1 /* 1 /*
2 * This file is subject to the terms and condi 2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the mai 3 * License. See the file "COPYING" in the main directory of this archive
4 * for more details. 4 * for more details.
5 * 5 *
6 * Copyright (C) 1995-99, 2000- 02, 06 Ralf Ba< 6 * Copyright (C) 1995-99, 2000- 02, 06 Ralf Baechle <ralf@linux-mips.org>
7 * Copyright (C) 2001 MIPS Technologies, Inc. 7 * Copyright (C) 2001 MIPS Technologies, Inc.
8 * Copyright (C) 2004 Thiemo Seufer 8 * Copyright (C) 2004 Thiemo Seufer
9 * Copyright (C) 2014 Imagination Technologies 9 * Copyright (C) 2014 Imagination Technologies Ltd.
10 */ 10 */
11 #include <linux/errno.h> 11 #include <linux/errno.h>
12 #include <asm/asm.h> 12 #include <asm/asm.h>
13 #include <asm/asmmacro.h> 13 #include <asm/asmmacro.h>
14 #include <asm/irqflags.h> 14 #include <asm/irqflags.h>
15 #include <asm/mipsregs.h> 15 #include <asm/mipsregs.h>
16 #include <asm/regdef.h> 16 #include <asm/regdef.h>
17 #include <asm/stackframe.h> 17 #include <asm/stackframe.h>
18 #include <asm/isadep.h> 18 #include <asm/isadep.h>
19 #include <asm/sysmips.h> 19 #include <asm/sysmips.h>
20 #include <asm/thread_info.h> 20 #include <asm/thread_info.h>
21 #include <asm/unistd.h> 21 #include <asm/unistd.h>
22 #include <asm/asm-offsets.h> 22 #include <asm/asm-offsets.h>
23 23
24 .align 5 24 .align 5
25 NESTED(handle_sys, PT_SIZE, sp) 25 NESTED(handle_sys, PT_SIZE, sp)
26 .set noat 26 .set noat
27 SAVE_SOME 27 SAVE_SOME
28 TRACE_IRQS_ON_RELOAD 28 TRACE_IRQS_ON_RELOAD
29 STI 29 STI
30 .set at 30 .set at
31 31
32 lw t1, PT_EPC(sp) # skip 32 lw t1, PT_EPC(sp) # skip syscall on return
33 33
34 addiu t1, 4 # skip 34 addiu t1, 4 # skip to next instruction
35 sw t1, PT_EPC(sp) 35 sw t1, PT_EPC(sp)
36 36
37 sw a3, PT_R26(sp) # save 37 sw a3, PT_R26(sp) # save a3 for syscall restarting
38 38
39 /* 39 /*
40 * More than four arguments. Try to d 40 * More than four arguments. Try to deal with it by copying the
41 * stack arguments from the user stack 41 * stack arguments from the user stack to the kernel stack.
42 * This Sucks (TM). 42 * This Sucks (TM).
43 */ 43 */
44 lw t0, PT_R29(sp) # get 44 lw t0, PT_R29(sp) # get old user stack pointer
45 45
46 /* 46 /*
47 * We intentionally keep the kernel st 47 * We intentionally keep the kernel stack a little below the top of
48 * userspace so we don't have to do a 48 * userspace so we don't have to do a slower byte accurate check here.
49 */ 49 */
50 addu t4, t0, 32 50 addu t4, t0, 32
51 bltz t4, bad_stack # -> s 51 bltz t4, bad_stack # -> sp is bad
52 52
53 /* 53 /*
54 * Ok, copy the args from the luser st 54 * Ok, copy the args from the luser stack to the kernel stack.
