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) 2010-2017 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#include "pub_core_basics_asm.h"
32
33#if defined(VGP_mips64_linux)
34
35#include "pub_core_vkiscnums_asm.h"
36#include "libvex_guest_offsets.h"
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 PC 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->v0. The syscall result is written
53   back to regs->v0 on completion.
54
55   VG_(fixup_guest_state_after_syscall_interrupted) does the
56   thread state fixup in the case where we were interrupted by a
57   signal.
58
59   Prototype:
60
61   UWord ML_(do_syscall_for_client_WRK)(
62             Int syscallno,                 // $4 - a0
63             void* guest_state,             // $5 - a1
64             const vki_sigset_t *sysmask,   // $6 - a2
65             const vki_sigset_t *postmask,  // $7 - a3
66             Int nsigwords)                 // $8 - a4
67*/
68
69/* from vki_arch.h */
70#define VKI_SIG_SETMASK 3
71
72.globl ML_(do_syscall_for_client_WRK)
73ML_(do_syscall_for_client_WRK):
74
75   /* save regs $a0 - $a4 on stack */
76   daddiu  $29, $29, -48
77   sd      $4, 0($29)                /* syscallno */
78   sd      $5, 8($29)                /* guest_state */
79   sd      $6, 16($29)               /* sysmask */
80   sd      $7, 24($29)               /* postmask */
81   sd      $8, 32($29)               /* nsigwords */
82
831: li      $2, __NR_rt_sigprocmask
84   li      $4, VKI_SIG_SETMASK
85   move    $5, $6                    /* sysmask */
86   move    $6, $7                    /* postmask */
87   move    $7, $8                    /* nsigwords */
88   syscall
89
90   bnez    $7, 7f
91   nop
92
93   /* Actually do the client syscall */
94   ld      $5, 8($29)                /* guest_state */
95   ld      $4, OFFSET_mips64_r4($5)  /* a0 */
96
97   ld      $6, OFFSET_mips64_r6($5)  /* a2 */
98   ld      $7, OFFSET_mips64_r7($5)  /* a3 */
99   ld      $8, OFFSET_mips64_r8($5)  /* a4 */
100   ld      $9, OFFSET_mips64_r9($5)  /* a5 */
101
102   ld      $5, OFFSET_mips64_r5($5)  /* a1 */
103   ld      $2, 0($29)                /* syscallno */
104
1052: syscall
106
107   /* Saving return values into Guest state  */
1083: ld      $5, 8($29)                /* guest_state */
109   sd      $2, OFFSET_mips64_r2($5)  /* v0 */
110   sd      $7, OFFSET_mips64_r7($5)  /* a3 */
111
1124: li      $2, __NR_rt_sigprocmask
113   li      $4, VKI_SIG_SETMASK
114   ld      $5, 24($29)               /* postmask */
115   move    $6, $0                    /* 0 (zero) */
116   ld      $7, 32($29)               /* nsigwords */
117   syscall
118
119   bnez    $7, 7f
120   nop
121
1225: /* restore 29 and return */
123   daddiu  $29, $29, 48
124   jr      $31
125   nop
126
1277: /* error */
128   daddiu  $29, $29, 48
129   li      $2, 0x8000
130   jr      $31
131   nop
132
133.section .rodata
134/* export the ranges so that
135   VG_(fixup_guest_state_after_syscall_interrupted) can do the
136   right thing */
137
138.globl ML_(blksys_setup)
139.globl ML_(blksys_restart)
140.globl ML_(blksys_complete)
141.globl ML_(blksys_committed)
142.globl ML_(blksys_finished)
143ML_(blksys_setup):      .quad 1b
144ML_(blksys_restart):    .quad 2b
145ML_(blksys_complete):   .quad 3b
146ML_(blksys_committed):  .quad 4b
147ML_(blksys_finished):   .quad 5b
148
149#endif // defined(VGP_mips64_linux)
150
151/* Let the linker know we don't need an executable stack */
152MARK_STACK_NO_EXEC
153
154/*--------------------------------------------------------------------*/
155/*--- end                                                          ---*/
156/*--------------------------------------------------------------------*/
157