1
2/*--------------------------------------------------------------------*/
3/*--- Support for doing system calls.      syscall-mips64-linux.S  ---*/
4/*--------------------------------------------------------------------*/
5
6/*
7  This file is part of Valgrind, a dynamic binary instrumentation
8  framework.
9
10   Copyright (C) 2010-2013 RT-RK
11      mips-valgrind@rt-rk.com
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
28   The GNU General Public License is contained in the file COPYING.
29*/
30
31#if defined(VGP_mips64_linux)
32
33#include "pub_core_basics_asm.h"
34#include "pub_core_vkiscnums_asm.h"
35#include "libvex_guest_offsets.h"
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 PC 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->v0. The syscall result is written
52   back to regs->v0 on completion.
53
54   VG_(fixup_guest_state_after_syscall_interrupted) does the
55   thread state fixup in the case where we were interrupted by a
56   signal.
57
58   Prototype:
59
60   UWord ML_(do_syscall_for_client_WRK)(
61             Int syscallno,                 // $4 - a0
62             void* guest_state,             // $5 - a1
63             const vki_sigset_t *sysmask,   // $6 - a2
64             const vki_sigset_t *postmask,  // $7 - a3
65             Int nsigwords)                 // $8 - a4
66*/
67
68/* from vki_arch.h */
69#define VKI_SIG_SETMASK 3
70
71.globl ML_(do_syscall_for_client_WRK)
72ML_(do_syscall_for_client_WRK):
73
74   /* save regs $a0 - $a4 on stack */
75   daddiu  $29, $29, -48
76   sd      $4, 0($29)                /* syscallno */
77   sd      $5, 8($29)                /* guest_state */
78   sd      $6, 16($29)               /* sysmask */
79   sd      $7, 24($29)               /* postmask */
80   sd      $8, 32($29)               /* nsigwords */
81
821: li      $2, __NR_rt_sigprocmask
83   li      $4, VKI_SIG_SETMASK
84   move    $5, $6                    /* sysmask */
85   move    $6, $7                    /* postmask */
86   move    $7, $8                    /* nsigwords */
87   syscall
88
89   bnez    $7, 7f
90   nop
91
92   /* Actually do the client syscall */
93   ld      $5, 8($29)                /* guest_state */
94   ld      $4, OFFSET_mips64_r4($5)  /* a0 */
95
96   ld      $6, OFFSET_mips64_r6($5)  /* a2 */
97   ld      $7, OFFSET_mips64_r7($5)  /* a3 */
98   ld      $8, OFFSET_mips64_r8($5)  /* a4 */
99   ld      $9, OFFSET_mips64_r9($5)  /* a5 */
100
101   ld      $5, OFFSET_mips64_r5($5)  /* a1 */
102   ld      $2, 0($29)                /* syscallno */
103
1042: syscall
105
106   /* Saving return values into Guest state  */
1073: ld      $5, 8($29)                /* guest_state */
108   sd      $2, OFFSET_mips64_r2($5)  /* v0 */
109   sd      $7, OFFSET_mips64_r7($5)  /* a3 */
110
1114: li      $2, __NR_rt_sigprocmask
112   li      $4, VKI_SIG_SETMASK
113   ld      $5, 24($29)               /* postmask */
114   move    $6, $0                    /* 0 (zero) */
115   ld      $7, 32($29)               /* nsigwords */
116   syscall
117
118   bnez    $7, 7f
119   nop
120
1215: /* restore 29 and return */
122   daddiu  $29, $29, 48
123   jr      $31
124   nop
125
1267: /* error */
127   daddiu  $29, $29, 48
128   li      $2, 0x8000
129   jr      $31
130   nop
131
132.section .rodata
133/* export the ranges so that
134   VG_(fixup_guest_state_after_syscall_interrupted) can do the
135   right thing */
136
137.globl ML_(blksys_setup)
138.globl ML_(blksys_restart)
139.globl ML_(blksys_complete)
140.globl ML_(blksys_committed)
141.globl ML_(blksys_finished)
142ML_(blksys_setup):      .quad 1b
143ML_(blksys_restart):    .quad 2b
144ML_(blksys_complete):   .quad 3b
145ML_(blksys_committed):  .quad 4b
146ML_(blksys_finished):   .quad 5b
147.previous
148/* Let the linker know we don't need an executable stack */
149.section .note.GNU-stack,"",%progbits
150
151#endif // defined(VGP_mips64_linux)
152
153/*--------------------------------------------------------------------*/
154/*--- end                                                          ---*/
155/*--------------------------------------------------------------------*/
156