1 // SPDX-License-Identifier: GPL-2.0
3 * linux/arch/parisc/traps.c
5 * Copyright (C) 1991, 1992 Linus Torvalds
6 * Copyright (C) 1999, 2000 Philipp Rumpf <prumpf@tux.org>
10 * 'Traps.c' handles hardware traps and faults after we have saved some
14 #include <linux/sched.h>
15 #include <linux/sched/debug.h>
16 #include <linux/kernel.h>
17 #include <linux/string.h>
18 #include <linux/errno.h>
19 #include <linux/ptrace.h>
20 #include <linux/timer.h>
21 #include <linux/delay.h>
23 #include <linux/module.h>
24 #include <linux/smp.h>
25 #include <linux/spinlock.h>
26 #include <linux/init.h>
27 #include <linux/interrupt.h>
28 #include <linux/console.h>
29 #include <linux/bug.h>
30 #include <linux/ratelimit.h>
31 #include <linux/uaccess.h>
32 #include <linux/kdebug.h>
33 #include <linux/kfence.h>
35 #include <asm/assembly.h>
38 #include <asm/traps.h>
39 #include <asm/unaligned.h>
40 #include <linux/atomic.h>
43 #include <asm/pdc_chassis.h>
44 #include <asm/unwind.h>
45 #include <asm/tlbflush.h>
46 #include <asm/cacheflush.h>
47 #include <linux/kgdb.h>
48 #include <linux/kprobes.h>
50 #include "../math-emu/math-emu.h" /* for handle_fpe() */
52 static void parisc_show_stack(struct task_struct *task,
53 struct pt_regs *regs, const char *loglvl);
55 static int printbinary(char *buf, unsigned long x, int nbits)
57 unsigned long mask = 1UL << (nbits - 1);
59 *buf++ = (mask & x ? '1' : '0');
72 #define FFMT "%016llx" /* fpregs are 64-bit always */
74 #define PRINTREGS(lvl,r,f,fmt,x) \
75 printk("%s%s%02d-%02d " fmt " " fmt " " fmt " " fmt "\n", \
76 lvl, f, (x), (x+3), (r)[(x)+0], (r)[(x)+1], \
77 (r)[(x)+2], (r)[(x)+3])
79 static void print_gr(const char *level, struct pt_regs *regs)
84 printk("%s\n", level);
85 printk("%s YZrvWESTHLNXBCVMcbcbcbcbOGFRQPDI\n", level);
86 printbinary(buf, regs->gr[0], 32);
87 printk("%sPSW: %s %s\n", level, buf, print_tainted());
89 for (i = 0; i < 32; i += 4)
90 PRINTREGS(level, regs->gr, "r", RFMT, i);
93 static void print_fr(const char *level, struct pt_regs *regs)
97 struct { u32 sw[2]; } s;
99 /* FR are 64bit everywhere. Need to use asm to get the content
100 * of fpsr/fper1, and we assume that we won't have a FP Identify
101 * in our way, otherwise we're screwed.
102 * The fldd is used to restore the T-bit if there was one, as the
103 * store clears it anyway.
