1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 *  Derived from "arch/i386/kernel/process.c"
   4 *    Copyright (C) 1995  Linus Torvalds
   5 *
   6 *  Updated and modified by Cort Dougan (cort@cs.nmt.edu) and
   7 *  Paul Mackerras (paulus@cs.anu.edu.au)
   8 *
   9 *  PowerPC version
  10 *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
  11 */
  12
  13#include <linux/errno.h>
  14#include <linux/sched.h>
  15#include <linux/sched/debug.h>
  16#include <linux/sched/task.h>
  17#include <linux/sched/task_stack.h>
  18#include <linux/kernel.h>
  19#include <linux/mm.h>
  20#include <linux/smp.h>
  21#include <linux/stddef.h>
  22#include <linux/unistd.h>
  23#include <linux/ptrace.h>
  24#include <linux/slab.h>
  25#include <linux/user.h>
  26#include <linux/elf.h>
  27#include <linux/prctl.h>
  28#include <linux/init_task.h>
  29#include <linux/export.h>
  30#include <linux/kallsyms.h>
  31#include <linux/mqueue.h>
  32#include <linux/hardirq.h>
  33#include <linux/utsname.h>
  34#include <linux/ftrace.h>
  35#include <linux/kernel_stat.h>
  36#include <linux/personality.h>
  37#include <linux/hw_breakpoint.h>
  38#include <linux/uaccess.h>
  39#include <linux/pkeys.h>
  40#include <linux/seq_buf.h>
  41
  42#include <asm/interrupt.h>
  43#include <asm/io.h>
  44#include <asm/processor.h>
  45#include <asm/mmu.h>
  46#include <asm/machdep.h>
  47#include <asm/time.h>
  48#include <asm/runlatch.h>
  49#include <asm/syscalls.h>
  50#include <asm/switch_to.h>
  51#include <asm/tm.h>
  52#include <asm/debug.h>
  53#ifdef CONFIG_PPC64
  54#include <asm/firmware.h>
  55#include <asm/hw_irq.h>
  56#endif
  57#include <asm/code-patching.h>
  58#include <asm/exec.h>
  59#include <asm/livepatch.h>
  60#include <asm/cpu_has_feature.h>
  61#include <asm/asm-prototypes.h>
  62#include <asm/stacktrace.h>
  63#include <asm/hw_breakpoint.h>
  64
  65#include <linux/kprobes.h>
  66#include <linux/kdebug.h>
  67
  68/* Transactional Memory debug */
  69#ifdef TM_DEBUG_SW
  70#define TM_DEBUG(x...) printk(KERN_INFO x)
  71#else
  72#define TM_DEBUG(x...) do { } while(0)
  73#endif
  74
  75extern unsigned long _get_SP(void);
  76
  77#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
  78/*
  79 * Are we running in "Suspend disabled" mode? If so we have to block any
  80 * sigreturn that would get us into suspended state, and we also warn in some
  81 * other paths that we should never reach with suspend disabled.
  82 */
  83bool tm_suspend_disabled __ro_after_init = false;
  84
  85static void check_if_tm_restore_required(struct task_struct *tsk)
  86{
  87	/*
  88	 * If we are saving the current thread's registers, and the
  89	 * thread is in a transactional state, set the TIF_RESTORE_TM
  90	 * bit so that we know to restore the registers before
  91	 * returning to userspace.
  92	 */
  93	if (tsk == current && tsk->thread.regs &&
  94	    MSR_TM_ACTIVE(tsk->thread.regs->msr) &&
  95	    !test_thread_flag(TIF_RESTORE_TM)) {
  96		regs_set_return_msr(&tsk->thread.ckpt_regs,
  97						tsk->thread.regs->msr);
  98		set_thread_flag(TIF_RESTORE_TM);
  99	}
 100}
 101
 102#else
 103static inline void check_if_tm_restore_required(struct task_struct *tsk) { }
 104#endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
 105
 106bool strict_msr_control;
 107EXPORT_SYMBOL(strict_msr_control);
 108
 109static int __init enable_strict_msr_control(char *str)
 110{
 111	strict_msr_control = true;
 112	pr_info("Enabling strict facility control\n");
 113
 114	return 0;
 115}
 116early_param("ppc_strict_facility_enable", enable_strict_msr_control);
 117
 118/* notrace because it's called by restore_math */
 119unsigned long notrace msr_check_and_set(unsigned long bits)
 120{
 121	unsigned long oldmsr = mfmsr();
 122	unsigned long newmsr;
 123
 124	newmsr = oldmsr | bits;
 125
 126	if (cpu_has_feature(CPU_FTR_VSX) && (bits & MSR_FP))
 127		newmsr |= MSR_VSX;
 128
 129	if (oldmsr != newmsr)
 130		newmsr = mtmsr_isync_irqsafe(newmsr);
 131
 132	return newmsr;
 133}
 134EXPORT_SYMBOL_GPL(msr_check_and_set);
 135
 136/* notrace because it's called by restore_math */
 137void notrace __msr_check_and_clear(unsigned long bits)
 138{
 139	unsigned long oldmsr = mfmsr();
 140	unsigned long newmsr;
 141
 142	newmsr = oldmsr & ~bits;
 143
 144	if (cpu_has_feature(CPU_FTR_VSX) && (bits & MSR_FP))
 145		newmsr &= ~MSR_VSX;
 146
 147	if (oldmsr != newmsr)
 148		mtmsr_isync_irqsafe(newmsr);
 149}
 150EXPORT_SYMBOL(__msr_check_and_clear);
 151
 152#ifdef CONFIG_PPC_FPU
 153static void __giveup_fpu(struct task_struct *tsk)
 154{
 155	unsigned long msr;
 156
 157	save_fpu(tsk);
 158	msr = tsk->thread.regs->msr;
 159	msr &= ~(MSR_FP|MSR_FE0|MSR_FE1);
 160	if (cpu_has_feature(CPU_FTR_VSX))
 161		msr &= ~MSR_VSX;
 162	regs_set_return_msr(tsk->thread.regs, msr);
 163}
 164
 165void giveup_fpu(struct task_struct *tsk)
 166{
 167	check_if_tm_restore_required(tsk);
 168
 169	msr_check_and_set(MSR_FP);
 170	__giveup_fpu(tsk);
 171	msr_check_and_clear(MSR_FP);
 172}
 173EXPORT_SYMBOL(giveup_fpu);
 174
 175/*
 176 * Make sure the floating-point register state in the
 177 * the thread_struct is up to date for task tsk.
 178 */
 179void flush_fp_to_thread(struct task_struct *tsk)
 180{
 181	if (tsk->thread.regs) {
 182		/*
 183		 * We need to disable preemption here because if we didn't,
 184		 * another process could get scheduled after the regs->msr
 185		 * test but before we have finished saving the FP registers
 186		 * to the thread_struct.  That process could take over the
 187		 * FPU, and then when we get scheduled again we would store
 188		 * bogus values for the remaining FP registers.
 189		 */
 190		preempt_disable();
 191		if (tsk->thread.regs->msr & MSR_FP) {
 192			/*
 193			 * This should only ever be called for current or
 194			 * for a stopped child process.  Since we save away
 195			 * the FP register state on context switch,
 196			 * there is something wrong if a stopped child appears
 197			 * to still have its FP state in the CPU registers.
 198			 */
 199			BUG_ON(tsk != current);
 200			giveup_fpu(tsk);
 201		}
 202		preempt_enable();
 203	}
 204}
 205EXPORT_SYMBOL_GPL(flush_fp_to_thread);
 206
 207void enable_kernel_fp(void)
 208{
 209	unsigned long cpumsr;
 210
 211	WARN_ON(preemptible());
 212
 213	cpumsr = msr_check_and_set(MSR_FP);
 214
 215	if (current->thread.regs && (current->thread.regs->msr & MSR_FP)) {
 216		check_if_tm_restore_required(current);
 217		/*
 218		 * If a thread has already been reclaimed then the
 219		 * checkpointed registers are on the CPU but have definitely
 220		 * been saved by the reclaim code. Don't need to and *cannot*
 221		 * giveup as this would save  to the 'live' structure not the
 222		 * checkpointed structure.
 223		 */
 224		if (!MSR_TM_ACTIVE(cpumsr) &&
 225		     MSR_TM_ACTIVE(current->thread.regs->msr))
 226			return;
 227		__giveup_fpu(current);
 228	}
 229}
 230EXPORT_SYMBOL(enable_kernel_fp);
 231#else
 232static inline void __giveup_fpu(struct task_struct *tsk) { }
 233#endif /* CONFIG_PPC_FPU */
 234
 235#ifdef CONFIG_ALTIVEC
 236static void __giveup_altivec(struct task_struct *tsk)
 237{
 238	unsigned long msr;
 239
 240	save_altivec(tsk);
 241	msr = tsk->thread.regs->msr;
 242	msr &= ~MSR_VEC;
 243	if (cpu_has_feature(CPU_FTR_VSX))
 244		msr &= ~MSR_VSX;
 245	regs_set_return_msr(tsk->thread.regs, msr);
 246}
 247
 248void giveup_altivec(struct task_struct *tsk)
 249{
 250	check_if_tm_restore_required(tsk);
 251
 252	msr_check_and_set(MSR_VEC);
 253	__giveup_altivec(tsk);
 254	msr_check_and_clear(MSR_VEC);
 255}
 256EXPORT_SYMBOL(giveup_altivec);
 257
 258void enable_kernel_altivec(void)
 259{
 260	unsigned long cpumsr;
 261
 262	WARN_ON(preemptible());
 263
 264	cpumsr = msr_check_and_set(MSR_VEC);
 265
 266	if (current->thread.regs && (current->thread.regs->msr & MSR_VEC)) {
 267		check_if_tm_restore_required(current);
 268		/*
 269		 * If a thread has already been reclaimed then the
 270		 * checkpointed registers are on the CPU but have definitely
 271		 * been saved by the reclaim code. Don't need to and *cannot*
 272		 * giveup as this would save  to the 'live' structure not the
 273		 * checkpointed structure.
 274		 */
 275		if (!MSR_TM_ACTIVE(cpumsr) &&
 276		     MSR_TM_ACTIVE(current->thread.regs->msr))
 277			return;
 278		__giveup_altivec(current);
 279	}
 280}
 281EXPORT_SYMBOL(enable_kernel_altivec);
 282
 283/*
 284 * Make sure the VMX/Altivec register state in the
 285 * the thread_struct is up to date for task tsk.
 286 */
 287void flush_altivec_to_thread(struct task_struct *tsk)
 288{
 289	if (tsk->thread.regs) {
 290		preempt_disable();
 291		if (tsk->thread.regs->msr & MSR_VEC) {
 292			BUG_ON(tsk != current);
 293			giveup_altivec(tsk);
 294		}
 295		preempt_enable();
 296	}
 297}
 298EXPORT_SYMBOL_GPL(flush_altivec_to_thread);
 299#endif /* CONFIG_ALTIVEC */
 300
