1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Derived from "arch/i386/kernel/process.c"
4 * Copyright (C) 1995 Linus Torvalds
6 * Updated and modified by Cort Dougan (cort@cs.nmt.edu) and
7 * Paul Mackerras (paulus@cs.anu.edu.au)
10 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
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>
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>
44 #include <asm/interrupt.h>
46 #include <asm/processor.h>
49 #include <asm/machdep.h>
51 #include <asm/runlatch.h>
52 #include <asm/syscalls.h>
53 #include <asm/switch_to.h>
55 #include <asm/debug.h>
57 #include <asm/firmware.h>
58 #include <asm/hw_irq.h>
60 #include <asm/code-patching.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>
68 #include <linux/kprobes.h>
69 #include <linux/kdebug.h>
71 /* Transactional Memory debug */
73 #define TM_DEBUG(x...) printk(KERN_INFO x)
75 #define TM_DEBUG(x...) do { } while(0)
78 extern unsigned long _get_SP(void);
80 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
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.
86 bool tm_suspend_disabled __ro_after_init = false;
88 static void check_if_tm_restore_required(struct task_struct *tsk)
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.
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);
106 static inline void check_if_tm_restore_required(struct task_struct *tsk) { }
107 #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
109 bool strict_msr_control;
110 EXPORT_SYMBOL(strict_msr_control);
112 static int __init enable_strict_msr_control(char *str)
114 strict_msr_control = true;
115 pr_info("Enabling strict facility control\n");
119 early_param("ppc_strict_facility_enable", enable_strict_msr_control);
121 /* notrace because it's called by restore_math */
122 unsigned long notrace msr_check_and_set(unsigned long bits)
124 unsigned long oldmsr = mfmsr();
125 unsigned long newmsr;
127 newmsr = oldmsr | bits;
129 if (cpu_has_feature(CPU_FTR_VSX) && (bits & MSR_FP))
132 if (oldmsr != newmsr)
137 EXPORT_SYMBOL_GPL(msr_check_and_set);
139 /* notrace because it's called by restore_math */
140 void notrace __msr_check_and_clear(unsigned long bits)
142 unsigned long oldmsr = mfmsr();
143 unsigned long newmsr;
145 newmsr = oldmsr & ~bits;
147 if (cpu_has_feature(CPU_FTR_VSX) && (bits & MSR_FP))
150 if (oldmsr != newmsr)
153 EXPORT_SYMBOL(__msr_check_and_clear);
155 #ifdef CONFIG_PPC_FPU
156 static void __giveup_fpu(struct task_struct *tsk)
161 msr = tsk->thread.regs->msr;
162 msr &= ~(MSR_FP|MSR_FE0|MSR_FE1);
163 if (cpu_has_feature(CPU_FTR_VSX))
165 regs_set_return_msr(tsk->thread.regs, msr);
168 void giveup_fpu(struct task_struct *tsk)
170 check_if_tm_restore_required(tsk);
172 msr_check_and_set(MSR_FP);
174 msr_check_and_clear(MSR_FP);
176 EXPORT_SYMBOL(giveup_fpu);
179 * Make sure the floating-point register state in the
180 * the thread_struct is up to date for task tsk.
182 void flush_fp_to_thread(struct task_struct *tsk)
184 if (tsk->thread.regs) {
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.
194 if (tsk->thread.regs->msr & MSR_FP) {
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.
202 BUG_ON(tsk != current);
208 EXPORT_SYMBOL_GPL(flush_fp_to_thread);
210 void enable_kernel_fp(void)
212 unsigned long cpumsr;
214 WARN_ON(preemptible());
216 cpumsr = msr_check_and_set(MSR_FP);
218 if (current->thread.regs && (current->thread.regs->msr & MSR_FP)) {
219 check_if_tm_restore_required(current);
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.
227 if (!MSR_TM_ACTIVE(cpumsr) &&
228 MSR_TM_ACTIVE(current->thread.regs->msr))
230 __giveup_fpu(current);
233 EXPORT_SYMBOL(enable_kernel_fp);
235 static inline void __giveup_fpu(struct task_struct *tsk) { }
236 #endif /* CONFIG_PPC_FPU */
238 #ifdef CONFIG_ALTIVEC
239 static void __giveup_altivec(struct task_struct *tsk)
244 msr = tsk->thread.regs->msr;
246 if (cpu_has_feature(CPU_FTR_VSX))
248 regs_set_return_msr(tsk->thread.regs, msr);
251 void giveup_altivec(struct task_struct *tsk)
253 check_if_tm_restore_required(tsk);
255 msr_check_and_set(MSR_VEC);
256 __giveup_altivec(tsk);
257 msr_check_and_clear(MSR_VEC);
259 EXPORT_SYMBOL(giveup_altivec);
261 void enable_kernel_altivec(void)
263 unsigned long cpumsr;
265 WARN_ON(preemptible());
267 cpumsr = msr_check_and_set(MSR_VEC);
269 if (current->thread.regs && (current->thread.regs->msr & MSR_VEC)) {
270 check_if_tm_restore_required(current);
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.
278 if (!MSR_TM_ACTIVE(cpumsr) &&
279 MSR_TM_ACTIVE(current->thread.regs->msr))
281 __giveup_altivec(current);
284 EXPORT_SYMBOL(enable_kernel_altivec);
287 * Make sure the VMX/Altivec register state in the
288 * the thread_struct is up to date for task tsk.
