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8b8a692cfd
This updates glibc for the changes in the ELFv2 relating to the stack frame layout. These are described in more detail here: http://gcc.gnu.org/ml/gcc-patches/2013-11/msg01149.html http://gcc.gnu.org/ml/gcc-patches/2013-11/msg01146.html Specifically, the "compiler and linker doublewords" were removed, which has the effect that the save slot for the TOC register is now at offset 24 rather than 40 to the stack pointer. In addition, a function may now no longer necessarily assume that its caller has set up a 64-byte register save area its use. To address the first change, the patch goes through all assembler files and replaces immediate offsets in instructions accessing the ABI-defined stack slots by symbolic offsets. Those already were defined in ucontext_i.sym and used in some of the context routines, but that doesn't really seem like the right place for those defines. The patch instead defines those symbolic offsets in sysdeps.h, in two variants for the old and new ABI, and uses them systematically in all assembler files, not just the context routines. The second change only affected a few assembler files that used the save area to temporarily store some registers. In those cases where this happens within a leaf function, this patch changes the code to store those registers to the "red zone" below the stack pointer. Otherwise, the functions already allocate a stack frame, and the patch changes them to add extra space in these frames as temporary space for the ELFv2 ABI.
143 lines
3.4 KiB
ArmAsm
143 lines
3.4 KiB
ArmAsm
/* Wrapper around clone system call. PowerPC64 version.
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Copyright (C) 1997-2013 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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<http://www.gnu.org/licenses/>. */
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#include <sysdep.h>
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#define _ERRNO_H 1
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#include <bits/errno.h>
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#define CLONE_VM 0x00000100
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#define CLONE_THREAD 0x00010000
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/* This is the only really unusual system call in PPC linux, but not
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because of any weirdness in the system call itself; because of
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all the freaky stuff we have to do to make the call useful. */
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/* int [r3] clone(int (*fn)(void *arg) [r3], void *child_stack [r4],
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int flags [r5], void *arg [r6], void *parent_tid [r7],
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void *tls [r8], void *child_tid [r9]); */
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ENTRY (__clone)
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CALL_MCOUNT 7
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/* Check for child_stack == NULL || fn == NULL. */
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cmpdi cr0,r4,0
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cmpdi cr1,r3,0
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cror cr0*4+eq,cr1*4+eq,cr0*4+eq
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beq- cr0,L(badargs)
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/* Save some regs in the "red zone". */
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#ifdef RESET_PID
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std r29,-24(r1)
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#endif
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std r30,-16(r1)
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std r31,-8(r1)
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#ifdef RESET_PID
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cfi_offset(r29,-24)
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#endif
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cfi_offset(r30,-16)
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cfi_offset(r31,-8)
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/* Set up stack frame for child. */
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clrrdi r4,r4,4
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li r0,0
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stdu r0,-FRAME_MIN_SIZE_PARM(r4)
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/* Save fn, args, stack across syscall. */
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mr r30,r3 /* Function in r30. */
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#ifdef RESET_PID
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mr r29,r5 /* Flags in r29. */
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#endif
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mr r31,r6 /* Argument in r31. */
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/* 'flags' argument is first parameter to clone syscall.
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Second is the stack pointer, already in r4. */
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mr r3,r5
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/* Move the parent_tid, child_tid and tls arguments. */
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mr r5,r7
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mr r6,r8
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mr r7,r9
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/* End FDE now, because in the child the unwind info will be
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wrong. */
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cfi_endproc
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/* Do the call. */
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DO_CALL(SYS_ify(clone))
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/* Check for child process. */
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cmpdi cr1,r3,0
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crandc cr1*4+eq,cr1*4+eq,cr0*4+so
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bne- cr1,L(parent) /* The '-' is to minimise the race. */
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#ifdef RESET_PID
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andis. r0,r29,CLONE_THREAD>>16
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bne+ cr0,L(oldpid)
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andi. r0,r29,CLONE_VM
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li r3,-1
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bne- cr0,L(nomoregetpid)
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DO_CALL(SYS_ify(getpid))
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L(nomoregetpid):
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stw r3,TID(r13)
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stw r3,PID(r13)
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L(oldpid):
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#endif
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std r2,FRAME_TOC_SAVE(r1)
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/* Call procedure. */
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PPC64_LOAD_FUNCPTR r30
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mr r3,r31
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bctrl
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ld r2,FRAME_TOC_SAVE(r1)
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/* Call _exit with result from procedure. */
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#ifdef SHARED
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b JUMPTARGET(__GI__exit)
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#else
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b JUMPTARGET(_exit)
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/* We won't ever get here but provide a nop so that the linker
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will insert a toc adjusting stub if necessary. */
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nop
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#endif
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L(badargs):
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cfi_startproc
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li r3,EINVAL
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TAIL_CALL_SYSCALL_ERROR
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L(parent):
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/* Parent. Restore registers & return. */
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#ifdef RESET_PID
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cfi_offset(r29,-24)
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#endif
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cfi_offset(r30,-16)
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cfi_offset(r31,-8)
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#ifdef RESET_PID
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ld r29,-24(r1)
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#endif
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ld r30,-16(r1)
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ld r31,-8(r1)
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#ifdef RESET_PID
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cfi_restore(r29)
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#endif
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cfi_restore(r30)
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cfi_restore(r31)
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PSEUDO_RET
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END (__clone)
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weak_alias (__clone, clone)
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