1 // SPDX-License-Identifier: GPL-2.0+ <<
2 /* 1 /*
3 * Author: Hanlu Li <lihanlu@loongson.cn> !! 2 * This file is subject to the terms and conditions of the GNU General Public
4 * Huacai Chen <chenhuacai@loongson.cn !! 3 * License. See the file "COPYING" in the main directory of this archive
>> 4 * for more details.
5 * 5 *
6 * Copyright (C) 2020-2022 Loongson Technology !! 6 * Copyright (C) 1995, 1996, 1997, 2000, 2001, 05 by Ralf Baechle
>> 7 * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
>> 8 * Copyright (C) 2001 MIPS Technologies, Inc.
7 */ 9 */
8 #include <linux/capability.h> 10 #include <linux/capability.h>
9 #include <linux/entry-common.h> <<
10 #include <linux/errno.h> 11 #include <linux/errno.h>
11 #include <linux/linkage.h> 12 #include <linux/linkage.h>
12 #include <linux/objtool.h> !! 13 #include <linux/fs.h>
13 #include <linux/randomize_kstack.h> !! 14 #include <linux/smp.h>
>> 15 #include <linux/ptrace.h>
>> 16 #include <linux/string.h>
14 #include <linux/syscalls.h> 17 #include <linux/syscalls.h>
>> 18 #include <linux/file.h>
>> 19 #include <linux/utsname.h>
15 #include <linux/unistd.h> 20 #include <linux/unistd.h>
>> 21 #include <linux/sem.h>
>> 22 #include <linux/msg.h>
>> 23 #include <linux/shm.h>
>> 24 #include <linux/compiler.h>
>> 25 #include <linux/ipc.h>
>> 26 #include <linux/uaccess.h>
>> 27 #include <linux/slab.h>
>> 28 #include <linux/elf.h>
>> 29 #include <linux/sched/task_stack.h>
16 30
17 #include <asm/asm.h> 31 #include <asm/asm.h>
18 #include <asm/exception.h> !! 32 #include <asm/asm-eva.h>
19 #include <asm/loongarch.h> !! 33 #include <asm/branch.h>
>> 34 #include <asm/cachectl.h>
>> 35 #include <asm/cacheflush.h>
>> 36 #include <asm/asm-offsets.h>
20 #include <asm/signal.h> 37 #include <asm/signal.h>
>> 38 #include <asm/sim.h>
>> 39 #include <asm/shmparam.h>
>> 40 #include <asm/sync.h>
>> 41 #include <asm/sysmips.h>
>> 42 #include <asm/syscalls.h>
21 #include <asm/switch_to.h> 43 #include <asm/switch_to.h>
22 #include <asm-generic/syscalls.h> <<
23 44
24 #undef __SYSCALL !! 45 /*
25 #define __SYSCALL(nr, call) [nr] = (call), !! 46 * For historic reasons the pipe(2) syscall on MIPS has an unusual calling
26 #define __SYSCALL_WITH_COMPAT(nr, native, comp !! 47 * convention. It returns results in registers $v0 / $v1 which means there
>> 48 * is no need for it to do verify the validity of a userspace pointer
>> 49 * argument. Historically that used to be expensive in Linux. These days
>> 50 * the performance advantage is negligible.