290 void flush_altivec_to_thread(struct task_struct *tsk)
292 if (tsk->thread.regs) {
294 if (tsk->thread.regs->msr & MSR_VEC) {
295 BUG_ON(tsk != current);
301 EXPORT_SYMBOL_GPL(flush_altivec_to_thread);
302 #endif /* CONFIG_ALTIVEC */
305 static void __giveup_vsx(struct task_struct *tsk)
307 unsigned long msr = tsk->thread.regs->msr;
310 * We should never be ssetting MSR_VSX without also setting
313 WARN_ON((msr & MSR_VSX) && !((msr & MSR_FP) && (msr & MSR_VEC)));
315 /* __giveup_fpu will clear MSR_VSX */
319 __giveup_altivec(tsk);
322 static void giveup_vsx(struct task_struct *tsk)
324 check_if_tm_restore_required(tsk);
326 msr_check_and_set(MSR_FP|MSR_VEC|MSR_VSX);
328 msr_check_and_clear(MSR_FP|MSR_VEC|MSR_VSX);
331 void enable_kernel_vsx(void)
333 unsigned long cpumsr;
335 WARN_ON(preemptible());
337 cpumsr = msr_check_and_set(MSR_FP|MSR_VEC|MSR_VSX);
339 if (current->thread.regs &&
340 (current->thread.regs->msr & (MSR_VSX|MSR_VEC|MSR_FP))) {
341 check_if_tm_restore_required(current);
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.
349 if (!MSR_TM_ACTIVE(cpumsr) &&
350 MSR_TM_ACTIVE(current->thread.regs->msr))
352 __giveup_vsx(current);
355 EXPORT_SYMBOL(enable_kernel_vsx);
357 void flush_vsx_to_thread(struct task_struct *tsk)
359 if (tsk->thread.regs) {
361 if (tsk->thread.regs->msr & (MSR_VSX|MSR_VEC|MSR_FP)) {
362 BUG_ON(tsk != current);
368 EXPORT_SYMBOL_GPL(flush_vsx_to_thread);
369 #endif /* CONFIG_VSX */
372 void giveup_spe(struct task_struct *tsk)
374 check_if_tm_restore_required(tsk);
376 msr_check_and_set(MSR_SPE);
378 msr_check_and_clear(MSR_SPE);
380 EXPORT_SYMBOL(giveup_spe);
382 void enable_kernel_spe(void)
384 WARN_ON(preemptible());
386 msr_check_and_set(MSR_SPE);
388 if (current->thread.regs && (current->thread.regs->msr & MSR_SPE)) {
389 check_if_tm_restore_required(current);
390 __giveup_spe(current);
393 EXPORT_SYMBOL(enable_kernel_spe);
395 void flush_spe_to_thread(struct task_struct *tsk)
397 if (tsk->thread.regs) {
399 if (tsk->thread.regs->msr & MSR_SPE) {
400 BUG_ON(tsk != current);
401 tsk->thread.spefscr = mfspr(SPRN_SPEFSCR);
407 #endif /* CONFIG_SPE */
409 static unsigned long msr_all_available;
411 static int __init init_msr_all_available(void)
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;
424 early_initcall(init_msr_all_available);
426 void giveup_all(struct task_struct *tsk)
428 unsigned long usermsr;
430 if (!tsk->thread.regs)
433 check_if_tm_restore_required(tsk);
435 usermsr = tsk->thread.regs->msr;
437 if ((usermsr & msr_all_available) == 0)
440 msr_check_and_set(msr_all_available);
442 WARN_ON((usermsr & MSR_VSX) && !((usermsr & MSR_FP) && (usermsr & MSR_VEC)));
444 if (usermsr & MSR_FP)
446 if (usermsr & MSR_VEC)
447 __giveup_altivec(tsk);
448 if (usermsr & MSR_SPE)
451 msr_check_and_clear(msr_all_available);
453 EXPORT_SYMBOL(giveup_all);
455 #ifdef CONFIG_PPC_BOOK3S_64
456 #ifdef CONFIG_PPC_FPU
457 static bool should_restore_fp(void)
459 if (current->thread.load_fp) {
460 current->thread.load_fp++;
466 static void do_restore_fp(void)
468 load_fp_state(¤t->thread.fp_state);
471 static bool should_restore_fp(void) { return false; }
472 static void do_restore_fp(void) { }
473 #endif /* CONFIG_PPC_FPU */
475 #ifdef CONFIG_ALTIVEC
476 static bool should_restore_altivec(void)
478 if (cpu_has_feature(CPU_FTR_ALTIVEC) && (current->thread.load_vec)) {
479 current->thread.load_vec++;
485 static void do_restore_altivec(void)
487 load_vr_state(¤t->thread.vr_state);
488 current->thread.used_vr = 1;
491 static bool should_restore_altivec(void) { return false; }
492 static void do_restore_altivec(void) { }
493 #endif /* CONFIG_ALTIVEC */
495 static bool should_restore_vsx(void)
497 if (cpu_has_feature(CPU_FTR_VSX))
502 static void do_restore_vsx(void)
504 current->thread.used_vsr = 1;
507 static void do_restore_vsx(void) { }
508 #endif /* CONFIG_VSX */
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.
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.
520 void notrace restore_math(struct pt_regs *regs)
523 unsigned long new_msr = 0;
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).
