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_ppc64be_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 .section ".opd","aw" 80 .align 3 81 ML_(do_syscall_for_client_WRK): 82 .quad .ML_(do_syscall_for_client_WRK),.TOC.@tocbase,0 83 .previous 84 .type .ML_(do_syscall_for_client_WRK),@function 85 .globl .ML_(do_syscall_for_client_WRK) 86 .ML_(do_syscall_for_client_WRK): 87 /* make a stack frame */ 88 stdu 1,-80(1) 89 std 31,72(1) 90 std 30,64(1) 91 std 29,56(1) 92 std 28,48(1) 93 mr 31,3 /* syscall number */ 94 mr 30,4 /* guest_state */ 95 mr 29,6 /* postmask */ 96 mr 28,7 /* sigsetSzB */ 97 98 /* set the signal mask for doing the system call */ 99 /* set up for sigprocmask(SIG_SETMASK, sysmask, postmask) */ 100 1: li 0,__NR_rt_sigprocmask 101 li 3,VKI_SIG_SETMASK 102 mr 4,5 103 mr 5,6 104 mr 6,7 105 sc /* set the mask */ 106 bso 7f /* if the sigprocmask fails */ 107 108 /* load up syscall args from the threadstate */ 109 ld 3,OFFSET_ppc64_GPR3(30) 110 ld 4,OFFSET_ppc64_GPR4(30) 111 ld 5,OFFSET_ppc64_GPR5(30) 112 ld 6,OFFSET_ppc64_GPR6(30) 113 ld 7,OFFSET_ppc64_GPR7(30) 114 ld 8,OFFSET_ppc64_GPR8(30) 115 mr 0,31 /* syscall number */ 116 2: sc /* do the syscall */ 117 118 /* put the result back in the threadstate */ 119 3: std 3,OFFSET_ppc64_GPR3(30) /* gst->GPR3 = sc result */ 120 /* copy cr0.so back to simulated state */ 121 mfcr 5 /* r5 = CR */ 122 rlwinm 5,5,4,31,31 /* r5 = (CR >> 28) & 1 */ 123 stb 5,OFFSET_ppc64_CR0_0(30) /* gst->CR0.SO = cr0.so */ 124 125 /* block signals again */ 126 /* set up for sigprocmask(SIG_SETMASK, postmask, NULL) */ 127 4: li 0,__NR_rt_sigprocmask 128 li 3,VKI_SIG_SETMASK 129 mr 4,29 130 li 5,0 131 mr 6,28 132 sc /* set the mask */ 133 bso 7f /* if the sigprocmask fails */ 134 /* now safe from signals */ 135 li 3,0 /* SUCCESS */ 136 137 /* pop off stack frame */ 138 5: ld 28,48(1) 139 ld 29,56(1) 140 ld 30,64(1) 141 ld 31,72(1) 142 addi 1,1,80 143 blr 144 145 /* failure: return 0x8000 | error code */ 146 7: ori 3,3,0x8000 /* FAILURE -- ensure return value is nonzero */ 147 b 5b 148 149 .section .rodata 150 /* export the ranges so that 151 VG_(fixup_guest_state_after_syscall_interrupted) can do the 152 right thing */ 153 154 .globl ML_(blksys_setup) 155 .globl ML_(blksys_restart) 156 .globl ML_(blksys_complete) 157 .globl ML_(blksys_committed) 158 .globl ML_(blksys_finished) 159 ML_(blksys_setup): .quad 1b 160 ML_(blksys_restart): .quad 2b 161 ML_(blksys_complete): .quad 3b 162 ML_(blksys_committed): .quad 4b 163 ML_(blksys_finished): .quad 5b 164 165 #endif // defined(VGP_ppc64be_linux) 166 167 /* Let the linker know we don't need an executable stack */ 168 MARK_STACK_NO_EXEC 169 170 /*--------------------------------------------------------------------*/ 171 /*--- end ---*/ 172 /*--------------------------------------------------------------------*/ 173
