sysdeps/unix/sysv/linux/mips/setcontext.S

   1 /* Set current context.
   2    Copyright (C) 2009-2018 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Maciej W. Rozycki <macro@codesourcery.com>.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library.  If not, see
  18    <http://www.gnu.org/licenses/>.  */
  19
  20 #include <sysdep.h>
  21 #include <sys/asm.h>
  22 #include <sys/fpregdef.h>
  23 #include <sys/regdef.h>
  24
  25 #include "ucontext_i.h"
  26
  27 /* int setcontext (const ucontext_t *ucp) */
  28
  29         .text
  30         .set    nomips16
  31 LOCALSZ = 0
  32 ARGSZ = 0
  33 MASK = 0x00000000
  34 #ifdef __PIC__
  35 LOCALSZ = 1                                             /* save gp */
  36 #endif
  37 #if _MIPS_SIM != _ABIO32
  38 ARGSZ = 1                                               /* save a0 */
  39 # ifdef __PIC__
  40 MASK = 0x10000000
  41 # endif
  42 #endif
  43 FRAMESZ = (((ARGSZ + LOCALSZ) * SZREG) + ALSZ) & ALMASK
  44 GPOFF = FRAMESZ - ((ARGSZ + 1) * SZREG)
  45 #if _MIPS_SIM != _ABIO32
  46 A0OFF = FRAMESZ - (1 * SZREG)                           /* callee-allocated */
  47 #else
  48 A0OFF = FRAMESZ + (0 * SZREG)                           /* caller-allocated */
  49 #endif
  50 MCONTEXT_GREGSZ = 8
  51 #if _MIPS_SIM == _ABIO32 && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
  52 MCONTEXT_GREGOFF = 4
  53 #else
  54 MCONTEXT_GREGOFF = 0
  55 #endif
  56
  57 NESTED (__setcontext, FRAMESZ, ra)
  58         .mask   MASK, -(ARGSZ * SZREG)
  59         .fmask  0x00000000, 0
  60
  61 #ifdef __PIC__
  62         SETUP_GP
  63 #endif
  64
  65         PTR_ADDIU sp, -FRAMESZ
  66         cfi_adjust_cfa_offset (FRAMESZ)
  67
  68 #ifdef __PIC__
  69         SETUP_GP64_STACK (GPOFF, __setcontext)
  70         SAVE_GP (GPOFF)
  71 #endif
  72
  73 #ifdef PROF
  74         .set    noat
  75         move    AT, ra
  76         jal     _mcount
  77         .set    at
  78 #endif
  79
  80         /* Check for the magic flag.  */
  81         li      v0, 1
  82         /* zero */
  83         REG_L   v1, (MCONTEXT_GREGOFF + 0 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(a0)
  84         bne     v0, v1, 98f
  85
  86         REG_S   a0, A0OFF(sp)
  87
  88 /* rt_sigprocmask (SIG_SETMASK, &ucp->uc_sigmask, NULL, _NSIG8) */
  89         li      a3, _NSIG8
  90         move    a2, zero
  91         PTR_ADDU a1, a0, UCONTEXT_SIGMASK
  92         li      a0, SIG_SETMASK
  93
  94         li      v0, SYS_ify (rt_sigprocmask)
  95         syscall
  96         bnez    a3, 99f
  97
  98         REG_L   v0, A0OFF(sp)
  99
 100 #ifdef __mips_hard_float
 101 # if _MIPS_SIM == _ABI64
 102         l.d     fs0, (24 * SZREG + MCONTEXT_FPREGS)(v0)
 103         l.d     fs1, (25 * SZREG + MCONTEXT_FPREGS)(v0)
 104         l.d     fs2, (26 * SZREG + MCONTEXT_FPREGS)(v0)
 105         l.d     fs3, (27 * SZREG + MCONTEXT_FPREGS)(v0)
 106         l.d     fs4, (28 * SZREG + MCONTEXT_FPREGS)(v0)
 107         l.d     fs5, (29 * SZREG + MCONTEXT_FPREGS)(v0)
 108         l.d     fs6, (30 * SZREG + MCONTEXT_FPREGS)(v0)
 109         l.d     fs7, (31 * SZREG + MCONTEXT_FPREGS)(v0)
 110
 111 # else  /* _MIPS_SIM != _ABI64 */
 112         l.d     fs0, (20 * SZREG + MCONTEXT_FPREGS)(v0)
 113         l.d     fs1, (22 * SZREG + MCONTEXT_FPREGS)(v0)
 114         l.d     fs2, (24 * SZREG + MCONTEXT_FPREGS)(v0)
 115         l.d     fs3, (26 * SZREG + MCONTEXT_FPREGS)(v0)
 116         l.d     fs4, (28 * SZREG + MCONTEXT_FPREGS)(v0)
 117         l.d     fs5, (30 * SZREG + MCONTEXT_FPREGS)(v0)
 118
 119 # endif /* _MIPS_SIM != _ABI64 */
 120
 121         lw      v1, MCONTEXT_FPC_CSR(v0)
 122         ctc1    v1, fcr31
 123 #endif /* __mips_hard_float */
 124
 125         /* Note the contents of argument registers will be random
 126            unless makecontext() has been called.  */
 127         REG_L   a0, (MCONTEXT_GREGOFF + 4 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(v0)
