1 // SPDX-License-Identifier: GPL-2.0-or-later <<
2 /* 1 /*
3 * Copyright (C) 2009 Sunplus Core Technology !! 2 * This file is subject to the terms and conditions of the GNU General Public
4 * Chen Liqin <liqin.chen@sunplusct.com> !! 3 * License. See the file "COPYING" in the main directory of this archive
5 * Lennox Wu <lennox.wu@sunplusct.com> !! 4 * for more details.
6 * Copyright (C) 2012 Regents of the Universit !! 5 *
7 * Copyright (C) 2017 SiFive !! 6 * Copyright (C) 1994 - 1999, 2000 by Ralf Baechle and others.
>> 7 * Copyright (C) 2005, 2006 by Ralf Baechle (ralf@linux-mips.org)
>> 8 * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
>> 9 * Copyright (C) 2004 Thiemo Seufer
>> 10 * Copyright (C) 2013 Imagination Technologies Ltd.
8 */ 11 */
9 <<
10 #include <linux/cpu.h> 12 #include <linux/cpu.h>
>> 13 #include <linux/errno.h>
>> 14 #include <linux/init.h>
>> 15 #include <linux/kallsyms.h>
11 #include <linux/kernel.h> 16 #include <linux/kernel.h>
>> 17 #include <linux/nmi.h>
>> 18 #include <linux/personality.h>
>> 19 #include <linux/prctl.h>
>> 20 #include <linux/random.h>
12 #include <linux/sched.h> 21 #include <linux/sched.h>
13 #include <linux/sched/debug.h> 22 #include <linux/sched/debug.h>
14 #include <linux/sched/task_stack.h> 23 #include <linux/sched/task_stack.h>
15 #include <linux/tick.h> <<
16 #include <linux/ptrace.h> <<
17 #include <linux/uaccess.h> <<
18 #include <linux/personality.h> <<
19 24
20 #include <asm/unistd.h> !! 25 #include <asm/abi.h>
>> 26 #include <asm/asm.h>
>> 27 #include <asm/dsemul.h>
>> 28 #include <asm/dsp.h>
>> 29 #include <asm/exec.h>
>> 30 #include <asm/fpu.h>
>> 31 #include <asm/inst.h>
>> 32 #include <asm/irq.h>
>> 33 #include <asm/irq_regs.h>
>> 34 #include <asm/isadep.h>
>> 35 #include <asm/msa.h>
>> 36 #include <asm/mips-cps.h>
>> 37 #include <asm/mipsregs.h>
21 #include <asm/processor.h> 38 #include <asm/processor.h>
22 #include <asm/csr.h> !! 39 #include <asm/reg.h>
23 #include <asm/stacktrace.h> 40 #include <asm/stacktrace.h>
24 #include <asm/string.h> <<
25 #include <asm/switch_to.h> <<
26 #include <asm/thread_info.h> <<
27 #include <asm/cpuidle.h> <<
28 #include <asm/vector.h> <<
29 #include <asm/cpufeature.h> <<
30 #include <asm/exec.h> <<
31 41
32 #if defined(CONFIG_STACKPROTECTOR) && !defined !! 42 #ifdef CONFIG_HOTPLUG_CPU
33 #include <linux/stackprotector.h> !! 43 void __noreturn arch_cpu_idle_dead(void)
34 unsigned long __stack_chk_guard __read_mostly; !! 44 {
35 EXPORT_SYMBOL(__stack_chk_guard); !! 45 play_dead();
>> 46 }
36 #endif 47 #endif
37 48
38 extern asmlinkage void ret_from_fork(void); !! 49 asmlinkage void ret_from_fork(void);
>> 50 asmlinkage void ret_from_kernel_thread(void);
>> 51
>> 52 void start_thread(struct pt_regs * regs, unsigned long pc, unsigned long sp)
>> 53 {
>> 54 unsigned long status;
>> 55
>> 56 /* New thread loses kernel privileges. */
>> 57 status = regs->cp0_status & ~(ST0_CU0|ST0_CU1|ST0_CU2|ST0_FR|KU_MASK);
>> 58 status |= KU_USER;
>> 59 regs->cp0_status = status;
>> 60 lose_fpu(0);
>> 61 clear_thread_flag(TIF_MSA_CTX_LIVE);
>> 62 clear_used_math();
>> 63 #ifdef CONFIG_MIPS_FP_SUPPORT
>> 64 atomic_set(¤t->thread.bd_emu_frame, BD_EMUFRAME_NONE);
>> 65 #endif
>> 66 init_dsp();
>> 67 regs->cp0_epc = pc;
>> 68 regs->regs[29] = sp;
>> 69 }
39 70
40 void noinstr arch_cpu_idle(void) !! 71 void exit_thread(struct task_struct *tsk)
41 { 72 {
42 cpu_do_idle(); !! 73 /*
>> 74 * User threads may have allocated a delay slot emulation frame.
>> 75 * If so, clean up that allocation.
>> 76 */
>> 77 if (!(current->flags & PF_KTHREAD))
>> 78 dsemul_thread_cleanup(tsk);
43 } 79 }
44 80
45 int set_unalign_ctl(struct task_struct *tsk, u !! 81 int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
46 { 82 {
47 if (!unaligned_ctl_available()) !! 83 /*
48 return -EINVAL; !! 84 * Save any process state which is live in hardware registers to the
>> 85 * parent context prior to duplication. This prevents the new child
>> 86 * state becoming stale if the parent is preempted before copy_thread()
>> 87 * gets a chance to save the parent's live hardware registers to the
>> 88 * child context.
