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/random.h>
  38#include <linux/hw_breakpoint.h>
  39#include <linux/uaccess.h>
  40#include <linux/elf-randomize.h>
  41#include <linux/pkeys.h>
  42#include <linux/seq_buf.h>
  43
  44#include <asm/interrupt.h>
  45#include <asm/io.h>
  46#include <asm/processor.h>
  47#include <asm/mmu.h>
  48#include <asm/prom.h>
  49#include <asm/machdep.h>
  50#include <asm/time.h>
  51#include <asm/runlatch.h>
  52#include <asm/syscalls.h>
  53#include <asm/switch_to.h>
  54#include <asm/tm.h>
  55#include <asm/debug.h>
  56#ifdef CONFIG_PPC64
  57#include <asm/firmware.h>
  58#include <asm/hw_irq.h>
  59#endif
  60#include <asm/code-patching.h>
  61#include <asm/exec.h>
  62#include <asm/livepatch.h>
  63#include <asm/cpu_has_feature.h>
  64#include <asm/asm-prototypes.h>
  65#include <asm/stacktrace.h>
  66#include <asm/hw_breakpoint.h>
  67
  68#include <linux/kprobes.h>
  69#include <linux/kdebug.h>
  70
  71/* Transactional Memory debug */
  72#ifdef TM_DEBUG_SW
  73#define TM_DEBUG(x...) printk(KERN_INFO x)
  74#else
  75#define TM_DEBUG(x...) do { } while(0)
  76#endif
  77
  78extern unsigned long _get_SP(void);
  79
  80#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
  81/*
  82 * Are we running in "Suspend disabled" mode? If so we have to block any
  83 * sigreturn that would get us into suspended state, and we also warn in some
  84 * other paths that we should never reach with suspend disabled.
  85 */
  86bool tm_suspend_disabled __ro_after_init = false;
  87
  88static void check_if_tm_restore_required(struct task_struct *tsk)
  89{
  90	/*
  91	 * If we are saving the current thread's registers, and the
  92	 * thread is in a transactional state, set the TIF_RESTORE_TM
  93	 * bit so that we know to restore the registers before
  94	 * returning to userspace.
  95	 */
  96	if (tsk == current && tsk->thread.regs &&
  97	    MSR_TM_ACTIVE(tsk->thread.regs->msr) &&
  98	    !test_thread_flag(TIF_RESTORE_TM)) {
  99		regs_set_return_msr(&tsk->thread.ckpt_regs,
 100						tsk->thread.regs->msr);
 101		set_thread_flag(TIF_RESTORE_TM);
 102	}
 103}
 104
 105#else
 106static inline void check_if_tm_restore_required(struct task_struct *tsk) { }
 107#endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
 108
 109bool strict_msr_control;
 110EXPORT_SYMBOL(strict_msr_control);
 111
 112static int __init enable_strict_msr_control(char *str)
 113{
 114	strict_msr_control = true;
 115	pr_info("Enabling strict facility control\n");
 116
 117	return 0;
 118}
 119early_param("ppc_strict_facility_enable", enable_strict_msr_control);
 120
 121/* notrace because it's called by restore_math */
 122unsigned long notrace msr_check_and_set(unsigned long bits)
 123{
 124	unsigned long oldmsr = mfmsr();
 125	unsigned long newmsr;
 126
 127	newmsr = oldmsr | bits;
 128
 
 129	if (cpu_has_feature(CPU_FTR_VSX) && (bits & MSR_FP))
 130		newmsr |= MSR_VSX;
 
 131
 132	if (oldmsr != newmsr)
 133		mtmsr_isync(newmsr);
 134
 135	return newmsr;
 136}
 137EXPORT_SYMBOL_GPL(msr_check_and_set);
 138
 139/* notrace because it's called by restore_math */
 140void notrace __msr_check_and_clear(unsigned long bits)
 141{
 142	unsigned long oldmsr = mfmsr();
 143	unsigned long newmsr;
 144
 145	newmsr = oldmsr & ~bits;
 146
 
 147	if (cpu_has_feature(CPU_FTR_VSX) && (bits & MSR_FP))
 148		newmsr &= ~MSR_VSX;
 
 149
 150	if (oldmsr != newmsr)
 151		mtmsr_isync(newmsr);
 152}
 153EXPORT_SYMBOL(__msr_check_and_clear);
 154
 155#ifdef CONFIG_PPC_FPU
 156static void __giveup_fpu(struct task_struct *tsk)
 157{
 158	unsigned long msr;
 159
 160	save_fpu(tsk);
 161	msr = tsk->thread.regs->msr;
 162	msr &= ~(MSR_FP|MSR_FE0|MSR_FE1);
 
 163	if (cpu_has_feature(CPU_FTR_VSX))
 164		msr &= ~MSR_VSX;
 165	regs_set_return_msr(tsk->thread.regs, msr);
 
 166}
 167
 168void giveup_fpu(struct task_struct *tsk)
 169{
 170	check_if_tm_restore_required(tsk);
 171
 172	msr_check_and_set(MSR_FP);
 173	__giveup_fpu(tsk);
 174	msr_check_and_clear(MSR_FP);
 175}
 176EXPORT_SYMBOL(giveup_fpu);
 177
 178/*
 179 * Make sure the floating-point register state in the
 180 * the thread_struct is up to date for task tsk.
 181 */
 182void flush_fp_to_thread(struct task_struct *tsk)
 183{
 184	if (tsk->thread.regs) {
 185		/*
 186		 * We need to disable preemption here because if we didn't,
 187		 * another process could get scheduled after the regs->msr
 188		 * test but before we have finished saving the FP registers
 189		 * to the thread_struct.  That process could take over the
 190		 * FPU, and then when we get scheduled again we would store
 191		 * bogus values for the remaining FP registers.
 192		 */
 193		preempt_disable();
 194		if (tsk->thread.regs->msr & MSR_FP) {
 195			/*
 196			 * This should only ever be called for current or
 197			 * for a stopped child process.  Since we save away
 198			 * the FP register state on context switch,
 199			 * there is something wrong if a stopped child appears
 200			 * to still have its FP state in the CPU registers.
 201			 */
 202			BUG_ON(tsk != current);
 203			giveup_fpu(tsk);
 204		}
 205		preempt_enable();
 206	}
 207}
 208EXPORT_SYMBOL_GPL(flush_fp_to_thread);
 209
 210void enable_kernel_fp(void)
 211{
 212	unsigned long cpumsr;
 213
 214	WARN_ON(preemptible());
 215
 216	cpumsr = msr_check_and_set(MSR_FP);
 217
 218	if (current->thread.regs && (current->thread.regs->msr & MSR_FP)) {
 219		check_if_tm_restore_required(current);
 220		/*
 221		 * If a thread has already been reclaimed then the
 222		 * checkpointed registers are on the CPU but have definitely
 223		 * been saved by the reclaim code. Don't need to and *cannot*
 224		 * giveup as this would save  to the 'live' structure not the
 225		 * checkpointed structure.
 226		 */
 227		if (!MSR_TM_ACTIVE(cpumsr) &&
 228		     MSR_TM_ACTIVE(current->thread.regs->msr))
 229			return;
 230		__giveup_fpu(current);
 231	}
 232}
 233EXPORT_SYMBOL(enable_kernel_fp);
 234#else
 235static inline void __giveup_fpu(struct task_struct *tsk) { }
 236#endif /* CONFIG_PPC_FPU */
 237
 238#ifdef CONFIG_ALTIVEC
 239static void __giveup_altivec(struct task_struct *tsk)
 240{
 241	unsigned long msr;
 242
 243	save_altivec(tsk);
 244	msr = tsk->thread.regs->msr;
 245	msr &= ~MSR_VEC;
 
 246	if (cpu_has_feature(CPU_FTR_VSX))
 247		msr &= ~MSR_VSX;
 248	regs_set_return_msr(tsk->thread.regs, msr);
 
 249}
 250
 251void giveup_altivec(struct task_struct *tsk)
 252{
 253	check_if_tm_restore_required(tsk);
 254
 255	msr_check_and_set(MSR_VEC);
 256	__giveup_altivec(tsk);
 257	msr_check_and_clear(MSR_VEC);
 258}
 259EXPORT_SYMBOL(giveup_altivec);
 260
 261void enable_kernel_altivec(void)
 262{
 263	unsigned long cpumsr;
 264
 265	WARN_ON(preemptible());
 266
 267	cpumsr = msr_check_and_set(MSR_VEC);
 268
 269	if (current->thread.regs && (current->thread.regs->msr & MSR_VEC)) {
 270		check_if_tm_restore_required(current);
 271		/*
 272		 * If a thread has already been reclaimed then the
 273		 * checkpointed registers are on the CPU but have definitely
 274		 * been saved by the reclaim code. Don't need to and *cannot*
 275		 * giveup as this would save  to the 'live' structure not the
 276		 * checkpointed structure.
 277		 */
 278		if (!MSR_TM_ACTIVE(cpumsr) &&
 279		     MSR_TM_ACTIVE(current->thread.regs->msr))
 280			return;
 281		__giveup_altivec(current);
 282	}
 283}
 284EXPORT_SYMBOL(enable_kernel_altivec);
 285
 286/*
 287 * Make sure the VMX/Altivec register state in the
 288 * the thread_struct is up to date for task tsk.
 289 */
 290void flush_altivec_to_thread(struct task_struct *tsk)
 291{
 292	if (tsk->thread.regs) {
 293		preempt_disable();
 294		if (tsk->thread.regs->msr & MSR_VEC) {
 295			BUG_ON(tsk != current);
 296			giveup_altivec(tsk);
 297		}
 298		preempt_enable();
 299	}
 300}
 301EXPORT_SYMBOL_GPL(flush_altivec_to_thread);
 302#endif /* CONFIG_ALTIVEC */
 303
 304#ifdef CONFIG_VSX
 305static void __giveup_vsx(struct task_struct *tsk)
 306{
 307	unsigned long msr = tsk->thread.regs->msr;
 308
 309	/*
 310	 * We should never be ssetting MSR_VSX without also setting
 311	 * MSR_FP and MSR_VEC
 312	 */
 313	WARN_ON((msr & MSR_VSX) && !((msr & MSR_FP) && (msr & MSR_VEC)));
 314
 315	/* __giveup_fpu will clear MSR_VSX */
 316	if (msr & MSR_FP)
 317		__giveup_fpu(tsk);
 318	if (msr & MSR_VEC)
 319		__giveup_altivec(tsk);
 320}
 321
 322static void giveup_vsx(struct task_struct *tsk)
 323{
 324	check_if_tm_restore_required(tsk);
 325
 326	msr_check_and_set(MSR_FP|MSR_VEC|MSR_VSX);
 327	__giveup_vsx(tsk);
 328	msr_check_and_clear(MSR_FP|MSR_VEC|MSR_VSX);
 329}
 330
 331void enable_kernel_vsx(void)
 332{
 333	unsigned long cpumsr;
 334
 335	WARN_ON(preemptible());
 336
 337	cpumsr = msr_check_and_set(MSR_FP|MSR_VEC|MSR_VSX);
 338
 339	if (current->thread.regs &&
 340	    (current->thread.regs->msr & (MSR_VSX|MSR_VEC|MSR_FP))) {
 341		check_if_tm_restore_required(current);
 342		/*
 343		 * If a thread has already been reclaimed then the
 344		 * checkpointed registers are on the CPU but have definitely
 345		 * been saved by the reclaim code. Don't need to and *cannot*
 346		 * giveup as this would save  to the 'live' structure not the
 347		 * checkpointed structure.
 348		 */
 349		if (!MSR_TM_ACTIVE(cpumsr) &&
 350		     MSR_TM_ACTIVE(current->thread.regs->msr))
 351			return;
 352		__giveup_vsx(current);
 353	}
 354}
 355EXPORT_SYMBOL(enable_kernel_vsx);
 356
 357void flush_vsx_to_thread(struct task_struct *tsk)
 358{
 359	if (tsk->thread.regs) {
 360		preempt_disable();
 361		if (tsk->thread.regs->msr & (MSR_VSX|MSR_VEC|MSR_FP)) {
 362			BUG_ON(tsk != current);
 363			giveup_vsx(tsk);
 364		}
 365		preempt_enable();
 366	}
 367}
 368EXPORT_SYMBOL_GPL(flush_vsx_to_thread);
 369#endif /* CONFIG_VSX */
 370
 371#ifdef CONFIG_SPE
 372void giveup_spe(struct task_struct *tsk)
 373{
 374	check_if_tm_restore_required(tsk);
 375
 376	msr_check_and_set(MSR_SPE);
 377	__giveup_spe(tsk);
 378	msr_check_and_clear(MSR_SPE);
 379}
 380EXPORT_SYMBOL(giveup_spe);
 381
 382void enable_kernel_spe(void)
 383{
 384	WARN_ON(preemptible());
 385
 386	msr_check_and_set(MSR_SPE);
 387
 388	if (current->thread.regs && (current->thread.regs->msr & MSR_SPE)) {
 389		check_if_tm_restore_required(current);
 390		__giveup_spe(current);
 391	}
 392}
 393EXPORT_SYMBOL(enable_kernel_spe);
 394
 395void flush_spe_to_thread(struct task_struct *tsk)
 396{
 397	if (tsk->thread.regs) {
 398		preempt_disable();
 399		if (tsk->thread.regs->msr & MSR_SPE) {
 400			BUG_ON(tsk != current);
 401			tsk->thread.spefscr = mfspr(SPRN_SPEFSCR);
 402			giveup_spe(tsk);
 403		}
 404		preempt_enable();
 405	}
 406}
 407#endif /* CONFIG_SPE */
 408
 409static unsigned long msr_all_available;
 410
 411static int __init init_msr_all_available(void)
 412{
 413	if (IS_ENABLED(CONFIG_PPC_FPU))
 414		msr_all_available |= MSR_FP;
 