 301#ifdef CONFIG_VSX
 302static void __giveup_vsx(struct task_struct *tsk)
 303{
 304	unsigned long msr = tsk->thread.regs->msr;
 305
 306	/*
 307	 * We should never be setting MSR_VSX without also setting
 308	 * MSR_FP and MSR_VEC
 309	 */
 310	WARN_ON((msr & MSR_VSX) && !((msr & MSR_FP) && (msr & MSR_VEC)));
 311
 312	/* __giveup_fpu will clear MSR_VSX */
 313	if (msr & MSR_FP)
 314		__giveup_fpu(tsk);
 315	if (msr & MSR_VEC)
 316		__giveup_altivec(tsk);
 317}
 318
 319static void giveup_vsx(struct task_struct *tsk)
 320{
 321	check_if_tm_restore_required(tsk);
 322
 323	msr_check_and_set(MSR_FP|MSR_VEC|MSR_VSX);
 324	__giveup_vsx(tsk);
 325	msr_check_and_clear(MSR_FP|MSR_VEC|MSR_VSX);
 326}
 327
 328void enable_kernel_vsx(void)
 329{
 330	unsigned long cpumsr;
 331
 332	WARN_ON(preemptible());
 333
 334	cpumsr = msr_check_and_set(MSR_FP|MSR_VEC|MSR_VSX);
 335
 336	if (current->thread.regs &&
 337	    (current->thread.regs->msr & (MSR_VSX|MSR_VEC|MSR_FP))) {
 338		check_if_tm_restore_required(current);
 339		/*
 340		 * If a thread has already been reclaimed then the
 341		 * checkpointed registers are on the CPU but have definitely
 342		 * been saved by the reclaim code. Don't need to and *cannot*
 343		 * giveup as this would save  to the 'live' structure not the
 344		 * checkpointed structure.
 345		 */
 346		if (!MSR_TM_ACTIVE(cpumsr) &&
 347		     MSR_TM_ACTIVE(current->thread.regs->msr))
 348			return;
 349		__giveup_vsx(current);
 350	}
 351}
 352EXPORT_SYMBOL(enable_kernel_vsx);
 353
 354void flush_vsx_to_thread(struct task_struct *tsk)
 355{
 356	if (tsk->thread.regs) {
 357		preempt_disable();
 358		if (tsk->thread.regs->msr & (MSR_VSX|MSR_VEC|MSR_FP)) {
 359			BUG_ON(tsk != current);
 360			giveup_vsx(tsk);
 361		}
 362		preempt_enable();
 363	}
 364}
 365EXPORT_SYMBOL_GPL(flush_vsx_to_thread);
 366#endif /* CONFIG_VSX */
 367
 368#ifdef CONFIG_SPE
 369void giveup_spe(struct task_struct *tsk)
 370{
 371	check_if_tm_restore_required(tsk);
 372
 373	msr_check_and_set(MSR_SPE);
 374	__giveup_spe(tsk);
 375	msr_check_and_clear(MSR_SPE);
 376}
 377EXPORT_SYMBOL(giveup_spe);
 378
 379void enable_kernel_spe(void)
 380{
 381	WARN_ON(preemptible());
 382
 383	msr_check_and_set(MSR_SPE);
 384
 385	if (current->thread.regs && (current->thread.regs->msr & MSR_SPE)) {
 386		check_if_tm_restore_required(current);
 387		__giveup_spe(current);
 388	}
 389}
 390EXPORT_SYMBOL(enable_kernel_spe);
 391
 392void flush_spe_to_thread(struct task_struct *tsk)
 393{
 394	if (tsk->thread.regs) {
 395		preempt_disable();
 396		if (tsk->thread.regs->msr & MSR_SPE) {
 397			BUG_ON(tsk != current);
 398			tsk->thread.spefscr = mfspr(SPRN_SPEFSCR);
 399			giveup_spe(tsk);
 400		}
 401		preempt_enable();
 402	}
 403}
 404#endif /* CONFIG_SPE */
 405
 406static unsigned long msr_all_available;
 407
 408static int __init init_msr_all_available(void)
 409{
 410	if (IS_ENABLED(CONFIG_PPC_FPU))
 411		msr_all_available |= MSR_FP;
 412	if (cpu_has_feature(CPU_FTR_ALTIVEC))
 413		msr_all_available |= MSR_VEC;
 414	if (cpu_has_feature(CPU_FTR_VSX))
 415		msr_all_available |= MSR_VSX;
 416	if (cpu_has_feature(CPU_FTR_SPE))
 417		msr_all_available |= MSR_SPE;
 418
 419	return 0;
 420}
 421early_initcall(init_msr_all_available);
 422
 423void giveup_all(struct task_struct *tsk)
 424{
 425	unsigned long usermsr;
 426
 427	if (!tsk->thread.regs)
 428		return;
 429
 430	check_if_tm_restore_required(tsk);
 431
 432	usermsr = tsk->thread.regs->msr;
 433
 434	if ((usermsr & msr_all_available) == 0)
 435		return;
 436
 437	msr_check_and_set(msr_all_available);
 438
 439	WARN_ON((usermsr & MSR_VSX) && !((usermsr & MSR_FP) && (usermsr & MSR_VEC)));
 440
 441	if (usermsr & MSR_FP)
 442		__giveup_fpu(tsk);
 443	if (usermsr & MSR_VEC)
 444		__giveup_altivec(tsk);
 445	if (usermsr & MSR_SPE)
 446		__giveup_spe(tsk);
 447
 448	msr_check_and_clear(msr_all_available);
 449}
 450EXPORT_SYMBOL(giveup_all);
 451
 452#ifdef CONFIG_PPC_BOOK3S_64
 453#ifdef CONFIG_PPC_FPU
 454static bool should_restore_fp(void)
 455{
 456	if (current->thread.load_fp) {
 457		current->thread.load_fp++;
 458		return true;
 459	}
 460	return false;
 461}
 462
 463static void do_restore_fp(void)
 464{
 465	load_fp_state(&current->thread.fp_state);
 466}
 467#else
 468static bool should_restore_fp(void) { return false; }
 469static void do_restore_fp(void) { }
 470#endif /* CONFIG_PPC_FPU */
 471
 472#ifdef CONFIG_ALTIVEC
 473static bool should_restore_altivec(void)
 474{
 475	if (cpu_has_feature(CPU_FTR_ALTIVEC) && (current->thread.load_vec)) {
 476		current->thread.load_vec++;
 477		return true;
 478	}
 479	return false;
 480}
 481
 482static void do_restore_altivec(void)
 483{
 484	load_vr_state(&current->thread.vr_state);
 485	current->thread.used_vr = 1;
 486}
 487#else
 488static bool should_restore_altivec(void) { return false; }
 489static void do_restore_altivec(void) { }
 490#endif /* CONFIG_ALTIVEC */
 491
 492static bool should_restore_vsx(void)
 493{
 494	if (cpu_has_feature(CPU_FTR_VSX))
 495		return true;
 496	return false;
 497}
 498#ifdef CONFIG_VSX
 499static void do_restore_vsx(void)
 500{
 501	current->thread.used_vsr = 1;
 502}
 503#else
 504static void do_restore_vsx(void) { }
 505#endif /* CONFIG_VSX */
 506
 507/*
 508 * The exception exit path calls restore_math() with interrupts hard disabled
 509 * but the soft irq state not "reconciled". ftrace code that calls
 510 * local_irq_save/restore causes warnings.
 511 *
 512 * Rather than complicate the exit path, just don't trace restore_math. This
 513 * could be done by having ftrace entry code check for this un-reconciled
 514 * condition where MSR[EE]=0 and PACA_IRQ_HARD_DIS is not set, and
 515 * temporarily fix it up for the duration of the ftrace call.
 516 */
 517void notrace restore_math(struct pt_regs *regs)
 518{
 519	unsigned long msr;
 520	unsigned long new_msr = 0;
 521
 522	msr = regs->msr;
 523
 524	/*
 525	 * new_msr tracks the facilities that are to be restored. Only reload
 526	 * if the bit is not set in the user MSR (if it is set, the registers
 527	 * are live for the user thread).
 528	 */
 529	if ((!(msr & MSR_FP)) && should_restore_fp())
 530		new_msr |= MSR_FP;
 531
 532	if ((!(msr & MSR_VEC)) && should_restore_altivec())
 533		new_msr |= MSR_VEC;
 534
 535	if ((!(msr & MSR_VSX)) && should_restore_vsx()) {
 536		if (((msr | new_msr) & (MSR_FP | MSR_VEC)) == (MSR_FP | MSR_VEC))
 537			new_msr |= MSR_VSX;
 538	}
 539
 540	if (new_msr) {
 541		unsigned long fpexc_mode = 0;
 542
 543		msr_check_and_set(new_msr);
 544
 545		if (new_msr & MSR_FP) {
 546			do_restore_fp();
 547
 548			// This also covers VSX, because VSX implies FP
 549			fpexc_mode = current->thread.fpexc_mode;
 550		}
 551
 552		if (new_msr & MSR_VEC)
 553			do_restore_altivec();
 554
 555		if (new_msr & MSR_VSX)
 556			do_restore_vsx();
 557
 558		msr_check_and_clear(new_msr);
 559
 560		regs_set_return_msr(regs, regs->msr | new_msr | fpexc_mode);
 561	}
 562}
 563#endif /* CONFIG_PPC_BOOK3S_64 */
 564
 565static void save_all(struct task_struct *tsk)
 566{
 567	unsigned long usermsr;
 568
 569	if (!tsk->thread.regs)
 570		return;
 571
 572	usermsr = tsk->thread.regs->msr;
 573
 574	if ((usermsr & msr_all_available) == 0)
 575		return;
 576
 577	msr_check_and_set(msr_all_available);
 578
 579	WARN_ON((usermsr & MSR_VSX) && !((usermsr & MSR_FP) && (usermsr & MSR_VEC)));
 580
 581	if (usermsr & MSR_FP)
 582		save_fpu(tsk);
 583
 584	if (usermsr & MSR_VEC)
 585		save_altivec(tsk);
 586
 587	if (usermsr & MSR_SPE)
 588		__giveup_spe(tsk);
 589
 590	msr_check_and_clear(msr_all_available);
 591}
 592
 593void flush_all_to_thread(struct task_struct *tsk)
 594{
 595	if (tsk->thread.regs) {
 596		preempt_disable();
 597		BUG_ON(tsk != current);
 598#ifdef CONFIG_SPE
 599		if (tsk->thread.regs->msr & MSR_SPE)
 600			tsk->thread.spefscr = mfspr(SPRN_SPEFSCR);
 601#endif
 602		save_all(tsk);
 603
 604		preempt_enable();
 605	}
 606}
 607EXPORT_SYMBOL(flush_all_to_thread);
 608
 609#ifdef CONFIG_PPC_ADV_DEBUG_REGS
 610void do_send_trap(struct pt_regs *regs, unsigned long address,
 611		  unsigned long error_code, int breakpt)
 612{
 613	current->thread.trap_nr = TRAP_HWBKPT;
 614	if (notify_die(DIE_DABR_MATCH, "dabr_match", regs, error_code,
 615			11, SIGSEGV) == NOTIFY_STOP)
 616		return;
 617
 618	/* Deliver the signal to userspace */
 619	force_sig_ptrace_errno_trap(breakpt, /* breakpoint or watchpoint id */
 620				    (void __user *)address);
 621}
 622#else	/* !CONFIG_PPC_ADV_DEBUG_REGS */
 623
 624static void do_break_handler(struct pt_regs *regs)
 625{
 626	struct arch_hw_breakpoint null_brk = {0};
 627	struct arch_hw_breakpoint *info;
 628	ppc_inst_t instr = ppc_inst(0);
 629	int type = 0;
 630	int size = 0;
 631	unsigned long ea;
 632	int i;
 633
 634	/*
 635	 * If underneath hw supports only one watchpoint, we know it
 636	 * caused exception. 8xx also falls into this category.
