1 2 /*--------------------------------------------------------------------*/ 3 /*--- Support for doing system calls. syscall-mips32-linux.S ---*/ 4 /*--------------------------------------------------------------------*/ 5 6 /* 7 This file is part of Valgrind, a dynamic binary instrumentation 8 framework. 9 10 Copyright (C) 2010-2012 RT-RK 11 mips-valgrind (at) rt-rk.com 12 13 This program is free software; you can redistribute it and/or 14 modify it under the terms of the GNU General Public License as 15 published by the Free Software Foundation; either version 2 of the 16 License, or (at your option) any later version. 17 18 This program is distributed in the hope that it will be useful, but 19 WITHOUT ANY WARRANTY; without even the implied warranty of 20 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 21 General Public License for more details. 22 23 You should have received a copy of the GNU General Public License 24 along with this program; if not, write to the Free Software 25 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 26 02111-1307, USA. 27 28 The GNU General Public License is contained in the file COPYING. 29 */ 30 31 #if defined(VGP_mips32_linux) 32 33 #include "pub_core_basics_asm.h" 34 #include "pub_core_vkiscnums_asm.h" 35 #include "libvex_guest_offsets.h" 36 37 38 /*----------------------------------------------------------------*/ 39 /* 40 Perform a syscall for the client. This will run a syscall 41 with the client's specific per-thread signal mask. 42 43 The structure of this function is such that, if the syscall is 44 interrupted by a signal, we can determine exactly what 45 execution state we were in with respect to the execution of 46 the syscall by examining the value of IP in the signal 47 handler. This means that we can always do the appropriate 48 thing to precisely emulate the kernel's signal/syscall 49 interactions. 50 51 The syscall number is taken from the argument, even though it 52 should also be in regs->v0. The syscall result is written 53 back to regs->v0 on completion. 54 55 Returns 0 if the syscall was successfully called (even if the 56 syscall itself failed), or a nonzero error code in the lowest 57 8 bits if one of the sigprocmasks failed (there's no way to 58 determine which one failed). And there's no obvious way to 59 recover from that either, but nevertheless we want to know. 60 61 VG_(fixup_guest_state_after_syscall_interrupted) does the 62 thread state fixup in the case where we were interrupted by a 63 signal. 64 65 Prototype: 66 67 UWord ML_(do_syscall_for_client_WRK)( 68 Int syscallno, // $4 - a0 69 void* guest_state, // $5 - a1 70 const vki_sigset_t *sysmask, // $6 - a2 71 const vki_sigset_t *postmask, // $7 - a3 72 Int nsigwords) // stack 73 */ 74 /* from vki_arch.h */ 75 #define VKI_SIG_SETMASK 3 76 77 .globl ML_(do_syscall_for_client_WRK) 78 ML_(do_syscall_for_client_WRK): 79 80 subu $29, $29, 56 #set up the steck frame, 81 sw $4, 52($29) 82 sw $5, 48($29) 83 sw $6, 44($29) 84 sw $7, 40($29) 85 sw $31, 36($29) 86 sw $30, 32($29) 87 sw $16, 28($29) 88 sw $17, 24($29) 89 sw $18, 20($29) 90 sw $19, 16($29) 91 sw $20, 12($29) 92 sw $21, 8($29) 93 sw $22, 4($29) 94 sw $23, 0($29) 95 addu $30, $29, 56 96 97 98 /* Set the signal mask which should be current during the syscall. */ 99 100 1: li $2, __NR_rt_sigprocmask 101 li $4, VKI_SIG_SETMASK 102 move $5, $6 /* sysmask */ 103 move $6, $7 /* postmask */ 104 lw $7, 72($29) /* nsigwords */ 105 syscall 106 nop 107 108 # TODO: this should remain, keep it just for now 109 bnez $7, 7f 110 nop 111 112 lw $8, 48($29) /* t0 == ThreadState */ 113 114 lw $2, 52($29) /* v0 == syscallno */ 115 lw $4, OFFSET_mips32_r4($8) 116 lw $5, OFFSET_mips32_r5($8) 117 lw $6, OFFSET_mips32_r6($8) 118 lw $7, OFFSET_mips32_r7($8) 119 subu $29, $29, 24 #set up the steck frame, 120 lw $9, OFFSET_mips32_r29($8) 121 lw $10, 16($9) 122 sw $10, 16($29) 123 lw $10, 20($9) 124 sw $10, 20($29) 125 126 2: syscall 127 128 3: addu $29, $29, 24 #set up the steck frame, 129 130 lw $8, 48($29) /* t0 == ThreadState */ 131 sw $2, OFFSET_mips32_r2($8) 132 sw $3, OFFSET_mips32_r3($8) 133 sw $7, OFFSET_mips32_r7($8) 134 135 4: li $2, __NR_rt_sigprocmask 136 li $4, VKI_SIG_SETMASK 137 lw $5, 40($29) 138 li $6, 0 139 lw $7, 72($29) /* nsigwords */ 140 syscall 141 nop 142 143 bnez $7, 7f 144 nop 145 146 /* Success */ 147 li $2, 0 148 149 5: lw $4, 52($29) 150 lw $5, 48($29) 151 lw $6, 44($29) 152 lw $7, 40($29) 153 lw $31, 36($29) 154 lw $30, 32($29) 155 lw $16, 28($29) 156 lw $17, 24($29) 157 lw $18, 20($29) 158 lw $19, 16($29) 159 lw $20, 12($29) 160 lw $21, 8($29) 161 lw $22, 4($29) 162 lw $23, 0($29) 163 addu $29, $29, 56 #release the stack frame. 164 165 jr $31 166 nop 167 168 7: /* Failure: return 0x8000 | error code */ 169 li $2, 0x8000 170 171 lw $4, 52($29) 172 lw $5, 48($29) 173 lw $6, 44($29) 174 lw $7, 40($29) 175 lw $31, 36($29) 176 lw $30, 32($29) 177 lw $16, 28($29) 178 lw $17, 24($29) 179 lw $18, 20($29) 180 lw $19, 16($29) 181 lw $20, 12($29) 182 lw $21, 8($29) 183 lw $22, 4($29) 184 lw $23, 0($29) 185 addu $29, $29, 56 #release the stack frame. 186 187 jr $31 188 nop 189 190 .section .rodata 191 /* export the ranges so that 192 VG_(fixup_guest_state_after_syscall_interrupted) can do the 193 right thing */ 194 195 .globl ML_(blksys_setup) 196 .globl ML_(blksys_restart) 197 .globl ML_(blksys_complete) 198 .globl ML_(blksys_committed) 199 .globl ML_(blksys_finished) 200 ML_(blksys_setup): .long 1b 201 ML_(blksys_restart): .long 2b 202 ML_(blksys_complete): .long 3b 203 ML_(blksys_committed): .long 4b 204 ML_(blksys_finished): .long 5b 205 .previous 206 /* Let the linker know we don't need an executable stack */ 207 .section .note.GNU-stack,"",%progbits 208 209 210 211 #endif // defined(VGP_mips32_linux) 212 213 /*--------------------------------------------------------------------*/ 214 /*--- end ---*/ 215 /*--------------------------------------------------------------------*/ 216