532 if ((!(msr & MSR_FP)) && should_restore_fp())
535 if ((!(msr & MSR_VEC)) && should_restore_altivec())
538 if ((!(msr & MSR_VSX)) && should_restore_vsx()) {
539 if (((msr | new_msr) & (MSR_FP | MSR_VEC)) == (MSR_FP | MSR_VEC))
544 unsigned long fpexc_mode = 0;
546 msr_check_and_set(new_msr);
548 if (new_msr & MSR_FP) {
551 // This also covers VSX, because VSX implies FP
552 fpexc_mode = current->thread.fpexc_mode;
555 if (new_msr & MSR_VEC)
556 do_restore_altivec();
558 if (new_msr & MSR_VSX)
561 msr_check_and_clear(new_msr);
563 regs_set_return_msr(regs, regs->msr | new_msr | fpexc_mode);
566 #endif /* CONFIG_PPC_BOOK3S_64 */
568 static void save_all(struct task_struct *tsk)
570 unsigned long usermsr;
572 if (!tsk->thread.regs)
575 usermsr = tsk->thread.regs->msr;
577 if ((usermsr & msr_all_available) == 0)
580 msr_check_and_set(msr_all_available);
582 WARN_ON((usermsr & MSR_VSX) && !((usermsr & MSR_FP) && (usermsr & MSR_VEC)));
584 if (usermsr & MSR_FP)
587 if (usermsr & MSR_VEC)
590 if (usermsr & MSR_SPE)
593 msr_check_and_clear(msr_all_available);
596 void flush_all_to_thread(struct task_struct *tsk)
598 if (tsk->thread.regs) {
600 BUG_ON(tsk != current);
602 if (tsk->thread.regs->msr & MSR_SPE)
603 tsk->thread.spefscr = mfspr(SPRN_SPEFSCR);
610 EXPORT_SYMBOL(flush_all_to_thread);
612 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
613 void do_send_trap(struct pt_regs *regs, unsigned long address,
614 unsigned long error_code, int breakpt)
616 current->thread.trap_nr = TRAP_HWBKPT;
617 if (notify_die(DIE_DABR_MATCH, "dabr_match", regs, error_code,
618 11, SIGSEGV) == NOTIFY_STOP)
621 /* Deliver the signal to userspace */
622 force_sig_ptrace_errno_trap(breakpt, /* breakpoint or watchpoint id */
623 (void __user *)address);
625 #else /* !CONFIG_PPC_ADV_DEBUG_REGS */
627 static void do_break_handler(struct pt_regs *regs)
629 struct arch_hw_breakpoint null_brk = {0};
630 struct arch_hw_breakpoint *info;
631 struct ppc_inst instr = ppc_inst(0);
638 * If underneath hw supports only one watchpoint, we know it
639 * caused exception. 8xx also falls into this category.
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;
648 /* Otherwise findout which DAWR caused exception and disable it. */
649 wp_get_instr_detail(regs, &instr, &type, &size, &ea);
651 for (i = 0; i < nr_wp_slots(); i++) {
652 info = ¤t->thread.hw_brk[i];
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;
664 DEFINE_INTERRUPT_HANDLER(do_break)
666 current->thread.trap_nr = TRAP_HWBKPT;
667 if (notify_die(DIE_DABR_MATCH, "dabr_match", regs, regs->dsisr,
668 11, SIGSEGV) == NOTIFY_STOP)
671 if (debugger_break_match(regs))
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.
681 if (!IS_ENABLED(CONFIG_HAVE_HW_BREAKPOINT))
682 do_break_handler(regs);
684 /* Deliver the signal to userspace */
685 force_sig_fault(SIGTRAP, TRAP_HWBKPT, (void __user *)regs->dar);
687 #endif /* CONFIG_PPC_ADV_DEBUG_REGS */
689 static DEFINE_PER_CPU(struct arch_hw_breakpoint, current_brk[HBP_NUM_MAX]);
691 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
693 * Set the debug registers back to their default "safe" values.
695 static void set_debug_reg_defaults(struct thread_struct *thread)
697 thread->debug.iac1 = thread->debug.iac2 = 0;
698 #if CONFIG_PPC_ADV_DEBUG_IACS > 2
699 thread->debug.iac3 = thread->debug.iac4 = 0;
701 thread->debug.dac1 = thread->debug.dac2 = 0;
702 #if CONFIG_PPC_ADV_DEBUG_DVCS > 0
703 thread->debug.dvc1 = thread->debug.dvc2 = 0;
705 thread->debug.dbcr0 = 0;
708 * Force User/Supervisor bits to b11 (user-only MSR[PR]=1)
710 thread->debug.dbcr1 = DBCR1_IAC1US | DBCR1_IAC2US |
711 DBCR1_IAC3US | DBCR1_IAC4US;
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.
716 thread->debug.dbcr2 = DBCR2_DAC1US | DBCR2_DAC2US;
718 thread->debug.dbcr1 = 0;
722 static void prime_debug_regs(struct debug_reg *debug)
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.
729 mtmsr(mfmsr() & ~MSR_DE);
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);
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);
743 mtspr(SPRN_DBCR0, debug->dbcr0);
744 mtspr(SPRN_DBCR1, debug->dbcr1);
746 mtspr(SPRN_DBCR2, debug->dbcr2);
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.
