sewardj | de4a1d0 | 2002-03-22 01:27:54 +0000 | [diff] [blame] | 1 | |
sewardj | 39e8160 | 2005-12-22 20:16:00 +0000 | [diff] [blame] | 2 | /*--------------------------------------------------------------------*/ |
| 3 | /*--- Support for doing system calls. syscall-x86-linux.S ---*/ |
| 4 | /*--------------------------------------------------------------------*/ |
sewardj | de4a1d0 | 2002-03-22 01:27:54 +0000 | [diff] [blame] | 5 | |
| 6 | /* |
njn | b9c427c | 2004-12-01 14:14:42 +0000 | [diff] [blame] | 7 | This file is part of Valgrind, a dynamic binary instrumentation |
| 8 | framework. |
sewardj | de4a1d0 | 2002-03-22 01:27:54 +0000 | [diff] [blame] | 9 | |
sewardj | 9eecbbb | 2010-05-03 21:37:12 +0000 | [diff] [blame] | 10 | Copyright (C) 2000-2010 Julian Seward |
sewardj | de4a1d0 | 2002-03-22 01:27:54 +0000 | [diff] [blame] | 11 | jseward@acm.org |
sewardj | de4a1d0 | 2002-03-22 01:27:54 +0000 | [diff] [blame] | 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 | |
njn25 | e49d8e7 | 2002-09-23 09:36:25 +0000 | [diff] [blame] | 28 | The GNU General Public License is contained in the file COPYING. |
sewardj | de4a1d0 | 2002-03-22 01:27:54 +0000 | [diff] [blame] | 29 | */ |
| 30 | |
njn | 8b68b64 | 2009-06-24 00:37:09 +0000 | [diff] [blame] | 31 | #if defined(VGP_x86_linux) |
| 32 | |
sewardj | 45f4e7c | 2005-09-27 19:20:21 +0000 | [diff] [blame] | 33 | #include "pub_core_basics_asm.h" |
njn | 1a1e95c | 2009-06-03 06:50:06 +0000 | [diff] [blame] | 34 | #include "pub_core_vkiscnums_asm.h" |
sewardj | b5f6f51 | 2005-03-10 23:59:00 +0000 | [diff] [blame] | 35 | #include "libvex_guest_offsets.h" |
| 36 | |
sewardj | b5f6f51 | 2005-03-10 23:59:00 +0000 | [diff] [blame] | 37 | |
sewardj | e7aa4ae | 2005-06-09 12:43:42 +0000 | [diff] [blame] | 38 | /*----------------------------------------------------------------*/ |
sewardj | b5f6f51 | 2005-03-10 23:59:00 +0000 | [diff] [blame] | 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 %eip 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_eax. The syscall result is written |
| 53 | back to regs->m_eax on completion. |
| 54 | |
| 55 | Returns 0 if the syscall was successfully called (even if the |
sewardj | 39e8160 | 2005-12-22 20:16:00 +0000 | [diff] [blame] | 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. |
sewardj | b5f6f51 | 2005-03-10 23:59:00 +0000 | [diff] [blame] | 60 | |
sewardj | 1b9cd1c | 2005-06-28 19:04:51 +0000 | [diff] [blame] | 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. |
sewardj | b5f6f51 | 2005-03-10 23:59:00 +0000 | [diff] [blame] | 64 | |
| 65 | Prototype: |
| 66 | |
sewardj | 39e8160 | 2005-12-22 20:16:00 +0000 | [diff] [blame] | 67 | UWord ML_(do_syscall_for_client_WRK)( |
sewardj | a8d8e23 | 2005-06-07 20:04:56 +0000 | [diff] [blame] | 68 | Int syscallno, // 0 |
sewardj | b5f6f51 | 2005-03-10 23:59:00 +0000 | [diff] [blame] | 69 | void* guest_state, // 4 |
| 70 | const vki_sigset_t *sysmask, // 8 |
| 71 | const vki_sigset_t *postmask, // 12 |
njn | cda2f0f | 2009-05-18 02:12:08 +0000 | [diff] [blame] | 72 | Int sigsetSzB) // 16 |
sewardj | b5f6f51 | 2005-03-10 23:59:00 +0000 | [diff] [blame] | 73 | |
| 74 | */ |
| 75 | |
| 76 | /* from vki_arch.h */ |
| 77 | #define VKI_SIG_SETMASK 2 |
| 78 | |
sewardj | 1b9cd1c | 2005-06-28 19:04:51 +0000 | [diff] [blame] | 79 | .globl ML_(do_syscall_for_client_WRK) |
| 80 | ML_(do_syscall_for_client_WRK): |
sewardj | b5f6f51 | 2005-03-10 23:59:00 +0000 | [diff] [blame] | 81 | /* save callee-saved regs */ |
| 82 | push %esi |
| 83 | push %edi |
| 84 | push %ebx |
| 85 | push %ebp |
| 86 | #define FSZ ((4+1)*4) /* 4 args + ret addr */ |
| 87 | |
| 88 | 1: /* Even though we can't take a signal until the sigprocmask completes, |
| 89 | start the range early. |
| 90 | If eip is in the range [1,2), the syscall hasn't been started yet */ |
| 91 | |
| 92 | /* Set the signal mask which should be current during the syscall. */ |
sewardj | cfdc5fd | 2007-08-24 20:37:09 +0000 | [diff] [blame] | 93 | movl $ __NR_rt_sigprocmask, %eax |