104 * PA2.0 book says "thou shall not use fstw on FPSR/FPERs" - T-Bone */
105 asm volatile ("fstd %%fr0,0(%1) \n\t"
106 "fldd 0(%1),%%fr0 \n\t"
107 : "=m" (s) : "r" (&s) : "r0");
109 printk("%s\n", level);
110 printk("%s VZOUICununcqcqcqcqcqcrmunTDVZOUI\n", level);
111 printbinary(buf, s.sw[0], 32);
112 printk("%sFPSR: %s\n", level, buf);
113 printk("%sFPER1: %08x\n", level, s.sw[1]);
115 /* here we'll print fr0 again, tho it'll be meaningless */
116 for (i = 0; i < 32; i += 4)
117 PRINTREGS(level, regs->fr, "fr", FFMT, i);
120 void show_regs(struct pt_regs *regs)
124 unsigned long cr30, cr31;
126 user = user_mode(regs);
127 level = user ? KERN_DEBUG : KERN_CRIT;
129 show_regs_print_info(level);
131 print_gr(level, regs);
133 for (i = 0; i < 8; i += 4)
134 PRINTREGS(level, regs->sr, "sr", RFMT, i);
137 print_fr(level, regs);
141 printk("%s\n", level);
142 printk("%sIASQ: " RFMT " " RFMT " IAOQ: " RFMT " " RFMT "\n",
143 level, regs->iasq[0], regs->iasq[1], regs->iaoq[0], regs->iaoq[1]);
144 printk("%s IIR: %08lx ISR: " RFMT " IOR: " RFMT "\n",
145 level, regs->iir, regs->isr, regs->ior);
146 printk("%s CPU: %8d CR30: " RFMT " CR31: " RFMT "\n",
147 level, task_cpu(current), cr30, cr31);
148 printk("%s ORIG_R28: " RFMT "\n", level, regs->orig_r28);
151 printk("%s IAOQ[0]: " RFMT "\n", level, regs->iaoq[0]);
152 printk("%s IAOQ[1]: " RFMT "\n", level, regs->iaoq[1]);
153 printk("%s RP(r2): " RFMT "\n", level, regs->gr[2]);
155 printk("%s IAOQ[0]: %pS\n", level, (void *) regs->iaoq[0]);
156 printk("%s IAOQ[1]: %pS\n", level, (void *) regs->iaoq[1]);
157 printk("%s RP(r2): %pS\n", level, (void *) regs->gr[2]);
159 parisc_show_stack(current, regs, KERN_DEFAULT);
163 static DEFINE_RATELIMIT_STATE(_hppa_rs,
164 DEFAULT_RATELIMIT_INTERVAL, DEFAULT_RATELIMIT_BURST);
166 #define parisc_printk_ratelimited(critical, regs, fmt, ...) { \
167 if ((critical || show_unhandled_signals) && __ratelimit(&_hppa_rs)) { \
168 printk(fmt, ##__VA_ARGS__); \
174 static void do_show_stack(struct unwind_frame_info *info, const char *loglvl)
178 printk("%sBacktrace:\n", loglvl);
179 while (i <= MAX_UNWIND_ENTRIES) {
180 if (unwind_once(info) < 0 || info->ip == 0)
183 if (__kernel_text_address(info->ip)) {
184 printk("%s [<" RFMT ">] %pS\n",
185 loglvl, info->ip, (void *) info->ip);
189 printk("%s\n", loglvl);
192 static void parisc_show_stack(struct task_struct *task,
193 struct pt_regs *regs, const char *loglvl)
195 struct unwind_frame_info info;
197 unwind_frame_init_task(&info, task, regs);
199 do_show_stack(&info, loglvl);
202 void show_stack(struct task_struct *t, unsigned long *sp, const char *loglvl)
204 parisc_show_stack(t, NULL, loglvl);
207 int is_valid_bugaddr(unsigned long iaoq)
212 void die_if_kernel(char *str, struct pt_regs *regs, long err)
214 if (user_mode(regs)) {
218 parisc_printk_ratelimited(1, regs,
219 KERN_CRIT "%s (pid %d): %s (code %ld) at " RFMT "\n",
220 current->comm, task_pid_nr(current), str, err, regs->iaoq[0]);
229 /* Amuse the user in a SPARC fashion */
230 if (err) printk(KERN_CRIT
231 " _______________________________ \n"
232 " < Your System ate a SPARC! Gah! >\n"
233 " ------------------------------- \n"
239 /* unlock the pdc lock if necessary */
240 pdc_emergency_unlock();
242 /* maybe the kernel hasn't booted very far yet and hasn't been able
243 * to initialize the serial or STI console. In that case we should
244 * re-enable the pdc console, so that the user will be able to
245 * identify the problem. */
246 if (!console_drivers)
247 pdc_console_restart();
250 printk(KERN_CRIT "%s (pid %d): %s (code %ld)\n",
