1 2 /*--------------------------------------------------------------------*/ 3 /*--- Support for doing system calls. syscall-ppc64-linux.S ---*/ 4 /*--------------------------------------------------------------------*/ 5 6 /* 7 This file is part of Valgrind, a dynamic binary instrumentation 8 framework. 9 10 Copyright (C) 2005-2017 Paul Mackerras <paulus (at) samba.org> 11 12 This program is free software; you can redistribute it and/or 13 modify it under the terms of the GNU General Public License as 14 published by the Free Software Foundation; either version 2 of the 15 License, or (at your option) any later version. 16 17 This program is distributed in the hope that it will be useful, but 18 WITHOUT ANY WARRANTY; without even the implied warranty of 19 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 20 General Public License for more details. 21 22 You should have received a copy of the GNU General Public License 23 along with this program; if not, write to the Free Software 24 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 25 02111-1307, USA. 26 27 The GNU General Public License is contained in the file COPYING. 28 */ 29 30 #include "pub_core_basics_asm.h" 31 32 #if defined(VGP_ppc64le_linux) 33 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 NIP 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->m_gpr[0]. The syscall result is written 53 back to regs->m_gpr[3]/m_xer/m_result 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, // r3 69 void* guest_state, // r4 70 const vki_sigset_t *sysmask, // r5 71 const vki_sigset_t *postmask, // r6 72 Int sigsetSzB) // r7 73 */ 74 /* from vki_arch.h */ 75 #define VKI_SIG_SETMASK 2 76 77 .align 2 78 .globl ML_(do_syscall_for_client_WRK) 79 #if _CALL_ELF == 2 80 .type .ML_(do_syscall_for_client_WRK),@function 81 ML_(do_syscall_for_client_WRK): 82 0: addis 2,12,.TOC.-0b@ha 83 addi 2,2,.TOC.-0b@l 84 .localentry ML_(do_syscall_for_client_WRK), .-ML_(do_syscall_for_client_WRK) 85 #else 86 .section ".opd","aw" 87 .align 3 88 ML_(do_syscall_for_client_WRK): 89 .quad .ML_(do_syscall_for_client_WRK),.TOC.@tocbase,0 90 .previous 91 #endif 92 #if _CALL_ELF == 2 93 0: addis 2,12,.TOC.-0b@ha 94 addi 2,2,.TOC.-0b@l 95 .localentry ML_(do_syscall_for_client_WRK), .-ML_(do_syscall_for_client_WRK) 96 #endif 97 .type .ML_(do_syscall_for_client_WRK),@function 98 .globl .ML_(do_syscall_for_client_WRK) 99 .ML_(do_syscall_for_client_WRK): 100 /* make a stack frame */ 101 stdu 1,-80(1) 102 std 31,72(1) 103 std 30,64(1) 104 std 29,56(1) 105 std 28,48(1) 106 mr 31,3 /* syscall number */ 107 mr 30,4 /* guest_state */ 108 mr 29,6 /* postmask */ 109 mr 28,7 /* sigsetSzB */ 110 111 /* set the signal mask for doing the system call */ 112 /* set up for sigprocmask(SIG_SETMASK, sysmask, postmask) */ 113 1: li 0,__NR_rt_sigprocmask 114 li 3,VKI_SIG_SETMASK 115 mr 4,5 116 mr 5,6 117 mr 6,7 118 sc /* set the mask */ 119 bso 7f /* if the sigprocmask fails */ 120 121 /* load up syscall args from the threadstate */ 122 ld 3,OFFSET_ppc64_GPR3(30) 123 ld 4,OFFSET_ppc64_GPR4(30) 124 ld 5,OFFSET_ppc64_GPR5(30) 125 ld 6,OFFSET_ppc64_GPR6(30) 126 ld 7,OFFSET_ppc64_GPR7(30) 127 ld 8,OFFSET_ppc64_GPR8(30) 128 mr 0,31 /* syscall number */ 129 2: sc /* do the syscall */ 130 131 /* put the result back in the threadstate */ 132 3: std 3,OFFSET_ppc64_GPR3(30) /* gst->GPR3 = sc result */ 133 /* copy cr0.so back to simulated state */ 134 mfcr 5 /* r5 = CR */ 135 rlwinm 5,5,4,31,31 /* r5 = (CR >> 28) & 1 */ 136 stb 5,OFFSET_ppc64_CR0_0(30) /* gst->CR0.SO = cr0.so */ 137 138 /* block signals again */ 139 /* set up for sigprocmask(SIG_SETMASK, postmask, NULL) */ 140 4: li 0,__NR_rt_sigprocmask 141 li 3,VKI_SIG_SETMASK 142 mr 4,29 143 li 5,0 144 mr 6,28 145 sc /* set the mask */ 146 bso 7f /* if the sigprocmask fails */ 147 /* now safe from signals */ 148 li 3,0 /* SUCCESS */ 149 150 /* pop off stack frame */ 151 5: ld 28,48(1) 152 ld 29,56(1) 153 ld 30,64(1) 154 ld 31,72(1) 155 addi 1,1,80 156 blr 157 158 /* failure: return 0x8000 | error code */ 159 7: ori 3,3,0x8000 /* FAILURE -- ensure return value is nonzero */ 160 b 5b 161 #if _CALL_ELF == 2 162 .size .ML_(do_syscall_for_client_WRK),.-.ML_(do_syscall_for_client_WRK) 163 #else 164 .size .ML_(do_syscall_for_client_WRK),.-.ML_(do_syscall_for_client_WRK) 165 #endif 166 .section .rodata 167 /* export the ranges so that 168 VG_(fixup_guest_state_after_syscall_interrupted) can do the 169 right thing */ 170 171 .globl ML_(blksys_setup) 172 .globl ML_(blksys_restart) 173 .globl ML_(blksys_complete) 174 .globl ML_(blksys_committed) 175 .globl ML_(blksys_finished) 176 ML_(blksys_setup): .quad 1b 177 ML_(blksys_restart): .quad 2b 178 ML_(blksys_complete): .quad 3b 179 ML_(blksys_committed): .quad 4b 180 ML_(blksys_finished): .quad 5b 181 182 #endif // defined(VGP_ppc64le_linux) 183 184 /* Let the linker know we don't need an executable stack */ 185 MARK_STACK_NO_EXEC 186 187 /*--------------------------------------------------------------------*/ 188 /*--- end ---*/ 189 /*--------------------------------------------------------------------*/ 190
