sysdeps/mips/setjmp_aux.c

   1 /* Copyright (C) 1996-2023 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library.  If not, see
  16    <https://www.gnu.org/licenses/>.  */
  17
  18 #include <setjmp.h>
  19
  20 /* This function is only called via the assembly language routine
  21    __sigsetjmp, which arranges to pass in the stack pointer and the frame
  22    pointer.  We do things this way because it's difficult to reliably
  23    access them in C.  */
  24
  25 /* Stack protection is disabled to avoid changing s0 (or any other
  26    caller-save register) before storing it to environment.
  27    See BZ #22624.  */
  28
  29 int __attribute__ ((nomips16))
  30 inhibit_stack_protector
  31 __sigsetjmp_aux (jmp_buf env, int savemask, int sp, int fp)
  32 {
  33 #ifdef __mips_hard_float
  34   /* Store the floating point callee-saved registers...  */
  35   asm volatile ("s.d $f20, %0" : : "m" (env[0].__jmpbuf[0].__fpregs[0]));
  36   asm volatile ("s.d $f22, %0" : : "m" (env[0].__jmpbuf[0].__fpregs[1]));
  37   asm volatile ("s.d $f24, %0" : : "m" (env[0].__jmpbuf[0].__fpregs[2]));
  38   asm volatile ("s.d $f26, %0" : : "m" (env[0].__jmpbuf[0].__fpregs[3]));
  39   asm volatile ("s.d $f28, %0" : : "m" (env[0].__jmpbuf[0].__fpregs[4]));
  40   asm volatile ("s.d $f30, %0" : : "m" (env[0].__jmpbuf[0].__fpregs[5]));
  41 #endif
  42
  43   /* .. and the PC;  */
  44   asm volatile ("sw $31, %0" : : "m" (env[0].__jmpbuf[0].__pc));
  45
  46   /* .. and the stack pointer;  */
  47   env[0].__jmpbuf[0].__sp = (void *) sp;
  48
  49   /* .. and the FP; it'll be in s8. */
  50   env[0].__jmpbuf[0].__fp = (void *) fp;
  51
  52   /* .. and the GP; */
  53   asm volatile ("sw $gp, %0" : : "m" (env[0].__jmpbuf[0].__gp));
  54
  55   /* .. and the callee-saved registers; */
  56   asm volatile ("sw $16, %0" : : "m" (env[0].__jmpbuf[0].__regs[0]));
  57   asm volatile ("sw $17, %0" : : "m" (env[0].__jmpbuf[0].__regs[1]));
  58   asm volatile ("sw $18, %0" : : "m" (env[0].__jmpbuf[0].__regs[2]));
  59   asm volatile ("sw $19, %0" : : "m" (env[0].__jmpbuf[0].__regs[3]));
  60   asm volatile ("sw $20, %0" : : "m" (env[0].__jmpbuf[0].__regs[4]));
  61   asm volatile ("sw $21, %0" : : "m" (env[0].__jmpbuf[0].__regs[5]));
  62   asm volatile ("sw $22, %0" : : "m" (env[0].__jmpbuf[0].__regs[6]));
  63   asm volatile ("sw $23, %0" : : "m" (env[0].__jmpbuf[0].__regs[7]));
  64
  65   /* Save the signal mask if requested.  */
  66   return __sigjmp_save (env, savemask);
  67 }