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f8e9c4d30c
In makecontext the FDE needs to be terminated before the return
trampoline otherwise backtrace called within a context created by
makecontext yields infinite backtrace.
This bug has been present for a long time, stdlib/tst-makecontext did
not fail until recent commit e535ce25. Tested on mips-linux-gnu and
mips64el-linux-gnuabi64 and mips-linux-gnu, no regression.
This fixes stdlib/tst-makecontext on MIPS.
Changelog:
[BZ #19792]
* sysdeps/unix/sysv/linux/mips/makecontext.S (__makecontext):
Terminate FDE before return label.
199 lines
4.2 KiB
ArmAsm
199 lines
4.2 KiB
ArmAsm
/* Modify saved context.
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Copyright (C) 2009-2016 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Contributed by Maciej W. Rozycki <macro@codesourcery.com>.
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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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#include <sys/asm.h>
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#include <sys/fpregdef.h>
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#include <sys/regdef.h>
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#include "ucontext_i.h"
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/* int makecontext (ucontext_t *ucp, (void *func) (), int argc, ...) */
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.text
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.set nomips16
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LOCALSZ = 0
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ARGSZ = 0
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MASK = 0x00000000
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#ifdef __PIC__
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LOCALSZ = 1 /* save gp */
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#endif
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#if _MIPS_SIM != _ABIO32
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ARGSZ = 5 /* save a3-a7 */
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# ifdef __PIC__
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MASK = 0x10000000
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# endif
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#endif
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FRAMESZ = (((ARGSZ + LOCALSZ) * SZREG) + ALSZ) & ALMASK
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GPOFF = FRAMESZ - ((ARGSZ + 1) * SZREG)
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#if _MIPS_SIM != _ABIO32
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A3OFF = FRAMESZ - (5 * SZREG) /* callee-allocated */
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A4OFF = FRAMESZ - (4 * SZREG)
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A5OFF = FRAMESZ - (3 * SZREG)
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A6OFF = FRAMESZ - (2 * SZREG)
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A7OFF = FRAMESZ - (1 * SZREG)
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NARGREGS = 8
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#else
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A3OFF = FRAMESZ + (3 * SZREG) /* caller-allocated */
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NARGREGS = 4
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#endif
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NESTED (__makecontext, FRAMESZ, ra)
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.mask MASK, -(ARGSZ * SZREG)
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.fmask 0x00000000, 0
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98:
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#ifdef __PIC__
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SETUP_GP
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#endif
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PTR_ADDIU sp, -FRAMESZ
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cfi_adjust_cfa_offset (FRAMESZ)
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#ifdef __PIC__
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SETUP_GP64_STACK (GPOFF, __makecontext)
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SAVE_GP (GPOFF)
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#endif
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#ifdef PROF
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.set noat
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move AT, ra
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jal _mcount
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.set at
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#endif
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/* Store args to be passed. */
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REG_S a3, A3OFF(sp)
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#if _MIPS_SIM != _ABIO32
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REG_S a4, A4OFF(sp)
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REG_S a5, A5OFF(sp)
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REG_S a6, A6OFF(sp)
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REG_S a7, A7OFF(sp)
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#endif
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/* Store a magic flag. */
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li v1, 1
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REG_S v1, (0 * SZREG + MCONTEXT_GREGS)(a0) /* zero */
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/* Set up the stack. */
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PTR_L t0, STACK_SP(a0)
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PTR_L t2, STACK_SIZE(a0)
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PTR_ADDIU t1, sp, A3OFF
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PTR_ADDU t0, t2
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and t0, ALMASK
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blez a2, 2f /* no arguments */
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/* Store register arguments. */
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PTR_ADDIU t2, a0, MCONTEXT_GREGS + 4 * SZREG
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move t3, zero
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0:
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addiu t3, 1
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REG_L v1, (t1)
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PTR_ADDIU t1, SZREG
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REG_S v1, (t2)
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PTR_ADDIU t2, SZREG
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bgeu t3, a2, 2f /* all done */
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bltu t3, NARGREGS, 0b /* next */
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/* Make room for stack arguments. */
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PTR_SUBU t2, a2, t3
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PTR_SLL t2, 3
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PTR_SUBU t0, t2
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and t0, ALMASK
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/* Store stack arguments. */
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move t2, t0
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1:
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addiu t3, 1
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REG_L v1, (t1)
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PTR_ADDIU t1, SZREG
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REG_S v1, (t2)
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PTR_ADDIU t2, SZREG
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bltu t3, a2, 1b /* next */
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2:
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#if _MIPS_SIM == _ABIO32
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/* Make room for a0-a3 storage. */
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PTR_ADDIU t0, -(NARGSAVE * SZREG)
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#endif
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PTR_L v1, UCONTEXT_LINK(a0)
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#ifdef __PIC__
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PTR_ADDIU t9, 99f - 98b
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#else
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PTR_LA t9, 99f
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#endif
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REG_S t0, (29 * SZREG + MCONTEXT_GREGS)(a0) /* sp */
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REG_S v1, (16 * SZREG + MCONTEXT_GREGS)(a0) /* s0 */
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#ifdef __PIC__
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REG_S gp, (17 * SZREG + MCONTEXT_GREGS)(a0) /* s1 */
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#endif
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REG_S t9, (31 * SZREG + MCONTEXT_GREGS)(a0) /* ra */
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REG_S a1, MCONTEXT_PC(a0)
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#ifdef __PIC__
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RESTORE_GP64_STACK
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PTR_ADDIU sp, FRAMESZ
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cfi_adjust_cfa_offset (-FRAMESZ)
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#endif
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jr ra
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/* We need to terminate the FDE to stop unwinding if backtrace was
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called within a context created by makecontext. */
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cfi_endproc
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nop
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99:
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#ifdef __PIC__
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move gp, s1
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#endif
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move a0, zero
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beqz s0, 0f
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/* setcontext (ucp) */
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move a0, s0
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#ifdef __PIC__
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PTR_LA t9, JUMPTARGET (__setcontext)
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jalr t9
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# if _MIPS_SIM == _ABIO32
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move gp, s1
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# endif
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#else
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jal JUMPTARGET (__setcontext)
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#endif
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move a0, v0
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0:
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/* exit (a0) */
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#ifdef __PIC__
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PTR_LA t9, HIDDEN_JUMPTARGET (exit)
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jalr t9
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#else
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jal HIDDEN_JUMPTARGET (exit)
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#endif
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/* You don't exist, you won't feel anything. */
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1:
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lb zero, (zero)
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b 1b
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cfi_startproc
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PSEUDO_END (__makecontext)
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weak_alias (__makecontext, makecontext)
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