754 void switch_booke_debug_regs(struct debug_reg *new_debug)
756 if ((current->thread.debug.dbcr0 & DBCR0_IDM)
757 || (new_debug->dbcr0 & DBCR0_IDM))
758 prime_debug_regs(new_debug);
760 EXPORT_SYMBOL_GPL(switch_booke_debug_regs);
761 #else /* !CONFIG_PPC_ADV_DEBUG_REGS */
762 #ifndef CONFIG_HAVE_HW_BREAKPOINT
763 static void set_breakpoint(int i, struct arch_hw_breakpoint *brk)
766 __set_breakpoint(i, brk);
770 static void set_debug_reg_defaults(struct thread_struct *thread)
773 struct arch_hw_breakpoint null_brk = {0};
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]);
782 static inline bool hw_brk_match(struct arch_hw_breakpoint *a,
783 struct arch_hw_breakpoint *b)
785 if (a->address != b->address)
787 if (a->type != b->type)
789 if (a->len != b->len)
791 /* no need to check hw_len. it's calculated from address and len */
795 static void switch_hw_breakpoint(struct task_struct *new)
799 for (i = 0; i < nr_wp_slots(); i++) {
800 if (likely(hw_brk_match(this_cpu_ptr(¤t_brk[i]),
801 &new->thread.hw_brk[i])))
804 __set_breakpoint(i, &new->thread.hw_brk[i]);
807 #endif /* !CONFIG_HAVE_HW_BREAKPOINT */
808 #endif /* CONFIG_PPC_ADV_DEBUG_REGS */
810 static inline int set_dabr(struct arch_hw_breakpoint *brk)
812 unsigned long dabr, dabrx;
814 dabr = brk->address | (brk->type & HW_BRK_TYPE_DABR);
815 dabrx = ((brk->type >> 3) & 0x7);
818 return ppc_md.set_dabr(dabr, dabrx);
820 if (IS_ENABLED(CONFIG_PPC_ADV_DEBUG_REGS)) {
821 mtspr(SPRN_DAC1, dabr);
822 if (IS_ENABLED(CONFIG_PPC_47x))
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);
835 static inline int set_breakpoint_8xx(struct arch_hw_breakpoint *brk)
837 unsigned long lctrl1 = LCTRL1_CTE_GT | LCTRL1_CTF_LT | LCTRL1_CRWE_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);
844 lctrl2 |= LCTRL2_LW0LA_F;
845 else if (end_addr == 0)
846 lctrl2 |= LCTRL2_LW0LA_E;
848 lctrl2 |= LCTRL2_LW0LA_EandF;
850 mtspr(SPRN_LCTRL2, 0);
852 if ((brk->type & HW_BRK_TYPE_RDWR) == 0)
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;
860 mtspr(SPRN_CMPE, start_addr - 1);
861 mtspr(SPRN_CMPF, end_addr);
862 mtspr(SPRN_LCTRL1, lctrl1);
863 mtspr(SPRN_LCTRL2, lctrl2);
868 void __set_breakpoint(int nr, struct arch_hw_breakpoint *brk)
870 memcpy(this_cpu_ptr(¤t_brk[nr]), brk, sizeof(*brk));
875 else if (IS_ENABLED(CONFIG_PPC_8xx))
876 set_breakpoint_8xx(brk);
877 else if (!cpu_has_feature(CPU_FTR_ARCH_207S))
881 // Shouldn't happen due to higher level checks
885 /* Check if we have DAWR or DABR hardware */
886 bool ppc_breakpoint_available(void)
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 */
895 EXPORT_SYMBOL_GPL(ppc_breakpoint_available);
897 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
899 static inline bool tm_enabled(struct task_struct *tsk)
901 return tsk && tsk->thread.regs && (tsk->thread.regs->msr & MSR_TM);
904 static void tm_reclaim_thread(struct thread_struct *thr, uint8_t cause)
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
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.
921 if (!MSR_TM_SUSPENDED(mfmsr()))
924 giveup_all(container_of(thr, struct task_struct, thread));
926 tm_reclaim(thr, cause);
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.
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));
948 void tm_reclaim_current(uint8_t cause)
951 tm_reclaim_thread(¤t->thread, cause);
954 static inline void tm_reclaim_task(struct task_struct *tsk)
956 /* We have to work out if we're switching from/to a task that's in the
957 * middle of a transaction.
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
964 * We also context switch (save) TFHAR/TEXASR/TFIAR in here.
966 struct thread_struct *thr = &tsk->thread;
971 if (!MSR_TM_ACTIVE(thr->regs->msr))
972 goto out_and_saveregs;
974 WARN_ON(tm_suspend_disabled);
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,
982 tm_reclaim_thread(thr, TM_CAUSE_RESCHED);
984 TM_DEBUG("--- tm_reclaim on pid %d complete\n",
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().
996 extern void __tm_recheckpoint(struct thread_struct *thread);
998 void tm_recheckpoint(struct thread_struct *thread)
1000 unsigned long flags;
1002 if (!(thread->regs->msr & MSR_TM))
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.
1009 local_irq_save(flags);
1012 /* The TM SPRs are restored here, so that TEXASR.FS can be set
1013 * before the trecheckpoint and no explosion occurs.
1015 tm_restore_sprs(thread);
1017 __tm_recheckpoint(thread);
1019 local_irq_restore(flags);
1022 static inline void tm_recheckpoint_new_task(struct task_struct *new)
1024 if (!cpu_has_feature(CPU_FTR_TM))
1027 /* Recheckpoint the registers of the thread we're about to switch to.
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.
1035 if (!tm_enabled(new))
1038 if (!MSR_TM_ACTIVE(new->thread.regs->msr)){
1039 tm_restore_sprs(&new->thread);
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);
1046 tm_recheckpoint(&new->thread);
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.
1053 new->thread.regs->msr &= ~(MSR_FP | MSR_VEC | MSR_VSX);
1055 TM_DEBUG("*** tm_recheckpoint of pid %d complete "
1056 "(kernel msr 0x%lx)\n",
1060 static inline void __switch_to_tm(struct task_struct *prev,
1061 struct task_struct *new)
1063 if (cpu_has_feature(CPU_FTR_TM)) {
1064 if (tm_enabled(prev) || tm_enabled(new))
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;
1074 tm_recheckpoint_new_task(new);
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
1092 void restore_tm_state(struct pt_regs *regs)
1094 unsigned long msr_diff;
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.