 
 415	if (cpu_has_feature(CPU_FTR_ALTIVEC))
 416		msr_all_available |= MSR_VEC;
 
 
 417	if (cpu_has_feature(CPU_FTR_VSX))
 418		msr_all_available |= MSR_VSX;
 
 
 419	if (cpu_has_feature(CPU_FTR_SPE))
 420		msr_all_available |= MSR_SPE;
 
 421
 422	return 0;
 423}
 424early_initcall(init_msr_all_available);
 425
 426void giveup_all(struct task_struct *tsk)
 427{
 428	unsigned long usermsr;
 429
 430	if (!tsk->thread.regs)
 431		return;
 432
 433	check_if_tm_restore_required(tsk);
 434
 435	usermsr = tsk->thread.regs->msr;
 436
 437	if ((usermsr & msr_all_available) == 0)
 438		return;
 439
 440	msr_check_and_set(msr_all_available);
 441
 442	WARN_ON((usermsr & MSR_VSX) && !((usermsr & MSR_FP) && (usermsr & MSR_VEC)));
 443
 
 444	if (usermsr & MSR_FP)
 445		__giveup_fpu(tsk);
 
 
 446	if (usermsr & MSR_VEC)
 447		__giveup_altivec(tsk);
 
 
 448	if (usermsr & MSR_SPE)
 449		__giveup_spe(tsk);
 
 450
 451	msr_check_and_clear(msr_all_available);
 452}
 453EXPORT_SYMBOL(giveup_all);
 454
 455#ifdef CONFIG_PPC_BOOK3S_64
 456#ifdef CONFIG_PPC_FPU
 457static bool should_restore_fp(void)
 458{
 459	if (current->thread.load_fp) {
 460		current->thread.load_fp++;
 461		return true;
 462	}
 463	return false;
 464}
 465
 466static void do_restore_fp(void)
 467{
 468	load_fp_state(&current->thread.fp_state);
 469}
 470#else
 471static bool should_restore_fp(void) { return false; }
 472static void do_restore_fp(void) { }
 473#endif /* CONFIG_PPC_FPU */
 474
 475#ifdef CONFIG_ALTIVEC
 476static bool should_restore_altivec(void)
 477{
 478	if (cpu_has_feature(CPU_FTR_ALTIVEC) && (current->thread.load_vec)) {
 479		current->thread.load_vec++;
 480		return true;
 481	}
 482	return false;
 483}
 484
 485static void do_restore_altivec(void)
 486{
 487	load_vr_state(&current->thread.vr_state);
 488	current->thread.used_vr = 1;
 489}
 490#else
 491static bool should_restore_altivec(void) { return false; }
 492static void do_restore_altivec(void) { }
 493#endif /* CONFIG_ALTIVEC */
 494
 
 495static bool should_restore_vsx(void)
 496{
 497	if (cpu_has_feature(CPU_FTR_VSX))
 498		return true;
 499	return false;
 500}
 501#ifdef CONFIG_VSX
 502static void do_restore_vsx(void)
 503{
 504	current->thread.used_vsr = 1;
 505}
 506#else
 
 507static void do_restore_vsx(void) { }
 508#endif /* CONFIG_VSX */
 509
 510/*
 511 * The exception exit path calls restore_math() with interrupts hard disabled
 512 * but the soft irq state not "reconciled". ftrace code that calls
 513 * local_irq_save/restore causes warnings.
 514 *
 515 * Rather than complicate the exit path, just don't trace restore_math. This
 516 * could be done by having ftrace entry code check for this un-reconciled
 517 * condition where MSR[EE]=0 and PACA_IRQ_HARD_DIS is not set, and
 518 * temporarily fix it up for the duration of the ftrace call.
 519 */
 520void notrace restore_math(struct pt_regs *regs)
 521{
 522	unsigned long msr;
 523	unsigned long new_msr = 0;
 524
 525	msr = regs->msr;
 526
 527	/*
 528	 * new_msr tracks the facilities that are to be restored. Only reload
 529	 * if the bit is not set in the user MSR (if it is set, the registers
 530	 * are live for the user thread).
 531	 */
 532	if ((!(msr & MSR_FP)) && should_restore_fp())
 533		new_msr |= MSR_FP;
 534
 535	if ((!(msr & MSR_VEC)) && should_restore_altivec())
 536		new_msr |= MSR_VEC;
 537
 538	if ((!(msr & MSR_VSX)) && should_restore_vsx()) {
 539		if (((msr | new_msr) & (MSR_FP | MSR_VEC)) == (MSR_FP | MSR_VEC))
 540			new_msr |= MSR_VSX;
 541	}
 542
 543	if (new_msr) {
 544		unsigned long fpexc_mode = 0;
 545
 546		msr_check_and_set(new_msr);
 547
 548		if (new_msr & MSR_FP) {
 549			do_restore_fp();
 550
 551			// This also covers VSX, because VSX implies FP
 552			fpexc_mode = current->thread.fpexc_mode;
 553		}
 554
 555		if (new_msr & MSR_VEC)
 556			do_restore_altivec();
 557
 558		if (new_msr & MSR_VSX)
 559			do_restore_vsx();
 560
 561		msr_check_and_clear(new_msr);
 562
 563		regs_set_return_msr(regs, regs->msr | new_msr | fpexc_mode);
 564	}
 565}
 566#endif /* CONFIG_PPC_BOOK3S_64 */
 567
 568static void save_all(struct task_struct *tsk)
 569{
 570	unsigned long usermsr;
 571
 572	if (!tsk->thread.regs)
 573		return;
 574
 575	usermsr = tsk->thread.regs->msr;
 576
 577	if ((usermsr & msr_all_available) == 0)
 578		return;
 579
 580	msr_check_and_set(msr_all_available);
 581
 582	WARN_ON((usermsr & MSR_VSX) && !((usermsr & MSR_FP) && (usermsr & MSR_VEC)));
 583
 584	if (usermsr & MSR_FP)
 585		save_fpu(tsk);
 586
 587	if (usermsr & MSR_VEC)
 588		save_altivec(tsk);
 589
 590	if (usermsr & MSR_SPE)
 591		__giveup_spe(tsk);
 592
 593	msr_check_and_clear(msr_all_available);
 