>> 89 */
>> 90 preempt_disable();
49 91
50 tsk->thread.align_ctl = val; !! 92 if (is_msa_enabled())
>> 93 save_msa(current);
>> 94 else if (is_fpu_owner())
>> 95 _save_fp(current);
>> 96
>> 97 save_dsp(current);
>> 98
>> 99 preempt_enable();
>> 100
>> 101 *dst = *src;
51 return 0; 102 return 0;
52 } 103 }
53 104
54 int get_unalign_ctl(struct task_struct *tsk, u !! 105 /*
>> 106 * Copy architecture-specific thread state
>> 107 */
>> 108 int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
>> 109 {
>> 110 unsigned long clone_flags = args->flags;
>> 111 unsigned long usp = args->stack;
>> 112 unsigned long tls = args->tls;
>> 113 struct thread_info *ti = task_thread_info(p);
>> 114 struct pt_regs *childregs, *regs = current_pt_regs();
>> 115 unsigned long childksp;
>> 116
>> 117 childksp = (unsigned long)task_stack_page(p) + THREAD_SIZE - 32;
>> 118
>> 119 /* set up new TSS. */
>> 120 childregs = (struct pt_regs *) childksp - 1;
>> 121 /* Put the stack after the struct pt_regs. */
>> 122 childksp = (unsigned long) childregs;
>> 123 p->thread.cp0_status = (read_c0_status() & ~(ST0_CU2|ST0_CU1)) | ST0_KERNEL_CUMASK;
>> 124
>> 125 /*
>> 126 * New tasks lose permission to use the fpu. This accelerates context
>> 127 * switching for most programs since they don't use the fpu.
>> 128 */
>> 129 clear_tsk_thread_flag(p, TIF_USEDFPU);
>> 130 clear_tsk_thread_flag(p, TIF_USEDMSA);
>> 131 clear_tsk_thread_flag(p, TIF_MSA_CTX_LIVE);
>> 132
>> 133 #ifdef CONFIG_MIPS_MT_FPAFF
>> 134 clear_tsk_thread_flag(p, TIF_FPUBOUND);
>> 135 #endif /* CONFIG_MIPS_MT_FPAFF */
>> 136
>> 137 if (unlikely(args->fn)) {
>> 138 /* kernel thread */
>> 139 unsigned long status = p->thread.cp0_status;
>> 140 memset(childregs, 0, sizeof(struct pt_regs));
>> 141 p->thread.reg16 = (unsigned long)args->fn;
>> 142 p->thread.reg17 = (unsigned long)args->fn_arg;
>> 143 p->thread.reg29 = childksp;
>> 144 p->thread.reg31 = (unsigned long) ret_from_kernel_thread;
>> 145 #if defined(CONFIG_CPU_R3000)
>> 146 status = (status & ~(ST0_KUP | ST0_IEP | ST0_IEC)) |
>> 147 ((status & (ST0_KUC | ST0_IEC)) << 2);
>> 148 #else
>> 149 status |= ST0_EXL;
>> 150 #endif
>> 151 childregs->cp0_status = status;
>> 152 return 0;
>> 153 }
>> 154
>> 155 /* user thread */
>> 156 *childregs = *regs;
>> 157 childregs->regs[7] = 0; /* Clear error flag */
>> 158 childregs->regs[2] = 0; /* Child gets zero as return value */
>> 159 if (usp)
>> 160 childregs->regs[29] = usp;
>> 161
>> 162 p->thread.reg29 = (unsigned long) childregs;
>> 163 p->thread.reg31 = (unsigned long) ret_from_fork;
>> 164
>> 165 childregs->cp0_status &= ~(ST0_CU2|ST0_CU1);
>> 166
>> 167 #ifdef CONFIG_MIPS_FP_SUPPORT
>> 168 atomic_set(&p->thread.bd_emu_frame, BD_EMUFRAME_NONE);
>> 169 #endif
>> 170
>> 171 if (clone_flags & CLONE_SETTLS)
>> 172 ti->tp_value = tls;
>> 173
>> 174 return 0;
>> 175 }
>> 176
>> 177 #ifdef CONFIG_STACKPROTECTOR
>> 178 #include <linux/stackprotector.h>
>> 179 unsigned long __stack_chk_guard __read_mostly;
>> 180 EXPORT_SYMBOL(__stack_chk_guard);
>> 181 #endif
>> 182
>> 183 struct mips_frame_info {
>> 184 void *func;
>> 185 unsigned long func_size;
>> 186 int frame_size;
>> 187 int pc_offset;
>> 188 };
>> 189
>> 190 #define J_TARGET(pc,target) \
>> 191 (((unsigned long)(pc) & 0xf0000000) | ((target) << 2))
>> 192
>> 193 static inline int is_jr_ra_ins(union mips_instruction *ip)
55 { 194 {
56 if (!unaligned_ctl_available()) !! 195 #ifdef CONFIG_CPU_MICROMIPS
57 return -EINVAL; !! 196 /*
>> 197 * jr16 ra
>> 198 * jr ra
>> 199 */
>> 200 if (mm_insn_16bit(ip->word >> 16)) {
>> 201 if (ip->mm16_r5_format.opcode == mm_pool16c_op &&
>> 202 ip->mm16_r5_format.rt == mm_jr16_op &&
>> 203 ip->mm16_r5_format.imm == 31)
>> 204 return 1;
>> 205 return 0;
>> 206 }
58 207
59 return put_user(tsk->thread.align_ctl, !! 208 if (ip->r_format.opcode == mm_pool32a_op &&
>> 209 ip->r_format.func == mm_pool32axf_op &&
>> 210 ((ip->u_format.uimmediate >> 6) & GENMASK(9, 0)) == mm_jalr_op &&
>> 211 ip->r_format.rt == 31)
>> 212 return 1;
>> 213 return 0;
>> 214 #else
>> 215 if (ip->r_format.opcode == spec_op &&
>> 216 ip->r_format.func == jr_op &&
>> 217 ip->r_format.rs == 31)
>> 218 return 1;
>> 219 return 0;
>> 220 #endif
60 } 221 }
61 222
62 void __show_regs(struct pt_regs *regs) !! 223 static inline int is_ra_save_ins(union mips_instruction *ip, int *poff)
63 { 224 {
64 show_regs_print_info(KERN_DEFAULT); !! 225 #ifdef CONFIG_CPU_MICROMIPS
>> 226 /*
>> 227 * swsp ra,offset
>> 228 * swm16 reglist,offset(sp)
>> 229 * swm32 reglist,offset(sp)
>> 230 * sw32 ra,offset(sp)
>> 231 * jradiussp - NOT SUPPORTED
>> 232 *
>> 233 * microMIPS is way more fun...