>> 51 */
>> 52 asmlinkage int sysm_pipe(void)
>> 53 {
>> 54 int fd[2];
>> 55 int error = do_pipe_flags(fd, 0);
>> 56 if (error)
>> 57 return error;
>> 58 current_pt_regs()->regs[3] = fd[1];
>> 59 return fd[0];
>> 60 }
27 61
28 SYSCALL_DEFINE6(mmap, unsigned long, addr, uns !! 62 SYSCALL_DEFINE6(mips_mmap, unsigned long, addr, unsigned long, len,
29 prot, unsigned long, flags, un !! 63 unsigned long, prot, unsigned long, flags, unsigned long,
>> 64 fd, off_t, offset)
30 { 65 {
31 if (offset & ~PAGE_MASK) 66 if (offset & ~PAGE_MASK)
32 return -EINVAL; 67 return -EINVAL;
33 !! 68 return ksys_mmap_pgoff(addr, len, prot, flags, fd,
34 return ksys_mmap_pgoff(addr, len, prot !! 69 offset >> PAGE_SHIFT);
35 } 70 }
36 71
37 void *sys_call_table[__NR_syscalls] = { !! 72 SYSCALL_DEFINE6(mips_mmap2, unsigned long, addr, unsigned long, len,
38 [0 ... __NR_syscalls - 1] = sys_ni_sys !! 73 unsigned long, prot, unsigned long, flags, unsigned long, fd,
39 #include <asm/syscall_table_64.h> !! 74 unsigned long, pgoff)
40 }; !! 75 {
>> 76 if (pgoff & (~PAGE_MASK >> 12))
>> 77 return -EINVAL;
41 78
42 typedef long (*sys_call_fn)(unsigned long, uns !! 79 return ksys_mmap_pgoff(addr, len, prot, flags, fd,
43 unsigned long, unsigned long, unsigned !! 80 pgoff >> (PAGE_SHIFT - 12));
>> 81 }
44 82
45 void noinstr __no_stack_protector do_syscall(s !! 83 save_static_function(sys_fork);
>> 84 save_static_function(sys_clone);
>> 85 save_static_function(sys_clone3);
>> 86
>> 87 SYSCALL_DEFINE1(set_thread_area, unsigned long, addr)
46 { 88 {
47 unsigned long nr; !! 89 struct thread_info *ti = task_thread_info(current);
48 sys_call_fn syscall_fn; <<
49 90
50 nr = regs->regs[11]; !! 91 ti->tp_value = addr;
51 /* Set for syscall restarting */ !! 92 if (cpu_has_userlocal)
52 if (nr < NR_syscalls) !! 93 write_c0_userlocal(addr);
53 regs->regs[0] = nr + 1; <<
54 94
55 regs->csr_era += 4; !! 95 return 0;
56 regs->orig_a0 = regs->regs[4]; !! 96 }
57 regs->regs[4] = -ENOSYS; <<
58 97
59 nr = syscall_enter_from_user_mode(regs !! 98 static inline int mips_atomic_set(unsigned long addr, unsigned long new)
>> 99 {
>> 100 unsigned long old, tmp;
>> 101 struct pt_regs *regs;
>> 102 unsigned int err;
60 103
61 add_random_kstack_offset(); !! 104 if (unlikely(addr & 3))
>> 105 return -EINVAL;
62 106
63 if (nr < NR_syscalls) { !! 107 if (unlikely(!access_ok((const void __user *)addr, 4)))
64 syscall_fn = sys_call_table[nr !! 108 return -EINVAL;
65 regs->regs[4] = syscall_fn(reg !! 109
66 reg !! 110 if (cpu_has_llsc && IS_ENABLED(CONFIG_WAR_R10000_LLSC)) {
>> 111 __asm__ __volatile__ (
>> 112 " .set push \n"
>> 113 " .set arch=r4000 \n"
>> 114 " li %[err], 0 \n"
>> 115 "1: ll %[old], (%[addr]) \n"
>> 116 " move %[tmp], %[new] \n"
>> 117 "2: sc %[tmp], (%[addr]) \n"
>> 118 " beqzl %[tmp], 1b \n"
>> 119 "3: \n"
>> 120 " .insn \n"
>> 121 " .section .fixup,\"ax\" \n"
>> 122 "4: li %[err], %[efault] \n"
>> 123 " j 3b \n"
>> 124 " .previous \n"
>> 125 " .section __ex_table,\"a\" \n"
>> 126 " "STR(PTR_WD)" 1b, 4b \n"
>> 127 " "STR(PTR_WD)" 2b, 4b \n"
>> 128 " .previous \n"
>> 129 " .set pop \n"
>> 130 : [old] "=&r" (old),
>> 131 [err] "=&r" (err),