1102 clear_thread_flag(TIF_RESTORE_TM);
1103 if (!MSR_TM_ACTIVE(regs->msr))
1106 msr_diff = current->thread.ckpt_regs.msr & ~regs->msr;
1107 msr_diff &= MSR_FP | MSR_VEC | MSR_VSX;
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;
1118 regs_set_return_msr(regs, regs->msr | msr_diff);
1121 #else /* !CONFIG_PPC_TRANSACTIONAL_MEM */
1122 #define tm_recheckpoint_new_task(new)
1123 #define __switch_to_tm(prev, new)
1124 void tm_reclaim_current(uint8_t cause) {}
1125 #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
1127 static inline void save_sprs(struct thread_struct *t)
1129 #ifdef CONFIG_ALTIVEC
1130 if (cpu_has_feature(CPU_FTR_ALTIVEC))
1131 t->vrsave = mfspr(SPRN_VRSAVE);
1134 if (cpu_has_feature(CPU_FTR_SPE))
1135 t->spefscr = mfspr(SPRN_SPEFSCR);
1137 #ifdef CONFIG_PPC_BOOK3S_64
1138 if (cpu_has_feature(CPU_FTR_DSCR))
1139 t->dscr = mfspr(SPRN_DSCR);
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);
1146 t->fscr = mfspr(SPRN_FSCR);
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).)
1154 t->tar = mfspr(SPRN_TAR);
1159 static inline void restore_sprs(struct thread_struct *old_thread,
1160 struct thread_struct *new_thread)
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);
1168 if (cpu_has_feature(CPU_FTR_SPE) &&
1169 old_thread->spefscr != new_thread->spefscr)
1170 mtspr(SPRN_SPEFSCR, new_thread->spefscr);
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;
1178 if (old_thread->dscr != dscr)
1179 mtspr(SPRN_DSCR, dscr);
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);
1190 if (old_thread->fscr != new_thread->fscr)
1191 mtspr(SPRN_FSCR, new_thread->fscr);
1193 if (old_thread->tar != new_thread->tar)
1194 mtspr(SPRN_TAR, new_thread->tar);
1197 if (cpu_has_feature(CPU_FTR_P9_TIDR) &&
1198 old_thread->tidr != new_thread->tidr)
1199 mtspr(SPRN_TIDR, new_thread->tidr);
1204 struct task_struct *__switch_to(struct task_struct *prev,
1205 struct task_struct *new)
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;
1213 new_thread = &new->thread;
1214 old_thread = ¤t->thread;
1216 WARN_ON(!irqs_disabled());
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;
1223 __flush_tlb_pending(batch);
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.
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 */
1241 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
1242 switch_booke_debug_regs(&new->thread.debug);
1245 * For PPC_BOOK3S_64, we use the hw-breakpoint interfaces that would
1248 #ifndef CONFIG_HAVE_HW_BREAKPOINT
1249 switch_hw_breakpoint(new);
1250 #endif /* CONFIG_HAVE_HW_BREAKPOINT */
1254 * We need to save SPRs before treclaim/trecheckpoint as these will
1255 * change a number of them.
1257 save_sprs(&prev->thread);
1259 /* Save FPU, Altivec, VSX and SPE state */
1262 __switch_to_tm(prev, new);
1264 if (!radix_enabled()) {
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.
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.
1280 restore_sprs(old_thread, new_thread);
1282 set_return_regs_changed(); /* _switch changes stack (and regs) */
1285 kuap_assert_locked();
1287 last = _switch(old_thread, new_thread);
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
1296 #ifdef CONFIG_PPC_BOOK3S_64
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
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);
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.
1314 if (current->thread.regs)
1315 restore_math(current->thread.regs);
1316 #endif /* CONFIG_PPC_BOOK3S_64 */
1321 #define NR_INSN_TO_PRINT 16
1323 static void show_instructions(struct pt_regs *regs)
1326 unsigned long nip = regs->nip;
1327 unsigned long pc = regs->nip - (NR_INSN_TO_PRINT * 3 / 4 * sizeof(int));
1329 printk("Instruction dump:");
1332 * If we were executing with the MMU off for instructions, adjust pc
1333 * rather than printing XXXXXXXX.
