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) 2005-2013 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 #if defined(VGP_ppc64_linux) 31 32 #include "pub_core_basics_asm.h" 33 #include "pub_core_vkiscnums_asm.h" 34 #include "libvex_guest_offsets.h" 35 36 37 /*----------------------------------------------------------------*/ 38 /* 39 Perform a syscall for the client. This will run a syscall 40 with the client's specific per-thread signal mask. 41 42 The structure of this function is such that, if the syscall is 43 interrupted by a signal, we can determine exactly what 44 execution state we were in with respect to the execution of 45 the syscall by examining the value of NIP in the signal 46 handler. This means that we can always do the appropriate 47 thing to precisely emulate the kernel's signal/syscall 48 interactions. 49 50 The syscall number is taken from the argument, even though it 51 should also be in regs->m_gpr[0]. The syscall result is written 52 back to regs->m_gpr[3]/m_xer/m_result on completion. 53 54 Returns 0 if the syscall was successfully called (even if the 55 syscall itself failed), or a nonzero error code in the lowest 56 8 bits if one of the sigprocmasks failed (there's no way to 57 determine which one failed). And there's no obvious way to 58 recover from that either, but nevertheless we want to know. 59 60 VG_(fixup_guest_state_after_syscall_interrupted) does the 61 thread state fixup in the case where we were interrupted by a 62 signal. 63 64 Prototype: 65 66 UWord ML_(do_syscall_for_client_WRK)( 67 Int syscallno, // r3 68 void* guest_state, // r4 69 const vki_sigset_t *sysmask, // r5 70 const vki_sigset_t *postmask, // r6 71 Int sigsetSzB) // r7 72 */ 73 /* from vki_arch.h */ 74 #define VKI_SIG_SETMASK 2 75 76 .align 2 77 .globl ML_(do_syscall_for_client_WRK) 78 .section ".opd","aw" 79 .align 3 80 ML_(do_syscall_for_client_WRK): 81 .quad .ML_(do_syscall_for_client_WRK),.TOC.@tocbase,0 82 .previous 83 .type .ML_(do_syscall_for_client_WRK),@function 84 .globl .ML_(do_syscall_for_client_WRK) 85 .ML_(do_syscall_for_client_WRK): 86 /* make a stack frame */ 87 stdu 1,-80(1) 88 std 31,72(1) 89 std 30,64(1) 90 std 29,56(1) 91 std 28,48(1) 92 mr 31,3 /* syscall number */ 93 mr 30,4 /* guest_state */ 94 mr 29,6 /* postmask */ 95 mr 28,7 /* sigsetSzB */ 96 97 /* set the signal mask for doing the system call */ 98 /* set up for sigprocmask(SIG_SETMASK, sysmask, postmask) */ 99 1: li 0,__NR_rt_sigprocmask 100 li 3,VKI_SIG_SETMASK 101 mr 4,5 102 mr 5,6 103 mr 6,7 104 sc /* set the mask */ 105 bso 7f /* if the sigprocmask fails */ 106 107 /* load up syscall args from the threadstate */ 108 ld 3,OFFSET_ppc64_GPR3(30) 109 ld 4,OFFSET_ppc64_GPR4(30) 110 ld 5,OFFSET_ppc64_GPR5(30) 111 ld 6,OFFSET_ppc64_GPR6(30) 112 ld 7,OFFSET_ppc64_GPR7(30) 113 ld 8,OFFSET_ppc64_GPR8(30) 114 mr 0,31 /* syscall number */ 115 2: sc /* do the syscall */ 116 117 /* put the result back in the threadstate */ 118 3: std 3,OFFSET_ppc64_GPR3(30) /* gst->GPR3 = sc result */ 119 /* copy cr0.so back to simulated state */ 120 mfcr 5 /* r5 = CR */ 121 rlwinm 5,5,4,31,31 /* r5 = (CR >> 28) & 1 */ 122 stb 5,OFFSET_ppc64_CR0_0(30) /* gst->CR0.SO = cr0.so */ 123 124 /* block signals again */ 125 /* set up for sigprocmask(SIG_SETMASK, postmask, NULL) */ 126 4: li 0,__NR_rt_sigprocmask 127 li 3,VKI_SIG_SETMASK 128 mr 4,29 129 li 5,0 130 mr 6,28 131 sc /* set the mask */ 132 bso 7f /* if the sigprocmask fails */ 133 /* now safe from signals */ 134 li 3,0 /* SUCCESS */ 135 136 /* pop off stack frame */ 137 5: ld 28,48(1) 138 ld 29,56(1) 139 ld 30,64(1) 140 ld 31,72(1) 141 addi 1,1,80 142 blr 143 144 /* failure: return 0x8000 | error code */ 145 7: ori 3,3,0x8000 /* FAILURE -- ensure return value is nonzero */ 146 b 5b 147 148 .section .rodata 149 /* export the ranges so that 150 VG_(fixup_guest_state_after_syscall_interrupted) can do the 151 right thing */ 152 153 .globl ML_(blksys_setup) 154 .globl ML_(blksys_restart) 155 .globl ML_(blksys_complete) 156 .globl ML_(blksys_committed) 157 .globl ML_(blksys_finished) 158 ML_(blksys_setup): .quad 1b 159 ML_(blksys_restart): .quad 2b 160 ML_(blksys_complete): .quad 3b 161 ML_(blksys_committed): .quad 4b 162 ML_(blksys_finished): .quad 5b 163 164 165 /* Let the linker know we don't need an executable stack */ 166 .section .note.GNU-stack,"",@progbits 167 168 #endif // defined(VGP_ppc64_linux) 169 170 /*--------------------------------------------------------------------*/ 171 /*--- end ---*/ 172 /*--------------------------------------------------------------------*/ 173