>> 234 */
>> 235 if (mm_insn_16bit(ip->word >> 16)) {
>> 236 switch (ip->mm16_r5_format.opcode) {
>> 237 case mm_swsp16_op:
>> 238 if (ip->mm16_r5_format.rt != 31)
>> 239 return 0;
>> 240
>> 241 *poff = ip->mm16_r5_format.imm;
>> 242 *poff = (*poff << 2) / sizeof(ulong);
>> 243 return 1;
>> 244
>> 245 case mm_pool16c_op:
>> 246 switch (ip->mm16_m_format.func) {
>> 247 case mm_swm16_op:
>> 248 *poff = ip->mm16_m_format.imm;
>> 249 *poff += 1 + ip->mm16_m_format.rlist;
>> 250 *poff = (*poff << 2) / sizeof(ulong);
>> 251 return 1;
>> 252
>> 253 default:
>> 254 return 0;
>> 255 }
>> 256
>> 257 default:
>> 258 return 0;
>> 259 }
>> 260 }
>> 261
>> 262 switch (ip->i_format.opcode) {
>> 263 case mm_sw32_op:
>> 264 if (ip->i_format.rs != 29)
>> 265 return 0;
>> 266 if (ip->i_format.rt != 31)
>> 267 return 0;
>> 268
>> 269 *poff = ip->i_format.simmediate / sizeof(ulong);
>> 270 return 1;
>> 271
>> 272 case mm_pool32b_op:
>> 273 switch (ip->mm_m_format.func) {
>> 274 case mm_swm32_func:
>> 275 if (ip->mm_m_format.rd < 0x10)
>> 276 return 0;
>> 277 if (ip->mm_m_format.base != 29)
>> 278 return 0;
>> 279
>> 280 *poff = ip->mm_m_format.simmediate;
>> 281 *poff += (ip->mm_m_format.rd & 0xf) * sizeof(u32);
>> 282 *poff /= sizeof(ulong);
>> 283 return 1;
>> 284 default:
>> 285 return 0;
>> 286 }
65 287
66 if (!user_mode(regs)) { !! 288 default:
67 pr_cont("epc : %pS\n", (void * !! 289 return 0;
68 pr_cont(" ra : %pS\n", (void * !! 290 }
>> 291 #else
>> 292 /* sw / sd $ra, offset($sp) */
>> 293 if ((ip->i_format.opcode == sw_op || ip->i_format.opcode == sd_op) &&
>> 294 ip->i_format.rs == 29 && ip->i_format.rt == 31) {
>> 295 *poff = ip->i_format.simmediate / sizeof(ulong);
>> 296 return 1;
>> 297 }
>> 298 #ifdef CONFIG_CPU_LOONGSON64
>> 299 if ((ip->loongson3_lswc2_format.opcode == swc2_op) &&
>> 300 (ip->loongson3_lswc2_format.ls == 1) &&
>> 301 (ip->loongson3_lswc2_format.fr == 0) &&
>> 302 (ip->loongson3_lswc2_format.base == 29)) {
>> 303 if (ip->loongson3_lswc2_format.rt == 31) {
>> 304 *poff = ip->loongson3_lswc2_format.offset << 1;
>> 305 return 1;
>> 306 }
>> 307 if (ip->loongson3_lswc2_format.rq == 31) {
>> 308 *poff = (ip->loongson3_lswc2_format.offset << 1) + 1;
>> 309 return 1;
>> 310 }
69 } 311 }
>> 312 #endif
>> 313 return 0;
>> 314 #endif
>> 315 }
70 316
71 pr_cont("epc : " REG_FMT " ra : " REG_ !! 317 static inline int is_jump_ins(union mips_instruction *ip)
72 regs->epc, regs->ra, regs->sp) !! 318 {
73 pr_cont(" gp : " REG_FMT " tp : " REG_ !! 319 #ifdef CONFIG_CPU_MICROMIPS
74 regs->gp, regs->tp, regs->t0); !! 320 /*
75 pr_cont(" t1 : " REG_FMT " t2 : " REG_ !! 321 * jr16,jrc,jalr16,jalr16
76 regs->t1, regs->t2, regs->s0); !! 322 * jal
77 pr_cont(" s1 : " REG_FMT " a0 : " REG_ !! 323 * jalr/jr,jalr.hb/jr.hb,jalrs,jalrs.hb
78 regs->s1, regs->a0, regs->a1); !! 324 * jraddiusp - NOT SUPPORTED
79 pr_cont(" a2 : " REG_FMT " a3 : " REG_ !! 325 *
80 regs->a2, regs->a3, regs->a4); !! 326 * microMIPS is kind of more fun...