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);
1340 for (i = 0; i < NR_INSN_TO_PRINT; i++) {
1346 if (!__kernel_text_address(pc) ||
1347 get_kernel_nofault(instr, (const void *)pc)) {
1348 pr_cont("XXXXXXXX ");
1351 pr_cont("<%08x> ", instr);
1353 pr_cont("%08x ", instr);
1362 void show_user_instructions(struct pt_regs *regs)
1365 int n = NR_INSN_TO_PRINT;
1367 char buf[96]; /* enough for 8 times 9 + 2 chars */
1369 pc = regs->nip - (NR_INSN_TO_PRINT * 3 / 4 * sizeof(int));
1371 seq_buf_init(&s, buf, sizeof(buf));
1378 for (i = 0; i < 8 && n; i++, n--, pc += sizeof(int)) {
1381 if (copy_from_user_nofault(&instr, (void __user *)pc,
1383 seq_buf_printf(&s, "XXXXXXXX ");
1386 seq_buf_printf(&s, regs->nip == pc ? "<%08x> " : "%08x ", instr);
1389 if (!seq_buf_has_overflowed(&s))
1390 pr_info("%s[%d]: code: %s\n", current->comm,
1391 current->pid, s.buffer);
1400 static struct regbit msr_bits[] = {
1401 #if defined(CONFIG_PPC64) && !defined(CONFIG_BOOKE)
1423 #ifndef CONFIG_BOOKE
1430 static void print_bits(unsigned long val, struct regbit *bits, const char *sep)
1434 for (; bits->bit; ++bits)
1435 if (val & bits->bit) {
1436 pr_cont("%s%s", s, bits->name);
1441 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1442 static struct regbit msr_tm_bits[] = {
1449 static void print_tm_bits(unsigned long val)
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)
1458 if (val & (MSR_TM | MSR_TS_S | MSR_TS_T)) {
1460 print_bits(val, msr_tm_bits, "");
1465 static void print_tm_bits(unsigned long val) {}
1468 static void print_msr_bits(unsigned long val)
1471 print_bits(val, msr_bits, ",");
1477 #define REG "%016lx"
1478 #define REGS_PER_LINE 4
1481 #define REGS_PER_LINE 8
1484 static void __show_regs(struct pt_regs *regs)
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);
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->dear, regs->esr);
1504 pr_cont("DAR: "REG" DSISR: %08lx ", regs->dar, regs->dsisr);
1508 pr_cont("IRQMASK: %lx ", regs->softe);
1510 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1511 if (MSR_TM_ACTIVE(regs->msr))
1512 pr_cont("\nPACATMSCRATCH: %016llx ", get_paca()->tm_scratch);
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]);
1522 * Lookup NIP late so we have the best change of getting the
1523 * above info out without failing
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);
1531 void show_regs(struct pt_regs *regs)
1533 show_regs_print_info(KERN_DEFAULT);
1535 show_stack(current, (unsigned long *) regs->gpr[1], KERN_DEFAULT);
1536 if (!user_mode(regs))
1537 show_instructions(regs);
1540 void flush_thread(void)
1542 #ifdef CONFIG_HAVE_HW_BREAKPOINT
1543 flush_ptrace_hw_breakpoint(current);
1544 #else /* CONFIG_HAVE_HW_BREAKPOINT */
1545 set_debug_reg_defaults(¤t->thread);
1546 #endif /* CONFIG_HAVE_HW_BREAKPOINT */
1549 void arch_setup_new_exec(void)
1552 #ifdef CONFIG_PPC_BOOK3S_64
1553 if (!radix_enabled())
1554 hash__setup_new_exec();
1557 * If we exec out of a kernel thread then thread.regs will not be
1560 if (!current->thread.regs) {
1561 struct pt_regs *regs = task_stack_page(current) + THREAD_SIZE;
1562 current->thread.regs = regs - 1;
1565 #ifdef CONFIG_PPC_MEM_KEYS
1566 current->thread.regs->amr = default_amr;
1567 current->thread.regs->iamr = default_iamr;
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.
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:
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
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.
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).
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
1603 * @t: the task to set the thread ID for
1605 int set_thread_tidr(struct task_struct *t)
1607 if (!cpu_has_feature(CPU_FTR_P9_TIDR))
1616 t->thread.tidr = (u16)task_pid_nr(t);
1617 mtspr(SPRN_TIDR, t->thread.tidr);
1621 EXPORT_SYMBOL_GPL(set_thread_tidr);
1623 #endif /* CONFIG_PPC64 */
1626 release_thread(struct task_struct *t)
1631 * this gets called so that we can store coprocessor state into memory and
1632 * copy the current task into the new thread.
1634 int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
1636 flush_all_to_thread(src);
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.
1644 * Can't pass dst because it isn't ready. Doesn't matter, passing
1645 * dst is only important for __switch_to()
1647 __switch_to_tm(src, src);
1651 clear_task_ebb(dst);
1656 static void setup_ksp_vsid(struct task_struct *p, unsigned long sp)
1658 #ifdef CONFIG_PPC_BOOK3S_64
1659 unsigned long sp_vsid;
1660 unsigned long llp = mmu_psize_defs[mmu_linear_psize].sllp;
1662 if (radix_enabled())
1665 if (mmu_has_feature(MMU_FTR_1T_SEGMENT))
1666 sp_vsid = get_kernel_vsid(sp, MMU_SEGSIZE_1T)
1667 << SLB_VSID_SHIFT_1T;
1669 sp_vsid = get_kernel_vsid(sp, MMU_SEGSIZE_256M)
1671 sp_vsid |= SLB_VSID_KERNEL | llp;
1672 p->thread.ksp_vsid = sp_vsid;
1681 * Copy architecture-specific thread state
1683 int copy_thread(unsigned long clone_flags, unsigned long usp,
1684 unsigned long kthread_arg, struct task_struct *p,
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);
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
1698 klp_init_thread_info(p);
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))) {
1705 memset(childregs, 0, sizeof(struct pt_regs));
1706 childregs->gpr[1] = sp + sizeof(struct pt_regs);
1709 childregs->gpr[14] = ppc_function_entry((void *)usp);
1711 clear_tsk_thread_flag(p, TIF_32BIT);
1712 childregs->softe = IRQS_ENABLED;
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;
1720 struct pt_regs *regs = current_pt_regs();
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;
1732 childregs->gpr[2] = tls;
1735 if (trap_is_scv(regs))
1736 f = ret_from_fork_scv;
1740 childregs->msr &= ~(MSR_FP|MSR_VEC|MSR_VSX);
1741 sp -= STACK_FRAME_OVERHEAD;
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.
