2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
6 * Copyright (C) 1995-99, 2000- 02, 06 Ralf Baechle <ralf@linux-mips.org>
7 * Copyright (C) 2001 MIPS Technologies, Inc.
8 * Copyright (C) 2004 Thiemo Seufer
9 * Copyright (C) 2014 Imagination Technologies Ltd.
11 #include <linux/errno.h>
13 #include <asm/asmmacro.h>
14 #include <asm/irqflags.h>
15 #include <asm/mipsregs.h>
16 #include <asm/regdef.h>
17 #include <asm/stackframe.h>
18 #include <asm/isadep.h>
19 #include <asm/sysmips.h>
20 #include <asm/thread_info.h>
21 #include <asm/unistd.h>
23 #include <asm/asm-offsets.h>
26 NESTED(handle_sys, PT_SIZE, sp)
33 lw t1, PT_EPC(sp) # skip syscall on return
35 addiu t1, 4 # skip to next instruction
38 sw a3, PT_R26(sp) # save a3 for syscall restarting
41 * More than four arguments. Try to deal with it by copying the
42 * stack arguments from the user stack to the kernel stack.
45 lw t0, PT_R29(sp) # get old user stack pointer
48 * We intentionally keep the kernel stack a little below the top of
49 * userspace so we don't have to do a slower byte accurate check here.
52 bltz t4, bad_stack # -> sp is bad
55 * Ok, copy the args from the luser stack to the kernel stack.
62 load_a4: user_lw(t5, 16(t0)) # argument #5 from usp
63 load_a5: user_lw(t6, 20(t0)) # argument #6 from usp
64 load_a6: user_lw(t7, 24(t0)) # argument #7 from usp
65 load_a7: user_lw(t8, 28(t0)) # argument #8 from usp
68 sw t5, 16(sp) # argument #5 to ksp
69 sw t6, 20(sp) # argument #6 to ksp
70 sw t7, 24(sp) # argument #7 to ksp
71 sw t8, 28(sp) # argument #8 to ksp
74 .section __ex_table,"a"
75 PTR load_a4, bad_stack_a4
76 PTR load_a5, bad_stack_a5
77 PTR load_a6, bad_stack_a6
78 PTR load_a7, bad_stack_a7
81 lw t0, TI_FLAGS($28) # syscall tracing enabled?
82 li t1, _TIF_WORK_SYSCALL_ENTRY
84 bnez t0, syscall_trace_entry # -> yes
86 subu v0, v0, __NR_O32_Linux # check syscall number
87 sltiu t0, v0, __NR_O32_Linux_syscalls
88 beqz t0, illegal_syscall
93 lw t2, (t1) # syscall routine
95 beqz t2, illegal_syscall
97 jalr t2 # Do The Real Thing (TM)
99 li t0, -EMAXERRNO - 1 # error?
101 sw t0, PT_R7(sp) # set error flag
104 lw t1, PT_R2(sp) # syscall number
106 sw t1, PT_R0(sp) # save it for syscall restarting
107 1: sw v0, PT_R2(sp) # result
110 j syscall_exit_partial
112 /* ------------------------------------------------------------------------ */
119 * syscall number is in v0 unless we called syscall(__NR_###)
120 * where the real syscall number is in a0
123 subu t2, v0, __NR_O32_Linux
124 bnez t2, 1f /* __NR_syscall at offset 0 */
127 1: jal syscall_trace_enter
129 bltz v0, 1f # seccomp failed? Skip syscall
132 lw v0, PT_R2(sp) # Restore syscall (maybe modified)
133 lw a0, PT_R4(sp) # Restore argument registers
141 /* ------------------------------------------------------------------------ */
144 * Our open-coded access area sanity test for the stack pointer
145 * failed. We probably should handle this case a bit more drastic.
150 li t0, 1 # set error flag
171 * The system call does not exist in this kernel
174 li v0, ENOSYS # error
176 li t0, 1 # set error flag
182 subu t0, a0, __NR_O32_Linux # check syscall number
183 sltiu v0, t0, __NR_O32_Linux_syscalls
184 beqz t0, einval # do not recurse
187 lw t2, sys_call_table(t1) # syscall routine
189 move a0, a1 # shift argument registers
202 einval: li v0, -ENOSYS
206 #ifdef CONFIG_MIPS_MT_FPAFF
208 * For FPU affinity scheduling on MIPS MT processors, we need to
209 * intercept sys_sched_xxxaffinity() calls until we get a proper hook
210 * in kernel/sched/core.c. Considered only temporary we only support
211 * these hooks for the 32-bit kernel - there is no MIPS64 MT processor
214 #define sys_sched_setaffinity mipsmt_sys_sched_setaffinity
215 #define sys_sched_getaffinity mipsmt_sys_sched_getaffinity
216 #endif /* CONFIG_MIPS_MT_FPAFF */
218 #define __SYSCALL_WITH_COMPAT(nr, native, compat) __SYSCALL(nr, native)
219 #define __SYSCALL(nr, entry) PTR entry
221 .type sys_call_table, @object
222 EXPORT(sys_call_table)
223 #include <asm/syscall_table_o32.h>