runtime Library Exception, version
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# 3.1, as published by the Free Software Foundation.
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# You should have received a copy of the GNU General Public License and
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# a copy of the GCC Runtime Library Exception along with this program;
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# see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
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# <http://www.gnu.org/licenses/>.
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# Support for allocating more stack space when using -fsplit-stack.
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# When a function discovers that it needs more stack space, it will
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# call __morestack with the size of the stack frame and the size of
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# the parameters to copy from the old stack frame to the new one.
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# The __morestack function preserves the parameter registers and
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# calls __generic_morestack to actually allocate the stack space.
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# When this is called stack space is very low, but we ensure that
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# there is enough space to push the parameter registers and to call
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# __generic_morestack.
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# When calling __generic_morestack, FRAME_SIZE points to the size of
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# the desired frame when the function is called, and the function
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# sets it to the size of the allocated stack. OLD_STACK points to
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# the parameters on the old stack and PARAM_SIZE is the number of
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# bytes of parameters to copy to the new stack. These are the
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# parameters of the function that called __morestack. The
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# __generic_morestack function returns the new stack pointer,
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# pointing to the address of the first copied parameter. The return
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# value minus the returned *FRAME_SIZE will be the first address on
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# the stack which we should not use.
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# void *__generic_morestack (size_t *frame_size, void *old_stack,
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# size_t param_size);
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# The __morestack routine has to arrange for the caller to return to a
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# stub on the new stack. The stub is responsible for restoring the
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# old stack pointer and returning to the caller's caller. This calls
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# __generic_releasestack to retrieve the old stack pointer and release
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# the newly allocated stack.
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# void *__generic_releasestack (size_t *available);
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# We do a little dance so that the processor's call/return return
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# address prediction works out. The compiler arranges for the caller
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# to look like this:
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# call __generic_morestack
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# ret
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# L:
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# // carry on with function
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# After we allocate more stack, we call L, which is in our caller.
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# When that returns (to the predicted instruction), we release the
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# stack segment and reset the stack pointer. We then return to the
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# predicted instruction, namely the ret instruction immediately after
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# the call to __generic_morestack. That then returns to the caller of
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# the original caller.
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# The amount of extra space we ask for. In general this has to be
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# enough for the dynamic loader to find a symbol and for a signal
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# handler to run.
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#ifndef __x86_64__
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#define BACKOFF (1024)
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#else
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#define BACKOFF (1536)
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#endif
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# The amount of space we ask for when calling non-split-stack code.
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#define NON_SPLIT_STACK 0x100000
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# This entry point is for split-stack code which calls non-split-stack
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# code. When the linker sees this case, it converts the call to
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# __morestack to call __morestack_non_split instead. We just bump the
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# requested stack space by 16K.
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.global __morestack_non_split
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.hidden __morestack_non_split
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#ifdef __ELF__
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.type __morestack_non_split,@function
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#endif
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__morestack_non_split:
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.cfi_startproc
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#ifndef __x86_64__
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# See below for an extended explanation of this.
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.cfi_def_cfa %esp,16
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pushl %eax # Save %eax in case it is a parameter.
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.cfi_adjust_cfa_offset 4 # Account for pushed register.
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movl %esp,%eax # Current stack,
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subl 8(%esp),%eax # less required stack frame size,
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subl $NON_SPLIT_STACK,%eax # less space for non-split code.
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cmpl %gs:0x30,%eax # See if we have enough space.
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jb 2f # Get more space if we need it.
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# Here the stack is
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# %esp + 20: stack pointer after two returns
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# %esp + 16: return address of morestack caller's caller
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# %esp + 12: size of parameters
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# %esp + 8: new stack frame size
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# %esp + 4: return address of this function
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# %esp: saved %eax
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#
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# Since we aren't doing a full split stack, we don't need to
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# do anything when our caller returns. So we return to our
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# caller rather than calling it, and let it return as usual.
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# To make that work we adjust the return address.