 637	 */
 638	if (nr_wp_slots() == 1) {
 639		__set_breakpoint(0, &null_brk);
 640		current->thread.hw_brk[0] = null_brk;
 641		current->thread.hw_brk[0].flags |= HW_BRK_FLAG_DISABLED;
 642		return;
 643	}
 644
 645	/* Otherwise find out which DAWR caused exception and disable it. */
 646	wp_get_instr_detail(regs, &instr, &type, &size, &ea);
 647
 648	for (i = 0; i < nr_wp_slots(); i++) {
 649		info = &current->thread.hw_brk[i];
 650		if (!info->address)
 651			continue;
 652
 653		if (wp_check_constraints(regs, instr, ea, type, size, info)) {
 654			__set_breakpoint(i, &null_brk);
 655			current->thread.hw_brk[i] = null_brk;
 656			current->thread.hw_brk[i].flags |= HW_BRK_FLAG_DISABLED;
 657		}
 658	}
 659}
 660
 661DEFINE_INTERRUPT_HANDLER(do_break)
 662{
 663	current->thread.trap_nr = TRAP_HWBKPT;
 664	if (notify_die(DIE_DABR_MATCH, "dabr_match", regs, regs->dsisr,
 665			11, SIGSEGV) == NOTIFY_STOP)
 666		return;
 667
 668	if (debugger_break_match(regs))
 669		return;
 670
 671	/*
 672	 * We reach here only when watchpoint exception is generated by ptrace
 673	 * event (or hw is buggy!). Now if CONFIG_HAVE_HW_BREAKPOINT is set,
 674	 * watchpoint is already handled by hw_breakpoint_handler() so we don't
 675	 * have to do anything. But when CONFIG_HAVE_HW_BREAKPOINT is not set,
 676	 * we need to manually handle the watchpoint here.
 677	 */
 678	if (!IS_ENABLED(CONFIG_HAVE_HW_BREAKPOINT))
 679		do_break_handler(regs);
 680
 681	/* Deliver the signal to userspace */
 682	force_sig_fault(SIGTRAP, TRAP_HWBKPT, (void __user *)regs->dar);
 683}
 684#endif	/* CONFIG_PPC_ADV_DEBUG_REGS */
 685
 686static DEFINE_PER_CPU(struct arch_hw_breakpoint, current_brk[HBP_NUM_MAX]);
 687
 688#ifdef CONFIG_PPC_ADV_DEBUG_REGS
 689/*
 690 * Set the debug registers back to their default "safe" values.
 691 */
 692static void set_debug_reg_defaults(struct thread_struct *thread)
 693{
 694	thread->debug.iac1 = thread->debug.iac2 = 0;
 695#if CONFIG_PPC_ADV_DEBUG_IACS > 2
 696	thread->debug.iac3 = thread->debug.iac4 = 0;
 697#endif
 698	thread->debug.dac1 = thread->debug.dac2 = 0;
 699#if CONFIG_PPC_ADV_DEBUG_DVCS > 0
 700	thread->debug.dvc1 = thread->debug.dvc2 = 0;
 701#endif
 702	thread->debug.dbcr0 = 0;
 703#ifdef CONFIG_BOOKE
 704	/*
 705	 * Force User/Supervisor bits to b11 (user-only MSR[PR]=1)
 706	 */
 707	thread->debug.dbcr1 = DBCR1_IAC1US | DBCR1_IAC2US |
 708			DBCR1_IAC3US | DBCR1_IAC4US;
 709	/*
 710	 * Force Data Address Compare User/Supervisor bits to be User-only
 711	 * (0b11 MSR[PR]=1) and set all other bits in DBCR2 register to be 0.
 712	 */
 713	thread->debug.dbcr2 = DBCR2_DAC1US | DBCR2_DAC2US;
 714#else
 715	thread->debug.dbcr1 = 0;
 716#endif
 717}
 718
 719static void prime_debug_regs(struct debug_reg *debug)
 720{
 721	/*
 722	 * We could have inherited MSR_DE from userspace, since
 723	 * it doesn't get cleared on exception entry.  Make sure
 724	 * MSR_DE is clear before we enable any debug events.
 725	 */
 726	mtmsr(mfmsr() & ~MSR_DE);
 727
 728	mtspr(SPRN_IAC1, debug->iac1);
 729	mtspr(SPRN_IAC2, debug->iac2);
 730#if CONFIG_PPC_ADV_DEBUG_IACS > 2
 731	mtspr(SPRN_IAC3, debug->iac3);
 732	mtspr(SPRN_IAC4, debug->iac4);
 733#endif
 734	mtspr(SPRN_DAC1, debug->dac1);
 735	mtspr(SPRN_DAC2, debug->dac2);
 736#if CONFIG_PPC_ADV_DEBUG_DVCS > 0
 737	mtspr(SPRN_DVC1, debug->dvc1);
 738	mtspr(SPRN_DVC2, debug->dvc2);
 739#endif
 740	mtspr(SPRN_DBCR0, debug->dbcr0);
 741	mtspr(SPRN_DBCR1, debug->dbcr1);
 742#ifdef CONFIG_BOOKE
 743	mtspr(SPRN_DBCR2, debug->dbcr2);
 744#endif
 745}
 746/*
 747 * Unless neither the old or new thread are making use of the
 748 * debug registers, set the debug registers from the values
 749 * stored in the new thread.
 750 */
 751void switch_booke_debug_regs(struct debug_reg *new_debug)
 752{
 753	if ((current->thread.debug.dbcr0 & DBCR0_IDM)
 754		|| (new_debug->dbcr0 & DBCR0_IDM))
 755			prime_debug_regs(new_debug);
 756}
 757EXPORT_SYMBOL_GPL(switch_booke_debug_regs);
 758#else	/* !CONFIG_PPC_ADV_DEBUG_REGS */
 759#ifndef CONFIG_HAVE_HW_BREAKPOINT
 760static void set_breakpoint(int i, struct arch_hw_breakpoint *brk)
 761{
 762	preempt_disable();
 763	__set_breakpoint(i, brk);
 764	preempt_enable();
 765}
 766
 767static void set_debug_reg_defaults(struct thread_struct *thread)
 768{
 769	int i;
 770	struct arch_hw_breakpoint null_brk = {0};
 771
 772	for (i = 0; i < nr_wp_slots(); i++) {
 773		thread->hw_brk[i] = null_brk;
 774		if (ppc_breakpoint_available())
 775			set_breakpoint(i, &thread->hw_brk[i]);
 776	}
 777}
 778
 779static inline bool hw_brk_match(struct arch_hw_breakpoint *a,
 780				struct arch_hw_breakpoint *b)
 781{
 782	if (a->address != b->address)
 783		return false;
 784	if (a->type != b->type)
 785		return false;
 786	if (a->len != b->len)
 787		return false;
 788	/* no need to check hw_len. it's calculated from address and len */
 789	return true;
 790}
 791
 792static void switch_hw_breakpoint(struct task_struct *new)
 793{
 794	int i;
 795
 796	for (i = 0; i < nr_wp_slots(); i++) {
 797		if (likely(hw_brk_match(this_cpu_ptr(&current_brk[i]),
 798					&new->thread.hw_brk[i])))
 799			continue;
 800
 801		__set_breakpoint(i, &new->thread.hw_brk[i]);
 802	}
 803}
 804#endif /* !CONFIG_HAVE_HW_BREAKPOINT */
 805#endif	/* CONFIG_PPC_ADV_DEBUG_REGS */
 806
 807static inline int set_dabr(struct arch_hw_breakpoint *brk)
 808{
 809	unsigned long dabr, dabrx;
 810
 811	dabr = brk->address | (brk->type & HW_BRK_TYPE_DABR);
 812	dabrx = ((brk->type >> 3) & 0x7);
 813
 814	if (ppc_md.set_dabr)
 815		return ppc_md.set_dabr(dabr, dabrx);
 816
 817	if (IS_ENABLED(CONFIG_PPC_ADV_DEBUG_REGS)) {
 818		mtspr(SPRN_DAC1, dabr);
 819		if (IS_ENABLED(CONFIG_PPC_47x))
 820			isync();
 821		return 0;
 822	} else if (IS_ENABLED(CONFIG_PPC_BOOK3S)) {
 823		mtspr(SPRN_DABR, dabr);
 824		if (cpu_has_feature(CPU_FTR_DABRX))
 825			mtspr(SPRN_DABRX, dabrx);
 826		return 0;
 827	} else {
 828		return -EINVAL;
 829	}
 830}
 831
 832static inline int set_breakpoint_8xx(struct arch_hw_breakpoint *brk)
 833{
 834	unsigned long lctrl1 = LCTRL1_CTE_GT | LCTRL1_CTF_LT | LCTRL1_CRWE_RW |
 835			       LCTRL1_CRWF_RW;
 836	unsigned long lctrl2 = LCTRL2_LW0EN | LCTRL2_LW0LADC | LCTRL2_SLW0EN;
 837	unsigned long start_addr = ALIGN_DOWN(brk->address, HW_BREAKPOINT_SIZE);
 838	unsigned long end_addr = ALIGN(brk->address + brk->len, HW_BREAKPOINT_SIZE);
 839
 840	if (start_addr == 0)
 841		lctrl2 |= LCTRL2_LW0LA_F;
 842	else if (end_addr == 0)
 843		lctrl2 |= LCTRL2_LW0LA_E;
 844	else
 845		lctrl2 |= LCTRL2_LW0LA_EandF;
 846
 847	mtspr(SPRN_LCTRL2, 0);
 848
 849	if ((brk->type & HW_BRK_TYPE_RDWR) == 0)
 850		return 0;
 851
 852	if ((brk->type & HW_BRK_TYPE_RDWR) == HW_BRK_TYPE_READ)
 853		lctrl1 |= LCTRL1_CRWE_RO | LCTRL1_CRWF_RO;
 854	if ((brk->type & HW_BRK_TYPE_RDWR) == HW_BRK_TYPE_WRITE)
 855		lctrl1 |= LCTRL1_CRWE_WO | LCTRL1_CRWF_WO;
 856
 857	mtspr(SPRN_CMPE, start_addr - 1);
 858	mtspr(SPRN_CMPF, end_addr);
 859	mtspr(SPRN_LCTRL1, lctrl1);
 860	mtspr(SPRN_LCTRL2, lctrl2);
 861
 862	return 0;
 863}
 864
 865static void set_hw_breakpoint(int nr, struct arch_hw_breakpoint *brk)
 866{
 867	if (dawr_enabled())
 868		// Power8 or later
 869		set_dawr(nr, brk);
 870	else if (IS_ENABLED(CONFIG_PPC_8xx))
 871		set_breakpoint_8xx(brk);
 872	else if (!cpu_has_feature(CPU_FTR_ARCH_207S))
 873		// Power7 or earlier
 874		set_dabr(brk);
 875	else
 876		// Shouldn't happen due to higher level checks
 877		WARN_ON_ONCE(1);
 878}
 879
 880void __set_breakpoint(int nr, struct arch_hw_breakpoint *brk)
 881{
 882	memcpy(this_cpu_ptr(&current_brk[nr]), brk, sizeof(*brk));
 883	set_hw_breakpoint(nr, brk);
 884}
 885
 886/* Check if we have DAWR or DABR hardware */
 887bool ppc_breakpoint_available(void)
 888{
 889	if (dawr_enabled())
 890		return true; /* POWER8 DAWR or POWER9 forced DAWR */
 891	if (cpu_has_feature(CPU_FTR_ARCH_207S))
 892		return false; /* POWER9 with DAWR disabled */
 893	/* DABR: Everything but POWER8 and POWER9 */
 894	return true;
 895}
 896EXPORT_SYMBOL_GPL(ppc_breakpoint_available);
 897
 898/* Disable the breakpoint in hardware without touching current_brk[] */
 899void suspend_breakpoints(void)
 900{
 901	struct arch_hw_breakpoint brk = {0};
 902	int i;
 903
 904	if (!ppc_breakpoint_available())
 905		return;
 906
 907	for (i = 0; i < nr_wp_slots(); i++)
 908		set_hw_breakpoint(i, &brk);
 909}
 910
 911/*
 912 * Re-enable breakpoints suspended by suspend_breakpoints() in hardware
 913 * from current_brk[]
 914 */
 915void restore_breakpoints(void)
 916{
 917	int i;
 918
 919	if (!ppc_breakpoint_available())
 920		return;
 921
 922	for (i = 0; i < nr_wp_slots(); i++)
 923		set_hw_breakpoint(i, this_cpu_ptr(&current_brk[i]));
 924}
 925
 926#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 927
 928static inline bool tm_enabled(struct task_struct *tsk)
 929{