81 pr_cont(" a5 : " REG_FMT " a6 : " REG_ !! 327 */
82 regs->a5, regs->a6, regs->a7); !! 328 if (mm_insn_16bit(ip->word >> 16)) {
83 pr_cont(" s2 : " REG_FMT " s3 : " REG_ !! 329 if ((ip->mm16_r5_format.opcode == mm_pool16c_op &&
84 regs->s2, regs->s3, regs->s4); !! 330 (ip->mm16_r5_format.rt & mm_jr16_op) == mm_jr16_op))
85 pr_cont(" s5 : " REG_FMT " s6 : " REG_ !! 331 return 1;
86 regs->s5, regs->s6, regs->s7); !! 332 return 0;
87 pr_cont(" s8 : " REG_FMT " s9 : " REG_ !! 333 }
88 regs->s8, regs->s9, regs->s10) <<
89 pr_cont(" s11: " REG_FMT " t3 : " REG_ <<
90 regs->s11, regs->t3, regs->t4) <<
91 pr_cont(" t5 : " REG_FMT " t6 : " REG_ <<
92 regs->t5, regs->t6); <<
93 334
94 pr_cont("status: " REG_FMT " badaddr: !! 335 if (ip->j_format.opcode == mm_j32_op)
95 regs->status, regs->badaddr, r !! 336 return 1;
>> 337 if (ip->j_format.opcode == mm_jal32_op)
>> 338 return 1;
>> 339 if (ip->r_format.opcode != mm_pool32a_op ||
>> 340 ip->r_format.func != mm_pool32axf_op)
>> 341 return 0;
>> 342 return ((ip->u_format.uimmediate >> 6) & mm_jalr_op) == mm_jalr_op;
>> 343 #else
>> 344 if (ip->j_format.opcode == j_op)
>> 345 return 1;
>> 346 if (ip->j_format.opcode == jal_op)
>> 347 return 1;
>> 348 if (ip->r_format.opcode != spec_op)
>> 349 return 0;
>> 350 return ip->r_format.func == jalr_op || ip->r_format.func == jr_op;
>> 351 #endif
96 } 352 }
97 void show_regs(struct pt_regs *regs) !! 353
>> 354 static inline int is_sp_move_ins(union mips_instruction *ip, int *frame_size)
98 { 355 {
99 __show_regs(regs); !! 356 #ifdef CONFIG_CPU_MICROMIPS
100 if (!user_mode(regs)) !! 357 unsigned short tmp;
101 dump_backtrace(regs, NULL, KER !! 358
>> 359 /*
>> 360 * addiusp -imm
>> 361 * addius5 sp,-imm
>> 362 * addiu32 sp,sp,-imm
>> 363 * jradiussp - NOT SUPPORTED
>> 364 *
>> 365 * microMIPS is not more fun...
>> 366 */
>> 367 if (mm_insn_16bit(ip->word >> 16)) {
>> 368 if (ip->mm16_r3_format.opcode == mm_pool16d_op &&
>> 369 ip->mm16_r3_format.simmediate & mm_addiusp_func) {
>> 370 tmp = ip->mm_b0_format.simmediate >> 1;
>> 371 tmp = ((tmp & 0x1ff) ^ 0x100) - 0x100;
>> 372 if ((tmp + 2) < 4) /* 0x0,0x1,0x1fe,0x1ff are special */
>> 373 tmp ^= 0x100;
>> 374 *frame_size = -(signed short)(tmp << 2);
>> 375 return 1;
>> 376 }
>> 377 if (ip->mm16_r5_format.opcode == mm_pool16d_op &&
>> 378 ip->mm16_r5_format.rt == 29) {
>> 379 tmp = ip->mm16_r5_format.imm >> 1;
>> 380 *frame_size = -(signed short)(tmp & 0xf);
>> 381 return 1;
>> 382 }
>> 383 return 0;
>> 384 }
>> 385
>> 386 if (ip->mm_i_format.opcode == mm_addiu32_op &&
>> 387 ip->mm_i_format.rt == 29 && ip->mm_i_format.rs == 29) {
>> 388 *frame_size = -ip->i_format.simmediate;
>> 389 return 1;
>> 390 }
>> 391 #else
>> 392 /* addiu/daddiu sp,sp,-imm */
>> 393 if (ip->i_format.rs != 29 || ip->i_format.rt != 29)
>> 394 return 0;
>> 395
>> 396 if (ip->i_format.opcode == addiu_op ||
>> 397 ip->i_format.opcode == daddiu_op) {
>> 398 *frame_size = -ip->i_format.simmediate;
>> 399 return 1;
>> 400 }
>> 401 #endif
>> 402 return 0;
102 } 403 }
103 404
104 unsigned long arch_align_stack(unsigned long s !! 405 static int get_frame_info(struct mips_frame_info *info)
105 { 406 {
106 if (!(current->personality & ADDR_NO_R !! 407 bool is_mmips = IS_ENABLED(CONFIG_CPU_MICROMIPS);
107 sp -= get_random_u32_below(PAG !! 408 union mips_instruction insn, *ip, *ip_end;
108 return sp & ~0xf; !! 409 unsigned int last_insn_size = 0;
>> 410 bool saw_jump = false;
>> 411
>> 412 info->pc_offset = -1;
>> 413 info->frame_size = 0;
>> 414
>> 415 ip = (void *)msk_isa16_mode((ulong)info->func);
>> 416 if (!ip)
>> 417 goto err;
>> 418
>> 419 ip_end = (void *)ip + (info->func_size ? info->func_size : 512);
>> 420
>> 421 while (ip < ip_end) {
>> 422 ip = (void *)ip + last_insn_size;
>> 423
>> 424 if (is_mmips && mm_insn_16bit(ip->halfword[0])) {
>> 425 insn.word = ip->halfword[0] << 16;
>> 426 last_insn_size = 2;
>> 427 } else if (is_mmips) {
>> 428 insn.word = ip->halfword[0] << 16 | ip->halfword[1];
>> 429 last_insn_size = 4;
>> 430 } else {
>> 431 insn.word = ip->word;
>> 432 last_insn_size = 4;
>> 433 }
>> 434
>> 435 if (is_jr_ra_ins(ip)) {
>> 436 break;
>> 437 } else if (!info->frame_size) {
>> 438 is_sp_move_ins(&insn, &info->frame_size);
>> 439 continue;
>> 440 } else if (!saw_jump && is_jump_ins(ip)) {
>> 441 /*
>> 442 * If we see a jump instruction, we are finished
>> 443 * with the frame save.
>> 444 *
>> 445 * Some functions can have a shortcut return at
>> 446 * the beginning of the function, so don't start
>> 447 * looking for jump instruction until we see the
>> 448 * frame setup.
>> 449 *
>> 450 * The RA save instruction can get put into the
>> 451 * delay slot of the jump instruction, so look
>> 452 * at the next instruction, too.