 594}
 595
 596void flush_all_to_thread(struct task_struct *tsk)
 597{
 598	if (tsk->thread.regs) {
 599		preempt_disable();
 600		BUG_ON(tsk != current);
 601#ifdef CONFIG_SPE
 602		if (tsk->thread.regs->msr & MSR_SPE)
 603			tsk->thread.spefscr = mfspr(SPRN_SPEFSCR);
 604#endif
 605		save_all(tsk);
 606
 607		preempt_enable();
 608	}
 609}
 610EXPORT_SYMBOL(flush_all_to_thread);
 611
 612#ifdef CONFIG_PPC_ADV_DEBUG_REGS
 613void do_send_trap(struct pt_regs *regs, unsigned long address,
 614		  unsigned long error_code, int breakpt)
 615{
 616	current->thread.trap_nr = TRAP_HWBKPT;
 617	if (notify_die(DIE_DABR_MATCH, "dabr_match", regs, error_code,
 618			11, SIGSEGV) == NOTIFY_STOP)
 619		return;
 620
 621	/* Deliver the signal to userspace */
 622	force_sig_ptrace_errno_trap(breakpt, /* breakpoint or watchpoint id */
 623				    (void __user *)address);
 624}
 625#else	/* !CONFIG_PPC_ADV_DEBUG_REGS */
 626
 627static void do_break_handler(struct pt_regs *regs)
 628{
 629	struct arch_hw_breakpoint null_brk = {0};
 630	struct arch_hw_breakpoint *info;
 631	struct ppc_inst instr = ppc_inst(0);
 632	int type = 0;
 633	int size = 0;
 634	unsigned long ea;
 635	int i;
 636
 637	/*
 638	 * If underneath hw supports only one watchpoint, we know it
 639	 * caused exception. 8xx also falls into this category.
 640	 */
 641	if (nr_wp_slots() == 1) {
 642		__set_breakpoint(0, &null_brk);
 643		current->thread.hw_brk[0] = null_brk;
 644		current->thread.hw_brk[0].flags |= HW_BRK_FLAG_DISABLED;
 645		return;
 646	}
 647
 648	/* Otherwise findout which DAWR caused exception and disable it. */
 649	wp_get_instr_detail(regs, &instr, &type, &size, &ea);
 650
 651	for (i = 0; i < nr_wp_slots(); i++) {
 652		info = &current->thread.hw_brk[i];
 653		if (!info->address)
 654			continue;
 655
 656		if (wp_check_constraints(regs, instr, ea, type, size, info)) {
 657			__set_breakpoint(i, &null_brk);
 658			current->thread.hw_brk[i] = null_brk;
 659			current->thread.hw_brk[i].flags |= HW_BRK_FLAG_DISABLED;
 660		}
 661	}
 662}
 663
 664DEFINE_INTERRUPT_HANDLER(do_break)
 665{
 666	current->thread.trap_nr = TRAP_HWBKPT;
 667	if (notify_die(DIE_DABR_MATCH, "dabr_match", regs, regs->dsisr,
 668			11, SIGSEGV) == NOTIFY_STOP)
 669		return;
 670
 671	if (debugger_break_match(regs))
 672		return;
 673
 674	/*
 675	 * We reach here only when watchpoint exception is generated by ptrace
 676	 * event (or hw is buggy!). Now if CONFIG_HAVE_HW_BREAKPOINT is set,
 677	 * watchpoint is already handled by hw_breakpoint_handler() so we don't
 678	 * have to do anything. But when CONFIG_HAVE_HW_BREAKPOINT is not set,
 679	 * we need to manually handle the watchpoint here.
 680	 */
 681	if (!IS_ENABLED(CONFIG_HAVE_HW_BREAKPOINT))
 682		do_break_handler(regs);
 683
 684	/* Deliver the signal to userspace */
 685	force_sig_fault(SIGTRAP, TRAP_HWBKPT, (void __user *)regs->dar);
 686}
 687#endif	/* CONFIG_PPC_ADV_DEBUG_REGS */
 688
 689static DEFINE_PER_CPU(struct arch_hw_breakpoint, current_brk[HBP_NUM_MAX]);
 690
 691#ifdef CONFIG_PPC_ADV_DEBUG_REGS
 692/*
 693 * Set the debug registers back to their default "safe" values.
 694 */
 695static void set_debug_reg_defaults(struct thread_struct *thread)
 696{
 697	thread->debug.iac1 = thread->debug.iac2 = 0;
 698#if CONFIG_PPC_ADV_DEBUG_IACS > 2
 699	thread->debug.iac3 = thread->debug.iac4 = 0;
 700#endif
 701	thread->debug.dac1 = thread->debug.dac2 = 0;
 702#if CONFIG_PPC_ADV_DEBUG_DVCS > 0
 703	thread->debug.dvc1 = thread->debug.dvc2 = 0;
 704#endif
 705	thread->debug.dbcr0 = 0;
 706#ifdef CONFIG_BOOKE
 707	/*
 708	 * Force User/Supervisor bits to b11 (user-only MSR[PR]=1)
 709	 */
 710	thread->debug.dbcr1 = DBCR1_IAC1US | DBCR1_IAC2US |
 711			DBCR1_IAC3US | DBCR1_IAC4US;
 712	/*
 713	 * Force Data Address Compare User/Supervisor bits to be User-only
 714	 * (0b11 MSR[PR]=1) and set all other bits in DBCR2 register to be 0.
 715	 */
 716	thread->debug.dbcr2 = DBCR2_DAC1US | DBCR2_DAC2US;
 717#else
 718	thread->debug.dbcr1 = 0;
 719#endif
 720}
 721
 722static void prime_debug_regs(struct debug_reg *debug)
 723{
 724	/*
 725	 * We could have inherited MSR_DE from userspace, since
 726	 * it doesn't get cleared on exception entry.  Make sure
 727	 * MSR_DE is clear before we enable any debug events.
 728	 */
 729	mtmsr(mfmsr() & ~MSR_DE);
 730
 731	mtspr(SPRN_IAC1, debug->iac1);
 732	mtspr(SPRN_IAC2, debug->iac2);
 733#if CONFIG_PPC_ADV_DEBUG_IACS > 2
 734	mtspr(SPRN_IAC3, debug->iac3);
 735	mtspr(SPRN_IAC4, debug->iac4);
 736#endif
 737	mtspr(SPRN_DAC1, debug->dac1);
 738	mtspr(SPRN_DAC2, debug->dac2);
 739#if CONFIG_PPC_ADV_DEBUG_DVCS > 0
 740	mtspr(SPRN_DVC1, debug->dvc1);
 741	mtspr(SPRN_DVC2, debug->dvc2);
 742#endif
 743	mtspr(SPRN_DBCR0, debug->dbcr0);
 744	mtspr(SPRN_DBCR1, debug->dbcr1);
 745#ifdef CONFIG_BOOKE
 746	mtspr(SPRN_DBCR2, debug->dbcr2);
 747#endif
 748}
 749/*
 750 * Unless neither the old or new thread are making use of the
 751 * debug registers, set the debug registers from the values
 752 * stored in the new thread.
 753 */
 754void switch_booke_debug_regs(struct debug_reg *new_debug)
 755{
 756	if ((current->thread.debug.dbcr0 & DBCR0_IDM)
 757		|| (new_debug->dbcr0 & DBCR0_IDM))
 758			prime_debug_regs(new_debug);
 759}
 760EXPORT_SYMBOL_GPL(switch_booke_debug_regs);
 761#else	/* !CONFIG_PPC_ADV_DEBUG_REGS */
 762#ifndef CONFIG_HAVE_HW_BREAKPOINT
 763static void set_breakpoint(int i, struct arch_hw_breakpoint *brk)
 764{
 765	preempt_disable();
 766	__set_breakpoint(i, brk);
 767	preempt_enable();
 768}
 769
 770static void set_debug_reg_defaults(struct thread_struct *thread)
 771{
 772	int i;
 773	struct arch_hw_breakpoint null_brk = {0};
 774
 775	for (i = 0; i < nr_wp_slots(); i++) {
 776		thread->hw_brk[i] = null_brk;
 777		if (ppc_breakpoint_available())
 778			set_breakpoint(i, &thread->hw_brk[i]);
 779	}
 780}
 781
 782static inline bool hw_brk_match(struct arch_hw_breakpoint *a,
 783				struct arch_hw_breakpoint *b)
 784{
 785	if (a->address != b->address)
 786		return false;
 787	if (a->type != b->type)
 788		return false;
 789	if (a->len != b->len)
 790		return false;
 791	/* no need to check hw_len. it's calculated from address and len */
 792	return true;
 793}
 794
 795static void switch_hw_breakpoint(struct task_struct *new)
 796{
 797	int i;
 798
 799	for (i = 0; i < nr_wp_slots(); i++) {
 800		if (likely(hw_brk_match(this_cpu_ptr(&current_brk[i]),
 801					&new->thread.hw_brk[i])))
 802			continue;
 803
 804		__set_breakpoint(i, &new->thread.hw_brk[i]);
 805	}
 806}
 807#endif /* !CONFIG_HAVE_HW_BREAKPOINT */
 808#endif	/* CONFIG_PPC_ADV_DEBUG_REGS */
 809
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 810static inline int set_dabr(struct arch_hw_breakpoint *brk)
 811{
 812	unsigned long dabr, dabrx;
 813
 814	dabr = brk->address | (brk->type & HW_BRK_TYPE_DABR);
 815	dabrx = ((brk->type >> 3) & 0x7);
 816
 817	if (ppc_md.set_dabr)
 818		return ppc_md.set_dabr(dabr, dabrx);
 819
 820	if (IS_ENABLED(CONFIG_PPC_ADV_DEBUG_REGS)) {
 821		mtspr(SPRN_DAC1, dabr);
 822		if (IS_ENABLED(CONFIG_PPC_47x))
 823			isync();
 824		return 0;
 825	} else if (IS_ENABLED(CONFIG_PPC_BOOK3S)) {
 826		mtspr(SPRN_DABR, dabr);
 827		if (cpu_has_feature(CPU_FTR_DABRX))
 828			mtspr(SPRN_DABRX, dabrx);
 829		return 0;
 830	} else {
 831		return -EINVAL;
 832	}
 833}
 834
 835static inline int set_breakpoint_8xx(struct arch_hw_breakpoint *brk)
 836{
 837	unsigned long lctrl1 = LCTRL1_CTE_GT | LCTRL1_CTF_LT | LCTRL1_CRWE_RW |
 838			       LCTRL1_CRWF_RW;
 839	unsigned long lctrl2 = LCTRL2_LW0EN | LCTRL2_LW0LADC | LCTRL2_SLW0EN;
 840	unsigned long start_addr = ALIGN_DOWN(brk->address, HW_BREAKPOINT_SIZE);
 841	unsigned long end_addr = ALIGN(brk->address + brk->len, HW_BREAKPOINT_SIZE);
 842
 843	if (start_addr == 0)
 844		lctrl2 |= LCTRL2_LW0LA_F;
 845	else if (end_addr == 0)
 846		lctrl2 |= LCTRL2_LW0LA_E;
 847	else
 848		lctrl2 |= LCTRL2_LW0LA_EandF;
 849
 850	mtspr(SPRN_LCTRL2, 0);
 851
 852	if ((brk->type & HW_BRK_TYPE_RDWR) == 0)
 853		return 0;
 854
 855	if ((brk->type & HW_BRK_TYPE_RDWR) == HW_BRK_TYPE_READ)
 856		lctrl1 |= LCTRL1_CRWE_RO | LCTRL1_CRWF_RO;
 857	if ((brk->type & HW_BRK_TYPE_RDWR) == HW_BRK_TYPE_WRITE)
 858		lctrl1 |= LCTRL1_CRWE_WO | LCTRL1_CRWF_WO;
 859
 860	mtspr(SPRN_CMPE, start_addr - 1);
 861	mtspr(SPRN_CMPF, end_addr);
 862	mtspr(SPRN_LCTRL1, lctrl1);
 863	mtspr(SPRN_LCTRL2, lctrl2);
 864
 865	return 0;
 866}
 867
 868void __set_breakpoint(int nr, struct arch_hw_breakpoint *brk)
 869{
 870	memcpy(this_cpu_ptr(&current_brk[nr]), brk, sizeof(*brk));
 871
 872	if (dawr_enabled())
 873		// Power8 or later
 874		set_dawr(nr, brk);
 875	else if (IS_ENABLED(CONFIG_PPC_8xx))
 876		set_breakpoint_8xx(brk);
 877	else if (!cpu_has_feature(CPU_FTR_ARCH_207S))
 878		// Power7 or earlier
 879		set_dabr(brk);
 880	else
 881		// Shouldn't happen due to higher level checks
 882		WARN_ON_ONCE(1);
 883}
 884
 885/* Check if we have DAWR or DABR hardware */
 886bool ppc_breakpoint_available(void)
 887{
 888	if (dawr_enabled())
 889		return true; /* POWER8 DAWR or POWER9 forced DAWR */
 890	if (cpu_has_feature(CPU_FTR_ARCH_207S))
 891		return false; /* POWER9 with DAWR disabled */
 892	/* DABR: Everything but POWER8 and POWER9 */
 893	return true;
 894}
 895EXPORT_SYMBOL_GPL(ppc_breakpoint_available);
 896
 897#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 898
 899static inline bool tm_enabled(struct task_struct *tsk)
 900{
 901	return tsk && tsk->thread.regs && (tsk->thread.regs->msr & MSR_TM);
 902}
 903
 904static void tm_reclaim_thread(struct thread_struct *thr, uint8_t cause)
 905{
 906	/*
 907	 * Use the current MSR TM suspended bit to track if we have
 908	 * checkpointed state outstanding.
 909	 * On signal delivery, we'd normally reclaim the checkpointed
 910	 * state to obtain stack pointer (see:get_tm_stackpointer()).
 911	 * This will then directly return to userspace without going
 912	 * through __switch_to(). However, if the stack frame is bad,
 913	 * we need to exit this thread which calls __switch_to() which
 914	 * will again attempt to reclaim the already saved tm state.
 915	 * Hence we need to check that we've not already reclaimed
 916	 * this state.
 917	 * We do this using the current MSR, rather tracking it in
 918	 * some specific thread_struct bit, as it has the additional
 919	 * benefit of checking for a potential TM bad thing exception.
 920	 */
 921	if (!MSR_TM_SUSPENDED(mfmsr()))
 922		return;
 923
 924	giveup_all(container_of(thr, struct task_struct, thread));
 925
 926	tm_reclaim(thr, cause);
 927
 928	/*
 929	 * If we are in a transaction and FP is off then we can't have
 930	 * used FP inside that transaction. Hence the checkpointed
 931	 * state is the same as the live state. We need to copy the
 932	 * live state to the checkpointed state so that when the
 933	 * transaction is restored, the checkpointed state is correct
 934	 * and the aborted transaction sees the correct state. We use
 935	 * ckpt_regs.msr here as that's what tm_reclaim will use to
 936	 * determine if it's going to write the checkpointed state or
 937	 * not. So either this will write the checkpointed registers,
 938	 * or reclaim will. Similarly for VMX.
 939	 */
 940	if ((thr->ckpt_regs.msr & MSR_FP) == 0)
 941		memcpy(&thr->ckfp_state, &thr->fp_state,
 942		       sizeof(struct thread_fp_state));
 943	if ((thr->ckpt_regs.msr & MSR_VEC) == 0)
 944		memcpy(&thr->ckvr_state, &thr->vr_state,
 945		       sizeof(struct thread_vr_state));
 946}
 947
 948void tm_reclaim_current(uint8_t cause)
 949{
 950	tm_enable();
 951	tm_reclaim_thread(&current->thread, cause);
 952}
 953
 954static inline void tm_reclaim_task(struct task_struct *tsk)
 955{
 956	/* We have to work out if we're switching from/to a task that's in the
 957	 * middle of a transaction.
 958	 *
 959	 * In switching we need to maintain a 2nd register state as
 960	 * oldtask->thread.ckpt_regs.  We tm_reclaim(oldproc); this saves the
 961	 * checkpointed (tbegin) state in ckpt_regs, ckfp_state and
 962	 * ckvr_state
 963	 *
 964	 * We also context switch (save) TFHAR/TEXASR/TFIAR in here.
 965	 */
 966	struct thread_struct *thr = &tsk->thread;
 967
 968	if (!thr->regs)
 969		return;
 970
 971	if (!MSR_TM_ACTIVE(thr->regs->msr))
 972		goto out_and_saveregs;
 973
 974	WARN_ON(tm_suspend_disabled);
 975
 976	TM_DEBUG("--- tm_reclaim on pid %d (NIP=%lx, "
 977		 "ccr=%lx, msr=%lx, trap=%lx)\n",
 978		 tsk->pid, thr->regs->nip,
 979		 thr->regs->ccr, thr->regs->msr,
 980		 thr->regs->trap);
 981
 982	tm_reclaim_thread(thr, TM_CAUSE_RESCHED);
 983
 984	TM_DEBUG("--- tm_reclaim on pid %d complete\n",
 985		 tsk->pid);
 986
 987out_and_saveregs:
 988	/* Always save the regs here, even if a transaction's not active.
 989	 * This context-switches a thread's TM info SPRs.  We do it here to
 990	 * be consistent with the restore path (in recheckpoint) which
 991	 * cannot happen later in _switch().
 992	 */
 993	tm_save_sprs(thr);
 994}
 995
 996extern void __tm_recheckpoint(struct thread_struct *thread);
 997
 998void tm_recheckpoint(struct thread_struct *thread)
 999{
1000	unsigned long flags;
1001
1002	if (!(thread->regs->msr & MSR_TM))
1003		return;
1004
1005	/* We really can't be interrupted here as the TEXASR registers can't
1006	 * change and later in the trecheckpoint code, we have a userspace R1.
1007	 * So let's hard disable over this region.
1008	 */
1009	local_irq_save(flags);
1010	hard_irq_disable();
1011
1012	/* The TM SPRs are restored here, so that TEXASR.FS can be set
1013	 * before the trecheckpoint and no explosion occurs.
1014	 */
1015	tm_restore_sprs(thread);
1016
1017	__tm_recheckpoint(thread);
1018
1019	local_irq_restore(flags);
1020}
1021
1022static inline void tm_recheckpoint_new_task(struct task_struct *new)
1023{
1024	if (!cpu_has_feature(CPU_FTR_TM))
1025		return;
1026
1027	/* Recheckpoint the registers of the thread we're about to switch to.
1028	 *
1029	 * If the task was using FP, we non-lazily reload both the original and
1030	 * the speculative FP register states.  This is because the kernel
1031	 * doesn't see if/when a TM rollback occurs, so if we take an FP
1032	 * unavailable later, we are unable to determine which set of FP regs
1033	 * need to be restored.
1034	 */
1035	if (!tm_enabled(new))
1036		return;
1037
1038	if (!MSR_TM_ACTIVE(new->thread.regs->msr)){
1039		tm_restore_sprs(&new->thread);
1040		return;
1041	}
1042	/* Recheckpoint to restore original checkpointed register state. */
1043	TM_DEBUG("*** tm_recheckpoint of pid %d (new->msr 0x%lx)\n",
1044		 new->pid, new->thread.regs->msr);
1045
1046	tm_recheckpoint(&new->thread);
1047
1048	/*
1049	 * The checkpointed state has been restored but the live state has
1050	 * not, ensure all the math functionality is turned off to trigger
1051	 * restore_math() to reload.
1052	 */
1053	new->thread.regs->msr &= ~(MSR_FP | MSR_VEC | MSR_VSX);
1054
1055	TM_DEBUG("*** tm_recheckpoint of pid %d complete "
1056		 "(kernel msr 0x%lx)\n",
1057		 new->pid, mfmsr());
1058}
1059
1060static inline void __switch_to_tm(struct task_struct *prev,
1061		struct task_struct *new)
1062{
1063	if (cpu_has_feature(CPU_FTR_TM)) {
1064		if (tm_enabled(prev) || tm_enabled(new))
1065			tm_enable();
1066
1067		if (tm_enabled(prev)) {
1068			prev->thread.load_tm++;
1069			tm_reclaim_task(prev);
1070			if (!MSR_TM_ACTIVE(prev->thread.regs->msr) && prev->thread.load_tm == 0)
1071				prev->thread.regs->msr &= ~MSR_TM;
1072		}
1073
1074		tm_recheckpoint_new_task(new);
1075	}
1076}
1077
1078/*
1079 * This is called if we are on the way out to userspace and the
1080 * TIF_RESTORE_TM flag is set.  It checks if we need to reload
1081 * FP and/or vector state and does so if necessary.
1082 * If userspace is inside a transaction (whether active or
1083 * suspended) and FP/VMX/VSX instructions have ever been enabled
1084 * inside that transaction, then we have to keep them enabled
1085 * and keep the FP/VMX/VSX state loaded while ever the transaction
1086 * continues.  The reason is that if we didn't, and subsequently
1087 * got a FP/VMX/VSX unavailable interrupt inside a transaction,
1088 * we don't know whether it's the same transaction, and thus we
1089 * don't know which of the checkpointed state and the transactional
1090 * state to use.
1091 */
1092void restore_tm_state(struct pt_regs *regs)
1093{
1094	unsigned long msr_diff;
1095
1096	/*
1097	 * This is the only moment we should clear TIF_RESTORE_TM as
1098	 * it is here that ckpt_regs.msr and pt_regs.msr become the same
1099	 * again, anything else could lead to an incorrect ckpt_msr being
1100	 * saved and therefore incorrect signal contexts.
1101	 */
1102	clear_thread_flag(TIF_RESTORE_TM);
1103	if (!MSR_TM_ACTIVE(regs->msr))
1104		return;
1105
1106	msr_diff = current->thread.ckpt_regs.msr & ~regs->msr;
1107	msr_diff &= MSR_FP | MSR_VEC | MSR_VSX;
1108
1109	/* Ensure that restore_math() will restore */
1110	if (msr_diff & MSR_FP)
1111		current->thread.load_fp = 1;
1112#ifdef CONFIG_ALTIVEC
1113	if (cpu_has_feature(CPU_FTR_ALTIVEC) && msr_diff & MSR_VEC)
1114		current->thread.load_vec = 1;
1115#endif
1116	restore_math(regs);
1117
1118	regs_set_return_msr(regs, regs->msr | msr_diff);
1119}
1120
1121#else /* !CONFIG_PPC_TRANSACTIONAL_MEM */
1122#define tm_recheckpoint_new_task(new)
1123#define __switch_to_tm(prev, new)
1124void tm_reclaim_current(uint8_t cause) {}
1125#endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
1126
1127static inline void save_sprs(struct thread_struct *t)
1128{
1129#ifdef CONFIG_ALTIVEC
1130	if (cpu_has_feature(CPU_FTR_ALTIVEC))
1131		t->vrsave = mfspr(SPRN_VRSAVE);
1132#endif
1133#ifdef CONFIG_SPE
1134	if (cpu_has_feature(CPU_FTR_SPE))
1135		t->spefscr = mfspr(SPRN_SPEFSCR);
1136#endif
1137#ifdef CONFIG_PPC_BOOK3S_64
1138	if (cpu_has_feature(CPU_FTR_DSCR))
1139		t->dscr = mfspr(SPRN_DSCR);
1140
1141	if (cpu_has_feature(CPU_FTR_ARCH_207S)) {
1142		t->bescr = mfspr(SPRN_BESCR);
1143		t->ebbhr = mfspr(SPRN_EBBHR);
1144		t->ebbrr = mfspr(SPRN_EBBRR);
1145
1146		t->fscr = mfspr(SPRN_FSCR);
1147
1148		/*
1149		 * Note that the TAR is not available for use in the kernel.
1150		 * (To provide this, the TAR should be backed up/restored on
1151		 * exception entry/exit instead, and be in pt_regs.  FIXME,
1152		 * this should be in pt_regs anyway (for debug).)
1153		 */
1154		t->tar = mfspr(SPRN_TAR);
1155	}
1156#endif
 