 930	return tsk && tsk->thread.regs && (tsk->thread.regs->msr & MSR_TM);
 931}
 932
 933static void tm_reclaim_thread(struct thread_struct *thr, uint8_t cause)
 934{
 935	/*
 936	 * Use the current MSR TM suspended bit to track if we have
 937	 * checkpointed state outstanding.
 938	 * On signal delivery, we'd normally reclaim the checkpointed
 939	 * state to obtain stack pointer (see:get_tm_stackpointer()).
 940	 * This will then directly return to userspace without going
 941	 * through __switch_to(). However, if the stack frame is bad,
 942	 * we need to exit this thread which calls __switch_to() which
 943	 * will again attempt to reclaim the already saved tm state.
 944	 * Hence we need to check that we've not already reclaimed
 945	 * this state.
 946	 * We do this using the current MSR, rather tracking it in
 947	 * some specific thread_struct bit, as it has the additional
 948	 * benefit of checking for a potential TM bad thing exception.
 949	 */
 950	if (!MSR_TM_SUSPENDED(mfmsr()))
 951		return;
 952
 953	giveup_all(container_of(thr, struct task_struct, thread));
 954
 955	tm_reclaim(thr, cause);
 956
 957	/*
 958	 * If we are in a transaction and FP is off then we can't have
 959	 * used FP inside that transaction. Hence the checkpointed
 960	 * state is the same as the live state. We need to copy the
 961	 * live state to the checkpointed state so that when the
 962	 * transaction is restored, the checkpointed state is correct
 963	 * and the aborted transaction sees the correct state. We use
 964	 * ckpt_regs.msr here as that's what tm_reclaim will use to
 965	 * determine if it's going to write the checkpointed state or
 966	 * not. So either this will write the checkpointed registers,
 967	 * or reclaim will. Similarly for VMX.
 968	 */
 969	if ((thr->ckpt_regs.msr & MSR_FP) == 0)
 970		memcpy(&thr->ckfp_state, &thr->fp_state,
 971		       sizeof(struct thread_fp_state));
 972	if ((thr->ckpt_regs.msr & MSR_VEC) == 0)
 973		memcpy(&thr->ckvr_state, &thr->vr_state,
 974		       sizeof(struct thread_vr_state));
 975}
 976
 977void tm_reclaim_current(uint8_t cause)
 978{
 979	tm_enable();
 980	tm_reclaim_thread(&current->thread, cause);
 981}
 982
 983static inline void tm_reclaim_task(struct task_struct *tsk)
 984{
 985	/* We have to work out if we're switching from/to a task that's in the
 986	 * middle of a transaction.
 987	 *
 988	 * In switching we need to maintain a 2nd register state as
 989	 * oldtask->thread.ckpt_regs.  We tm_reclaim(oldproc); this saves the
 990	 * checkpointed (tbegin) state in ckpt_regs, ckfp_state and
 991	 * ckvr_state
 992	 *
 993	 * We also context switch (save) TFHAR/TEXASR/TFIAR in here.
 994	 */
 995	struct thread_struct *thr = &tsk->thread;
 996
 997	if (!thr->regs)
 998		return;
 999
1000	if (!MSR_TM_ACTIVE(thr->regs->msr))
1001		goto out_and_saveregs;
1002
1003	WARN_ON(tm_suspend_disabled);
1004
1005	TM_DEBUG("--- tm_reclaim on pid %d (NIP=%lx, "
1006		 "ccr=%lx, msr=%lx, trap=%lx)\n",
1007		 tsk->pid, thr->regs->nip,
1008		 thr->regs->ccr, thr->regs->msr,
1009		 thr->regs->trap);
1010
1011	tm_reclaim_thread(thr, TM_CAUSE_RESCHED);
1012
1013	TM_DEBUG("--- tm_reclaim on pid %d complete\n",
1014		 tsk->pid);
1015
1016out_and_saveregs:
1017	/* Always save the regs here, even if a transaction's not active.
1018	 * This context-switches a thread's TM info SPRs.  We do it here to
1019	 * be consistent with the restore path (in recheckpoint) which
1020	 * cannot happen later in _switch().
1021	 */
1022	tm_save_sprs(thr);
1023}
1024
1025extern void __tm_recheckpoint(struct thread_struct *thread);
1026
1027void tm_recheckpoint(struct thread_struct *thread)
1028{
1029	unsigned long flags;
1030
1031	if (!(thread->regs->msr & MSR_TM))
1032		return;
1033
1034	/* We really can't be interrupted here as the TEXASR registers can't
1035	 * change and later in the trecheckpoint code, we have a userspace R1.
1036	 * So let's hard disable over this region.
1037	 */
1038	local_irq_save(flags);
1039	hard_irq_disable();
1040
1041	/* The TM SPRs are restored here, so that TEXASR.FS can be set
1042	 * before the trecheckpoint and no explosion occurs.
1043	 */
1044	tm_restore_sprs(thread);
1045
1046	__tm_recheckpoint(thread);
1047
1048	local_irq_restore(flags);
1049}
1050
1051static inline void tm_recheckpoint_new_task(struct task_struct *new)
1052{
1053	if (!cpu_has_feature(CPU_FTR_TM))
1054		return;
1055
1056	/* Recheckpoint the registers of the thread we're about to switch to.
1057	 *
1058	 * If the task was using FP, we non-lazily reload both the original and
1059	 * the speculative FP register states.  This is because the kernel
1060	 * doesn't see if/when a TM rollback occurs, so if we take an FP
1061	 * unavailable later, we are unable to determine which set of FP regs
1062	 * need to be restored.
1063	 */
1064	if (!tm_enabled(new))
1065		return;
1066
1067	if (!MSR_TM_ACTIVE(new->thread.regs->msr)){
1068		tm_restore_sprs(&new->thread);
1069		return;
1070	}
1071	/* Recheckpoint to restore original checkpointed register state. */
1072	TM_DEBUG("*** tm_recheckpoint of pid %d (new->msr 0x%lx)\n",
1073		 new->pid, new->thread.regs->msr);
1074
1075	tm_recheckpoint(&new->thread);
1076
1077	/*
1078	 * The checkpointed state has been restored but the live state has
1079	 * not, ensure all the math functionality is turned off to trigger
1080	 * restore_math() to reload.
1081	 */
1082	new->thread.regs->msr &= ~(MSR_FP | MSR_VEC | MSR_VSX);
1083
1084	TM_DEBUG("*** tm_recheckpoint of pid %d complete "
1085		 "(kernel msr 0x%lx)\n",
1086		 new->pid, mfmsr());
1087}
1088
1089static inline void __switch_to_tm(struct task_struct *prev,
1090		struct task_struct *new)
1091{
1092	if (cpu_has_feature(CPU_FTR_TM)) {
1093		if (tm_enabled(prev) || tm_enabled(new))
1094			tm_enable();
1095
1096		if (tm_enabled(prev)) {
1097			prev->thread.load_tm++;
1098			tm_reclaim_task(prev);
1099			if (!MSR_TM_ACTIVE(prev->thread.regs->msr) && prev->thread.load_tm == 0)
1100				prev->thread.regs->msr &= ~MSR_TM;
1101		}
1102
1103		tm_recheckpoint_new_task(new);
1104	}
1105}
1106
1107/*
1108 * This is called if we are on the way out to userspace and the
1109 * TIF_RESTORE_TM flag is set.  It checks if we need to reload
1110 * FP and/or vector state and does so if necessary.
1111 * If userspace is inside a transaction (whether active or
1112 * suspended) and FP/VMX/VSX instructions have ever been enabled
1113 * inside that transaction, then we have to keep them enabled
1114 * and keep the FP/VMX/VSX state loaded while ever the transaction
1115 * continues.  The reason is that if we didn't, and subsequently
1116 * got a FP/VMX/VSX unavailable interrupt inside a transaction,
1117 * we don't know whether it's the same transaction, and thus we
1118 * don't know which of the checkpointed state and the transactional
1119 * state to use.
1120 */
1121void restore_tm_state(struct pt_regs *regs)
1122{
1123	unsigned long msr_diff;
1124
1125	/*
1126	 * This is the only moment we should clear TIF_RESTORE_TM as
1127	 * it is here that ckpt_regs.msr and pt_regs.msr become the same
1128	 * again, anything else could lead to an incorrect ckpt_msr being
1129	 * saved and therefore incorrect signal contexts.
1130	 */
1131	clear_thread_flag(TIF_RESTORE_TM);
1132	if (!MSR_TM_ACTIVE(regs->msr))
1133		return;
1134
1135	msr_diff = current->thread.ckpt_regs.msr & ~regs->msr;
1136	msr_diff &= MSR_FP | MSR_VEC | MSR_VSX;
1137
1138	/* Ensure that restore_math() will restore */
1139	if (msr_diff & MSR_FP)
1140		current->thread.load_fp = 1;
1141#ifdef CONFIG_ALTIVEC
1142	if (cpu_has_feature(CPU_FTR_ALTIVEC) && msr_diff & MSR_VEC)
1143		current->thread.load_vec = 1;
1144#endif
1145	restore_math(regs);
1146
1147	regs_set_return_msr(regs, regs->msr | msr_diff);
1148}
1149
1150#else /* !CONFIG_PPC_TRANSACTIONAL_MEM */
1151#define tm_recheckpoint_new_task(new)
1152#define __switch_to_tm(prev, new)
1153void tm_reclaim_current(uint8_t cause) {}
1154#endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
1155
1156static inline void save_sprs(struct thread_struct *t)
1157{
1158#ifdef CONFIG_ALTIVEC
1159	if (cpu_has_feature(CPU_FTR_ALTIVEC))
1160		t->vrsave = mfspr(SPRN_VRSAVE);
1161#endif
1162#ifdef CONFIG_SPE
1163	if (cpu_has_feature(CPU_FTR_SPE))
1164		t->spefscr = mfspr(SPRN_SPEFSCR);
1165#endif
1166#ifdef CONFIG_PPC_BOOK3S_64
1167	if (cpu_has_feature(CPU_FTR_DSCR))
1168		t->dscr = mfspr(SPRN_DSCR);
1169
1170	if (cpu_has_feature(CPU_FTR_ARCH_207S)) {
1171		t->bescr = mfspr(SPRN_BESCR);
1172		t->ebbhr = mfspr(SPRN_EBBHR);
1173		t->ebbrr = mfspr(SPRN_EBBRR);
1174
1175		t->fscr = mfspr(SPRN_FSCR);
1176
1177		/*
1178		 * Note that the TAR is not available for use in the kernel.
1179		 * (To provide this, the TAR should be backed up/restored on
1180		 * exception entry/exit instead, and be in pt_regs.  FIXME,
1181		 * this should be in pt_regs anyway (for debug).)
1182		 */
1183		t->tar = mfspr(SPRN_TAR);
1184	}
 
