sewardj | c68994d | 2012-06-07 09:23:23 +0000 | [diff] [blame] | 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 | |
sewardj | 0f157dd | 2013-10-18 14:27:36 +0000 | [diff] [blame] | 10 | Copyright (C) 2010-2013 RT-RK |
sewardj | c68994d | 2012-06-07 09:23:23 +0000 | [diff] [blame] | 11 | mips-valgrind@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 | /*--------------------------------------------------------------------*/ |