1 2 /*--------------------------------------------------------------------*/ 3 /*--- Support for doing system calls. syscall-amd64-darwin.S ---*/ 4 /*--------------------------------------------------------------------*/ 5 6 /* 7 This file is part of Valgrind, a dynamic binary instrumentation 8 framework. 9 10 Copyright (C) 2000-2017 Julian Seward 11 jseward (at) acm.org 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 #include "pub_core_basics_asm.h" 32 33 #if defined(VGP_amd64_darwin) 34 35 #include "pub_core_vkiscnums_asm.h" 36 #include "libvex_guest_offsets.h" 37 38 39 /*----------------------------------------------------------------*/ 40 /* 41 Perform a syscall for the client. This will run a syscall 42 with the client's specific per-thread signal mask. 43 44 The structure of this function is such that, if the syscall is 45 interrupted by a signal, we can determine exactly what 46 execution state we were in with respect to the execution of 47 the syscall by examining the value of %eip in the signal 48 handler. This means that we can always do the appropriate 49 thing to precisely emulate the kernel's signal/syscall 50 interactions. 51 52 The syscall number is taken from the argument, even though it 53 should also be in guest_state->guest_RAX. The syscall result 54 is written back to guest_state->guest_RAX on completion. 55 56 Returns 0 if the syscall was successfully called (even if the 57 syscall itself failed), or a -ve error code if one of the 58 sigprocmasks failed (there's no way to determine which one 59 failed). 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 Int ML_(do_syscall_for_client_WRK( 68 Int syscallno, // rdi 69 void* guest_state, // rsi 70 const vki_sigset_t *sysmask, // rdx 71 const vki_sigset_t *postmask, // rcx 72 Int sigsetSzB) // r8 73 74 Note that sigsetSzB is totally ignored (and irrelevant). 75 */ 76 77 /* from vki_arch.h */ 78 #define VKI_SIG_SETMASK 3 79 80 /* DO_SYSCALL MACH|MDEP|UNIX */ 81 #define MACH 1 82 #define MDEP 2 83 #define UNIX 3 84 85 .macro DO_SYSCALL 86 /* save callee-saved regs */ 87 pushq %rbp 88 movq %rsp, %rbp 89 // stack is now aligned 90 pushq %rdi // -8(%rbp) syscallno 91 pushq %rsi // -16(%rbp) guest_state 92 pushq %rdx // -24(%rbp) sysmask 93 pushq %rcx // -32(%rbp) postmask 94 pushq %r8 // -40(%rbp) sigsetSzB 95 // stack is now aligned 96 97 L_$0_1: /* Even though we can't take a signal until the sigprocmask completes, 98 start the range early. 99 If rip is in the range [1,2), the syscall hasn't been started yet */ 100 101 /* Set the signal mask which should be current during the syscall. */ 102 /* GrP fixme signals 103 DDD: JRS fixme: use __NR___pthread_sigmask, not __NR_rt_sigprocmask 104 movq $__NR_rt_sigprocmask, %rax // syscall # 105 movq $VKI_SIG_SETMASK, %rdi // how 106 movq -24(%rbp), %rsi // sysmask 107 movq -32(%rbp), %rdx // postmask 108 movq -40(%rbp), %r10 // sigsetSzB in r10 not rcx 109 DDD: fixme return address 110 syscall 111 112 jnc 7f // sigprocmask failed 113 */ 114 115 /* OK, that worked. Now do the syscall proper. */ 116 117 /* 6 register parameters */ 118 movq -16(%rbp), %r11 /* r11 = VexGuestAMD64State * */ 119 movq OFFSET_amd64_RDI(%r11), %rdi 120 movq OFFSET_amd64_RSI(%r11), %rsi 121 movq OFFSET_amd64_RDX(%r11), %rdx 122 movq OFFSET_amd64_RCX(%r11), %r10 /* rcx is passed in r10 instead */ 123 movq OFFSET_amd64_R8(%r11), %r8 124 movq OFFSET_amd64_R9(%r11), %r9 125 /* 2 stack parameters plus return address (ignored by syscall) */ 126 movq OFFSET_amd64_RSP(%r11), %r11 /* r11 = simulated RSP */ 127 movq 16(%r11), %rax 128 pushq %rax 129 movq 8(%r11), %rax 130 pushq %rax 131 /* stack is currently aligned - return address misaligns */ 132 movq 0(%r11), %rax 133 pushq %rax 134 /* syscallno */ 135 movq -8(%rbp), %rax 136 137 /* If rip==2, then the syscall was either just about 138 to start, or was interrupted and the kernel was 139 restarting it. */ 140 L_$0_2: syscall 141 L_$0_3: /* In the range [3, 4), the syscall result is in %rax, 