1751 ((unsigned long *)sp)[0] = 0;
1752 sp -= sizeof(struct pt_regs);
1753 kregs = (struct pt_regs *) sp;
1754 sp -= STACK_FRAME_OVERHEAD;
1756 #ifdef CONFIG_HAVE_HW_BREAKPOINT
1757 for (i = 0; i < nr_wp_slots(); i++)
1758 p->thread.ptrace_bps[i] = NULL;
1761 #ifdef CONFIG_PPC_FPU_REGS
1762 p->thread.fp_save_area = NULL;
1764 #ifdef CONFIG_ALTIVEC
1765 p->thread.vr_save_area = NULL;
1767 #if defined(CONFIG_PPC_BOOK3S_32) && defined(CONFIG_PPC_KUAP)
1768 p->thread.kuap = KUAP_NONE;
1771 setup_ksp_vsid(p, sp);
1774 if (cpu_has_feature(CPU_FTR_DSCR)) {
1775 p->thread.dscr_inherit = current->thread.dscr_inherit;
1776 p->thread.dscr = mfspr(SPRN_DSCR);
1778 if (cpu_has_feature(CPU_FTR_HAS_PPR))
1779 childregs->ppr = DEFAULT_PPR;
1784 * Run with the current AMR value of the kernel
1786 #ifdef CONFIG_PPC_PKEY
1787 if (mmu_has_feature(MMU_FTR_BOOK3S_KUAP))
1788 kregs->amr = AMR_KUAP_BLOCKED;
1790 if (mmu_has_feature(MMU_FTR_BOOK3S_KUEP))
1791 kregs->iamr = AMR_KUEP_BLOCKED;
1793 kregs->nip = ppc_function_entry(f);
1797 void preload_new_slb_context(unsigned long start, unsigned long sp);
1800 * Set up a thread for executing a new program
1802 void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp)
1805 unsigned long load_addr = regs->gpr[2]; /* saved by ELF_PLAT_INIT */
1807 if (IS_ENABLED(CONFIG_PPC_BOOK3S_64) && !radix_enabled())
1808 preload_new_slb_context(start, sp);
1811 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
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
1817 if (MSR_TM_SUSPENDED(mfmsr()))
1818 tm_reclaim_current(0);
1821 memset(®s->gpr[1], 0, sizeof(regs->gpr) - sizeof(regs->gpr[0]));
1831 regs->msr = MSR_USER;
1833 if (!is_32bit_task()) {
1834 unsigned long entry;
1836 if (is_elf2_task()) {
1837 /* Look ma, no function descriptors! */
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).
1848 regs->gpr[12] = start;
1849 /* Make sure that's restored on entry to userspace. */
1850 set_thread_flag(TIF_RESTOREALL);
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.
1860 __get_user(entry, (unsigned long __user *)start);
1861 __get_user(toc, (unsigned long __user *)start+1);
1863 /* Check whether the e_entry function descriptor entries
1864 * need to be relocated before we can use them.
1866 if (load_addr != 0) {
1872 regs_set_return_ip(regs, entry);
1873 regs_set_return_msr(regs, MSR_USER64);
1876 regs_set_return_ip(regs, start);
1877 regs_set_return_msr(regs, MSR_USER32);
1882 current->thread.used_vsr = 0;
1884 current->thread.load_slb = 0;
1885 current->thread.load_fp = 0;
1886 #ifdef CONFIG_PPC_FPU_REGS
1887 memset(¤t->thread.fp_state, 0, sizeof(current->thread.fp_state));
1888 current->thread.fp_save_area = NULL;
1890 #ifdef CONFIG_ALTIVEC
1891 memset(¤t->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 */
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 */
1911 EXPORT_SYMBOL(start_thread);
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)
1916 int set_fpexc_mode(struct task_struct *tsk, unsigned int val)
1918 struct pt_regs *regs = tsk->thread.regs;
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)) {
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.
1939 tsk->thread.spefscr_last = mfspr(SPRN_SPEFSCR);
1940 tsk->thread.fpexc_mode = val &
1941 (PR_FP_EXC_SW_ENABLE | PR_FP_ALL_EXCEPT);
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)
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);
1964 int get_fpexc_mode(struct task_struct *tsk, unsigned long adr)
1966 unsigned int val = 0;
1968 if (tsk->thread.fpexc_mode & PR_FP_EXC_SW_ENABLE) {
1969 if (cpu_has_feature(CPU_FTR_SPE)) {
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.
1983 tsk->thread.spefscr_last = mfspr(SPRN_SPEFSCR);
1984 val = tsk->thread.fpexc_mode;
1989 val = __unpack_fe01(tsk->thread.fpexc_mode);
1991 return put_user(val, (unsigned int __user *) adr);
1994 int set_endian(struct task_struct *tsk, unsigned int val)
1996 struct pt_regs *regs = tsk->thread.regs;
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)))
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);
2015 int get_endian(struct task_struct *tsk, unsigned long adr)
2017 struct pt_regs *regs = tsk->thread.regs;
2020 if (!cpu_has_feature(CPU_FTR_PPC_LE) &&
2021 !cpu_has_feature(CPU_FTR_REAL_LE))
2027 if (regs->msr & MSR_LE) {
2028 if (cpu_has_feature(CPU_FTR_REAL_LE))
2029 val = PR_ENDIAN_LITTLE;
2031 val = PR_ENDIAN_PPC_LITTLE;
2033 val = PR_ENDIAN_BIG;
2035 return put_user(val, (unsigned int __user *)adr);
2038 int set_unalign_ctl(struct task_struct *tsk, unsigned int val)
2040 tsk->thread.align_ctl = val;
2044 int get_unalign_ctl(struct task_struct *tsk, unsigned long adr)