 
 
 
 
 
1185#endif
1186}
1187
1188#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
1189void kvmppc_save_user_regs(void)
1190{
1191	unsigned long usermsr;
1192
1193	if (!current->thread.regs)
1194		return;
1195
1196	usermsr = current->thread.regs->msr;
1197
 
1198	if (usermsr & MSR_FP)
1199		save_fpu(current);
1200
1201	if (usermsr & MSR_VEC)
1202		save_altivec(current);
1203
1204#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1205	if (usermsr & MSR_TM) {
1206		current->thread.tm_tfhar = mfspr(SPRN_TFHAR);
1207		current->thread.tm_tfiar = mfspr(SPRN_TFIAR);
1208		current->thread.tm_texasr = mfspr(SPRN_TEXASR);
1209		current->thread.regs->msr &= ~MSR_TM;
1210	}
1211#endif
1212}
1213EXPORT_SYMBOL_GPL(kvmppc_save_user_regs);
1214
1215void kvmppc_save_current_sprs(void)
1216{
1217	save_sprs(&current->thread);
1218}
1219EXPORT_SYMBOL_GPL(kvmppc_save_current_sprs);
1220#endif /* CONFIG_KVM_BOOK3S_HV_POSSIBLE */
1221
1222static inline void restore_sprs(struct thread_struct *old_thread,
1223				struct thread_struct *new_thread)
1224{
1225#ifdef CONFIG_ALTIVEC
1226	if (cpu_has_feature(CPU_FTR_ALTIVEC) &&
1227	    old_thread->vrsave != new_thread->vrsave)
1228		mtspr(SPRN_VRSAVE, new_thread->vrsave);
1229#endif
1230#ifdef CONFIG_SPE
1231	if (cpu_has_feature(CPU_FTR_SPE) &&
1232	    old_thread->spefscr != new_thread->spefscr)
1233		mtspr(SPRN_SPEFSCR, new_thread->spefscr);
1234#endif
1235#ifdef CONFIG_PPC_BOOK3S_64
1236	if (cpu_has_feature(CPU_FTR_DSCR)) {
1237		u64 dscr = get_paca()->dscr_default;
1238		if (new_thread->dscr_inherit)
1239			dscr = new_thread->dscr;
1240
1241		if (old_thread->dscr != dscr)
1242			mtspr(SPRN_DSCR, dscr);
1243	}
1244
1245	if (cpu_has_feature(CPU_FTR_ARCH_207S)) {
1246		if (old_thread->bescr != new_thread->bescr)
1247			mtspr(SPRN_BESCR, new_thread->bescr);
1248		if (old_thread->ebbhr != new_thread->ebbhr)
1249			mtspr(SPRN_EBBHR, new_thread->ebbhr);
1250		if (old_thread->ebbrr != new_thread->ebbrr)
1251			mtspr(SPRN_EBBRR, new_thread->ebbrr);
1252
1253		if (old_thread->fscr != new_thread->fscr)
1254			mtspr(SPRN_FSCR, new_thread->fscr);
1255
1256		if (old_thread->tar != new_thread->tar)
1257			mtspr(SPRN_TAR, new_thread->tar);
1258	}
1259
1260	if (cpu_has_feature(CPU_FTR_P9_TIDR) &&
1261	    old_thread->tidr != new_thread->tidr)
1262		mtspr(SPRN_TIDR, new_thread->tidr);
 
 
 
 
 
 
 
 
1263#endif
1264
1265}
1266
1267struct task_struct *__switch_to(struct task_struct *prev,
1268	struct task_struct *new)
1269{
1270	struct thread_struct *new_thread, *old_thread;
1271	struct task_struct *last;
1272#ifdef CONFIG_PPC_64S_HASH_MMU
1273	struct ppc64_tlb_batch *batch;
1274#endif
1275
1276	new_thread = &new->thread;
1277	old_thread = &current->thread;
1278
1279	WARN_ON(!irqs_disabled());
1280
1281#ifdef CONFIG_PPC_64S_HASH_MMU
1282	batch = this_cpu_ptr(&ppc64_tlb_batch);
1283	if (batch->active) {
1284		current_thread_info()->local_flags |= _TLF_LAZY_MMU;
1285		if (batch->index)
1286			__flush_tlb_pending(batch);
1287		batch->active = 0;
1288	}
1289
1290	/*
1291	 * On POWER9 the copy-paste buffer can only paste into
1292	 * foreign real addresses, so unprivileged processes can not
1293	 * see the data or use it in any way unless they have
1294	 * foreign real mappings. If the new process has the foreign
1295	 * real address mappings, we must issue a cp_abort to clear
1296	 * any state and prevent snooping, corruption or a covert
1297	 * channel. ISA v3.1 supports paste into local memory.
1298	 */
1299	if (new->mm && (cpu_has_feature(CPU_FTR_ARCH_31) ||
1300			atomic_read(&new->mm->context.vas_windows)))
1301		asm volatile(PPC_CP_ABORT);
1302#endif /* CONFIG_PPC_BOOK3S_64 */
1303
1304#ifdef CONFIG_PPC_ADV_DEBUG_REGS
1305	switch_booke_debug_regs(&new->thread.debug);
1306#else
1307/*
1308 * For PPC_BOOK3S_64, we use the hw-breakpoint interfaces that would
1309 * schedule DABR
1310 */
1311#ifndef CONFIG_HAVE_HW_BREAKPOINT
1312	switch_hw_breakpoint(new);
1313#endif /* CONFIG_HAVE_HW_BREAKPOINT */
1314#endif
1315
1316	/*
1317	 * We need to save SPRs before treclaim/trecheckpoint as these will
1318	 * change a number of them.
1319	 */
1320	save_sprs(&prev->thread);
1321
1322	/* Save FPU, Altivec, VSX and SPE state */
1323	giveup_all(prev);
1324
1325	__switch_to_tm(prev, new);
1326
1327	if (!radix_enabled()) {
1328		/*
1329		 * We can't take a PMU exception inside _switch() since there
1330		 * is a window where the kernel stack SLB and the kernel stack
1331		 * are out of sync. Hard disable here.
1332		 */
1333		hard_irq_disable();
1334	}
1335
1336	/*
1337	 * Call restore_sprs() and set_return_regs_changed() before calling
1338	 * _switch(). If we move it after _switch() then we miss out on calling
1339	 * it for new tasks. The reason for this is we manually create a stack
1340	 * frame for new tasks that directly returns through ret_from_fork() or
1341	 * ret_from_kernel_thread(). See copy_thread() for details.
1342	 */
1343	restore_sprs(old_thread, new_thread);
1344
1345	set_return_regs_changed(); /* _switch changes stack (and regs) */
1346
1347	if (!IS_ENABLED(CONFIG_PPC_BOOK3S_64))
1348		kuap_assert_locked();
1349
1350	last = _switch(old_thread, new_thread);
1351
1352	/*
1353	 * Nothing after _switch will be run for newly created tasks,
1354	 * because they switch directly to ret_from_fork/ret_from_kernel_thread
1355	 * etc. Code added here should have a comment explaining why that is
1356	 * okay.
1357	 */
1358
1359#ifdef CONFIG_PPC_BOOK3S_64
1360#ifdef CONFIG_PPC_64S_HASH_MMU
1361	/*
1362	 * This applies to a process that was context switched while inside
1363	 * arch_enter_lazy_mmu_mode(), to re-activate the batch that was
1364	 * deactivated above, before _switch(). This will never be the case
1365	 * for new tasks.
1366	 */
1367	if (current_thread_info()->local_flags & _TLF_LAZY_MMU) {
1368		current_thread_info()->local_flags &= ~_TLF_LAZY_MMU;
1369		batch = this_cpu_ptr(&ppc64_tlb_batch);
1370		batch->active = 1;
1371	}
1372#endif
1373
1374	/*
1375	 * Math facilities are masked out of the child MSR in copy_thread.
1376	 * A new task does not need to restore_math because it will
1377	 * demand fault them.
1378	 */
1379	if (current->thread.regs)
1380		restore_math(current->thread.regs);
1381#endif /* CONFIG_PPC_BOOK3S_64 */
1382
1383	return last;
1384}
1385
1386#define NR_INSN_TO_PRINT	16
1387
1388static void show_instructions(struct pt_regs *regs)
1389{
1390	int i;
1391	unsigned long nip = regs->nip;
1392	unsigned long pc = regs->nip - (NR_INSN_TO_PRINT * 3 / 4 * sizeof(int));
1393
1394	printk("Code: ");
1395
1396	/*
1397	 * If we were executing with the MMU off for instructions, adjust pc
1398	 * rather than printing XXXXXXXX.
1399	 */
1400	if (!IS_ENABLED(CONFIG_BOOKE) && !(regs->msr & MSR_IR)) {
1401		pc = (unsigned long)phys_to_virt(pc);
1402		nip = (unsigned long)phys_to_virt(regs->nip);
1403	}
1404
1405	for (i = 0; i < NR_INSN_TO_PRINT; i++) {
1406		int instr;
1407
1408		if (!__kernel_text_address(pc) ||
1409		    get_kernel_nofault(instr, (const void *)pc)) {
1410			pr_cont("XXXXXXXX ");
1411		} else {
1412			if (nip == pc)
1413				pr_cont("<%08x> ", instr);
1414			else
1415				pr_cont("%08x ", instr);
1416		}
1417
1418		pc += sizeof(int);
1419	}
1420
1421	pr_cont("\n");
1422}
1423
1424void show_user_instructions(struct pt_regs *regs)
1425{
1426	unsigned long pc;
1427	int n = NR_INSN_TO_PRINT;
1428	struct seq_buf s;
1429	char buf[96]; /* enough for 8 times 9 + 2 chars */
1430
1431	pc = regs->nip - (NR_INSN_TO_PRINT * 3 / 4 * sizeof(int));
1432
1433	seq_buf_init(&s, buf, sizeof(buf));
1434
1435	while (n) {
1436		int i;
1437
1438		seq_buf_clear(&s);
1439
1440		for (i = 0; i < 8 && n; i++, n--, pc += sizeof(int)) {
1441			int instr;
1442
1443			if (copy_from_user_nofault(&instr, (void __user *)pc,
1444					sizeof(instr))) {
1445				seq_buf_printf(&s, "XXXXXXXX ");
1446				continue;
1447			}
1448			seq_buf_printf(&s, regs->nip == pc ? "<%08x> " : "%08x ", instr);
1449		}
1450
1451		if (!seq_buf_has_overflowed(&s))
1452			pr_info("%s[%d]: code: %s\n", current->comm,
1453				current->pid, s.buffer);
1454	}
1455}
1456
1457struct regbit {
1458	unsigned long bit;
1459	const char *name;
1460};
1461
1462static struct regbit msr_bits[] = {
1463#if defined(CONFIG_PPC64) && !defined(CONFIG_BOOKE)
1464	{MSR_SF,	"SF"},
1465	{MSR_HV,	"HV"},
1466#endif
1467	{MSR_VEC,	"VEC"},
1468	{MSR_VSX,	"VSX"},
1469#ifdef CONFIG_BOOKE
1470	{MSR_CE,	"CE"},
1471#endif
1472	{MSR_EE,	"EE"},
1473	{MSR_PR,	"PR"},
1474	{MSR_FP,	"FP"},
1475	{MSR_ME,	"ME"},
1476#ifdef CONFIG_BOOKE
1477	{MSR_DE,	"DE"},
1478#else
1479	{MSR_SE,	"SE"},
1480	{MSR_BE,	"BE"},
1481#endif
1482	{MSR_IR,	"IR"},
1483	{MSR_DR,	"DR"},
1484	{MSR_PMM,	"PMM"},
1485#ifndef CONFIG_BOOKE
1486	{MSR_RI,	"RI"},
1487	{MSR_LE,	"LE"},
1488#endif
1489	{0,		NULL}
1490};
1491
1492static void print_bits(unsigned long val, struct regbit *bits, const char *sep)
1493{
1494	const char *s = "";
1495
1496	for (; bits->bit; ++bits)
1497		if (val & bits->bit) {
1498			pr_cont("%s%s", s, bits->name);
1499			s = sep;
1500		}
1501}
1502
1503#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1504static struct regbit msr_tm_bits[] = {
1505	{MSR_TS_T,	"T"},
1506	{MSR_TS_S,	"S"},
1507	{MSR_TM,	"E"},
1508	{0,		NULL}
1509};
1510
1511static void print_tm_bits(unsigned long val)
1512{
1513/*
1514 * This only prints something if at least one of the TM bit is set.
1515 * Inside the TM[], the output means:
1516 *   E: Enabled		(bit 32)
1517 *   S: Suspended	(bit 33)
1518 *   T: Transactional	(bit 34)
1519 */
1520	if (val & (MSR_TM | MSR_TS_S | MSR_TS_T)) {
1521		pr_cont(",TM[");
1522		print_bits(val, msr_tm_bits, "");
1523		pr_cont("]");
1524	}
1525}
1526#else
1527static void print_tm_bits(unsigned long val) {}
1528#endif
1529
1530static void print_msr_bits(unsigned long val)
1531{
1532	pr_cont("<");
1533	print_bits(val, msr_bits, ",");
1534	print_tm_bits(val);
1535	pr_cont(">");
1536}
1537
1538#ifdef CONFIG_PPC64
1539#define REG		"%016lx"
1540#define REGS_PER_LINE	4
1541#else
1542#define REG		"%08lx"
1543#define REGS_PER_LINE	8
1544#endif
1545
1546static void __show_regs(struct pt_regs *regs)
1547{
1548	int i, trap;
1549
1550	printk("NIP:  "REG" LR: "REG" CTR: "REG"\n",
1551	       regs->nip, regs->link, regs->ctr);
1552	printk("REGS: %px TRAP: %04lx   %s  (%s)\n",
1553	       regs, regs->trap, print_tainted(), init_utsname()->release);
1554	printk("MSR:  "REG" ", regs->msr);
1555	print_msr_bits(regs->msr);
1556	pr_cont("  CR: %08lx  XER: %08lx\n", regs->ccr, regs->xer);
1557	trap = TRAP(regs);
1558	if (!trap_is_syscall(regs) && cpu_has_feature(CPU_FTR_CFAR))
1559		pr_cont("CFAR: "REG" ", regs->orig_gpr3);
1560	if (trap == INTERRUPT_MACHINE_CHECK ||
1561	    trap == INTERRUPT_DATA_STORAGE ||
1562	    trap == INTERRUPT_ALIGNMENT) {
1563		if (IS_ENABLED(CONFIG_4xx) || IS_ENABLED(CONFIG_BOOKE))
1564			pr_cont("DEAR: "REG" ESR: "REG" ", regs->dear, regs->esr);
1565		else
1566			pr_cont("DAR: "REG" DSISR: %08lx ", regs->dar, regs->dsisr);
1567	}
1568
1569#ifdef CONFIG_PPC64
1570	pr_cont("IRQMASK: %lx ", regs->softe);
1571#endif
1572#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1573	if (MSR_TM_ACTIVE(regs->msr))
1574		pr_cont("\nPACATMSCRATCH: %016llx ", get_paca()->tm_scratch);
1575#endif
1576
1577	for (i = 0;  i < 32;  i++) {
1578		if ((i % REGS_PER_LINE) == 0)
1579			pr_cont("\nGPR%02d: ", i);
1580		pr_cont(REG " ", regs->gpr[i]);
1581	}
1582	pr_cont("\n");
1583	/*
1584	 * Lookup NIP late so we have the best change of getting the
1585	 * above info out without failing
1586	 */
1587	if (IS_ENABLED(CONFIG_KALLSYMS)) {
1588		printk("NIP ["REG"] %pS\n", regs->nip, (void *)regs->nip);
1589		printk("LR ["REG"] %pS\n", regs->link, (void *)regs->link);
1590	}
1591}
1592
1593void show_regs(struct pt_regs *regs)
1594{
1595	show_regs_print_info(KERN_DEFAULT);
1596	__show_regs(regs);
1597	show_stack(current, (unsigned long *) regs->gpr[1], KERN_DEFAULT);
1598	if (!user_mode(regs))
1599		show_instructions(regs);
1600}
1601
1602void flush_thread(void)
1603{
1604#ifdef CONFIG_HAVE_HW_BREAKPOINT
1605	flush_ptrace_hw_breakpoint(current);
1606#else /* CONFIG_HAVE_HW_BREAKPOINT */
1607	set_debug_reg_defaults(&current->thread);
1608#endif /* CONFIG_HAVE_HW_BREAKPOINT */
1609}
1610
1611void arch_setup_new_exec(void)
1612{
1613
1614#ifdef CONFIG_PPC_BOOK3S_64
1615	if (!radix_enabled())
1616		hash__setup_new_exec();
1617#endif
1618	/*
1619	 * If we exec out of a kernel thread then thread.regs will not be
1620	 * set.  Do it now.
1621	 */
1622	if (!current->thread.regs) {
1623		struct pt_regs *regs = task_stack_page(current) + THREAD_SIZE;
1624		current->thread.regs = regs - 1;
1625	}
1626
1627#ifdef CONFIG_PPC_MEM_KEYS
1628	current->thread.regs->amr  = default_amr;
1629	current->thread.regs->iamr  = default_iamr;
1630#endif
 