>> 453 */
>> 454 saw_jump = true;
>> 455 continue;
>> 456 }
>> 457 if (info->pc_offset == -1 &&
>> 458 is_ra_save_ins(&insn, &info->pc_offset))
>> 459 break;
>> 460 if (saw_jump)
>> 461 break;
>> 462 }
>> 463 if (info->frame_size && info->pc_offset >= 0) /* nested */
>> 464 return 0;
>> 465 if (info->pc_offset < 0) /* leaf */
>> 466 return 1;
>> 467 /* prologue seems bogus... */
>> 468 err:
>> 469 return -1;
109 } 470 }
110 471
111 #ifdef CONFIG_COMPAT !! 472 static struct mips_frame_info schedule_mfi __read_mostly;
112 static bool compat_mode_supported __read_mostl <<
113 473
114 bool compat_elf_check_arch(Elf32_Ehdr *hdr) !! 474 #ifdef CONFIG_KALLSYMS
>> 475 static unsigned long get___schedule_addr(void)
>> 476 {
>> 477 return kallsyms_lookup_name("__schedule");
>> 478 }
>> 479 #else
>> 480 static unsigned long get___schedule_addr(void)
115 { 481 {
116 return compat_mode_supported && !! 482 union mips_instruction *ip = (void *)schedule;
117 hdr->e_machine == EM_RISCV && !! 483 int max_insns = 8;
118 hdr->e_ident[EI_CLASS] == ELFCL !! 484 int i;
>> 485
>> 486 for (i = 0; i < max_insns; i++, ip++) {
>> 487 if (ip->j_format.opcode == j_op)
>> 488 return J_TARGET(ip, ip->j_format.target);
>> 489 }
>> 490 return 0;
119 } 491 }
>> 492 #endif
120 493
121 static int __init compat_mode_detect(void) !! 494 static int __init frame_info_init(void)
122 { 495 {
123 unsigned long tmp = csr_read(CSR_STATU !! 496 unsigned long size = 0;
>> 497 #ifdef CONFIG_KALLSYMS
>> 498 unsigned long ofs;
>> 499 #endif
>> 500 unsigned long addr;
>> 501
>> 502 addr = get___schedule_addr();
>> 503 if (!addr)
>> 504 addr = (unsigned long)schedule;
124 505
125 csr_write(CSR_STATUS, (tmp & ~SR_UXL) !! 506 #ifdef CONFIG_KALLSYMS
126 compat_mode_supported = !! 507 kallsyms_lookup_size_offset(addr, &size, &ofs);
127 (csr_read(CSR_STATUS) !! 508 #endif
>> 509 schedule_mfi.func = (void *)addr;
>> 510 schedule_mfi.func_size = size;
128 511
129 csr_write(CSR_STATUS, tmp); !! 512 get_frame_info(&schedule_mfi);
130 513
131 pr_info("riscv: ELF compat mode %s", !! 514 /*
132 compat_mode_supported !! 515 * Without schedule() frame info, result given by
>> 516 * thread_saved_pc() and __get_wchan() are not reliable.
>> 517 */
>> 518 if (schedule_mfi.pc_offset < 0)
>> 519 printk("Can't analyze schedule() prologue at %p\n", schedule);
133 520
134 return 0; 521 return 0;
135 } 522 }
136 early_initcall(compat_mode_detect); <<
137 #endif <<
138 523
139 void start_thread(struct pt_regs *regs, unsign !! 524 arch_initcall(frame_info_init);
140 unsigned long sp) !! 525
>> 526 /*
>> 527 * Return saved PC of a blocked thread.
>> 528 */
>> 529 static unsigned long thread_saved_pc(struct task_struct *tsk)
141 { 530 {
142 regs->status = SR_PIE; !! 531 struct thread_struct *t = &tsk->thread;
143 if (has_fpu()) { !! 532
144 regs->status |= SR_FS_INITIAL; !! 533 /* New born processes are a special case */
>> 534 if (t->reg31 == (unsigned long) ret_from_fork)
>> 535 return t->reg31;
>> 536 if (schedule_mfi.pc_offset < 0)
>> 537 return 0;
>> 538 return ((unsigned long *)t->reg29)[schedule_mfi.pc_offset];
>> 539 }
>> 540
>> 541
>> 542 #ifdef CONFIG_KALLSYMS
>> 543 /* generic stack unwinding function */
>> 544 unsigned long notrace unwind_stack_by_address(unsigned long stack_page,
>> 545 unsigned long *sp,
>> 546 unsigned long pc,
>> 547 unsigned long *ra)
>> 548 {
>> 549 unsigned long low, high, irq_stack_high;
>> 550 struct mips_frame_info info;
>> 551 unsigned long size, ofs;
>> 552 struct pt_regs *regs;
>> 553 int leaf;
>> 554
>> 555 if (!stack_page)
>> 556 return 0;
>> 557
>> 558 /*
>> 559 * IRQ stacks start at IRQ_STACK_START
>> 560 * task stacks at THREAD_SIZE - 32
>> 561 */
>> 562 low = stack_page;
>> 563 if (!preemptible() && on_irq_stack(raw_smp_processor_id(), *sp)) {
>> 564 high = stack_page + IRQ_STACK_START;
>> 565 irq_stack_high = high;
>> 566 } else {
>> 567 high = stack_page + THREAD_SIZE - 32;
>> 568 irq_stack_high = 0;
>> 569 }
>> 570
>> 571 /*
>> 572 * If we reached the top of the interrupt stack, start unwinding
>> 573 * the interrupted task stack.
>> 574 */
>> 575 if (unlikely(*sp == irq_stack_high)) {
>> 576 unsigned long task_sp = *(unsigned long *)*sp;
>> 577
145 /* 578 /*
146 * Restore the initial value t !! 579 * Check that the pointer saved in the IRQ stack head points to
147 * before starting the user pr !! 580 * something within the stack of the current task
148 */ 581 */
149 fstate_restore(current, regs); !! 582 if (!object_is_on_stack((void *)task_sp))
>> 583 return 0;
>> 584
>> 585 /*
>> 586 * Follow pointer to tasks kernel stack frame where interrupted
>> 587 * state was saved.