 
1157}
1158
1159static inline void restore_sprs(struct thread_struct *old_thread,
1160				struct thread_struct *new_thread)
1161{
1162#ifdef CONFIG_ALTIVEC
1163	if (cpu_has_feature(CPU_FTR_ALTIVEC) &&
1164	    old_thread->vrsave != new_thread->vrsave)
1165		mtspr(SPRN_VRSAVE, new_thread->vrsave);
1166#endif
1167#ifdef CONFIG_SPE
1168	if (cpu_has_feature(CPU_FTR_SPE) &&
1169	    old_thread->spefscr != new_thread->spefscr)
1170		mtspr(SPRN_SPEFSCR, new_thread->spefscr);
1171#endif
1172#ifdef CONFIG_PPC_BOOK3S_64
1173	if (cpu_has_feature(CPU_FTR_DSCR)) {
1174		u64 dscr = get_paca()->dscr_default;
1175		if (new_thread->dscr_inherit)
1176			dscr = new_thread->dscr;
1177
1178		if (old_thread->dscr != dscr)
1179			mtspr(SPRN_DSCR, dscr);
1180	}
1181
1182	if (cpu_has_feature(CPU_FTR_ARCH_207S)) {
1183		if (old_thread->bescr != new_thread->bescr)
1184			mtspr(SPRN_BESCR, new_thread->bescr);
1185		if (old_thread->ebbhr != new_thread->ebbhr)
1186			mtspr(SPRN_EBBHR, new_thread->ebbhr);
1187		if (old_thread->ebbrr != new_thread->ebbrr)
1188			mtspr(SPRN_EBBRR, new_thread->ebbrr);
1189
1190		if (old_thread->fscr != new_thread->fscr)
1191			mtspr(SPRN_FSCR, new_thread->fscr);
1192
1193		if (old_thread->tar != new_thread->tar)
1194			mtspr(SPRN_TAR, new_thread->tar);
1195	}
1196
1197	if (cpu_has_feature(CPU_FTR_P9_TIDR) &&
1198	    old_thread->tidr != new_thread->tidr)
1199		mtspr(SPRN_TIDR, new_thread->tidr);
1200#endif
1201
 