251 current->comm, task_pid_nr(current), str, err);
253 /* Wot's wrong wif bein' racy? */
254 if (current->thread.flags & PARISC_KERNEL_DEATH) {
255 printk(KERN_CRIT "%s() recursion detected.\n", __func__);
259 current->thread.flags |= PARISC_KERNEL_DEATH;
263 add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
266 panic("Fatal exception in interrupt");
269 panic("Fatal exception");
272 make_task_dead(SIGSEGV);
275 /* gdb uses break 4,8 */
276 #define GDB_BREAK_INSN 0x10004
277 static void handle_gdb_break(struct pt_regs *regs, int wot)
279 force_sig_fault(SIGTRAP, wot,
280 (void __user *) (regs->iaoq[0] & ~3));
283 static void handle_break(struct pt_regs *regs)
285 unsigned iir = regs->iir;
287 if (unlikely(iir == PARISC_BUG_BREAK_INSN && !user_mode(regs))) {
288 /* check if a BUG() or WARN() trapped here. */
289 enum bug_trap_type tt;
290 tt = report_bug(regs->iaoq[0] & ~3, regs);
291 if (tt == BUG_TRAP_TYPE_WARN) {
294 return; /* return to next instruction when WARN_ON(). */
296 die_if_kernel("Unknown kernel breakpoint", regs,
297 (tt == BUG_TRAP_TYPE_NONE) ? 9 : 0);
300 #ifdef CONFIG_KPROBES
301 if (unlikely(iir == PARISC_KPROBES_BREAK_INSN)) {
302 parisc_kprobe_break_handler(regs);
305 if (unlikely(iir == PARISC_KPROBES_BREAK_INSN2)) {
306 parisc_kprobe_ss_handler(regs);
312 if (unlikely(iir == PARISC_KGDB_COMPILED_BREAK_INSN ||
313 iir == PARISC_KGDB_BREAK_INSN)) {
314 kgdb_handle_exception(9, SIGTRAP, 0, regs);
319 if (unlikely(iir != GDB_BREAK_INSN))
320 parisc_printk_ratelimited(0, regs,
321 KERN_DEBUG "break %d,%d: pid=%d command='%s'\n",
322 iir & 31, (iir>>13) & ((1<<13)-1),
323 task_pid_nr(current), current->comm);
325 /* send standard GDB signal */
326 handle_gdb_break(regs, TRAP_BRKPT);
329 static void default_trap(int code, struct pt_regs *regs)
331 printk(KERN_ERR "Trap %d on CPU %d\n", code, smp_processor_id());
335 void (*cpu_lpmc) (int code, struct pt_regs *regs) __read_mostly = default_trap;
338 void transfer_pim_to_trap_frame(struct pt_regs *regs)
341 extern unsigned int hpmc_pim_data[];
342 struct pdc_hpmc_pim_11 *pim_narrow;
343 struct pdc_hpmc_pim_20 *pim_wide;
345 if (boot_cpu_data.cpu_type >= pcxu) {
347 pim_wide = (struct pdc_hpmc_pim_20 *)hpmc_pim_data;
350 * Note: The following code will probably generate a
351 * bunch of truncation error warnings from the compiler.
352 * Could be handled with an ifdef, but perhaps there
356 regs->gr[0] = pim_wide->cr[22];
358 for (i = 1; i < 32; i++)
359 regs->gr[i] = pim_wide->gr[i];
361 for (i = 0; i < 32; i++)
362 regs->fr[i] = pim_wide->fr[i];
364 for (i = 0; i < 8; i++)
365 regs->sr[i] = pim_wide->sr[i];
367 regs->iasq[0] = pim_wide->cr[17];
368 regs->iasq[1] = pim_wide->iasq_back;
369 regs->iaoq[0] = pim_wide->cr[18];
370 regs->iaoq[1] = pim_wide->iaoq_back;
372 regs->sar = pim_wide->cr[11];
373 regs->iir = pim_wide->cr[19];
374 regs->isr = pim_wide->cr[20];
375 regs->ior = pim_wide->cr[21];
378 pim_narrow = (struct pdc_hpmc_pim_11 *)hpmc_pim_data;
380 regs->gr[0] = pim_narrow->cr[22];
382 for (i = 1; i < 32; i++)
383 regs->gr[i] = pim_narrow->gr[i];
385 for (i = 0; i < 32; i++)
386 regs->fr[i] = pim_narrow->fr[i];
388 for (i = 0; i < 8; i++)
389 regs->sr[i] = pim_narrow->sr[i];
391 regs->iasq[0] = pim_narrow->cr[17];
392 regs->iasq[1] = pim_narrow->iasq_back;
393 regs->iaoq[0] = pim_narrow->cr[18];
394 regs->iaoq[1] = pim_narrow->iaoq_back;
396 regs->sar = pim_narrow->cr[11];
397 regs->iir = pim_narrow->cr[19];
398 regs->isr = pim_narrow->cr[20];
399 regs->ior = pim_narrow->cr[21];
403 * The following fields only have meaning if we came through
404 * another path. So just zero them here.