>> 588 */
>> 589 regs = (struct pt_regs *)task_sp;
>> 590 pc = regs->cp0_epc;
>> 591 if (!user_mode(regs) && __kernel_text_address(pc)) {
>> 592 *sp = regs->regs[29];
>> 593 *ra = regs->regs[31];
>> 594 return pc;
>> 595 }
>> 596 return 0;
>> 597 }
>> 598 if (!kallsyms_lookup_size_offset(pc, &size, &ofs))
>> 599 return 0;
>> 600 /*
>> 601 * Return ra if an exception occurred at the first instruction
>> 602 */
>> 603 if (unlikely(ofs == 0)) {
>> 604 pc = *ra;
>> 605 *ra = 0;
>> 606 return pc;
150 } 607 }
151 regs->epc = pc; <<
152 regs->sp = sp; <<
153 608
154 #ifdef CONFIG_64BIT !! 609 info.func = (void *)(pc - ofs);
155 regs->status &= ~SR_UXL; !! 610 info.func_size = ofs; /* analyze from start to ofs */
>> 611 leaf = get_frame_info(&info);
>> 612 if (leaf < 0)
>> 613 return 0;
>> 614
>> 615 if (*sp < low || *sp + info.frame_size > high)
>> 616 return 0;
156 617
157 if (is_compat_task()) !! 618 if (leaf)
158 regs->status |= SR_UXL_32; !! 619 /*
>> 620 * For some extreme cases, get_frame_info() can
>> 621 * consider wrongly a nested function as a leaf
>> 622 * one. In that cases avoid to return always the
>> 623 * same value.
>> 624 */
>> 625 pc = pc != *ra ? *ra : 0;
159 else 626 else
160 regs->status |= SR_UXL_64; !! 627 pc = ((unsigned long *)(*sp))[info.pc_offset];
161 #endif !! 628
>> 629 *sp += info.frame_size;
>> 630 *ra = 0;
>> 631 return __kernel_text_address(pc) ? pc : 0;
>> 632 }
>> 633 EXPORT_SYMBOL(unwind_stack_by_address);
>> 634
>> 635 /* used by show_backtrace() */
>> 636 unsigned long unwind_stack(struct task_struct *task, unsigned long *sp,
>> 637 unsigned long pc, unsigned long *ra)
>> 638 {
>> 639 unsigned long stack_page = 0;
>> 640 int cpu;
>> 641
>> 642 for_each_possible_cpu(cpu) {
>> 643 if (on_irq_stack(cpu, *sp)) {
>> 644 stack_page = (unsigned long)irq_stack[cpu];
>> 645 break;
>> 646 }
>> 647 }
>> 648
>> 649 if (!stack_page)
>> 650 stack_page = (unsigned long)task_stack_page(task);
>> 651
>> 652 return unwind_stack_by_address(stack_page, sp, pc, ra);
162 } 653 }
>> 654 #endif
163 655
164 void flush_thread(void) !! 656 /*
>> 657 * __get_wchan - a maintenance nightmare^W^Wpain in the ass ...
>> 658 */
>> 659 unsigned long __get_wchan(struct task_struct *task)
165 { 660 {
166 #ifdef CONFIG_FPU !! 661 unsigned long pc = 0;
167 /* !! 662 #ifdef CONFIG_KALLSYMS
168 * Reset FPU state and context !! 663 unsigned long sp;
169 * frm: round to nearest, ties to !! 664 unsigned long ra = 0;
170 * fflags: accrued exceptions cle <<
171 */ <<
172 fstate_off(current, task_pt_regs(curre <<
173 memset(¤t->thread.fstate, 0, siz <<
174 #endif 665 #endif
175 #ifdef CONFIG_RISCV_ISA_V !! 666
176 /* Reset vector state */ !! 667 if (!task_stack_page(task))
177 riscv_v_vstate_ctrl_init(current); !! 668 goto out;
178 riscv_v_vstate_off(task_pt_regs(curren !! 669
179 kfree(current->thread.vstate.datap); !! 670 pc = thread_saved_pc(task);
180 memset(¤t->thread.vstate, 0, siz !! 671
181 clear_tsk_thread_flag(current, TIF_RIS !! 672 #ifdef CONFIG_KALLSYMS
>> 673 sp = task->thread.reg29 + schedule_mfi.frame_size;
>> 674
>> 675 while (in_sched_functions(pc))
>> 676 pc = unwind_stack(task, &sp, pc, &ra);
182 #endif 677 #endif
>> 678
>> 679 out:
>> 680 return pc;
183 } 681 }
184 682
185 void arch_release_task_struct(struct task_stru !! 683 unsigned long mips_stack_top(void)
186 { 684 {
187 /* Free the vector context of datap. * !! 685 unsigned long top = TASK_SIZE & PAGE_MASK;
188 if (has_vector()) !! 686
189 riscv_v_thread_free(tsk); !! 687 if (IS_ENABLED(CONFIG_MIPS_FP_SUPPORT)) {
>> 688 /* One page for branch delay slot "emulation" */
>> 689 top -= PAGE_SIZE;
>> 690 }
>> 691
>> 692 /* Space for the VDSO, data page & GIC user page */
>> 693 top -= PAGE_ALIGN(current->thread.abi->vdso->size);
>> 694 top -= PAGE_SIZE;
>> 695 top -= mips_gic_present() ? PAGE_SIZE : 0;
>> 696
>> 697 /* Space for cache colour alignment */
>> 698 if (cpu_has_dc_aliases)
>> 699 top -= shm_align_mask + 1;
>> 700
>> 701 /* Space to randomize the VDSO base */
>> 702 if (current->flags & PF_RANDOMIZE)
>> 703 top -= VDSO_RANDOMIZE_SIZE;
>> 704
>> 705 return top;
190 } 706 }
191 707
192 int arch_dup_task_struct(struct task_struct *d !! 708 /*
>> 709 * Don't forget that the stack pointer must be aligned on a 8 bytes
>> 710 * boundary for 32-bits ABI and 16 bytes for 64-bits ABI.