 
 
 
 
 
 
1631}
1632
1633#ifdef CONFIG_PPC64
1634/**
1635 * Assign a TIDR (thread ID) for task @t and set it in the thread
1636 * structure. For now, we only support setting TIDR for 'current' task.
1637 *
1638 * Since the TID value is a truncated form of it PID, it is possible
1639 * (but unlikely) for 2 threads to have the same TID. In the unlikely event
1640 * that 2 threads share the same TID and are waiting, one of the following
1641 * cases will happen:
1642 *
1643 * 1. The correct thread is running, the wrong thread is not
1644 * In this situation, the correct thread is woken and proceeds to pass it's
1645 * condition check.
1646 *
1647 * 2. Neither threads are running
1648 * In this situation, neither thread will be woken. When scheduled, the waiting
1649 * threads will execute either a wait, which will return immediately, followed
1650 * by a condition check, which will pass for the correct thread and fail
1651 * for the wrong thread, or they will execute the condition check immediately.
1652 *
1653 * 3. The wrong thread is running, the correct thread is not
1654 * The wrong thread will be woken, but will fail it's condition check and
1655 * re-execute wait. The correct thread, when scheduled, will execute either
1656 * it's condition check (which will pass), or wait, which returns immediately
1657 * when called the first time after the thread is scheduled, followed by it's
1658 * condition check (which will pass).
1659 *
1660 * 4. Both threads are running
1661 * Both threads will be woken. The wrong thread will fail it's condition check
1662 * and execute another wait, while the correct thread will pass it's condition
1663 * check.
1664 *
1665 * @t: the task to set the thread ID for
1666 */
1667int set_thread_tidr(struct task_struct *t)
1668{
1669	if (!cpu_has_feature(CPU_FTR_P9_TIDR))
1670		return -EINVAL;
1671
1672	if (t != current)
1673		return -EINVAL;
1674
1675	if (t->thread.tidr)
1676		return 0;
1677
1678	t->thread.tidr = (u16)task_pid_nr(t);
1679	mtspr(SPRN_TIDR, t->thread.tidr);
1680
1681	return 0;
1682}
1683EXPORT_SYMBOL_GPL(set_thread_tidr);
1684
1685#endif /* CONFIG_PPC64 */
1686
1687/*
1688 * this gets called so that we can store coprocessor state into memory and
1689 * copy the current task into the new thread.
1690 */
1691int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
1692{
1693	flush_all_to_thread(src);
1694	/*
1695	 * Flush TM state out so we can copy it.  __switch_to_tm() does this
1696	 * flush but it removes the checkpointed state from the current CPU and
1697	 * transitions the CPU out of TM mode.  Hence we need to call
1698	 * tm_recheckpoint_new_task() (on the same task) to restore the
1699	 * checkpointed state back and the TM mode.
1700	 *
1701	 * Can't pass dst because it isn't ready. Doesn't matter, passing
1702	 * dst is only important for __switch_to()
1703	 */
1704	__switch_to_tm(src, src);
1705
1706	*dst = *src;
1707
1708	clear_task_ebb(dst);
1709
1710	return 0;
1711}
1712
1713static void setup_ksp_vsid(struct task_struct *p, unsigned long sp)
1714{
1715#ifdef CONFIG_PPC_64S_HASH_MMU
1716	unsigned long sp_vsid;
1717	unsigned long llp = mmu_psize_defs[mmu_linear_psize].sllp;
1718
1719	if (radix_enabled())
1720		return;
1721
1722	if (mmu_has_feature(MMU_FTR_1T_SEGMENT))
1723		sp_vsid = get_kernel_vsid(sp, MMU_SEGSIZE_1T)
1724			<< SLB_VSID_SHIFT_1T;
1725	else
1726		sp_vsid = get_kernel_vsid(sp, MMU_SEGSIZE_256M)
1727			<< SLB_VSID_SHIFT;
1728	sp_vsid |= SLB_VSID_KERNEL | llp;
1729	p->thread.ksp_vsid = sp_vsid;
1730#endif
1731}
1732
1733/*
1734 * Copy a thread..
1735 */
1736
1737/*
1738 * Copy architecture-specific thread state
1739 */
1740int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
1741{
1742	unsigned long clone_flags = args->flags;
1743	unsigned long usp = args->stack;
1744	unsigned long tls = args->tls;
1745	struct pt_regs *childregs, *kregs;
1746	extern void ret_from_fork(void);
1747	extern void ret_from_fork_scv(void);
1748	extern void ret_from_kernel_thread(void);
 
1749	void (*f)(void);
1750	unsigned long sp = (unsigned long)task_stack_page(p) + THREAD_SIZE;
1751	struct thread_info *ti = task_thread_info(p);
1752#ifdef CONFIG_HAVE_HW_BREAKPOINT
1753	int i;
1754#endif
1755
1756	klp_init_thread_info(p);
1757
1758	/* Create initial stack frame. */
1759	sp -= STACK_USER_INT_FRAME_SIZE;
1760	*(unsigned long *)(sp + STACK_INT_FRAME_MARKER) = STACK_FRAME_REGS_MARKER;
1761
1762	/* Copy registers */
1763	childregs = (struct pt_regs *)(sp + STACK_INT_FRAME_REGS);
1764	if (unlikely(args->fn)) {
1765		/* kernel thread */
 
 
 