1202}
1203
1204struct task_struct *__switch_to(struct task_struct *prev,
1205	struct task_struct *new)
1206{
1207	struct thread_struct *new_thread, *old_thread;
1208	struct task_struct *last;
1209#ifdef CONFIG_PPC_BOOK3S_64
1210	struct ppc64_tlb_batch *batch;
1211#endif
1212
1213	new_thread = &new->thread;
1214	old_thread = &current->thread;
1215
1216	WARN_ON(!irqs_disabled());
1217
1218#ifdef CONFIG_PPC_BOOK3S_64
1219	batch = this_cpu_ptr(&ppc64_tlb_batch);
1220	if (batch->active) {
1221		current_thread_info()->local_flags |= _TLF_LAZY_MMU;
1222		if (batch->index)
1223			__flush_tlb_pending(batch);
1224		batch->active = 0;
1225	}
1226
1227	/*
1228	 * On POWER9 the copy-paste buffer can only paste into
1229	 * foreign real addresses, so unprivileged processes can not
1230	 * see the data or use it in any way unless they have
1231	 * foreign real mappings. If the new process has the foreign
1232	 * real address mappings, we must issue a cp_abort to clear
1233	 * any state and prevent snooping, corruption or a covert
1234	 * channel. ISA v3.1 supports paste into local memory.
1235	 */
1236	if (new->mm && (cpu_has_feature(CPU_FTR_ARCH_31) ||
1237			atomic_read(&new->mm->context.vas_windows)))
1238		asm volatile(PPC_CP_ABORT);
1239#endif /* CONFIG_PPC_BOOK3S_64 */
1240
1241#ifdef CONFIG_PPC_ADV_DEBUG_REGS
1242	switch_booke_debug_regs(&new->thread.debug);
1243#else
1244/*
1245 * For PPC_BOOK3S_64, we use the hw-breakpoint interfaces that would
1246 * schedule DABR
1247 */
1248#ifndef CONFIG_HAVE_HW_BREAKPOINT
1249	switch_hw_breakpoint(new);
1250#endif /* CONFIG_HAVE_HW_BREAKPOINT */
1251#endif
1252
1253	/*
1254	 * We need to save SPRs before treclaim/trecheckpoint as these will
1255	 * change a number of them.
1256	 */
1257	save_sprs(&prev->thread);
1258
1259	/* Save FPU, Altivec, VSX and SPE state */
1260	giveup_all(prev);
1261
1262	__switch_to_tm(prev, new);
1263
1264	if (!radix_enabled()) {
1265		/*
1266		 * We can't take a PMU exception inside _switch() since there
1267		 * is a window where the kernel stack SLB and the kernel stack
1268		 * are out of sync. Hard disable here.
1269		 */
1270		hard_irq_disable();
1271	}
1272
1273	/*
1274	 * Call restore_sprs() and set_return_regs_changed() before calling
1275	 * _switch(). If we move it after _switch() then we miss out on calling
1276	 * it for new tasks. The reason for this is we manually create a stack
1277	 * frame for new tasks that directly returns through ret_from_fork() or
1278	 * ret_from_kernel_thread(). See copy_thread() for details.
1279	 */
1280	restore_sprs(old_thread, new_thread);
1281
1282	set_return_regs_changed(); /* _switch changes stack (and regs) */
1283
1284#ifdef CONFIG_PPC32
1285	kuap_assert_locked();
1286#endif
1287	last = _switch(old_thread, new_thread);
1288
1289	/*
1290	 * Nothing after _switch will be run for newly created tasks,
1291	 * because they switch directly to ret_from_fork/ret_from_kernel_thread
1292	 * etc. Code added here should have a comment explaining why that is
1293	 * okay.
1294	 */
1295
1296#ifdef CONFIG_PPC_BOOK3S_64
1297	/*
1298	 * This applies to a process that was context switched while inside
1299	 * arch_enter_lazy_mmu_mode(), to re-activate the batch that was
1300	 * deactivated above, before _switch(). This will never be the case
1301	 * for new tasks.
1302	 */
1303	if (current_thread_info()->local_flags & _TLF_LAZY_MMU) {
1304		current_thread_info()->local_flags &= ~_TLF_LAZY_MMU;
1305		batch = this_cpu_ptr(&ppc64_tlb_batch);
1306		batch->active = 1;
1307	}
1308
1309	/*
1310	 * Math facilities are masked out of the child MSR in copy_thread.
1311	 * A new task does not need to restore_math because it will
1312	 * demand fault them.
1313	 */
1314	if (current->thread.regs)
1315		restore_math(current->thread.regs);
 
 
 
 
 
 
 
 
 
 
 
 
 
1316#endif /* CONFIG_PPC_BOOK3S_64 */
1317
1318	return last;
1319}
1320
1321#define NR_INSN_TO_PRINT	16
1322
1323static void show_instructions(struct pt_regs *regs)
1324{
1325	int i;
1326	unsigned long nip = regs->nip;
1327	unsigned long pc = regs->nip - (NR_INSN_TO_PRINT * 3 / 4 * sizeof(int));
1328
1329	printk("Instruction dump:");
1330
1331	/*
1332	 * If we were executing with the MMU off for instructions, adjust pc
1333	 * rather than printing XXXXXXXX.
1334	 */
1335	if (!IS_ENABLED(CONFIG_BOOKE) && !(regs->msr & MSR_IR)) {
1336		pc = (unsigned long)phys_to_virt(pc);
1337		nip = (unsigned long)phys_to_virt(regs->nip);
1338	}
1339
1340	for (i = 0; i < NR_INSN_TO_PRINT; i++) {
1341		int instr;
1342
1343		if (!(i % 8))
1344			pr_cont("\n");
1345
1346		if (!__kernel_text_address(pc) ||
1347		    get_kernel_nofault(instr, (const void *)pc)) {
1348			pr_cont("XXXXXXXX ");
1349		} else {
1350			if (nip == pc)
1351				pr_cont("<%08x> ", instr);
1352			else
1353				pr_cont("%08x ", instr);
1354		}
1355
1356		pc += sizeof(int);
1357	}
1358
1359	pr_cont("\n");
1360}
1361
1362void show_user_instructions(struct pt_regs *regs)
1363{
1364	unsigned long pc;
1365	int n = NR_INSN_TO_PRINT;
1366	struct seq_buf s;
1367	char buf[96]; /* enough for 8 times 9 + 2 chars */
1368
1369	pc = regs->nip - (NR_INSN_TO_PRINT * 3 / 4 * sizeof(int));
1370
1371	seq_buf_init(&s, buf, sizeof(buf));
1372
1373	while (n) {
1374		int i;
1375
1376		seq_buf_clear(&s);
1377
1378		for (i = 0; i < 8 && n; i++, n--, pc += sizeof(int)) {
1379			int instr;
1380
1381			if (copy_from_user_nofault(&instr, (void __user *)pc,
1382					sizeof(instr))) {
1383				seq_buf_printf(&s, "XXXXXXXX ");
1384				continue;
1385			}
1386			seq_buf_printf(&s, regs->nip == pc ? "<%08x> " : "%08x ", instr);
1387		}
1388
1389		if (!seq_buf_has_overflowed(&s))
1390			pr_info("%s[%d]: code: %s\n", current->comm,
1391				current->pid, s.buffer);
1392	}
1393}
1394
1395struct regbit {
1396	unsigned long bit;
1397	const char *name;
1398};
1399
1400static struct regbit msr_bits[] = {
1401#if defined(CONFIG_PPC64) && !defined(CONFIG_BOOKE)
1402	{MSR_SF,	"SF"},
1403	{MSR_HV,	"HV"},
1404#endif
1405	{MSR_VEC,	"VEC"},
1406	{MSR_VSX,	"VSX"},
1407#ifdef CONFIG_BOOKE
1408	{MSR_CE,	"CE"},
1409#endif
1410	{MSR_EE,	"EE"},
1411	{MSR_PR,	"PR"},
1412	{MSR_FP,	"FP"},
1413	{MSR_ME,	"ME"},
1414#ifdef CONFIG_BOOKE
1415	{MSR_DE,	"DE"},
1416#else
1417	{MSR_SE,	"SE"},
1418	{MSR_BE,	"BE"},
1419#endif
1420	{MSR_IR,	"IR"},
1421	{MSR_DR,	"DR"},
1422	{MSR_PMM,	"PMM"},
1423#ifndef CONFIG_BOOKE
1424	{MSR_RI,	"RI"},
1425	{MSR_LE,	"LE"},
1426#endif
1427	{0,		NULL}
1428};
1429
1430static void print_bits(unsigned long val, struct regbit *bits, const char *sep)
1431{
1432	const char *s = "";
1433
1434	for (; bits->bit; ++bits)
1435		if (val & bits->bit) {
1436			pr_cont("%s%s", s, bits->name);
1437			s = sep;
1438		}
1439}
1440
1441#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1442static struct regbit msr_tm_bits[] = {
1443	{MSR_TS_T,	"T"},
1444	{MSR_TS_S,	"S"},
1445	{MSR_TM,	"E"},
1446	{0,		NULL}
1447};
1448
1449static void print_tm_bits(unsigned long val)
1450{
1451/*
1452 * This only prints something if at least one of the TM bit is set.
1453 * Inside the TM[], the output means:
1454 *   E: Enabled		(bit 32)
1455 *   S: Suspended	(bit 33)
1456 *   T: Transactional	(bit 34)
1457 */
1458	if (val & (MSR_TM | MSR_TS_S | MSR_TS_T)) {
1459		pr_cont(",TM[");
1460		print_bits(val, msr_tm_bits, "");
1461		pr_cont("]");
1462	}
1463}
1464#else
1465static void print_tm_bits(unsigned long val) {}
1466#endif
1467
1468static void print_msr_bits(unsigned long val)
1469{
1470	pr_cont("<");
1471	print_bits(val, msr_bits, ",");
1472	print_tm_bits(val);
1473	pr_cont(">");
1474}
1475
1476#ifdef CONFIG_PPC64
1477#define REG		"%016lx"
1478#define REGS_PER_LINE	4
 