414 * This routine is called as a last resort when everything else
415 * has gone clearly wrong. We get called for faults in kernel space,
418 void parisc_terminate(char *msg, struct pt_regs *regs, int code, unsigned long offset)
420 static DEFINE_SPINLOCK(terminate_lock);
422 (void)notify_die(DIE_OOPS, msg, regs, 0, code, SIGTRAP);
427 spin_lock(&terminate_lock);
429 /* unlock the pdc lock if necessary */
430 pdc_emergency_unlock();
432 /* restart pdc console if necessary */
433 if (!console_drivers)
434 pdc_console_restart();
436 /* Not all paths will gutter the processor... */
440 transfer_pim_to_trap_frame(regs);
449 /* show_stack(NULL, (unsigned long *)regs->gr[30]); */
450 struct unwind_frame_info info;
451 unwind_frame_init(&info, current, regs);
452 do_show_stack(&info, KERN_CRIT);
456 pr_crit("%s: Code=%d (%s) at addr " RFMT "\n",
457 msg, code, trap_name(code), offset);
460 spin_unlock(&terminate_lock);
462 /* put soft power button back under hardware control;
463 * if the user had pressed it once at any time, the
464 * system will shut down immediately right here. */
465 pdc_soft_power_button(0);
467 /* Call kernel panic() so reboot timeouts work properly
468 * FIXME: This function should be on the list of
469 * panic notifiers, and we should call panic
470 * directly from the location that we wish.
471 * e.g. We should not call panic from
472 * parisc_terminate, but rather the other way around.
473 * This hack works, prints the panic message twice,
474 * and it enables reboot timers!
479 void notrace handle_interruption(int code, struct pt_regs *regs)
481 unsigned long fault_address = 0;
482 unsigned long fault_space = 0;
486 pdc_console_restart(); /* switch back to pdc if HPMC */
487 else if (!irqs_disabled_flags(regs->gr[0]))
491 * If the priority level is still user, and the
492 * faulting space is not equal to the active space
493 * then the user is attempting something in a space
494 * that does not belong to them. Kill the process.
496 * This is normally the situation when the user
497 * attempts to jump into the kernel space at the
498 * wrong offset, be it at the gateway page or a
501 * We cannot normally signal the process because it
502 * could *be* on the gateway page, and processes
503 * executing on the gateway page can't have signals
506 * We merely readjust the address into the users
507 * space, at a destination address of zero, and
508 * allow processing to continue.
510 if (((unsigned long)regs->iaoq[0] & 3) &&
511 ((unsigned long)regs->iasq[0] != (unsigned long)regs->sr[7])) {
512 /* Kill the user process later */
513 regs->iaoq[0] = 0 | 3;
514 regs->iaoq[1] = regs->iaoq[0] + 4;
515 regs->iasq[0] = regs->iasq[1] = regs->sr[7];
516 regs->gr[0] &= ~PSW_B;
521 printk(KERN_CRIT "Interruption # %d\n", code);
527 /* High-priority machine check (HPMC) */
529 /* set up a new led state on systems shipped with a LED State panel */
530 pdc_chassis_send_status(PDC_CHASSIS_DIRECT_HPMC);
532 parisc_terminate("High Priority Machine Check (HPMC)",
537 /* Power failure interrupt */
538 printk(KERN_CRIT "Power failure interrupt !\n");
542 /* Recovery counter trap */
543 regs->gr[0] &= ~PSW_R;
546 if (kgdb_single_step) {
547 kgdb_handle_exception(0, SIGTRAP, 0, regs);
552 if (user_space(regs))
553 handle_gdb_break(regs, TRAP_TRACE);
554 /* else this must be the start of a syscall - just let it run */
558 /* Low-priority machine check */
559 pdc_chassis_send_status(PDC_CHASSIS_DIRECT_LPMC);
566 case PARISC_ITLB_TRAP:
567 /* Instruction TLB miss fault/Instruction page fault */
568 fault_address = regs->iaoq[0];
569 fault_space = regs->iasq[0];
573 /* Illegal instruction trap */
574 die_if_kernel("Illegal instruction", regs, code);
575 si_code = ILL_ILLOPC;
579 /* Break instruction trap */
584 /* Privileged operation trap */
585 die_if_kernel("Privileged operation", regs, code);
586 si_code = ILL_PRVOPC;
590 /* Privileged register trap */
591 if ((regs->iir & 0xffdfffe0) == 0x034008a0) {
593 /* This is a MFCTL cr26/cr27 to gr instruction.