>> 132 [tmp] "=&r" (tmp)
>> 133 : [addr] "r" (addr),
>> 134 [new] "r" (new),
>> 135 [efault] "i" (-EFAULT)
>> 136 : "memory");
>> 137 } else if (cpu_has_llsc) {
>> 138 __asm__ __volatile__ (
>> 139 " .set push \n"
>> 140 " .set "MIPS_ISA_ARCH_LEVEL" \n"
>> 141 " li %[err], 0 \n"
>> 142 "1: \n"
>> 143 " " __SYNC(full, loongson3_war) " \n"
>> 144 user_ll("%[old]", "(%[addr])")
>> 145 " move %[tmp], %[new] \n"
>> 146 "2: \n"
>> 147 user_sc("%[tmp]", "(%[addr])")
>> 148 " beqz %[tmp], 1b \n"
>> 149 "3: \n"
>> 150 " .insn \n"
>> 151 " .section .fixup,\"ax\" \n"
>> 152 "5: li %[err], %[efault] \n"
>> 153 " j 3b \n"
>> 154 " .previous \n"
>> 155 " .section __ex_table,\"a\" \n"
>> 156 " "STR(PTR_WD)" 1b, 5b \n"
>> 157 " "STR(PTR_WD)" 2b, 5b \n"
>> 158 " .previous \n"
>> 159 " .set pop \n"
>> 160 : [old] "=&r" (old),
>> 161 [err] "=&r" (err),
>> 162 [tmp] "=&r" (tmp)
>> 163 : [addr] "r" (addr),
>> 164 [new] "r" (new),
>> 165 [efault] "i" (-EFAULT)
>> 166 : "memory");
>> 167 } else {
>> 168 do {
>> 169 preempt_disable();
>> 170 ll_bit = 1;
>> 171 ll_task = current;
>> 172 preempt_enable();
>> 173
>> 174 err = __get_user(old, (unsigned int *) addr);
>> 175 err |= __put_user(new, (unsigned int *) addr);
>> 176 if (err)
>> 177 break;
>> 178 rmb();
>> 179 } while (!ll_bit);
67 } 180 }
68 181
>> 182 if (unlikely(err))
>> 183 return err;
>> 184
>> 185 regs = current_pt_regs();
>> 186 regs->regs[2] = old;
>> 187 regs->regs[7] = 0; /* No error */
>> 188
69 /* 189 /*
70 * This value will get limited by KSTA !! 190 * Don't let your children do this ...
71 * bits. The actual entropy will be fu <<
72 * when applying stack alignment const <<
73 * aligned, which will remove the 4 lo <<
74 * here. <<
75 * <<
76 * The resulting 6 bits of entropy is <<
77 */ 191 */
78 choose_random_kstack_offset(drdtime()) !! 192 __asm__ __volatile__(
>> 193 " move $29, %0 \n"
>> 194 " j syscall_exit \n"
>> 195 : /* no outputs */
>> 196 : "r" (regs));
>> 197
>> 198 /* unreached. Honestly. */
>> 199 unreachable();
>> 200 }
>> 201
>> 202 /*
>> 203 * mips_atomic_set() normally returns directly via syscall_exit potentially
>> 204 * clobbering static registers, so be sure to preserve them.
>> 205 */
>> 206 save_static_function(sys_sysmips);
>> 207
>> 208 SYSCALL_DEFINE3(sysmips, long, cmd, long, arg1, long, arg2)
>> 209 {
>> 210 switch (cmd) {
>> 211 case MIPS_ATOMIC_SET:
>> 212 return mips_atomic_set(arg1, arg2);
>> 213
>> 214 case MIPS_FIXADE:
>> 215 if (arg1 & ~3)
>> 216 return -EINVAL;
>> 217
>> 218 if (arg1 & 1)
>> 219 set_thread_flag(TIF_FIXADE);
>> 220 else
>> 221 clear_thread_flag(TIF_FIXADE);
>> 222 if (arg1 & 2)
>> 223 set_thread_flag(TIF_LOGADE);
>> 224 else
>> 225 clear_thread_flag(TIF_LOGADE);
>> 226
>> 227 return 0;
>> 228
>> 229 case FLUSH_CACHE:
>> 230 __flush_cache_all();
>> 231 return 0;
>> 232 }
>> 233
>> 234 return -EINVAL;
>> 235 }
79 236
80 syscall_exit_to_user_mode(regs); !! 237 /*
>> 238 * No implemented yet ...
>> 239 */
>> 240 SYSCALL_DEFINE3(cachectl, char *, addr, int, nbytes, int, op)
>> 241 {
>> 242 return -ENOSYS;
81 } 243 }
82 244
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