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# This breaks call/return address prediction for the call to
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# this function. I can't figure out a way to make it work
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# short of copying the parameters down the stack, which will
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# probably take more clock cycles than we will lose breaking
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# call/return address prediction. We will only break
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# prediction for this call, not for our caller.
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movl 4(%esp),%eax # Increment the return address
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cmpb $0xc3,(%eax) # to skip the ret instruction;
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je 1f # see above.
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addl $2,%eax
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1: inc %eax
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# If the instruction that we return to is
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# leal 20(%ebp),{%eax,%ecx,%edx}
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# then we have been called by a varargs function that expects
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# %ebp to hold a real value. That can only work if we do the
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# full stack split routine. FIXME: This is fragile.
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cmpb $0x8d,(%eax)
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jne 3f
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cmpb $0x14,2(%eax)
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jne 3f
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cmpb $0x45,1(%eax)
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je 2f
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cmpb $0x4d,1(%eax)
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je 2f
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cmpb $0x55,1(%eax)
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je 2f
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3:
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movl %eax,4(%esp) # Update return address.
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popl %eax # Restore %eax and stack.
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.cfi_adjust_cfa_offset -4 # Account for popped register.
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ret $8 # Return to caller, popping args.
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2:
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.cfi_adjust_cfa_offset 4 # Back to where we were.
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popl %eax # Restore %eax and stack.
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.cfi_adjust_cfa_offset -4 # Account for popped register.
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# Increment space we request.
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addl $NON_SPLIT_STACK+0x1000+BACKOFF,4(%esp)
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# Fall through into morestack.
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#else
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# See below for an extended explanation of this.
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.cfi_def_cfa %rsp,16
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pushq %rax # Save %rax in case caller is using
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# it to preserve original %r10.
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.cfi_adjust_cfa_offset 8 # Adjust for pushed register.
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movq %rsp,%rax # Current stack,
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subq %r10,%rax # less required stack frame size,
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subq $NON_SPLIT_STACK,%rax # less space for non-split code.
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#ifdef __LP64__
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cmpq %fs:0x70,%rax # See if we have enough space.
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#else
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cmpl %fs:0x40,%eax
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#endif
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jb 2f # Get more space if we need it.
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# If the instruction that we return to is
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# leaq 24(%rbp), %r11n
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# then we have been called by a varargs function that expects
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# %ebp to hold a real value. That can only work if we do the
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# full stack split routine. FIXME: This is fragile.
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movq 8(%rsp),%rax
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incq %rax # Skip ret instruction in caller.
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cmpl $0x185d8d4c,(%rax)
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je 2f
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# This breaks call/return prediction, as described above.
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incq 8(%rsp) # Increment the return address.
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popq %rax # Restore register.
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.cfi_adjust_cfa_offset -8 # Adjust for popped register.
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ret # Return to caller.
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2:
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popq %rax # Restore register.
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.cfi_adjust_cfa_offset -8 # Adjust for popped register.
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# Increment space we request.
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addq $NON_SPLIT_STACK+0x1000+BACKOFF,%r10
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# Fall through into morestack.
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#endif
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.cfi_endproc
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#ifdef __ELF__
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.size __morestack_non_split, . - __morestack_non_split
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#endif
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# __morestack_non_split falls through into __morestack.
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# The __morestack function.
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.global __morestack
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.hidden __morestack
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#ifdef __ELF__
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.type __morestack,@function
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#endif
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__morestack:
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.LFB1:
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.cfi_startproc
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#ifndef __x86_64__
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# The 32-bit __morestack function.
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# We use a cleanup to restore the stack guard if an exception
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# is thrown through this code.
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#ifndef __PIC__
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.cfi_personality 0,__gcc_personality_v0
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.cfi_lsda 0,.LLSDA1
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#else
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.cfi_personality 0x9b,DW.ref.__gcc_personality_v0
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.cfi_lsda 0x1b,.LLSDA1
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#endif
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# We return below with a ret $8. We will return to a single
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# return instruction, which will return to the caller of our
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# caller. We let the unwinder skip that single return
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# instruction, and just return to the real caller.