1766		((unsigned long *)sp)[0] = 0;
1767		memset(childregs, 0, sizeof(struct pt_regs));
1768		childregs->gpr[1] = sp + STACK_USER_INT_FRAME_SIZE;
1769		/* function */
1770		if (args->fn)
1771			childregs->gpr[14] = ppc_function_entry((void *)args->fn);
1772#ifdef CONFIG_PPC64
1773		clear_tsk_thread_flag(p, TIF_32BIT);
1774		childregs->softe = IRQS_ENABLED;
1775#endif
1776		childregs->gpr[15] = (unsigned long)args->fn_arg;
1777		p->thread.regs = NULL;	/* no user register state */
1778		ti->flags |= _TIF_RESTOREALL;
1779		f = ret_from_kernel_thread;
1780	} else {
1781		/* user thread */
1782		struct pt_regs *regs = current_pt_regs();
1783		*childregs = *regs;
1784		if (usp)
1785			childregs->gpr[1] = usp;
1786		((unsigned long *)sp)[0] = childregs->gpr[1];
1787		p->thread.regs = childregs;
1788		/* 64s sets this in ret_from_fork */
1789		if (!IS_ENABLED(CONFIG_PPC_BOOK3S_64))
1790			childregs->gpr[3] = 0;  /* Result from fork() */
1791		if (clone_flags & CLONE_SETTLS) {
1792			if (!is_32bit_task())
1793				childregs->gpr[13] = tls;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1794			else
1795				childregs->gpr[2] = tls;
1796		}
1797
1798		if (trap_is_scv(regs))
1799			f = ret_from_fork_scv;
1800		else
1801			f = ret_from_fork;
1802	}
1803	childregs->msr &= ~(MSR_FP|MSR_VEC|MSR_VSX);
1804
1805	/*
1806	 * The way this works is that at some point in the future
1807	 * some task will call _switch to switch to the new task.
1808	 * That will pop off the stack frame created below and start
1809	 * the new task running at ret_from_fork.  The new task will
1810	 * do some house keeping and then return from the fork or clone
1811	 * system call, using the stack frame created above.
1812	 */
1813	((unsigned long *)sp)[STACK_FRAME_LR_SAVE] = (unsigned long)f;
1814	sp -= STACK_SWITCH_FRAME_SIZE;
1815	((unsigned long *)sp)[0] = sp + STACK_SWITCH_FRAME_SIZE;
1816	kregs = (struct pt_regs *)(sp + STACK_SWITCH_FRAME_REGS);
 
 
 
 
 
 
 
 
 
 
1817	p->thread.ksp = sp;
1818
1819#ifdef CONFIG_HAVE_HW_BREAKPOINT
1820	for (i = 0; i < nr_wp_slots(); i++)
1821		p->thread.ptrace_bps[i] = NULL;
1822#endif
1823
1824#ifdef CONFIG_PPC_FPU_REGS
1825	p->thread.fp_save_area = NULL;
1826#endif
1827#ifdef CONFIG_ALTIVEC
1828	p->thread.vr_save_area = NULL;
1829#endif
1830#if defined(CONFIG_PPC_BOOK3S_32) && defined(CONFIG_PPC_KUAP)
1831	p->thread.kuap = KUAP_NONE;
1832#endif
1833#if defined(CONFIG_BOOKE_OR_40x) && defined(CONFIG_PPC_KUAP)
1834	p->thread.pid = MMU_NO_CONTEXT;
1835#endif
1836
1837	setup_ksp_vsid(p, sp);
1838
1839#ifdef CONFIG_PPC64 
1840	if (cpu_has_feature(CPU_FTR_DSCR)) {
1841		p->thread.dscr_inherit = current->thread.dscr_inherit;
1842		p->thread.dscr = mfspr(SPRN_DSCR);
1843	}
1844	if (cpu_has_feature(CPU_FTR_HAS_PPR))
1845		childregs->ppr = DEFAULT_PPR;
1846
1847	p->thread.tidr = 0;
1848#endif
1849	/*
1850	 * Run with the current AMR value of the kernel
1851	 */
1852#ifdef CONFIG_PPC_PKEY
1853	if (mmu_has_feature(MMU_FTR_BOOK3S_KUAP))
1854		kregs->amr = AMR_KUAP_BLOCKED;
1855
1856	if (mmu_has_feature(MMU_FTR_BOOK3S_KUEP))
1857		kregs->iamr = AMR_KUEP_BLOCKED;
1858#endif
1859	kregs->nip = ppc_function_entry(f);
1860	return 0;
1861}
1862
1863void preload_new_slb_context(unsigned long start, unsigned long sp);
1864
1865/*
1866 * Set up a thread for executing a new program
1867 */
1868void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp)
1869{
1870#ifdef CONFIG_PPC64
1871	unsigned long load_addr = regs->gpr[2];	/* saved by ELF_PLAT_INIT */
1872
1873	if (IS_ENABLED(CONFIG_PPC_BOOK3S_64) && !radix_enabled())
1874		preload_new_slb_context(start, sp);
1875#endif
1876
1877#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1878	/*
1879	 * Clear any transactional state, we're exec()ing. The cause is
1880	 * not important as there will never be a recheckpoint so it's not
1881	 * user visible.
1882	 */
1883	if (MSR_TM_SUSPENDED(mfmsr()))
1884		tm_reclaim_current(0);
1885#endif
1886
1887	memset(&regs->gpr[1], 0, sizeof(regs->gpr) - sizeof(regs->gpr[0]));
1888	regs->ctr = 0;
1889	regs->link = 0;
1890	regs->xer = 0;
1891	regs->ccr = 0;
1892	regs->gpr[1] = sp;
1893
1894#ifdef CONFIG_PPC32
1895	regs->mq = 0;
1896	regs->nip = start;
1897	regs->msr = MSR_USER;
1898#else
1899	if (!is_32bit_task()) {
1900		unsigned long entry;
1901
1902		if (is_elf2_task()) {
1903			/* Look ma, no function descriptors! */
1904			entry = start;
1905
1906			/*
1907			 * Ulrich says:
1908			 *   The latest iteration of the ABI requires that when
1909			 *   calling a function (at its global entry point),
1910			 *   the caller must ensure r12 holds the entry point
1911			 *   address (so that the function can quickly
1912			 *   establish addressability).
1913			 */
1914			regs->gpr[12] = start;
1915			/* Make sure that's restored on entry to userspace. */
1916			set_thread_flag(TIF_RESTOREALL);
1917		} else {
1918			unsigned long toc;
1919
1920			/* start is a relocated pointer to the function
1921			 * descriptor for the elf _start routine.  The first
1922			 * entry in the function descriptor is the entry
1923			 * address of _start and the second entry is the TOC
1924			 * value we need to use.
1925			 */
1926			__get_user(entry, (unsigned long __user *)start);
1927			__get_user(toc, (unsigned long __user *)start+1);
1928
1929			/* Check whether the e_entry function descriptor entries
1930			 * need to be relocated before we can use them.
1931			 */
1932			if (load_addr != 0) {
1933				entry += load_addr;
1934				toc   += load_addr;
1935			}
1936			regs->gpr[2] = toc;
1937		}
1938		regs_set_return_ip(regs, entry);
1939		regs_set_return_msr(regs, MSR_USER64);
1940	} else {
1941		regs->gpr[2] = 0;
1942		regs_set_return_ip(regs, start);
1943		regs_set_return_msr(regs, MSR_USER32);
1944	}
1945
1946#endif
1947#ifdef CONFIG_VSX
1948	current->thread.used_vsr = 0;
1949#endif
1950	current->thread.load_slb = 0;
1951	current->thread.load_fp = 0;
1952#ifdef CONFIG_PPC_FPU_REGS
1953	memset(&current->thread.fp_state, 0, sizeof(current->thread.fp_state));
1954	current->thread.fp_save_area = NULL;
1955#endif
1956#ifdef CONFIG_ALTIVEC
1957	memset(&current->thread.vr_state, 0, sizeof(current->thread.vr_state));
1958	current->thread.vr_state.vscr.u[3] = 0x00010000; /* Java mode disabled */
1959	current->thread.vr_save_area = NULL;
1960	current->thread.vrsave = 0;
1961	current->thread.used_vr = 0;
1962	current->thread.load_vec = 0;
1963#endif /* CONFIG_ALTIVEC */
1964#ifdef CONFIG_SPE
1965	memset(current->thread.evr, 0, sizeof(current->thread.evr));
1966	current->thread.acc = 0;
1967	current->thread.spefscr = 0;
1968	current->thread.used_spe = 0;
1969#endif /* CONFIG_SPE */
1970#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1971	current->thread.tm_tfhar = 0;
1972	current->thread.tm_texasr = 0;
1973	current->thread.tm_tfiar = 0;
1974	current->thread.load_tm = 0;
1975#endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
 
 
 
 
 