1479#else
1480#define REG		"%08lx"
1481#define REGS_PER_LINE	8
 
1482#endif
1483
1484static void __show_regs(struct pt_regs *regs)
1485{
1486	int i, trap;
1487
 
 
1488	printk("NIP:  "REG" LR: "REG" CTR: "REG"\n",
1489	       regs->nip, regs->link, regs->ctr);
1490	printk("REGS: %px TRAP: %04lx   %s  (%s)\n",
1491	       regs, regs->trap, print_tainted(), init_utsname()->release);
1492	printk("MSR:  "REG" ", regs->msr);
1493	print_msr_bits(regs->msr);
1494	pr_cont("  CR: %08lx  XER: %08lx\n", regs->ccr, regs->xer);
1495	trap = TRAP(regs);
1496	if (!trap_is_syscall(regs) && cpu_has_feature(CPU_FTR_CFAR))
1497		pr_cont("CFAR: "REG" ", regs->orig_gpr3);
1498	if (trap == INTERRUPT_MACHINE_CHECK ||
1499	    trap == INTERRUPT_DATA_STORAGE ||
1500	    trap == INTERRUPT_ALIGNMENT) {
1501		if (IS_ENABLED(CONFIG_4xx) || IS_ENABLED(CONFIG_BOOKE))
1502			pr_cont("DEAR: "REG" ESR: "REG" ", regs->dar, regs->dsisr);
1503		else
1504			pr_cont("DAR: "REG" DSISR: %08lx ", regs->dar, regs->dsisr);
1505	}
1506
1507#ifdef CONFIG_PPC64
1508	pr_cont("IRQMASK: %lx ", regs->softe);
1509#endif
1510#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1511	if (MSR_TM_ACTIVE(regs->msr))
1512		pr_cont("\nPACATMSCRATCH: %016llx ", get_paca()->tm_scratch);
1513#endif
1514
1515	for (i = 0;  i < 32;  i++) {
1516		if ((i % REGS_PER_LINE) == 0)
1517			pr_cont("\nGPR%02d: ", i);
1518		pr_cont(REG " ", regs->gpr[i]);
 
 
1519	}
1520	pr_cont("\n");
 
1521	/*
1522	 * Lookup NIP late so we have the best change of getting the
1523	 * above info out without failing
1524	 */
1525	if (IS_ENABLED(CONFIG_KALLSYMS)) {
1526		printk("NIP ["REG"] %pS\n", regs->nip, (void *)regs->nip);
1527		printk("LR ["REG"] %pS\n", regs->link, (void *)regs->link);
1528	}
1529}
1530
1531void show_regs(struct pt_regs *regs)
1532{
1533	show_regs_print_info(KERN_DEFAULT);
1534	__show_regs(regs);
1535	show_stack(current, (unsigned long *) regs->gpr[1], KERN_DEFAULT);
1536	if (!user_mode(regs))
1537		show_instructions(regs);
1538}
1539
1540void flush_thread(void)
1541{
1542#ifdef CONFIG_HAVE_HW_BREAKPOINT
1543	flush_ptrace_hw_breakpoint(current);
1544#else /* CONFIG_HAVE_HW_BREAKPOINT */
1545	set_debug_reg_defaults(&current->thread);
1546#endif /* CONFIG_HAVE_HW_BREAKPOINT */
1547}
1548
 
1549void arch_setup_new_exec(void)
1550{
1551
1552#ifdef CONFIG_PPC_BOOK3S_64
1553	if (!radix_enabled())
1554		hash__setup_new_exec();
1555#endif
1556	/*
1557	 * If we exec out of a kernel thread then thread.regs will not be
1558	 * set.  Do it now.
1559	 */
1560	if (!current->thread.regs) {
1561		struct pt_regs *regs = task_stack_page(current) + THREAD_SIZE;
1562		current->thread.regs = regs - 1;
1563	}
1564
1565#ifdef CONFIG_PPC_MEM_KEYS
1566	current->thread.regs->amr  = default_amr;
1567	current->thread.regs->iamr  = default_iamr;
1568#endif
1569}
 
1570
1571#ifdef CONFIG_PPC64
1572/**
1573 * Assign a TIDR (thread ID) for task @t and set it in the thread
1574 * structure. For now, we only support setting TIDR for 'current' task.
1575 *
1576 * Since the TID value is a truncated form of it PID, it is possible
1577 * (but unlikely) for 2 threads to have the same TID. In the unlikely event
1578 * that 2 threads share the same TID and are waiting, one of the following
1579 * cases will happen:
1580 *
1581 * 1. The correct thread is running, the wrong thread is not
1582 * In this situation, the correct thread is woken and proceeds to pass it's
1583 * condition check.
1584 *
1585 * 2. Neither threads are running
1586 * In this situation, neither thread will be woken. When scheduled, the waiting
1587 * threads will execute either a wait, which will return immediately, followed
1588 * by a condition check, which will pass for the correct thread and fail
1589 * for the wrong thread, or they will execute the condition check immediately.
1590 *
1591 * 3. The wrong thread is running, the correct thread is not
1592 * The wrong thread will be woken, but will fail it's condition check and
1593 * re-execute wait. The correct thread, when scheduled, will execute either
1594 * it's condition check (which will pass), or wait, which returns immediately
1595 * when called the first time after the thread is scheduled, followed by it's
1596 * condition check (which will pass).
1597 *
1598 * 4. Both threads are running
1599 * Both threads will be woken. The wrong thread will fail it's condition check
1600 * and execute another wait, while the correct thread will pass it's condition
1601 * check.
1602 *
1603 * @t: the task to set the thread ID for
1604 */
1605int set_thread_tidr(struct task_struct *t)
1606{
1607	if (!cpu_has_feature(CPU_FTR_P9_TIDR))
1608		return -EINVAL;
1609
1610	if (t != current)
1611		return -EINVAL;
1612
1613	if (t->thread.tidr)
1614		return 0;
1615
1616	t->thread.tidr = (u16)task_pid_nr(t);
1617	mtspr(SPRN_TIDR, t->thread.tidr);
1618
1619	return 0;
1620}
1621EXPORT_SYMBOL_GPL(set_thread_tidr);
1622
1623#endif /* CONFIG_PPC64 */
1624
1625void
1626release_thread(struct task_struct *t)
1627{
1628}
1629
1630/*
1631 * this gets called so that we can store coprocessor state into memory and
1632 * copy the current task into the new thread.
1633 */
1634int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
1635{
1636	flush_all_to_thread(src);
1637	/*
1638	 * Flush TM state out so we can copy it.  __switch_to_tm() does this
1639	 * flush but it removes the checkpointed state from the current CPU and
1640	 * transitions the CPU out of TM mode.  Hence we need to call
1641	 * tm_recheckpoint_new_task() (on the same task) to restore the
1642	 * checkpointed state back and the TM mode.
1643	 *
1644	 * Can't pass dst because it isn't ready. Doesn't matter, passing
1645	 * dst is only important for __switch_to()
1646	 */
1647	__switch_to_tm(src, src);
1648
1649	*dst = *src;
1650
1651	clear_task_ebb(dst);
1652
1653	return 0;
1654}
1655
1656static void setup_ksp_vsid(struct task_struct *p, unsigned long sp)
1657{
1658#ifdef CONFIG_PPC_BOOK3S_64
1659	unsigned long sp_vsid;
1660	unsigned long llp = mmu_psize_defs[mmu_linear_psize].sllp;
1661
1662	if (radix_enabled())
1663		return;
1664
1665	if (mmu_has_feature(MMU_FTR_1T_SEGMENT))
1666		sp_vsid = get_kernel_vsid(sp, MMU_SEGSIZE_1T)
1667			<< SLB_VSID_SHIFT_1T;
1668	else
1669		sp_vsid = get_kernel_vsid(sp, MMU_SEGSIZE_256M)
1670			<< SLB_VSID_SHIFT;
1671	sp_vsid |= SLB_VSID_KERNEL | llp;
1672	p->thread.ksp_vsid = sp_vsid;
1673#endif
1674}
1675
1676/*
1677 * Copy a thread..
1678 */
1679
1680/*
1681 * Copy architecture-specific thread state
1682 */
1683int copy_thread(unsigned long clone_flags, unsigned long usp,
1684		unsigned long kthread_arg, struct task_struct *p,
1685		unsigned long tls)
1686{
1687	struct pt_regs *childregs, *kregs;
1688	extern void ret_from_fork(void);
1689	extern void ret_from_fork_scv(void);
1690	extern void ret_from_kernel_thread(void);
1691	void (*f)(void);
1692	unsigned long sp = (unsigned long)task_stack_page(p) + THREAD_SIZE;
1693	struct thread_info *ti = task_thread_info(p);
1694#ifdef CONFIG_HAVE_HW_BREAKPOINT
1695	int i;
1696#endif
1697
1698	klp_init_thread_info(p);
1699
1700	/* Copy registers */
1701	sp -= sizeof(struct pt_regs);
1702	childregs = (struct pt_regs *) sp;
1703	if (unlikely(p->flags & (PF_KTHREAD | PF_IO_WORKER))) {
1704		/* kernel thread */
1705		memset(childregs, 0, sizeof(struct pt_regs));
1706		childregs->gpr[1] = sp + sizeof(struct pt_regs);
1707		/* function */
1708		if (usp)
1709			childregs->gpr[14] = ppc_function_entry((void *)usp);
1710#ifdef CONFIG_PPC64
1711		clear_tsk_thread_flag(p, TIF_32BIT);
1712		childregs->softe = IRQS_ENABLED;
1713#endif
1714		childregs->gpr[15] = kthread_arg;
1715		p->thread.regs = NULL;	/* no user register state */
1716		ti->flags |= _TIF_RESTOREALL;
1717		f = ret_from_kernel_thread;
1718	} else {
1719		/* user thread */
1720		struct pt_regs *regs = current_pt_regs();
 
1721		*childregs = *regs;
1722		if (usp)
1723			childregs->gpr[1] = usp;
1724		p->thread.regs = childregs;
1725		/* 64s sets this in ret_from_fork */
1726		if (!IS_ENABLED(CONFIG_PPC_BOOK3S_64))
1727			childregs->gpr[3] = 0;  /* Result from fork() */
1728		if (clone_flags & CLONE_SETTLS) {
1729			if (!is_32bit_task())
1730				childregs->gpr[13] = tls;
1731			else
1732				childregs->gpr[2] = tls;
1733		}
1734
1735		if (trap_is_scv(regs))
1736			f = ret_from_fork_scv;
1737		else
1738			f = ret_from_fork;
1739	}
1740	childregs->msr &= ~(MSR_FP|MSR_VEC|MSR_VSX);
1741	sp -= STACK_FRAME_OVERHEAD;
1742
1743	/*
1744	 * The way this works is that at some point in the future
1745	 * some task will call _switch to switch to the new task.
1746	 * That will pop off the stack frame created below and start
1747	 * the new task running at ret_from_fork.  The new task will
1748	 * do some house keeping and then return from the fork or clone
1749	 * system call, using the stack frame created above.
1750	 */
1751	((unsigned long *)sp)[0] = 0;
1752	sp -= sizeof(struct pt_regs);
1753	kregs = (struct pt_regs *) sp;
1754	sp -= STACK_FRAME_OVERHEAD;
1755	p->thread.ksp = sp;
 
