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132 lines
4.8 KiB
ArmAsm
132 lines
4.8 KiB
ArmAsm
/* Install given context.
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Copyright (C) 2008-2020 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Contributed by David S. Miller <davem@davemloft.net>, 2008.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<https://www.gnu.org/licenses/>. */
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#include <sysdep.h>
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#include <sys/trap.h>
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#include "ucontext_i.h"
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/* int __setcontext (const ucontext_t *ucp)
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Restores the machine context in UCP and thereby resumes execution
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in that context.
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This implementation is intended to be used for *synchronous* context
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switches only. Therefore, it does not have to restore anything
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other than the PRESERVED state. */
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ENTRY(__setcontext)
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save %sp, -112, %sp
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mov SIG_SETMASK, %o0
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add %i0, UC_SIGMASK, %o1
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clr %o2
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mov 8, %o3
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mov __NR_rt_sigprocmask, %g1
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ta 0x10
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/* This is a bit on the expensive side, and we could optimize
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the unwind similar to how the 32-bit sparc longjmp code
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does if performance of this routine really matters. */
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ta ST_FLUSH_WINDOWS
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ldub [%i0 + UC_MCONTEXT + MC_FPREGS + FPU_EN], %g1
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cmp %g1, 0
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be 1f
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nop
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ld [%i0 + UC_MCONTEXT + MC_FPREGS + FPU_FSR], %fsr
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ldd [%i0 + UC_MCONTEXT + MC_FPREGS + FPU_D0], %f0
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ldd [%i0 + UC_MCONTEXT + MC_FPREGS + FPU_D2], %f2
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ldd [%i0 + UC_MCONTEXT + MC_FPREGS + FPU_D4], %f4
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ldd [%i0 + UC_MCONTEXT + MC_FPREGS + FPU_D6], %f6
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ldd [%i0 + UC_MCONTEXT + MC_FPREGS + FPU_D8], %f8
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ldd [%i0 + UC_MCONTEXT + MC_FPREGS + FPU_D10], %f10
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ldd [%i0 + UC_MCONTEXT + MC_FPREGS + FPU_D12], %f12
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ldd [%i0 + UC_MCONTEXT + MC_FPREGS + FPU_D14], %f14
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ldd [%i0 + UC_MCONTEXT + MC_FPREGS + FPU_D16], %f16
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ldd [%i0 + UC_MCONTEXT + MC_FPREGS + FPU_D18], %f18
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ldd [%i0 + UC_MCONTEXT + MC_FPREGS + FPU_D20], %f20
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ldd [%i0 + UC_MCONTEXT + MC_FPREGS + FPU_D22], %f22
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ldd [%i0 + UC_MCONTEXT + MC_FPREGS + FPU_D24], %f24
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ldd [%i0 + UC_MCONTEXT + MC_FPREGS + FPU_D26], %f26
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ldd [%i0 + UC_MCONTEXT + MC_FPREGS + FPU_D28], %f28
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ldd [%i0 + UC_MCONTEXT + MC_FPREGS + FPU_D30], %f30
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1:
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ld [%i0 + UC_MCONTEXT + MC_GREGS + GREG_Y], %g1
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wr %g1, 0x0, %y
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/* We specifically do not restore %g1 since we need it here as
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a temporary. */
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ld [%i0 + UC_MCONTEXT + MC_GREGS + GREG_G2], %g2
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ld [%i0 + UC_MCONTEXT + MC_GREGS + GREG_G3], %g3
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ld [%i0 + UC_MCONTEXT + MC_GREGS + GREG_G4], %g4
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ld [%i0 + UC_MCONTEXT + MC_GREGS + GREG_G5], %g5
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ld [%i0 + UC_MCONTEXT + MC_GREGS + GREG_G6], %g6
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ld [%i0 + UC_MCONTEXT + MC_GREGS + GREG_G7], %g7
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ld [%i0 + UC_MCONTEXT + MC_GREGS + GREG_O1], %i1
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ld [%i0 + UC_MCONTEXT + MC_GREGS + GREG_O2], %i2
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ld [%i0 + UC_MCONTEXT + MC_GREGS + GREG_O3], %i3
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ld [%i0 + UC_MCONTEXT + MC_GREGS + GREG_O4], %i4
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ld [%i0 + UC_MCONTEXT + MC_GREGS + GREG_O5], %i5
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ld [%i0 + UC_MCONTEXT + MC_GREGS + GREG_O6], %i6
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restore
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ld [%o0 + UC_MCONTEXT + MC_GREGS + GREG_O7], %o7
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ld [%o0 + UC_MCONTEXT + MC_GREGS + GREG_PC], %g1
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jmpl %g1, %g0
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ld [%o0 + UC_MCONTEXT + MC_GREGS + GREG_O0], %o0
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END(__setcontext)
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weak_alias (__setcontext, setcontext)
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/* We add an NOP here to separate between __setcontext/__startcontext. The
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wanted behavior that happens is: when unwinding from a function called
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inside a makecontext() context, FDE lookup will use '&__startcontext - 1',
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then returns NULL for no FDE found, and immediately ends the unwind, in
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a normal fashion.
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If this NOP word does not exist, FDE lookup just repeatedly finds
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__setcontext's FDE in an infinite loop, due to the convention of using
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'address - 1' for FDE lookup. Modifiying/deleting the below
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__startcontext's FDE has no help on this. */
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nop
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/* This is the helper code which gets called if a function which is
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registered with 'makecontext' returns. In this case we have to
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install the context listed in the uc_link element of the context
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'makecontext' manipulated at the time of the 'makecontext' call.
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If the pointer is NULL the process must terminate. */
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ENTRY(__start_context)
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ld [%sp + (16 * 4)], %g1
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cmp %g1, 0
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be,a 1f
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clr %o0
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call __setcontext
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mov %g1, %o0
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/* If this returns (which can happen if the syscall fails) we'll
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exit the program with the return error value (-1). */
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1: call HIDDEN_JUMPTARGET(exit)
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nop
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/* The 'exit' call should never return. In case it does cause
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the process to terminate. */
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unimp
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END(__start_context)
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