142 but hasn't been committed to RAX. */ 143 144 /* stack contents: 3 words for syscall above, plus our prologue */ 145 setc 0(%rsp) /* stash returned carry flag */ 146 147 movq -16(%rbp), %r11 /* r11 = VexGuestAMD64State * */ 148 movq %rax, OFFSET_amd64_RAX(%r11) /* save back to RAX */ 149 movq %rdx, OFFSET_amd64_RDX(%r11) /* save back to RDX */ 150 151 .if $0 == UNIX 152 /* save carry flag to VEX */ 153 xor %rax, %rax 154 movb 0(%rsp), %al 155 movq %rax, %rdi /* arg1 = new flag */ 156 movq %r11, %rsi /* arg2 = vex state */ 157 addq $$24, %rsp /* remove syscall parameters */ 158 call _LibVEX_GuestAMD64_put_rflag_c 159 .else 160 addq $$24, %rsp /* remove syscall parameters*/ 161 .endif 162 163 L_$0_4: /* Re-block signals. If eip is in [4,5), then the syscall 164 is complete and we needn't worry about it. */ 165 /* GrP fixme signals 166 DDD: JRS fixme: use __NR___pthread_sigmask, not __NR_rt_sigprocmask 167 PUSH_di_si_dx_cx_8 168 169 movq $__NR_rt_sigprocmask, %rax // syscall # 170 movq $VKI_SIG_SETMASK, %rdi // how 171 movq %rcx, %rsi // postmask 172 xorq %rdx, %rdx // NULL 173 movq %r8, %r10 // sigsetSzB 174 DDD: fixme return address 175 syscall 176 177 POP_di_si_dx_cx_8 178 179 jnc 7f // sigprocmask failed 180 */ 181 L_$0_5: /* now safe from signals */ 182 movq $$0, %rax /* SUCCESS */ 183 movq %rbp, %rsp 184 popq %rbp 185 ret 186 187 /* GrP fixme signals 188 L_$0_7: // failure: return 0x8000 | error code 189 DDD: fixme return value 190 movq %rbp, %rsp 191 popq %rbp 192 ret 193 */ 194 195 .endmacro 196 197 198 .globl ML_(do_syscall_for_client_unix_WRK) 199 ML_(do_syscall_for_client_unix_WRK): 200 DO_SYSCALL UNIX 201 202 .globl ML_(do_syscall_for_client_mach_WRK) 203 ML_(do_syscall_for_client_mach_WRK): 204 DO_SYSCALL MACH 205 206 .globl ML_(do_syscall_for_client_mdep_WRK) 207 ML_(do_syscall_for_client_mdep_WRK): 208 DO_SYSCALL MDEP 209 210 .data 211 /* export the ranges so that 212 VG_(fixup_guest_state_after_syscall_interrupted) can do the 213 right thing */ 214 215 /* eg MK_L_SCLASS_N(UNIX,99) produces L_3_99 216 since UNIX is #defined to 3 at the top of this file */ 217 #define FOO(scclass,labelno) L_##scclass##_##labelno 218 #define MK_L_SCCLASS_N(scclass,labelno) FOO(scclass,labelno) 219 220 .globl ML_(blksys_setup_MACH) 221 .globl ML_(blksys_restart_MACH) 222 .globl ML_(blksys_complete_MACH) 223 .globl ML_(blksys_committed_MACH) 224 .globl ML_(blksys_finished_MACH) 225 ML_(blksys_setup_MACH): .quad MK_L_SCCLASS_N(MACH,1) 226 ML_(blksys_restart_MACH): .quad MK_L_SCCLASS_N(MACH,2) 227 ML_(blksys_complete_MACH): .quad MK_L_SCCLASS_N(MACH,3) 228 ML_(blksys_committed_MACH): .quad MK_L_SCCLASS_N(MACH,4) 229 ML_(blksys_finished_MACH): .quad MK_L_SCCLASS_N(MACH,5) 230 231 .globl ML_(blksys_setup_MDEP) 232 .globl ML_(blksys_restart_MDEP) 233 .globl ML_(blksys_complete_MDEP) 234 .globl ML_(blksys_committed_MDEP) 235 .globl ML_(blksys_finished_MDEP) 236 ML_(blksys_setup_MDEP): .quad MK_L_SCCLASS_N(MDEP,1) 237 ML_(blksys_restart_MDEP): .quad MK_L_SCCLASS_N(MDEP,2) 238 ML_(blksys_complete_MDEP): .quad MK_L_SCCLASS_N(MDEP,3) 239 ML_(blksys_committed_MDEP): .quad MK_L_SCCLASS_N(MDEP,4) 240 ML_(blksys_finished_MDEP): .quad MK_L_SCCLASS_N(MDEP,5) 241 242 .globl ML_(blksys_setup_UNIX) 243 .globl ML_(blksys_restart_UNIX) 244 .globl ML_(blksys_complete_UNIX) 245 .globl ML_(blksys_committed_UNIX) 246 .globl ML_(blksys_finished_UNIX) 247 ML_(blksys_setup_UNIX): .quad MK_L_SCCLASS_N(UNIX,1) 248 ML_(blksys_restart_UNIX): .quad MK_L_SCCLASS_N(UNIX,2) 249 ML_(blksys_complete_UNIX): .quad MK_L_SCCLASS_N(UNIX,3) 250 ML_(blksys_committed_UNIX): .quad MK_L_SCCLASS_N(UNIX,4) 251 ML_(blksys_finished_UNIX): .quad MK_L_SCCLASS_N(UNIX,5) 252 253 #endif // defined(VGP_amd64_darwin) 254 255 /* Let the linker know we don't need an executable stack */ 256 MARK_STACK_NO_EXEC 257 258 /*--------------------------------------------------------------------*/ 259 /*--- end ---*/ 260 /*--------------------------------------------------------------------*/ 261