 
1976}
1977EXPORT_SYMBOL(start_thread);
1978
1979#define PR_FP_ALL_EXCEPT (PR_FP_EXC_DIV | PR_FP_EXC_OVF | PR_FP_EXC_UND \
1980		| PR_FP_EXC_RES | PR_FP_EXC_INV)
1981
1982int set_fpexc_mode(struct task_struct *tsk, unsigned int val)
1983{
1984	struct pt_regs *regs = tsk->thread.regs;
1985
1986	/* This is a bit hairy.  If we are an SPE enabled  processor
1987	 * (have embedded fp) we store the IEEE exception enable flags in
1988	 * fpexc_mode.  fpexc_mode is also used for setting FP exception
1989	 * mode (asyn, precise, disabled) for 'Classic' FP. */
1990	if (val & PR_FP_EXC_SW_ENABLE) {
1991		if (cpu_has_feature(CPU_FTR_SPE)) {
1992			/*
1993			 * When the sticky exception bits are set
1994			 * directly by userspace, it must call prctl
1995			 * with PR_GET_FPEXC (with PR_FP_EXC_SW_ENABLE
1996			 * in the existing prctl settings) or
1997			 * PR_SET_FPEXC (with PR_FP_EXC_SW_ENABLE in
1998			 * the bits being set).  <fenv.h> functions
1999			 * saving and restoring the whole
2000			 * floating-point environment need to do so
2001			 * anyway to restore the prctl settings from
2002			 * the saved environment.
2003			 */
2004#ifdef CONFIG_SPE
2005			tsk->thread.spefscr_last = mfspr(SPRN_SPEFSCR);
2006			tsk->thread.fpexc_mode = val &
2007				(PR_FP_EXC_SW_ENABLE | PR_FP_ALL_EXCEPT);
2008#endif
2009			return 0;
2010		} else {
2011			return -EINVAL;
2012		}
2013	}
2014
2015	/* on a CONFIG_SPE this does not hurt us.  The bits that
2016	 * __pack_fe01 use do not overlap with bits used for
2017	 * PR_FP_EXC_SW_ENABLE.  Additionally, the MSR[FE0,FE1] bits
2018	 * on CONFIG_SPE implementations are reserved so writing to
2019	 * them does not change anything */
2020	if (val > PR_FP_EXC_PRECISE)
2021		return -EINVAL;
2022	tsk->thread.fpexc_mode = __pack_fe01(val);
2023	if (regs != NULL && (regs->msr & MSR_FP) != 0) {
2024		regs_set_return_msr(regs, (regs->msr & ~(MSR_FE0|MSR_FE1))
2025						| tsk->thread.fpexc_mode);
2026	}
2027	return 0;
2028}
2029
2030int get_fpexc_mode(struct task_struct *tsk, unsigned long adr)
2031{
2032	unsigned int val = 0;
2033
2034	if (tsk->thread.fpexc_mode & PR_FP_EXC_SW_ENABLE) {
2035		if (cpu_has_feature(CPU_FTR_SPE)) {
2036			/*
2037			 * When the sticky exception bits are set
2038			 * directly by userspace, it must call prctl
2039			 * with PR_GET_FPEXC (with PR_FP_EXC_SW_ENABLE
2040			 * in the existing prctl settings) or
2041			 * PR_SET_FPEXC (with PR_FP_EXC_SW_ENABLE in
2042			 * the bits being set).  <fenv.h> functions
2043			 * saving and restoring the whole
2044			 * floating-point environment need to do so
2045			 * anyway to restore the prctl settings from
2046			 * the saved environment.
2047			 */
2048#ifdef CONFIG_SPE
2049			tsk->thread.spefscr_last = mfspr(SPRN_SPEFSCR);
2050			val = tsk->thread.fpexc_mode;
2051#endif
2052		} else
2053			return -EINVAL;
2054	} else {
2055		val = __unpack_fe01(tsk->thread.fpexc_mode);
2056	}
2057	return put_user(val, (unsigned int __user *) adr);
2058}
2059
2060int set_endian(struct task_struct *tsk, unsigned int val)
2061{
2062	struct pt_regs *regs = tsk->thread.regs;
2063
2064	if ((val == PR_ENDIAN_LITTLE && !cpu_has_feature(CPU_FTR_REAL_LE)) ||
2065	    (val == PR_ENDIAN_PPC_LITTLE && !cpu_has_feature(CPU_FTR_PPC_LE)))
2066		return -EINVAL;
2067
2068	if (regs == NULL)
2069		return -EINVAL;
2070
2071	if (val == PR_ENDIAN_BIG)
2072		regs_set_return_msr(regs, regs->msr & ~MSR_LE);
2073	else if (val == PR_ENDIAN_LITTLE || val == PR_ENDIAN_PPC_LITTLE)
2074		regs_set_return_msr(regs, regs->msr | MSR_LE);
2075	else
2076		return -EINVAL;
2077
2078	return 0;
2079}
2080
2081int get_endian(struct task_struct *tsk, unsigned long adr)
2082{
2083	struct pt_regs *regs = tsk->thread.regs;
2084	unsigned int val;
2085
2086	if (!cpu_has_feature(CPU_FTR_PPC_LE) &&
2087	    !cpu_has_feature(CPU_FTR_REAL_LE))
2088		return -EINVAL;
2089
2090	if (regs == NULL)
2091		return -EINVAL;
2092
2093	if (regs->msr & MSR_LE) {
2094		if (cpu_has_feature(CPU_FTR_REAL_LE))
2095			val = PR_ENDIAN_LITTLE;
2096		else
2097			val = PR_ENDIAN_PPC_LITTLE;
2098	} else
2099		val = PR_ENDIAN_BIG;
2100
2101	return put_user(val, (unsigned int __user *)adr);
2102}
2103
2104int set_unalign_ctl(struct task_struct *tsk, unsigned int val)
2105{
2106	tsk->thread.align_ctl = val;
2107	return 0;
2108}
2109
2110int get_unalign_ctl(struct task_struct *tsk, unsigned long adr)
2111{
2112	return put_user(tsk->thread.align_ctl, (unsigned int __user *)adr);
2113}
2114
2115static inline int valid_irq_stack(unsigned long sp, struct task_struct *p,
2116				  unsigned long nbytes)
2117{
2118	unsigned long stack_page;
2119	unsigned long cpu = task_cpu(p);
2120
 
 
 
2121	stack_page = (unsigned long)hardirq_ctx[cpu];
2122	if (sp >= stack_page && sp <= stack_page + THREAD_SIZE - nbytes)
2123		return 1;
2124
2125	stack_page = (unsigned long)softirq_ctx[cpu];
2126	if (sp >= stack_page && sp <= stack_page + THREAD_SIZE - nbytes)
2127		return 1;
2128
2129	return 0;
2130}
2131
 
2132static inline int valid_emergency_stack(unsigned long sp, struct task_struct *p,
2133					unsigned long nbytes)
2134{
2135#ifdef CONFIG_PPC64
2136	unsigned long stack_page;
2137	unsigned long cpu = task_cpu(p);
2138
2139	if (!paca_ptrs)
2140		return 0;
2141
 
 
 
 
 
 
 
 
2142	stack_page = (unsigned long)paca_ptrs[cpu]->emergency_sp - THREAD_SIZE;
2143	if (sp >= stack_page && sp <= stack_page + THREAD_SIZE - nbytes)
2144		return 1;
2145
2146# ifdef CONFIG_PPC_BOOK3S_64
2147	stack_page = (unsigned long)paca_ptrs[cpu]->nmi_emergency_sp - THREAD_SIZE;
2148	if (sp >= stack_page && sp <= stack_page + THREAD_SIZE - nbytes)
2149		return 1;
2150
2151	stack_page = (unsigned long)paca_ptrs[cpu]->mc_emergency_sp - THREAD_SIZE;
2152	if (sp >= stack_page && sp <= stack_page + THREAD_SIZE - nbytes)
2153		return 1;
2154# endif
2155#endif
2156
2157	return 0;
2158}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2159
2160/*
2161 * validate the stack frame of a particular minimum size, used for when we are
2162 * looking at a certain object in the stack beyond the minimum.
2163 */
2164int validate_sp_size(unsigned long sp, struct task_struct *p,
2165		     unsigned long nbytes)
2166{
2167	unsigned long stack_page = (unsigned long)task_stack_page(p);
2168
2169	if (sp < THREAD_SIZE)
2170		return 0;
2171
2172	if (sp >= stack_page && sp <= stack_page + THREAD_SIZE - nbytes)
2173		return 1;
2174
2175	if (valid_irq_stack(sp, p, nbytes))
2176		return 1;
2177
2178	return valid_emergency_stack(sp, p, nbytes);
2179}
2180
2181int validate_sp(unsigned long sp, struct task_struct *p)
2182{
2183	return validate_sp_size(sp, p, STACK_FRAME_MIN_SIZE);
2184}
2185
2186static unsigned long ___get_wchan(struct task_struct *p)
2187{
2188	unsigned long ip, sp;
2189	int count = 0;
2190
2191	sp = p->thread.ksp;
2192	if (!validate_sp(sp, p))
2193		return 0;
2194
2195	do {
2196		sp = READ_ONCE_NOCHECK(*(unsigned long *)sp);
2197		if (!validate_sp(sp, p) || task_is_running(p))
2198			return 0;
2199		if (count > 0) {
2200			ip = READ_ONCE_NOCHECK(((unsigned long *)sp)[STACK_FRAME_LR_SAVE]);
2201			if (!in_sched_functions(ip))
2202				return ip;
2203		}
2204	} while (count++ < 16);
2205	return 0;
2206}
2207
2208unsigned long __get_wchan(struct task_struct *p)
2209{
2210	unsigned long ret;
2211
2212	if (!try_get_task_stack(p))
2213		return 0;
2214
2215	ret = ___get_wchan(p);
2216
2217	put_task_stack(p);
2218
2219	return ret;
2220}
2221
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2222static int kstack_depth_to_print = CONFIG_PRINT_STACK_DEPTH;
2223
2224void __no_sanitize_address show_stack(struct task_struct *tsk,
2225				      unsigned long *stack,
2226				      const char *loglvl)
2227{
2228	unsigned long sp, ip, lr, newsp;
2229	int count = 0;
2230	int firstframe = 1;
2231	unsigned long ret_addr;
2232	int ftrace_idx = 0;
2233
2234	if (tsk == NULL)
2235		tsk = current;
2236
2237	if (!try_get_task_stack(tsk))
2238		return;
2239
2240	sp = (unsigned long) stack;
2241	if (sp == 0) {
2242		if (tsk == current)
2243			sp = current_stack_frame();
2244		else
2245			sp = tsk->thread.ksp;
2246	}
2247
2248	lr = 0;
2249	printk("%sCall Trace:\n", loglvl);
2250	do {
2251		if (!validate_sp(sp, tsk))
2252			break;
2253
2254		stack = (unsigned long *) sp;
2255		newsp = stack[0];
2256		ip = stack[STACK_FRAME_LR_SAVE];
2257		if (!firstframe || ip != lr) {
2258			printk("%s["REG"] ["REG"] %pS",
2259				loglvl, sp, ip, (void *)ip);
2260			ret_addr = ftrace_graph_ret_addr(current,
2261						&ftrace_idx, ip, stack);
2262			if (ret_addr != ip)
2263				pr_cont(" (%pS)", (void *)ret_addr);
2264			if (firstframe)
2265				pr_cont(" (unreliable)");
2266			pr_cont("\n");
2267		}
2268		firstframe = 0;
2269
2270		/*
2271		 * See if this is an exception frame.
2272		 * We look for the "regs" marker in the current frame.
2273		 *
2274		 * STACK_SWITCH_FRAME_SIZE being the smallest frame that
2275		 * could hold a pt_regs, if that does not fit then it can't
2276		 * have regs.
2277		 */
2278		if (validate_sp_size(sp, tsk, STACK_SWITCH_FRAME_SIZE)
2279		    && stack[STACK_INT_FRAME_MARKER_LONGS] == STACK_FRAME_REGS_MARKER) {
2280			struct pt_regs *regs = (struct pt_regs *)
2281				(sp + STACK_INT_FRAME_REGS);
2282
2283			lr = regs->link;
2284			printk("%s--- interrupt: %lx at %pS\n",
2285			       loglvl, regs->trap, (void *)regs->nip);
2286			__show_regs(regs);
2287			printk("%s--- interrupt: %lx\n",
2288			       loglvl, regs->trap);
 
 
 
 
2289
2290			firstframe = 1;
2291		}
2292
2293		sp = newsp;
2294	} while (count++ < kstack_depth_to_print);
2295
2296	put_task_stack(tsk);
2297}
2298
2299#ifdef CONFIG_PPC64
2300/* Called with hard IRQs off */
2301void notrace __ppc64_runlatch_on(void)
2302{
2303	struct thread_info *ti = current_thread_info();
2304
2305	if (cpu_has_feature(CPU_FTR_ARCH_206)) {
2306		/*
2307		 * Least significant bit (RUN) is the only writable bit of
2308		 * the CTRL register, so we can avoid mfspr. 2.06 is not the
2309		 * earliest ISA where this is the case, but it's convenient.
2310		 */
2311		mtspr(SPRN_CTRLT, CTRL_RUNLATCH);
2312	} else {
2313		unsigned long ctrl;
2314
2315		/*
2316		 * Some architectures (e.g., Cell) have writable fields other
2317		 * than RUN, so do the read-modify-write.
2318		 */
2319		ctrl = mfspr(SPRN_CTRLF);
2320		ctrl |= CTRL_RUNLATCH;
2321		mtspr(SPRN_CTRLT, ctrl);
2322	}
2323
2324	ti->local_flags |= _TLF_RUNLATCH;
2325}
2326
2327/* Called with hard IRQs off */
2328void notrace __ppc64_runlatch_off(void)
2329{
2330	struct thread_info *ti = current_thread_info();
2331
2332	ti->local_flags &= ~_TLF_RUNLATCH;
2333
2334	if (cpu_has_feature(CPU_FTR_ARCH_206)) {
2335		mtspr(SPRN_CTRLT, 0);
2336	} else {
2337		unsigned long ctrl;
2338
2339		ctrl = mfspr(SPRN_CTRLF);
2340		ctrl &= ~CTRL_RUNLATCH;
2341		mtspr(SPRN_CTRLT, ctrl);
2342	}
2343}
2344#endif /* CONFIG_PPC64 */
2345
2346unsigned long arch_align_stack(unsigned long sp)
2347{
2348	if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
2349		sp -= get_random_u32_below(PAGE_SIZE);
2350	return sp & ~0xf;
2351}