sewardj | 59570ff | 2010-01-01 11:59:33 +0000 | [diff] [blame] | 1 | |
| 2 | /*--------------------------------------------------------------------*/ |
| 3 | /*--- Support for doing system calls. syscall-arm-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) 2008-2013 Evan Geller (gaze@bea.ms) |
sewardj | 59570ff | 2010-01-01 11:59:33 +0000 | [diff] [blame] | 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_arm_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 IP 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_R7. The syscall result is written |
| 52 | back to regs->m_R0 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, // r0 |
| 68 | void* guest_state, // r1 |
| 69 | const vki_sigset_t *sysmask, // r2 |
| 70 | const vki_sigset_t *postmask, // r3 |
| 71 | Int nsigwords) // [sp, #0] |
| 72 | */ |
| 73 | /* from vki_arch.h */ |
| 74 | #define VKI_SIG_SETMASK 2 |
| 75 | |
| 76 | .globl ML_(do_syscall_for_client_WRK) |
| 77 | ML_(do_syscall_for_client_WRK): |
| 78 | |
| 79 | /* Stash callee-saves and our args on the stack */ |
| 80 | push {r0, r1, r3, r4, r5, r7, fp, lr} |
| 81 | |
| 82 | 1: |
| 83 | |
| 84 | mov r7, #__NR_rt_sigprocmask |
| 85 | mov r0, #VKI_SIG_SETMASK |
| 86 | mov r1, r2 /* sysmask */ |
| 87 | mov r2, r3 /* postmask */ |
| 88 | ldr r3, [sp, #32] /* nsigwords */ |
| 89 | svc 0x00000000 |
| 90 | |
| 91 | |
| 92 | ldr r5, [sp, #4] /* guest_state */ |
| 93 | |
| 94 | ldr r7, [sp, #0] /* syscall# */ |
| 95 | ldr r0, [r5, #OFFSET_arm_R0] |
| 96 | ldr r1, [r5, #OFFSET_arm_R1] |
| 97 | ldr r2, [r5, #OFFSET_arm_R2] |
| 98 | ldr r3, [r5, #OFFSET_arm_R3] |
| 99 | ldr r4, [r5, #OFFSET_arm_R4] |
| 100 | ldr r5, [r5, #OFFSET_arm_R5] |
| 101 | |
| 102 | 2: svc 0x00000000 |
| 103 | 3: |
| 104 | ldr r5, [sp, #4] /* guest_state */ |
| 105 | str r0, [r5, #OFFSET_arm_R0] |
| 106 | |
| 107 | 4: |
| 108 | mov r7, #__NR_rt_sigprocmask |
| 109 | mov r0, #VKI_SIG_SETMASK |
| 110 | ldr r1, [sp, #8] /* postmask */ |
| 111 | mov r2, #0 |
| 112 | ldr r3, [sp, #32] /* nsigwords */ |
| 113 | svc 0x00000000 |
| 114 | |
sewardj | f0c1250 | 2014-01-12 12:54:00 +0000 | [diff] [blame] | 115 | cmp r0, #0 |
sewardj | 59570ff | 2010-01-01 11:59:33 +0000 | [diff] [blame] | 116 | blt 7f |
| 117 | add sp, sp, #4 /* r0 contains return value */ |
| 118 | |
| 119 | 5: /* Success */ |
| 120 | mov r0, #0 |
| 121 | pop {r1, r3, r4, r5, r7, fp, pc} |
| 122 | |
| 123 | 7: /* Failure: return 0x8000 | error code */ |
| 124 | orr r0, r0, #0x8000 |
| 125 | pop {r1, r3, r4, r5, r7, fp, pc} |
| 126 | |
| 127 | |
| 128 | .section .rodata |
| 129 | /* export the ranges so that |
| 130 | VG_(fixup_guest_state_after_syscall_interrupted) can do the |
| 131 | right thing */ |
| 132 | |
| 133 | .globl ML_(blksys_setup) |
| 134 | .globl ML_(blksys_restart) |
| 135 | .globl ML_(blksys_complete) |
| 136 | .globl ML_(blksys_committed) |
| 137 | .globl ML_(blksys_finished) |
| 138 | ML_(blksys_setup): .long 1b |
| 139 | ML_(blksys_restart): .long 2b |
| 140 | ML_(blksys_complete): .long 3b |
| 141 | ML_(blksys_committed): .long 4b |
| 142 | ML_(blksys_finished): .long 5b |
| 143 | |
| 144 | /* Let the linker know we don't need an executable stack */ |
| 145 | .section .note.GNU-stack,"",%progbits |
| 146 | |
| 147 | .previous |
| 148 | |
| 149 | #endif // defined(VGP_arm_linux) |
| 150 | |
| 151 | /*--------------------------------------------------------------------*/ |
| 152 | /*--- end ---*/ |
| 153 | /*--------------------------------------------------------------------*/ |