>> 711 */
>> 712 unsigned long arch_align_stack(unsigned long sp)
193 { 713 {
194 fstate_save(src, task_pt_regs(src)); !! 714 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
195 *dst = *src; !! 715 sp -= get_random_u32_below(PAGE_SIZE);
196 /* clear entire V context, including d !! 716
197 memset(&dst->thread.vstate, 0, sizeof( !! 717 return sp & ALMASK;
198 memset(&dst->thread.kernel_vstate, 0, !! 718 }
199 clear_tsk_thread_flag(dst, TIF_RISCV_V !! 719
>> 720 static struct cpumask backtrace_csd_busy;
>> 721
>> 722 static void handle_backtrace(void *info)
>> 723 {
>> 724 nmi_cpu_backtrace(get_irq_regs());
>> 725 cpumask_clear_cpu(smp_processor_id(), &backtrace_csd_busy);
>> 726 }
>> 727
>> 728 static DEFINE_PER_CPU(call_single_data_t, backtrace_csd) =
>> 729 CSD_INIT(handle_backtrace, NULL);
>> 730
>> 731 static void raise_backtrace(cpumask_t *mask)
>> 732 {
>> 733 call_single_data_t *csd;
>> 734 int cpu;
>> 735
>> 736 for_each_cpu(cpu, mask) {
>> 737 /*
>> 738 * If we previously sent an IPI to the target CPU & it hasn't
>> 739 * cleared its bit in the busy cpumask then it didn't handle
>> 740 * our previous IPI & it's not safe for us to reuse the
>> 741 * call_single_data_t.
>> 742 */
>> 743 if (cpumask_test_and_set_cpu(cpu, &backtrace_csd_busy)) {
>> 744 pr_warn("Unable to send backtrace IPI to CPU%u - perhaps it hung?\n",
>> 745 cpu);
>> 746 continue;
>> 747 }
>> 748
>> 749 csd = &per_cpu(backtrace_csd, cpu);
>> 750 smp_call_function_single_async(cpu, csd);
>> 751 }
>> 752 }
>> 753
>> 754 void arch_trigger_cpumask_backtrace(const cpumask_t *mask, int exclude_cpu)
>> 755 {
>> 756 nmi_trigger_cpumask_backtrace(mask, exclude_cpu, raise_backtrace);
>> 757 }
>> 758
>> 759 int mips_get_process_fp_mode(struct task_struct *task)
>> 760 {
>> 761 int value = 0;
>> 762
>> 763 if (!test_tsk_thread_flag(task, TIF_32BIT_FPREGS))
>> 764 value |= PR_FP_MODE_FR;
>> 765 if (test_tsk_thread_flag(task, TIF_HYBRID_FPREGS))
>> 766 value |= PR_FP_MODE_FRE;
>> 767
>> 768 return value;
>> 769 }
200 770
>> 771 static long prepare_for_fp_mode_switch(void *unused)
>> 772 {
>> 773 /*
>> 774 * This is icky, but we use this to simply ensure that all CPUs have
>> 775 * context switched, regardless of whether they were previously running
>> 776 * kernel or user code. This ensures that no CPU that a mode-switching
>> 777 * program may execute on keeps its FPU enabled (& in the old mode)
>> 778 * throughout the mode switch.
>> 779 */
201 return 0; 780 return 0;
202 } 781 }
203 782
204 int copy_thread(struct task_struct *p, const s !! 783 int mips_set_process_fp_mode(struct task_struct *task, unsigned int value)
205 { 784 {
206 unsigned long clone_flags = args->flag !! 785 const unsigned int known_bits = PR_FP_MODE_FR | PR_FP_MODE_FRE;
207 unsigned long usp = args->stack; !! 786 struct task_struct *t;
208 unsigned long tls = args->tls; !! 787 struct cpumask process_cpus;
209 struct pt_regs *childregs = task_pt_re !! 788 int cpu;
>> 789
>> 790 /* If nothing to change, return right away, successfully. */
>> 791 if (value == mips_get_process_fp_mode(task))
>> 792 return 0;
>> 793
>> 794 /* Only accept a mode change if 64-bit FP enabled for o32. */
>> 795 if (!IS_ENABLED(CONFIG_MIPS_O32_FP64_SUPPORT))
>> 796 return -EOPNOTSUPP;
>> 797
>> 798 /* And only for o32 tasks. */
>> 799 if (IS_ENABLED(CONFIG_64BIT) && !test_thread_flag(TIF_32BIT_REGS))
>> 800 return -EOPNOTSUPP;
>> 801
>> 802 /* Check the value is valid */
>> 803 if (value & ~known_bits)
>> 804 return -EOPNOTSUPP;
>> 805
>> 806 /* Setting FRE without FR is not supported. */
>> 807 if ((value & (PR_FP_MODE_FR | PR_FP_MODE_FRE)) == PR_FP_MODE_FRE)
>> 808 return -EOPNOTSUPP;
>> 809
>> 810 /* Avoid inadvertently triggering emulation */
>> 811 if ((value & PR_FP_MODE_FR) && raw_cpu_has_fpu &&
>> 812 !(raw_current_cpu_data.fpu_id & MIPS_FPIR_F64))
>> 813 return -EOPNOTSUPP;
>> 814 if ((value & PR_FP_MODE_FRE) && raw_cpu_has_fpu && !cpu_has_fre)
>> 815 return -EOPNOTSUPP;
>> 816
>> 817 /* FR = 0 not supported in MIPS R6 */
>> 818 if (!(value & PR_FP_MODE_FR) && raw_cpu_has_fpu && cpu_has_mips_r6)
>> 819 return -EOPNOTSUPP;
>> 820
>> 821 /* Indicate the new FP mode in each thread */
>> 822 for_each_thread(task, t) {
>> 823 /* Update desired FP register width */
>> 824 if (value & PR_FP_MODE_FR) {
>> 825 clear_tsk_thread_flag(t, TIF_32BIT_FPREGS);
>> 826 } else {
>> 827 set_tsk_thread_flag(t, TIF_32BIT_FPREGS);
>> 828 clear_tsk_thread_flag(t, TIF_MSA_CTX_LIVE);
>> 829 }
>> 830
>> 831 /* Update desired FP single layout */
>> 832 if (value & PR_FP_MODE_FRE)
>> 833 set_tsk_thread_flag(t, TIF_HYBRID_FPREGS);
>> 834 else
>> 835 clear_tsk_thread_flag(t, TIF_HYBRID_FPREGS);
>> 836 }
210 837
211 memset(&p->thread.s, 0, sizeof(p->thre !! 838 /*
>> 839 * We need to ensure that all threads in the process have switched mode
>> 840 * before returning, in order to allow userland to not worry about
>> 841 * races. We can do this by forcing all CPUs that any thread in the
>> 842 * process may be running on to schedule something else - in this case
>> 843 * prepare_for_fp_mode_switch().