| 94 | movl $ VKI_SIG_SETMASK, %ebx |
sewardj | b5f6f51 | 2005-03-10 23:59:00 +0000 | [diff] [blame] | 95 | movl 8+FSZ(%esp), %ecx |
| 96 | movl 12+FSZ(%esp), %edx |
| 97 | movl 16+FSZ(%esp), %esi |
| 98 | int $0x80 |
| 99 | testl %eax, %eax |
sewardj | 39e8160 | 2005-12-22 20:16:00 +0000 | [diff] [blame] | 100 | js 7f /* sigprocmask failed */ |
sewardj | b5f6f51 | 2005-03-10 23:59:00 +0000 | [diff] [blame] | 101 | |
| 102 | movl 4+FSZ(%esp), %eax /* eax == ThreadState * */ |
| 103 | |
| 104 | movl OFFSET_x86_EBX(%eax), %ebx |
| 105 | movl OFFSET_x86_ECX(%eax), %ecx |
| 106 | movl OFFSET_x86_EDX(%eax), %edx |
| 107 | movl OFFSET_x86_ESI(%eax), %esi |
| 108 | movl OFFSET_x86_EDI(%eax), %edi |
| 109 | movl OFFSET_x86_EBP(%eax), %ebp |
| 110 | movl 0+FSZ(%esp), %eax /* use syscallno argument rather than thread EAX */ |
| 111 | |
| 112 | /* If eip==2, then the syscall was either just about to start, |
| 113 | or was interrupted and the kernel was restarting it. */ |
| 114 | 2: int $0x80 |
| 115 | 3: /* In the range [3, 4), the syscall result is in %eax, but hasn't been |
| 116 | committed to EAX. */ |
| 117 | movl 4+FSZ(%esp), %ebx |
| 118 | movl %eax, OFFSET_x86_EAX(%ebx) /* save back to EAX */ |
| 119 | |
| 120 | 4: /* Re-block signals. If eip is in [4,5), then the syscall is complete and |
| 121 | we needn't worry about it. */ |
sewardj | cfdc5fd | 2007-08-24 20:37:09 +0000 | [diff] [blame] | 122 | movl $ __NR_rt_sigprocmask, %eax |
| 123 | movl $ VKI_SIG_SETMASK, %ebx |
sewardj | b5f6f51 | 2005-03-10 23:59:00 +0000 | [diff] [blame] | 124 | movl 12+FSZ(%esp), %ecx |
| 125 | xorl %edx, %edx |
| 126 | movl 16+FSZ(%esp), %esi |
| 127 | int $0x80 |
sewardj | 39e8160 | 2005-12-22 20:16:00 +0000 | [diff] [blame] | 128 | testl %eax, %eax |
| 129 | js 7f /* sigprocmask failed */ |
sewardj | b5f6f51 | 2005-03-10 23:59:00 +0000 | [diff] [blame] | 130 | |
| 131 | 5: /* now safe from signals */ |
sewardj | 39e8160 | 2005-12-22 20:16:00 +0000 | [diff] [blame] | 132 | movl $0, %eax /* SUCCESS */ |
sewardj | b5f6f51 | 2005-03-10 23:59:00 +0000 | [diff] [blame] | 133 | popl %ebp |
| 134 | popl %ebx |
| 135 | popl %edi |
| 136 | popl %esi |
sewardj | b5f6f51 | 2005-03-10 23:59:00 +0000 | [diff] [blame] | 137 | ret |
| 138 | |
sewardj | 39e8160 | 2005-12-22 20:16:00 +0000 | [diff] [blame] | 139 | 7: /* failure: return 0x8000 | error code */ |
| 140 | negl %eax |
| 141 | andl $0x7FFF, %eax |
| 142 | orl $0x8000, %eax |
| 143 | popl %ebp |
| 144 | popl %ebx |
| 145 | popl %edi |
| 146 | popl %esi |
| 147 | ret |
| 148 | #undef FSZ |
| 149 | |
| 150 | |
sewardj | b5f6f51 | 2005-03-10 23:59:00 +0000 | [diff] [blame] | 151 | .section .rodata |
sewardj | a8d8e23 | 2005-06-07 20:04:56 +0000 | [diff] [blame] | 152 | /* export the ranges so that |
| 153 | VG_(fixup_guest_state_after_syscall_interrupted) can do the |
| 154 | right thing */ |
sewardj | b5f6f51 | 2005-03-10 23:59:00 +0000 | [diff] [blame] | 155 | |
sewardj | 1b9cd1c | 2005-06-28 19:04:51 +0000 | [diff] [blame] | 156 | .globl ML_(blksys_setup) |
| 157 | .globl ML_(blksys_restart) |
| 158 | .globl ML_(blksys_complete) |
| 159 | .globl ML_(blksys_committed) |
| 160 | .globl ML_(blksys_finished) |
| 161 | ML_(blksys_setup): .long 1b |
| 162 | ML_(blksys_restart): .long 2b |
| 163 | ML_(blksys_complete): .long 3b |
| 164 | ML_(blksys_committed): .long 4b |
| 165 | ML_(blksys_finished): .long 5b |
sewardj | b5f6f51 | 2005-03-10 23:59:00 +0000 | [diff] [blame] | 166 | .previous |
| 167 | |
thughes | 4ad52d0 | 2004-06-27 17:37:21 +0000 | [diff] [blame] | 168 | /* Let the linker know we don't need an executable stack */ |
| 169 | .section .note.GNU-stack,"",@progbits |
| 170 | |
njn | 8b68b64 | 2009-06-24 00:37:09 +0000 | [diff] [blame] | 171 | #endif // defined(VGP_x86_linux) |
| 172 | |
sewardj | 39e8160 | 2005-12-22 20:16:00 +0000 | [diff] [blame] | 173 | /*--------------------------------------------------------------------*/ |
| 174 | /*--- end ---*/ |
| 175 | /*--------------------------------------------------------------------*/ |