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# Here CFA points just past the return address on the stack,
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# e.g., on function entry it is %esp + 4. The stack looks
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# like this:
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# CFA + 12: stack pointer after two returns
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# CFA + 8: return address of morestack caller's caller
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# CFA + 4: size of parameters
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# CFA: new stack frame size
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# CFA - 4: return address of this function
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# CFA - 8: previous value of %ebp; %ebp points here
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# Setting the new CFA to be the current CFA + 12 (i.e., %esp +
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# 16) will make the unwinder pick up the right return address.
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.cfi_def_cfa %esp,16
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pushl %ebp
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.cfi_adjust_cfa_offset 4
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.cfi_offset %ebp, -20
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movl %esp,%ebp
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.cfi_def_cfa_register %ebp
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# In 32-bit mode the parameters are pushed on the stack. The
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# argument size is pushed then the new stack frame size is
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# pushed.
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# In the body of a non-leaf function, the stack pointer will
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# be aligned to a 16-byte boundary. That is CFA + 12 in the
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# stack picture above: (CFA + 12) % 16 == 0. At this point we
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# have %esp == CFA - 8, so %esp % 16 == 12. We need some
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# space for saving registers and passing parameters, and we
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# need to wind up with %esp % 16 == 0.
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subl $44,%esp
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# Because our cleanup code may need to clobber %ebx, we need
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# to save it here so the unwinder can restore the value used
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# by the caller. Note that we don't have to restore the
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# register, since we don't change it, we just have to save it
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# for the unwinder.
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movl %ebx,-4(%ebp)
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.cfi_offset %ebx, -24
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# In 32-bit mode the registers %eax, %edx, and %ecx may be
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# used for parameters, depending on the regparm and fastcall
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# attributes.
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movl %eax,-8(%ebp)
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movl %edx,-12(%ebp)
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movl %ecx,-16(%ebp)
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call __morestack_block_signals
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movl 12(%ebp),%eax # The size of the parameters.
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movl %eax,8(%esp)
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leal 20(%ebp),%eax # Address of caller's parameters.
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movl %eax,4(%esp)
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addl $BACKOFF,8(%ebp) # Ask for backoff bytes.
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leal 8(%ebp),%eax # The address of the new frame size.
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movl %eax,(%esp)
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call __generic_morestack
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movl %eax,%esp # Switch to the new stack.
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subl 8(%ebp),%eax # The end of the stack space.
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addl $BACKOFF,%eax # Back off 512 bytes.
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.LEHB0:
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# FIXME: The offset must match
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# TARGET_THREAD_SPLIT_STACK_OFFSET in
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# gcc/config/i386/linux.h.
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movl %eax,%gs:0x30 # Save the new stack boundary.
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call __morestack_unblock_signals
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movl -12(%ebp),%edx # Restore registers.
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movl -16(%ebp),%ecx
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movl 4(%ebp),%eax # Increment the return address
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cmpb $0xc3,(%eax) # to skip the ret instruction;
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je 1f # see above.
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addl $2,%eax
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1: inc %eax
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movl %eax,-12(%ebp) # Store return address in an
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# unused slot.
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movl -8(%ebp),%eax # Restore the last register.
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call *-12(%ebp) # Call our caller!
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# The caller will return here, as predicted.
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# Save the registers which may hold a return value. We
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# assume that __generic_releasestack does not touch any
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# floating point or vector registers.
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pushl %eax
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pushl %edx
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# Push the arguments to __generic_releasestack now so that the
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# stack is at a 16-byte boundary for
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# __morestack_block_signals.
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pushl $0 # Where the available space is returned.
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leal 0(%esp),%eax # Push its address.
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push %eax
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call __morestack_block_signals
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call __generic_releasestack
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subl 4(%esp),%eax # Subtract available space.
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addl $BACKOFF,%eax # Back off 512 bytes.
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.LEHE0:
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movl %eax,%gs:0x30 # Save the new stack boundary.
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addl $8,%esp # Remove values from stack.