 128         REG_L   a1, (MCONTEXT_GREGOFF + 5 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(v0)
 129         REG_L   a2, (MCONTEXT_GREGOFF + 6 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(v0)
 130         REG_L   a3, (MCONTEXT_GREGOFF + 7 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(v0)
 131 #if _MIPS_SIM != _ABIO32
 132         REG_L   a4, (MCONTEXT_GREGOFF + 8 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(v0)
 133         REG_L   a5, (MCONTEXT_GREGOFF + 9 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(v0)
 134         REG_L   a6, (MCONTEXT_GREGOFF + 10 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(v0)
 135         REG_L   a7, (MCONTEXT_GREGOFF + 11 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(v0)
 136 #endif
 137
 138         REG_L   s0, (MCONTEXT_GREGOFF + 16 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(v0)
 139         REG_L   s1, (MCONTEXT_GREGOFF + 17 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(v0)
 140         REG_L   s2, (MCONTEXT_GREGOFF + 18 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(v0)
 141         REG_L   s3, (MCONTEXT_GREGOFF + 19 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(v0)
 142         REG_L   s4, (MCONTEXT_GREGOFF + 20 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(v0)
 143         REG_L   s5, (MCONTEXT_GREGOFF + 21 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(v0)
 144         REG_L   s6, (MCONTEXT_GREGOFF + 22 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(v0)
 145         REG_L   s7, (MCONTEXT_GREGOFF + 23 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(v0)
 146 #if ! defined (__PIC__) || _MIPS_SIM != _ABIO32
 147         REG_L   gp, (MCONTEXT_GREGOFF + 28 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(v0)
 148 #endif
 149         REG_L   sp, (MCONTEXT_GREGOFF + 29 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(v0)
 150         REG_L   fp, (MCONTEXT_GREGOFF + 30 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(v0)
 151         REG_L   ra, (MCONTEXT_GREGOFF + 31 * MCONTEXT_GREGSZ + MCONTEXT_GREGS)(v0)
 152         REG_L   t9, (MCONTEXT_GREGOFF + MCONTEXT_PC)(v0)
 153
 154         move    v0, zero
 155         jr      t9
 156
 157 98:
 158         /* This is a context obtained from a signal handler.
 159            Perform a full restore by pushing the context
 160            passed onto a simulated signal frame on the stack
 161            and call the signal return syscall as if a signal
 162            handler exited normally.  */
 163         PTR_ADDIU sp, -((RT_SIGFRAME_SIZE + ALSZ) & ALMASK)
 164         cfi_adjust_cfa_offset ((RT_SIGFRAME_SIZE + ALSZ) & ALMASK)
 165
 166         /* Only ucontext is referred to from rt_sigreturn,
 167            copy it.  */
 168         PTR_ADDIU t1, sp, RT_SIGFRAME_UCONTEXT
 169         li      t3, ((UCONTEXT_SIZE + SZREG - 1) / SZREG) - 1
 170 0:
 171         REG_L   t2, (a0)
 172         PTR_ADDIU a0, SZREG
 173         REG_S   t2, (t1)
 174         PTR_ADDIU t1, SZREG
 175         .set    noreorder
 176         bgtz    t3, 0b
 177          addiu  t3, -1
 178         .set    reorder
 179
 180 /* rt_sigreturn () -- no arguments, sp points to struct rt_sigframe.  */
 181         li      v0, SYS_ify (rt_sigreturn)
 182         syscall
 183
 184         /* Restore the stack and fall through to the error
 185            path.  Successful rt_sigreturn never returns to
 186            its calling place.  */
 187         PTR_ADDIU sp, ((RT_SIGFRAME_SIZE + ALSZ) & ALMASK)
 188         cfi_adjust_cfa_offset (-((RT_SIGFRAME_SIZE + ALSZ) & ALMASK))
 189 99:
 190 #ifdef __PIC__
 191         PTR_LA  t9, JUMPTARGET (__syscall_error)
 192         RESTORE_GP64_STACK
 193         PTR_ADDIU sp, FRAMESZ
 194         cfi_adjust_cfa_offset (-FRAMESZ)
 195         jr      t9
 196
 197 #else  /* ! __PIC__ */
 198
 199         j       JUMPTARGET (__syscall_error)
 200 #endif /* ! __PIC__ */
 201 PSEUDO_END (__setcontext)
 202
 203 weak_alias (__setcontext, setcontext)