55 */ 55 */
56 56
57 .set push 57 .set push
58 .set noreorder 58 .set noreorder
59 .set nomacro 59 .set nomacro
60 60
61 load_a4: user_lw(t5, 16(t0)) # argu 61 load_a4: user_lw(t5, 16(t0)) # argument #5 from usp
62 load_a5: user_lw(t6, 20(t0)) # argu 62 load_a5: user_lw(t6, 20(t0)) # argument #6 from usp
63 load_a6: user_lw(t7, 24(t0)) # argu 63 load_a6: user_lw(t7, 24(t0)) # argument #7 from usp
64 load_a7: user_lw(t8, 28(t0)) # argu 64 load_a7: user_lw(t8, 28(t0)) # argument #8 from usp
65 loads_done: 65 loads_done:
66 66
67 sw t5, 16(sp) # argu 67 sw t5, 16(sp) # argument #5 to ksp
68 sw t6, 20(sp) # argu 68 sw t6, 20(sp) # argument #6 to ksp
69 sw t7, 24(sp) # argu 69 sw t7, 24(sp) # argument #7 to ksp
70 sw t8, 28(sp) # argu 70 sw t8, 28(sp) # argument #8 to ksp
71 .set pop 71 .set pop
72 72
73 .section __ex_table,"a" 73 .section __ex_table,"a"
74 PTR_WD load_a4, bad_stack_a4 74 PTR_WD load_a4, bad_stack_a4
75 PTR_WD load_a5, bad_stack_a5 75 PTR_WD load_a5, bad_stack_a5
76 PTR_WD load_a6, bad_stack_a6 76 PTR_WD load_a6, bad_stack_a6
77 PTR_WD load_a7, bad_stack_a7 77 PTR_WD load_a7, bad_stack_a7
78 .previous 78 .previous
79 79
80 /* 80 /*
81 * syscall number is in v0 unless we c 81 * syscall number is in v0 unless we called syscall(__NR_###)
82 * where the real syscall number is in 82 * where the real syscall number is in a0
83 */ 83 */
84 subu t2, v0, __NR_O32_Linux 84 subu t2, v0, __NR_O32_Linux
85 bnez t2, 1f /* __NR_syscall at offs 85 bnez t2, 1f /* __NR_syscall at offset 0 */
86 LONG_S a0, TI_SYSCALL($28) # Save 86 LONG_S a0, TI_SYSCALL($28) # Save a0 as syscall number
87 b 2f 87 b 2f
88 1: 88 1:
89 LONG_S v0, TI_SYSCALL($28) # Save 89 LONG_S v0, TI_SYSCALL($28) # Save v0 as syscall number
90 2: 90 2:
91 91
92 lw t0, TI_FLAGS($28) # sysc 92 lw t0, TI_FLAGS($28) # syscall tracing enabled?
93 li t1, _TIF_WORK_SYSCALL_ENTRY 93 li t1, _TIF_WORK_SYSCALL_ENTRY
94 and t0, t1 94 and t0, t1
95 bnez t0, syscall_trace_entry # -> y 95 bnez t0, syscall_trace_entry # -> yes
96 syscall_common: 96 syscall_common:
97 subu v0, v0, __NR_O32_Linux # chec 97 subu v0, v0, __NR_O32_Linux # check syscall number
98 sltiu t0, v0, __NR_O32_Linux_syscall 98 sltiu t0, v0, __NR_O32_Linux_syscalls
99 beqz t0, illegal_syscall 99 beqz t0, illegal_syscall
100 100
101 sll t0, v0, 2 101 sll t0, v0, 2
102 la t1, sys_call_table 102 la t1, sys_call_table
103 addu t1, t0 103 addu t1, t0
104 lw t2, (t1) # sysc 104 lw t2, (t1) # syscall routine
105 105
106 beqz t2, illegal_syscall 106 beqz t2, illegal_syscall
107 107
108 jalr t2 # Do T 108 jalr t2 # Do The Real Thing (TM)
109 109
110 li t0, -EMAXERRNO - 1 # erro 110 li t0, -EMAXERRNO - 1 # error?
111 sltu t0, t0, v0 111 sltu t0, t0, v0
112 sw t0, PT_R7(sp) # set 112 sw t0, PT_R7(sp) # set error flag
113 beqz t0, 1f 113 beqz t0, 1f
114 114
115 lw t1, PT_R2(sp) # sysc 115 lw t1, PT_R2(sp) # syscall number
116 negu v0 # erro 116 negu v0 # error
117 sw t1, PT_R0(sp) # save 117 sw t1, PT_R0(sp) # save it for syscall restarting
118 1: sw v0, PT_R2(sp) # resu 118 1: sw v0, PT_R2(sp) # result
119 119
120 o32_syscall_exit: 120 o32_syscall_exit:
121 j syscall_exit_partial 121 j syscall_exit_partial
122 122
123 /* ------------------------------------------- 123 /* ------------------------------------------------------------------------ */
124 124
125 syscall_trace_entry: 125 syscall_trace_entry:
126 SAVE_STATIC 126 SAVE_STATIC
127 move a0, sp 127 move a0, sp
128 128
129 jal syscall_trace_enter 129 jal syscall_trace_enter
130 130
131 bltz v0, 1f # secc 131 bltz v0, 1f # seccomp failed? Skip syscall
132 132
133 RESTORE_STATIC 133 RESTORE_STATIC
134 lw v0, PT_R2(sp) # Rest 134 lw v0, PT_R2(sp) # Restore syscall (maybe modified)
135 lw a0, PT_R4(sp) # Rest 135 lw a0, PT_R4(sp) # Restore argument registers
136 lw a1, PT_R5(sp) 136 lw a1, PT_R5(sp)
137 lw a2, PT_R6(sp) 137 lw a2, PT_R6(sp)
138 lw a3, PT_R7(sp) 138 lw a3, PT_R7(sp)
139 j syscall_common 139 j syscall_common
140 140
141 1: j syscall_exit 141 1: j syscall_exit
142 142
143 /* ------------------------------------------- 143 /* ------------------------------------------------------------------------ */
144 144
145 /* 145 /*
146 * Our open-coded access area sanity t 146 * Our open-coded access area sanity test for the stack pointer
147 * failed. We probably should handle t 147 * failed. We probably should handle this case a bit more drastic.