594 * PCXS traps on this, so we need to emulate it.
597 if (regs->iir & 0x00200000)
598 regs->gr[regs->iir & 0x1f] = mfctl(27);
600 regs->gr[regs->iir & 0x1f] = mfctl(26);
602 regs->iaoq[0] = regs->iaoq[1];
604 regs->iasq[0] = regs->iasq[1];
608 die_if_kernel("Privileged register usage", regs, code);
609 si_code = ILL_PRVREG;
611 force_sig_fault(SIGILL, si_code,
612 (void __user *) regs->iaoq[0]);
616 /* Overflow Trap, let the userland signal handler do the cleanup */
617 force_sig_fault(SIGFPE, FPE_INTOVF,
618 (void __user *) regs->iaoq[0]);
623 The condition succeeds in an instruction which traps
626 /* Let userspace app figure it out from the insn pointed
629 force_sig_fault(SIGFPE, FPE_CONDTRAP,
630 (void __user *) regs->iaoq[0]);
633 /* The kernel doesn't want to handle condition codes */
637 /* Assist Exception Trap, i.e. floating point exception. */
638 die_if_kernel("Floating point exception", regs, 0); /* quiet */
639 __inc_irq_stat(irq_fpassist_count);
644 /* Data TLB miss fault/Data page fault */
647 /* Non-access instruction TLB miss fault */
648 /* The instruction TLB entry needed for the target address of the FIC
649 is absent, and hardware can't find it, so we get to cleanup */
652 /* Non-access data TLB miss fault/Non-access data page fault */
654 Still need to add slow path emulation code here!
655 If the insn used a non-shadow register, then the tlb
656 handlers could not have their side-effect (e.g. probe
657 writing to a target register) emulated since rfir would
658 erase the changes to said register. Instead we have to
659 setup everything, call this function we are in, and emulate
660 by hand. Technically we need to emulate:
661 fdc,fdce,pdc,"fic,4f",prober,probeir,probew, probeiw
663 if (code == 17 && handle_nadtlb_fault(regs))
665 fault_address = regs->ior;
666 fault_space = regs->isr;
670 /* PCXS only -- later cpu's split this into types 26,27 & 28 */
671 /* Check for unaligned access */
672 if (check_unaligned(regs)) {
673 handle_unaligned(regs);
678 /* PCXL: Data memory access rights trap */
679 fault_address = regs->ior;
680 fault_space = regs->isr;
684 /* Data memory break trap */
685 regs->gr[0] |= PSW_X; /* So we can single-step over the trap */
688 /* Page reference trap */
689 handle_gdb_break(regs, TRAP_HWBKPT);
693 /* Taken branch trap */
694 regs->gr[0] &= ~PSW_T;
695 if (user_space(regs))
696 handle_gdb_break(regs, TRAP_BRANCH);
697 /* else this must be the start of a syscall - just let it
703 /* Instruction access rights */
704 /* PCXL: Instruction memory protection trap */
707 * This could be caused by either: 1) a process attempting
708 * to execute within a vma that does not have execute
709 * permission, or 2) an access rights violation caused by a
710 * flush only translation set up by ptep_get_and_clear().
711 * So we check the vma permissions to differentiate the two.
712 * If the vma indicates we have execute permission, then
713 * the cause is the latter one. In this case, we need to
714 * call do_page_fault() to fix the problem.