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# We need to restore the old stack pointer, which is in %rbp,
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# before we unblock signals. We also need to restore %eax and
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# %edx after we unblock signals but before we return. Do this
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# by moving %eax and %edx from the current stack to the old
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# stack.
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popl %edx # Pop return value from current stack.
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popl %eax
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movl %ebp,%esp # Restore stack pointer.
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# As before, we now have %esp % 16 == 12.
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pushl %eax # Push return value on old stack.
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pushl %edx
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subl $4,%esp # Align stack to 16-byte boundary.
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call __morestack_unblock_signals
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addl $4,%esp
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popl %edx # Restore return value.
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popl %eax
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.cfi_remember_state
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# We never changed %ebx, so we don't have to actually restore it.
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.cfi_restore %ebx
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popl %ebp
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.cfi_restore %ebp
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.cfi_def_cfa %esp, 16
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ret $8 # Return to caller, which will
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# immediately return. Pop
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# arguments as we go.
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# This is the cleanup code called by the stack unwinder when unwinding
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# through the code between .LEHB0 and .LEHE0 above.
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.L1:
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.cfi_restore_state
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subl $16,%esp # Maintain 16 byte alignment.
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movl %eax,4(%esp) # Save exception header.
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movl %ebp,(%esp) # Stack pointer after resume.
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call __generic_findstack
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movl %ebp,%ecx # Get the stack pointer.
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subl %eax,%ecx # Subtract available space.
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addl $BACKOFF,%ecx # Back off 512 bytes.
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movl %ecx,%gs:0x30 # Save new stack boundary.
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movl 4(%esp),%eax # Function argument.
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movl %eax,(%esp)
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#ifdef __PIC__
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call __x86.get_pc_thunk.bx # %ebx may not be set up for us.
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addl $_GLOBAL_OFFSET_TABLE_, %ebx
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call _Unwind_Resume@PLT # Resume unwinding.
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#else
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call _Unwind_Resume
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#endif
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#else /* defined(__x86_64__) */
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# The 64-bit __morestack function.
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# We use a cleanup to restore the stack guard if an exception
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# is thrown through this code.
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#ifndef __PIC__
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.cfi_personality 0x3,__gcc_personality_v0
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.cfi_lsda 0x3,.LLSDA1
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#else
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.cfi_personality 0x9b,DW.ref.__gcc_personality_v0
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.cfi_lsda 0x1b,.LLSDA1
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#endif
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# We will return a single return instruction, which will
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# return to the caller of our caller. Let the unwinder skip
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# that single return instruction, and just return to the real
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# caller.
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.cfi_def_cfa %rsp,16
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# Set up a normal backtrace.
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pushq %rbp
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.cfi_adjust_cfa_offset 8
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.cfi_offset %rbp, -24
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movq %rsp, %rbp
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.cfi_def_cfa_register %rbp
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# In 64-bit mode the new stack frame size is passed in r10
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# and the argument size is passed in r11.
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addq $BACKOFF,%r10 # Ask for backoff bytes.
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pushq %r10 # Save new frame size.
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# In 64-bit mode the registers %rdi, %rsi, %rdx, %rcx, %r8,
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# and %r9 may be used for parameters. We also preserve %rax
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# which the caller may use to hold %r10.
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pushq %rax
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pushq %rdi
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pushq %rsi
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pushq %rdx
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pushq %rcx
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pushq %r8
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pushq %r9
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pushq %r11
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# We entered morestack with the stack pointer aligned to a
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# 16-byte boundary (the call to morestack's caller used 8
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# bytes, and the call to morestack used 8 bytes). We have now
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# pushed 10 registers, so we are still aligned to a 16-byte
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# boundary.
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call __morestack_block_signals
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leaq -8(%rbp),%rdi # Address of new frame size.
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leaq 24(%rbp),%rsi # The caller's parameters.
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popq %rdx # The size of the parameters.
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subq $8,%rsp # Align stack.
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call __generic_morestack
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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
|
|
|
|
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:
|
|
|
|
#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.
|
|
|
|
.section .ctors.65535,"aw",@progbits
|
|
|
|
#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
|