 
 
1756#ifdef CONFIG_HAVE_HW_BREAKPOINT
1757	for (i = 0; i < nr_wp_slots(); i++)
1758		p->thread.ptrace_bps[i] = NULL;
1759#endif
1760
1761#ifdef CONFIG_PPC_FPU_REGS
1762	p->thread.fp_save_area = NULL;
1763#endif
1764#ifdef CONFIG_ALTIVEC
1765	p->thread.vr_save_area = NULL;
1766#endif
1767#if defined(CONFIG_PPC_BOOK3S_32) && defined(CONFIG_PPC_KUAP)
1768	p->thread.kuap = KUAP_NONE;
1769#endif
1770
1771	setup_ksp_vsid(p, sp);
1772
1773#ifdef CONFIG_PPC64 
1774	if (cpu_has_feature(CPU_FTR_DSCR)) {
1775		p->thread.dscr_inherit = current->thread.dscr_inherit;
1776		p->thread.dscr = mfspr(SPRN_DSCR);
1777	}
1778	if (cpu_has_feature(CPU_FTR_HAS_PPR))
1779		childregs->ppr = DEFAULT_PPR;
1780
1781	p->thread.tidr = 0;
1782#endif
1783	/*
1784	 * Run with the current AMR value of the kernel
1785	 */
1786#ifdef CONFIG_PPC_PKEY
1787	if (mmu_has_feature(MMU_FTR_BOOK3S_KUAP))
1788		kregs->amr = AMR_KUAP_BLOCKED;
1789
1790	if (mmu_has_feature(MMU_FTR_BOOK3S_KUEP))
1791		kregs->iamr = AMR_KUEP_BLOCKED;
1792#endif
1793	kregs->nip = ppc_function_entry(f);
1794	return 0;
1795}
1796
1797void preload_new_slb_context(unsigned long start, unsigned long sp);
1798
1799/*
1800 * Set up a thread for executing a new program
1801 */
1802void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp)
1803{
1804#ifdef CONFIG_PPC64
1805	unsigned long load_addr = regs->gpr[2];	/* saved by ELF_PLAT_INIT */
1806
1807	if (IS_ENABLED(CONFIG_PPC_BOOK3S_64) && !radix_enabled())
 
1808		preload_new_slb_context(start, sp);
1809#endif
 
 
 
 
 
 
 
 
 
 
1810
1811#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1812	/*
1813	 * Clear any transactional state, we're exec()ing. The cause is
1814	 * not important as there will never be a recheckpoint so it's not
1815	 * user visible.
1816	 */
1817	if (MSR_TM_SUSPENDED(mfmsr()))
1818		tm_reclaim_current(0);
1819#endif
1820
1821	memset(regs->gpr, 0, sizeof(regs->gpr));
1822	regs->ctr = 0;
1823	regs->link = 0;
1824	regs->xer = 0;
1825	regs->ccr = 0;
1826	regs->gpr[1] = sp;
1827
 
 
 
 
 
 
 
1828#ifdef CONFIG_PPC32
1829	regs->mq = 0;
1830	regs->nip = start;
1831	regs->msr = MSR_USER;
1832#else
1833	if (!is_32bit_task()) {
1834		unsigned long entry;
1835
1836		if (is_elf2_task()) {
1837			/* Look ma, no function descriptors! */
1838			entry = start;
1839
1840			/*
1841			 * Ulrich says:
1842			 *   The latest iteration of the ABI requires that when
1843			 *   calling a function (at its global entry point),
1844			 *   the caller must ensure r12 holds the entry point
1845			 *   address (so that the function can quickly
1846			 *   establish addressability).
1847			 */
1848			regs->gpr[12] = start;
1849			/* Make sure that's restored on entry to userspace. */
1850			set_thread_flag(TIF_RESTOREALL);
1851		} else {
1852			unsigned long toc;
1853
1854			/* start is a relocated pointer to the function
1855			 * descriptor for the elf _start routine.  The first
1856			 * entry in the function descriptor is the entry
1857			 * address of _start and the second entry is the TOC
1858			 * value we need to use.
1859			 */
1860			__get_user(entry, (unsigned long __user *)start);
1861			__get_user(toc, (unsigned long __user *)start+1);
1862
1863			/* Check whether the e_entry function descriptor entries
1864			 * need to be relocated before we can use them.
1865			 */
1866			if (load_addr != 0) {
1867				entry += load_addr;
1868				toc   += load_addr;
1869			}
1870			regs->gpr[2] = toc;
1871		}
1872		regs_set_return_ip(regs, entry);
1873		regs_set_return_msr(regs, MSR_USER64);
1874	} else {
 
1875		regs->gpr[2] = 0;
1876		regs_set_return_ip(regs, start);
1877		regs_set_return_msr(regs, MSR_USER32);
1878	}
1879
1880#endif
1881#ifdef CONFIG_VSX
1882	current->thread.used_vsr = 0;
1883#endif
1884	current->thread.load_slb = 0;
1885	current->thread.load_fp = 0;
1886#ifdef CONFIG_PPC_FPU_REGS
1887	memset(&current->thread.fp_state, 0, sizeof(current->thread.fp_state));
1888	current->thread.fp_save_area = NULL;
1889#endif
1890#ifdef CONFIG_ALTIVEC
1891	memset(&current->thread.vr_state, 0, sizeof(current->thread.vr_state));
1892	current->thread.vr_state.vscr.u[3] = 0x00010000; /* Java mode disabled */
1893	current->thread.vr_save_area = NULL;
1894	current->thread.vrsave = 0;
1895	current->thread.used_vr = 0;
1896	current->thread.load_vec = 0;
1897#endif /* CONFIG_ALTIVEC */
1898#ifdef CONFIG_SPE
1899	memset(current->thread.evr, 0, sizeof(current->thread.evr));
1900	current->thread.acc = 0;
1901	current->thread.spefscr = 0;
1902	current->thread.used_spe = 0;
1903#endif /* CONFIG_SPE */
1904#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1905	current->thread.tm_tfhar = 0;
1906	current->thread.tm_texasr = 0;
1907	current->thread.tm_tfiar = 0;
1908	current->thread.load_tm = 0;
1909#endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
 
 
1910}
1911EXPORT_SYMBOL(start_thread);
1912
1913#define PR_FP_ALL_EXCEPT (PR_FP_EXC_DIV | PR_FP_EXC_OVF | PR_FP_EXC_UND \
1914		| PR_FP_EXC_RES | PR_FP_EXC_INV)
1915
1916int set_fpexc_mode(struct task_struct *tsk, unsigned int val)
1917{
1918	struct pt_regs *regs = tsk->thread.regs;
1919
1920	/* This is a bit hairy.  If we are an SPE enabled  processor
1921	 * (have embedded fp) we store the IEEE exception enable flags in
1922	 * fpexc_mode.  fpexc_mode is also used for setting FP exception
1923	 * mode (asyn, precise, disabled) for 'Classic' FP. */
1924	if (val & PR_FP_EXC_SW_ENABLE) {
 
1925		if (cpu_has_feature(CPU_FTR_SPE)) {
1926			/*
1927			 * When the sticky exception bits are set
1928			 * directly by userspace, it must call prctl
1929			 * with PR_GET_FPEXC (with PR_FP_EXC_SW_ENABLE
1930			 * in the existing prctl settings) or
1931			 * PR_SET_FPEXC (with PR_FP_EXC_SW_ENABLE in
1932			 * the bits being set).  <fenv.h> functions
1933			 * saving and restoring the whole
1934			 * floating-point environment need to do so
1935			 * anyway to restore the prctl settings from
1936			 * the saved environment.
1937			 */
1938#ifdef CONFIG_SPE
1939			tsk->thread.spefscr_last = mfspr(SPRN_SPEFSCR);
1940			tsk->thread.fpexc_mode = val &
1941				(PR_FP_EXC_SW_ENABLE | PR_FP_ALL_EXCEPT);
1942#endif
1943			return 0;
1944		} else {
1945			return -EINVAL;
1946		}
 
 
 
1947	}
1948
1949	/* on a CONFIG_SPE this does not hurt us.  The bits that
1950	 * __pack_fe01 use do not overlap with bits used for
1951	 * PR_FP_EXC_SW_ENABLE.  Additionally, the MSR[FE0,FE1] bits
1952	 * on CONFIG_SPE implementations are reserved so writing to
1953	 * them does not change anything */
1954	if (val > PR_FP_EXC_PRECISE)
1955		return -EINVAL;
1956	tsk->thread.fpexc_mode = __pack_fe01(val);
1957	if (regs != NULL && (regs->msr & MSR_FP) != 0) {
1958		regs_set_return_msr(regs, (regs->msr & ~(MSR_FE0|MSR_FE1))
1959						| tsk->thread.fpexc_mode);
1960	}
1961	return 0;
1962}
1963
1964int get_fpexc_mode(struct task_struct *tsk, unsigned long adr)
1965{
1966	unsigned int val = 0;
1967
1968	if (tsk->thread.fpexc_mode & PR_FP_EXC_SW_ENABLE) {
 
1969		if (cpu_has_feature(CPU_FTR_SPE)) {
1970			/*
1971			 * When the sticky exception bits are set
1972			 * directly by userspace, it must call prctl
1973			 * with PR_GET_FPEXC (with PR_FP_EXC_SW_ENABLE
1974			 * in the existing prctl settings) or
1975			 * PR_SET_FPEXC (with PR_FP_EXC_SW_ENABLE in
1976			 * the bits being set).  <fenv.h> functions
1977			 * saving and restoring the whole
1978			 * floating-point environment need to do so
1979			 * anyway to restore the prctl settings from
1980			 * the saved environment.
1981			 */
1982#ifdef CONFIG_SPE
1983			tsk->thread.spefscr_last = mfspr(SPRN_SPEFSCR);
1984			val = tsk->thread.fpexc_mode;
1985#endif
1986		} else
1987			return -EINVAL;
1988	} else {
 
 
 