2046 return put_user(tsk->thread.align_ctl, (unsigned int __user *)adr);
2049 static inline int valid_irq_stack(unsigned long sp, struct task_struct *p,
2050 unsigned long nbytes)
2052 unsigned long stack_page;
2053 unsigned long cpu = task_cpu(p);
2055 stack_page = (unsigned long)hardirq_ctx[cpu];
2056 if (sp >= stack_page && sp <= stack_page + THREAD_SIZE - nbytes)
2059 stack_page = (unsigned long)softirq_ctx[cpu];
2060 if (sp >= stack_page && sp <= stack_page + THREAD_SIZE - nbytes)
2066 static inline int valid_emergency_stack(unsigned long sp, struct task_struct *p,
2067 unsigned long nbytes)
2070 unsigned long stack_page;
2071 unsigned long cpu = task_cpu(p);
2076 stack_page = (unsigned long)paca_ptrs[cpu]->emergency_sp - THREAD_SIZE;
2077 if (sp >= stack_page && sp <= stack_page + THREAD_SIZE - nbytes)
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)
2085 stack_page = (unsigned long)paca_ptrs[cpu]->mc_emergency_sp - THREAD_SIZE;
2086 if (sp >= stack_page && sp <= stack_page + THREAD_SIZE - nbytes)
2095 int validate_sp(unsigned long sp, struct task_struct *p,
2096 unsigned long nbytes)
2098 unsigned long stack_page = (unsigned long)task_stack_page(p);
2100 if (sp < THREAD_SIZE)
2103 if (sp >= stack_page && sp <= stack_page + THREAD_SIZE - nbytes)
2106 if (valid_irq_stack(sp, p, nbytes))
2109 return valid_emergency_stack(sp, p, nbytes);
2112 EXPORT_SYMBOL(validate_sp);
2114 static unsigned long __get_wchan(struct task_struct *p)
2116 unsigned long ip, sp;
2119 if (!p || p == current || task_is_running(p))
2123 if (!validate_sp(sp, p, STACK_FRAME_OVERHEAD))
2127 sp = READ_ONCE_NOCHECK(*(unsigned long *)sp);
2128 if (!validate_sp(sp, p, STACK_FRAME_OVERHEAD) ||
2132 ip = READ_ONCE_NOCHECK(((unsigned long *)sp)[STACK_FRAME_LR_SAVE]);
2133 if (!in_sched_functions(ip))
2136 } while (count++ < 16);
2140 unsigned long get_wchan(struct task_struct *p)
2144 if (!try_get_task_stack(p))
2147 ret = __get_wchan(p);
2154 static int kstack_depth_to_print = CONFIG_PRINT_STACK_DEPTH;
2156 void __no_sanitize_address show_stack(struct task_struct *tsk,
2157 unsigned long *stack,
2160 unsigned long sp, ip, lr, newsp;
2163 unsigned long ret_addr;
2169 if (!try_get_task_stack(tsk))
2172 sp = (unsigned long) stack;
2175 sp = current_stack_frame();
2177 sp = tsk->thread.ksp;
2181 printk("%sCall Trace:\n", loglvl);
2183 if (!validate_sp(sp, tsk, STACK_FRAME_OVERHEAD))
2186 stack = (unsigned long *) sp;
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);
2195 pr_cont(" (%pS)", (void *)ret_addr);
2197 pr_cont(" (unreliable)");
2203 * See if this is an exception frame.
2204 * We look for the "regshere" marker in the current frame.
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);
2212 printk("%s--- interrupt: %lx at %pS\n",
2213 loglvl, regs->trap, (void *)regs->nip);
2215 printk("%s--- interrupt: %lx\n",
2216 loglvl, regs->trap);
2222 } while (count++ < kstack_depth_to_print);
2224 put_task_stack(tsk);
2228 /* Called with hard IRQs off */
2229 void notrace __ppc64_runlatch_on(void)
2231 struct thread_info *ti = current_thread_info();
2233 if (cpu_has_feature(CPU_FTR_ARCH_206)) {
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.
2239 mtspr(SPRN_CTRLT, CTRL_RUNLATCH);
2244 * Some architectures (e.g., Cell) have writable fields other
2245 * than RUN, so do the read-modify-write.
2247 ctrl = mfspr(SPRN_CTRLF);
2248 ctrl |= CTRL_RUNLATCH;
2249 mtspr(SPRN_CTRLT, ctrl);
2252 ti->local_flags |= _TLF_RUNLATCH;
2255 /* Called with hard IRQs off */
2256 void notrace __ppc64_runlatch_off(void)
2258 struct thread_info *ti = current_thread_info();
2260 ti->local_flags &= ~_TLF_RUNLATCH;
2262 if (cpu_has_feature(CPU_FTR_ARCH_206)) {
2263 mtspr(SPRN_CTRLT, 0);
2267 ctrl = mfspr(SPRN_CTRLF);
2268 ctrl &= ~CTRL_RUNLATCH;
2269 mtspr(SPRN_CTRLT, ctrl);
2272 #endif /* CONFIG_PPC64 */
2274 unsigned long arch_align_stack(unsigned long sp)
2276 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
2277 sp -= get_random_int() & ~PAGE_MASK;
2281 static inline unsigned long brk_rnd(void)
2283 unsigned long rnd = 0;
2285 /* 8MB for 32bit, 1GB for 64bit */
2286 if (is_32bit_task())
2287 rnd = (get_random_long() % (1UL<<(23-PAGE_SHIFT)));
2289 rnd = (get_random_long() % (1UL<<(30-PAGE_SHIFT)));
2291 return rnd << PAGE_SHIFT;
2294 unsigned long arch_randomize_brk(struct mm_struct *mm)
2296 unsigned long base = mm->brk;
2299 #ifdef CONFIG_PPC_BOOK3S_64
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.
2308 if (!is_32bit_task() && (mmu_highuser_ssize == MMU_SEGSIZE_1T))
2309 base = max_t(unsigned long, mm->brk, 1UL << SID_SHIFT_1T);
2312 ret = PAGE_ALIGN(base + brk_rnd());