148 */ 148 */
149 bad_stack: 149 bad_stack:
150 li v0, EFAULT 150 li v0, EFAULT
151 sw v0, PT_R2(sp) 151 sw v0, PT_R2(sp)
152 li t0, 1 152 li t0, 1 # set error flag
153 sw t0, PT_R7(sp) 153 sw t0, PT_R7(sp)
154 j o32_syscall_exit 154 j o32_syscall_exit
155 155
156 bad_stack_a4: 156 bad_stack_a4:
157 li t5, 0 157 li t5, 0
158 b load_a5 158 b load_a5
159 159
160 bad_stack_a5: 160 bad_stack_a5:
161 li t6, 0 161 li t6, 0
162 b load_a6 162 b load_a6
163 163
164 bad_stack_a6: 164 bad_stack_a6:
165 li t7, 0 165 li t7, 0
166 b load_a7 166 b load_a7
167 167
168 bad_stack_a7: 168 bad_stack_a7:
169 li t8, 0 169 li t8, 0
170 b loads_done 170 b loads_done
171 171
172 /* 172 /*
173 * The system call does not exist in t 173 * The system call does not exist in this kernel
174 */ 174 */
175 illegal_syscall: 175 illegal_syscall:
176 li v0, ENOSYS 176 li v0, ENOSYS # error
177 sw v0, PT_R2(sp) 177 sw v0, PT_R2(sp)
178 li t0, 1 178 li t0, 1 # set error flag
179 sw t0, PT_R7(sp) 179 sw t0, PT_R7(sp)
180 j o32_syscall_exit 180 j o32_syscall_exit
181 END(handle_sys) 181 END(handle_sys)
182 182
183 LEAF(sys_syscall) 183 LEAF(sys_syscall)
184 subu t0, a0, __NR_O32_Linux # chec 184 subu t0, a0, __NR_O32_Linux # check syscall number
185 sltiu v0, t0, __NR_O32_Linux_syscall 185 sltiu v0, t0, __NR_O32_Linux_syscalls
186 beqz t0, einval # do n 186 beqz t0, einval # do not recurse
187 sll t1, t0, 2 187 sll t1, t0, 2
188 beqz v0, einval 188 beqz v0, einval
189 lw t2, sys_call_table(t1) 189 lw t2, sys_call_table(t1) # syscall routine
190 190
191 move a0, a1 191 move a0, a1 # shift argument registers
192 move a1, a2 192 move a1, a2
193 move a2, a3 193 move a2, a3
194 lw a3, 16(sp) 194 lw a3, 16(sp)
195 lw t4, 20(sp) 195 lw t4, 20(sp)
196 lw t5, 24(sp) 196 lw t5, 24(sp)
197 lw t6, 28(sp) 197 lw t6, 28(sp)
198 sw t4, 16(sp) 198 sw t4, 16(sp)
199 sw t5, 20(sp) 199 sw t5, 20(sp)
200 sw t6, 24(sp) 200 sw t6, 24(sp)
201 jr t2 201 jr t2
202 /* Unreached */ 202 /* Unreached */
203 203
204 einval: li v0, -ENOSYS 204 einval: li v0, -ENOSYS
205 jr ra 205 jr ra
206 END(sys_syscall) 206 END(sys_syscall)
207 207
208 #ifdef CONFIG_MIPS_MT_FPAFF 208 #ifdef CONFIG_MIPS_MT_FPAFF
209 /* 209 /*
210 * For FPU affinity scheduling on MIPS 210 * For FPU affinity scheduling on MIPS MT processors, we need to
211 * intercept sys_sched_xxxaffinity() c 211 * intercept sys_sched_xxxaffinity() calls until we get a proper hook
212 * in kernel/sched/core.c. Considered 212 * in kernel/sched/core.c. Considered only temporary we only support
213 * these hooks for the 32-bit kernel - 213 * these hooks for the 32-bit kernel - there is no MIPS64 MT processor
214 * atm. 214 * atm.
215 */ 215 */
216 #define sys_sched_setaffinity mipsmt_sys_sch 216 #define sys_sched_setaffinity mipsmt_sys_sched_setaffinity
217 #define sys_sched_getaffinity mipsmt_sys_sch 217 #define sys_sched_getaffinity mipsmt_sys_sched_getaffinity
218 #endif /* CONFIG_MIPS_MT_FPAFF */ 218 #endif /* CONFIG_MIPS_MT_FPAFF */
219 219
220 #define __SYSCALL_WITH_COMPAT(nr, native, comp 220 #define __SYSCALL_WITH_COMPAT(nr, native, compat) __SYSCALL(nr, native)
221 #define __SYSCALL(nr, entry) PTR_WD entry 221 #define __SYSCALL(nr, entry) PTR_WD entry
222 .align 2 222 .align 2
223 .type sys_call_table, @object 223 .type sys_call_table, @object
224 EXPORT(sys_call_table) 224 EXPORT(sys_call_table)
225 #include <asm/syscall_table_o32.h> 225 #include <asm/syscall_table_o32.h>
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