1989		val = __unpack_fe01(tsk->thread.fpexc_mode);
1990	}
1991	return put_user(val, (unsigned int __user *) adr);
1992}
1993
1994int set_endian(struct task_struct *tsk, unsigned int val)
1995{
1996	struct pt_regs *regs = tsk->thread.regs;
1997
1998	if ((val == PR_ENDIAN_LITTLE && !cpu_has_feature(CPU_FTR_REAL_LE)) ||
1999	    (val == PR_ENDIAN_PPC_LITTLE && !cpu_has_feature(CPU_FTR_PPC_LE)))
2000		return -EINVAL;
2001
2002	if (regs == NULL)
2003		return -EINVAL;
2004
2005	if (val == PR_ENDIAN_BIG)
2006		regs_set_return_msr(regs, regs->msr & ~MSR_LE);
2007	else if (val == PR_ENDIAN_LITTLE || val == PR_ENDIAN_PPC_LITTLE)
2008		regs_set_return_msr(regs, regs->msr | MSR_LE);
2009	else
2010		return -EINVAL;
2011
2012	return 0;
2013}
2014
2015int get_endian(struct task_struct *tsk, unsigned long adr)
2016{
2017	struct pt_regs *regs = tsk->thread.regs;
2018	unsigned int val;
2019
2020	if (!cpu_has_feature(CPU_FTR_PPC_LE) &&
2021	    !cpu_has_feature(CPU_FTR_REAL_LE))
2022		return -EINVAL;
2023
2024	if (regs == NULL)
2025		return -EINVAL;
2026
2027	if (regs->msr & MSR_LE) {
2028		if (cpu_has_feature(CPU_FTR_REAL_LE))
2029			val = PR_ENDIAN_LITTLE;
2030		else
2031			val = PR_ENDIAN_PPC_LITTLE;
2032	} else
2033		val = PR_ENDIAN_BIG;
2034
2035	return put_user(val, (unsigned int __user *)adr);
2036}
2037
2038int set_unalign_ctl(struct task_struct *tsk, unsigned int val)
2039{
2040	tsk->thread.align_ctl = val;
2041	return 0;
2042}
2043
2044int get_unalign_ctl(struct task_struct *tsk, unsigned long adr)
2045{
2046	return put_user(tsk->thread.align_ctl, (unsigned int __user *)adr);
2047}
2048
2049static inline int valid_irq_stack(unsigned long sp, struct task_struct *p,
2050				  unsigned long nbytes)
2051{
2052	unsigned long stack_page;
2053	unsigned long cpu = task_cpu(p);
2054
2055	stack_page = (unsigned long)hardirq_ctx[cpu];
2056	if (sp >= stack_page && sp <= stack_page + THREAD_SIZE - nbytes)
2057		return 1;
2058
2059	stack_page = (unsigned long)softirq_ctx[cpu];
2060	if (sp >= stack_page && sp <= stack_page + THREAD_SIZE - nbytes)
2061		return 1;
2062
2063	return 0;
2064}
2065
2066static inline int valid_emergency_stack(unsigned long sp, struct task_struct *p,
2067					unsigned long nbytes)
2068{
2069#ifdef CONFIG_PPC64
2070	unsigned long stack_page;
2071	unsigned long cpu = task_cpu(p);
2072
2073	if (!paca_ptrs)
2074		return 0;
2075
2076	stack_page = (unsigned long)paca_ptrs[cpu]->emergency_sp - THREAD_SIZE;
2077	if (sp >= stack_page && sp <= stack_page + THREAD_SIZE - nbytes)
2078		return 1;
2079
2080# ifdef CONFIG_PPC_BOOK3S_64
2081	stack_page = (unsigned long)paca_ptrs[cpu]->nmi_emergency_sp - THREAD_SIZE;
2082	if (sp >= stack_page && sp <= stack_page + THREAD_SIZE - nbytes)
2083		return 1;
2084
2085	stack_page = (unsigned long)paca_ptrs[cpu]->mc_emergency_sp - THREAD_SIZE;
2086	if (sp >= stack_page && sp <= stack_page + THREAD_SIZE - nbytes)
2087		return 1;
2088# endif
2089#endif
2090
2091	return 0;
2092}
2093
2094
2095int validate_sp(unsigned long sp, struct task_struct *p,
2096		       unsigned long nbytes)
2097{
2098	unsigned long stack_page = (unsigned long)task_stack_page(p);
2099
2100	if (sp < THREAD_SIZE)
2101		return 0;
2102
2103	if (sp >= stack_page && sp <= stack_page + THREAD_SIZE - nbytes)
2104		return 1;
2105
2106	if (valid_irq_stack(sp, p, nbytes))
2107		return 1;
2108
2109	return valid_emergency_stack(sp, p, nbytes);
2110}
2111
2112EXPORT_SYMBOL(validate_sp);
2113
2114static unsigned long __get_wchan(struct task_struct *p)
2115{
2116	unsigned long ip, sp;
2117	int count = 0;
2118
2119	if (!p || p == current || task_is_running(p))
2120		return 0;
2121
2122	sp = p->thread.ksp;
2123	if (!validate_sp(sp, p, STACK_FRAME_OVERHEAD))
2124		return 0;
2125
2126	do {
2127		sp = *(unsigned long *)sp;
2128		if (!validate_sp(sp, p, STACK_FRAME_OVERHEAD) ||
2129		    task_is_running(p))
2130			return 0;
2131		if (count > 0) {
2132			ip = ((unsigned long *)sp)[STACK_FRAME_LR_SAVE];
2133			if (!in_sched_functions(ip))
2134				return ip;
2135		}
2136	} while (count++ < 16);
2137	return 0;
2138}
2139
2140unsigned long get_wchan(struct task_struct *p)
2141{
2142	unsigned long ret;
2143
2144	if (!try_get_task_stack(p))
2145		return 0;
2146
2147	ret = __get_wchan(p);
2148
2149	put_task_stack(p);
2150
2151	return ret;
2152}
2153
2154static int kstack_depth_to_print = CONFIG_PRINT_STACK_DEPTH;
2155
2156void __no_sanitize_address show_stack(struct task_struct *tsk,
2157				      unsigned long *stack,
2158				      const char *loglvl)
2159{
2160	unsigned long sp, ip, lr, newsp;
2161	int count = 0;
2162	int firstframe = 1;
 
2163	unsigned long ret_addr;
2164	int ftrace_idx = 0;
 
2165
2166	if (tsk == NULL)
2167		tsk = current;
2168
2169	if (!try_get_task_stack(tsk))
2170		return;
2171
2172	sp = (unsigned long) stack;
2173	if (sp == 0) {
2174		if (tsk == current)
2175			sp = current_stack_frame();
2176		else
2177			sp = tsk->thread.ksp;
2178	}
2179
2180	lr = 0;
2181	printk("%sCall Trace:\n", loglvl);
2182	do {
2183		if (!validate_sp(sp, tsk, STACK_FRAME_OVERHEAD))
2184			break;
2185
2186		stack = (unsigned long *) sp;
2187		newsp = stack[0];
2188		ip = stack[STACK_FRAME_LR_SAVE];
2189		if (!firstframe || ip != lr) {
2190			printk("%s["REG"] ["REG"] %pS",
2191				loglvl, sp, ip, (void *)ip);
 
2192			ret_addr = ftrace_graph_ret_addr(current,
2193						&ftrace_idx, ip, stack);
2194			if (ret_addr != ip)
2195				pr_cont(" (%pS)", (void *)ret_addr);
 
2196			if (firstframe)
2197				pr_cont(" (unreliable)");
2198			pr_cont("\n");
2199		}
2200		firstframe = 0;
2201
2202		/*
2203		 * See if this is an exception frame.
2204		 * We look for the "regshere" marker in the current frame.
2205		 */
2206		if (validate_sp(sp, tsk, STACK_FRAME_WITH_PT_REGS)
2207		    && stack[STACK_FRAME_MARKER] == STACK_FRAME_REGS_MARKER) {
2208			struct pt_regs *regs = (struct pt_regs *)
2209				(sp + STACK_FRAME_OVERHEAD);
2210
2211			lr = regs->link;
2212			printk("%s--- interrupt: %lx at %pS\n",
2213			       loglvl, regs->trap, (void *)regs->nip);
2214			__show_regs(regs);
2215			printk("%s--- interrupt: %lx\n",
2216			       loglvl, regs->trap);
2217
2218			firstframe = 1;
2219		}
2220
2221		sp = newsp;
2222	} while (count++ < kstack_depth_to_print);
2223
2224	put_task_stack(tsk);
2225}
2226
2227#ifdef CONFIG_PPC64
2228/* Called with hard IRQs off */
2229void notrace __ppc64_runlatch_on(void)
2230{
2231	struct thread_info *ti = current_thread_info();
2232
2233	if (cpu_has_feature(CPU_FTR_ARCH_206)) {
2234		/*
2235		 * Least significant bit (RUN) is the only writable bit of
2236		 * the CTRL register, so we can avoid mfspr. 2.06 is not the
2237		 * earliest ISA where this is the case, but it's convenient.
2238		 */
2239		mtspr(SPRN_CTRLT, CTRL_RUNLATCH);
2240	} else {
2241		unsigned long ctrl;
2242
2243		/*
2244		 * Some architectures (e.g., Cell) have writable fields other
2245		 * than RUN, so do the read-modify-write.
2246		 */
2247		ctrl = mfspr(SPRN_CTRLF);
2248		ctrl |= CTRL_RUNLATCH;
2249		mtspr(SPRN_CTRLT, ctrl);
2250	}
2251
2252	ti->local_flags |= _TLF_RUNLATCH;
2253}
2254
2255/* Called with hard IRQs off */
2256void notrace __ppc64_runlatch_off(void)
2257{
2258	struct thread_info *ti = current_thread_info();
2259
2260	ti->local_flags &= ~_TLF_RUNLATCH;
2261
2262	if (cpu_has_feature(CPU_FTR_ARCH_206)) {
2263		mtspr(SPRN_CTRLT, 0);
2264	} else {
2265		unsigned long ctrl;
2266
2267		ctrl = mfspr(SPRN_CTRLF);
2268		ctrl &= ~CTRL_RUNLATCH;
2269		mtspr(SPRN_CTRLT, ctrl);
2270	}
2271}
2272#endif /* CONFIG_PPC64 */
2273
2274unsigned long arch_align_stack(unsigned long sp)
2275{
2276	if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
2277		sp -= get_random_int() & ~PAGE_MASK;
2278	return sp & ~0xf;
2279}
2280
2281static inline unsigned long brk_rnd(void)
2282{
2283        unsigned long rnd = 0;
2284
2285	/* 8MB for 32bit, 1GB for 64bit */
2286	if (is_32bit_task())
2287		rnd = (get_random_long() % (1UL<<(23-PAGE_SHIFT)));
2288	else
2289		rnd = (get_random_long() % (1UL<<(30-PAGE_SHIFT)));
2290
2291	return rnd << PAGE_SHIFT;
2292}
2293
2294unsigned long arch_randomize_brk(struct mm_struct *mm)
2295{
2296	unsigned long base = mm->brk;
2297	unsigned long ret;
2298
2299#ifdef CONFIG_PPC_BOOK3S_64
2300	/*
2301	 * If we are using 1TB segments and we are allowed to randomise
2302	 * the heap, we can put it above 1TB so it is backed by a 1TB
2303	 * segment. Otherwise the heap will be in the bottom 1TB
2304	 * which always uses 256MB segments and this may result in a
2305	 * performance penalty. We don't need to worry about radix. For
2306	 * radix, mmu_highuser_ssize remains unchanged from 256MB.
2307	 */
2308	if (!is_32bit_task() && (mmu_highuser_ssize == MMU_SEGSIZE_1T))
2309		base = max_t(unsigned long, mm->brk, 1UL << SID_SHIFT_1T);
2310#endif
2311
2312	ret = PAGE_ALIGN(base + brk_rnd());
2313
2314	if (ret < mm->brk)
2315		return mm->brk;
2316
2317	return ret;
2318}
2319