>> 844 *
>> 845 * We begin by generating a mask of all CPUs that any thread in the
>> 846 * process may be running on.
>> 847 */
>> 848 cpumask_clear(&process_cpus);
>> 849 for_each_thread(task, t)
>> 850 cpumask_set_cpu(task_cpu(t), &process_cpus);
212 851
213 /* p->thread holds context to be resto !! 852 /*
214 if (unlikely(args->fn)) { !! 853 * Now we schedule prepare_for_fp_mode_switch() on each of those CPUs.
215 /* Kernel thread */ !! 854 *
216 memset(childregs, 0, sizeof(st !! 855 * The CPUs may have rescheduled already since we switched mode or
217 /* Supervisor/Machine, irqs on !! 856 * generated the cpumask, but that doesn't matter. If the task in this
218 childregs->status = SR_PP | SR !! 857 * process is scheduled out then our scheduling
>> 858 * prepare_for_fp_mode_switch() will simply be redundant. If it's
>> 859 * scheduled in then it will already have picked up the new FP mode
>> 860 * whilst doing so.
>> 861 */
>> 862 cpus_read_lock();
>> 863 for_each_cpu_and(cpu, &process_cpus, cpu_online_mask)
>> 864 work_on_cpu(cpu, prepare_for_fp_mode_switch, NULL);
>> 865 cpus_read_unlock();
219 866
220 p->thread.s[0] = (unsigned lon <<
221 p->thread.s[1] = (unsigned lon <<
222 } else { <<
223 *childregs = *(current_pt_regs <<
224 /* Turn off status.VS */ <<
225 riscv_v_vstate_off(childregs); <<
226 if (usp) /* User fork */ <<
227 childregs->sp = usp; <<
228 if (clone_flags & CLONE_SETTLS <<
229 childregs->tp = tls; <<
230 childregs->a0 = 0; /* Return v <<
231 p->thread.s[0] = 0; <<
232 } <<
233 p->thread.riscv_v_flags = 0; <<
234 if (has_vector()) <<
235 riscv_v_thread_alloc(p); <<
236 p->thread.ra = (unsigned long)ret_from <<
237 p->thread.sp = (unsigned long)childreg <<
238 return 0; 867 return 0;
239 } 868 }
240 869
241 void __init arch_task_cache_init(void) !! 870 #if defined(CONFIG_32BIT) || defined(CONFIG_MIPS32_O32)
>> 871 void mips_dump_regs32(u32 *uregs, const struct pt_regs *regs)
>> 872 {
>> 873 unsigned int i;
>> 874
>> 875 for (i = MIPS32_EF_R1; i <= MIPS32_EF_R31; i++) {
>> 876 /* k0/k1 are copied as zero. */
>> 877 if (i == MIPS32_EF_R26 || i == MIPS32_EF_R27)
>> 878 uregs[i] = 0;
>> 879 else
>> 880 uregs[i] = regs->regs[i - MIPS32_EF_R0];
>> 881 }
>> 882
>> 883 uregs[MIPS32_EF_LO] = regs->lo;
>> 884 uregs[MIPS32_EF_HI] = regs->hi;
>> 885 uregs[MIPS32_EF_CP0_EPC] = regs->cp0_epc;
>> 886 uregs[MIPS32_EF_CP0_BADVADDR] = regs->cp0_badvaddr;
>> 887 uregs[MIPS32_EF_CP0_STATUS] = regs->cp0_status;
>> 888 uregs[MIPS32_EF_CP0_CAUSE] = regs->cp0_cause;
>> 889 }
>> 890 #endif /* CONFIG_32BIT || CONFIG_MIPS32_O32 */
>> 891
>> 892 #ifdef CONFIG_64BIT
>> 893 void mips_dump_regs64(u64 *uregs, const struct pt_regs *regs)
242 { 894 {
243 riscv_v_setup_ctx_cache(); !! 895 unsigned int i;
>> 896
>> 897 for (i = MIPS64_EF_R1; i <= MIPS64_EF_R31; i++) {
>> 898 /* k0/k1 are copied as zero. */
>> 899 if (i == MIPS64_EF_R26 || i == MIPS64_EF_R27)
>> 900 uregs[i] = 0;
>> 901 else
>> 902 uregs[i] = regs->regs[i - MIPS64_EF_R0];
>> 903 }
>> 904
>> 905 uregs[MIPS64_EF_LO] = regs->lo;
>> 906 uregs[MIPS64_EF_HI] = regs->hi;
>> 907 uregs[MIPS64_EF_CP0_EPC] = regs->cp0_epc;
>> 908 uregs[MIPS64_EF_CP0_BADVADDR] = regs->cp0_badvaddr;
>> 909 uregs[MIPS64_EF_CP0_STATUS] = regs->cp0_status;
>> 910 uregs[MIPS64_EF_CP0_CAUSE] = regs->cp0_cause;
244 } 911 }
>> 912 #endif /* CONFIG_64BIT */
245 913
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.