717 if (user_mode(regs)) {
718 struct vm_area_struct *vma;
720 mmap_read_lock(current->mm);
721 vma = find_vma(current->mm,regs->iaoq[0]);
722 if (vma && (regs->iaoq[0] >= vma->vm_start)
723 && (vma->vm_flags & VM_EXEC)) {
725 fault_address = regs->iaoq[0];
726 fault_space = regs->iasq[0];
728 mmap_read_unlock(current->mm);
729 break; /* call do_page_fault() */
731 mmap_read_unlock(current->mm);
733 /* CPU could not fetch instruction, so clear stale IIR value. */
734 regs->iir = 0xbaadf00d;
737 /* Data memory protection ID trap */
738 if (code == 27 && !user_mode(regs) &&
739 fixup_exception(regs))
742 die_if_kernel("Protection id trap", regs, code);
743 force_sig_fault(SIGSEGV, SEGV_MAPERR,
745 ((void __user *) regs->iaoq[0]) :
746 ((void __user *) regs->ior));
750 /* Unaligned data reference trap */
751 handle_unaligned(regs);
755 if (user_mode(regs)) {
756 parisc_printk_ratelimited(0, regs, KERN_DEBUG
757 "handle_interruption() pid=%d command='%s'\n",
758 task_pid_nr(current), current->comm);
759 /* SIGBUS, for lack of a better one. */
760 force_sig_fault(SIGBUS, BUS_OBJERR,
761 (void __user *)regs->ior);
764 pdc_chassis_send_status(PDC_CHASSIS_DIRECT_PANIC);
766 parisc_terminate("Unexpected interruption", regs, code, 0);
770 if (user_mode(regs)) {
771 if ((fault_space >> SPACEID_SHIFT) != (regs->sr[7] >> SPACEID_SHIFT)) {
772 parisc_printk_ratelimited(0, regs, KERN_DEBUG
773 "User fault %d on space 0x%08lx, pid=%d command='%s'\n",
775 task_pid_nr(current), current->comm);
776 force_sig_fault(SIGSEGV, SEGV_MAPERR,
777 (void __user *)regs->ior);
784 * The kernel should never fault on its own address space,
785 * unless pagefault_disable() was called before.
788 if (faulthandler_disabled() || fault_space == 0)
790 /* Clean up and return if in exception table. */
791 if (fixup_exception(regs))
793 /* Clean up and return if handled by kfence. */
794 if (kfence_handle_page_fault(fault_address,
795 parisc_acctyp(code, regs->iir) == VM_WRITE, regs))
797 pdc_chassis_send_status(PDC_CHASSIS_DIRECT_PANIC);
798 parisc_terminate("Kernel Fault", regs, code, fault_address);
802 do_page_fault(regs, code, fault_address);
806 void __init initialize_ivt(const void *iva)
808 extern const u32 os_hpmc[];
816 if (strcmp((const char *)iva, "cows can fly"))
817 panic("IVT invalid");
821 for (i = 0; i < 8; i++)
825 * Use PDC_INSTR firmware function to get instruction that invokes
826 * PDCE_CHECK in HPMC handler. See programming note at page 1-31 of
827 * the PA 1.1 Firmware Architecture document.
829 if (pdc_instr(&instr) == PDC_OK)
833 * Rules for the checksum of the HPMC handler:
834 * 1. The IVA does not point to PDC/PDH space (ie: the OS has installed
836 * 2. The word at IVA + 32 is nonzero.
837 * 3. If Length (IVA + 60) is not zero, then Length (IVA + 60) and
838 * Address (IVA + 56) are word-aligned.
839 * 4. The checksum of the 8 words starting at IVA + 32 plus the sum of
840 * the Length/4 words starting at Address is zero.
843 /* Setup IVA and compute checksum for HPMC handler */
844 ivap[6] = (u32)__pa(os_hpmc);
846 hpmcp = (u32 *)os_hpmc;
852 pr_debug("initialize_ivt: IVA[6] = 0x%08x\n", ivap[6]);
856 /* early_trap_init() is called before we set up kernel mappings and
857 * write-protect the kernel */
858 void __init early_trap_init(void)
860 extern const void fault_vector_20;
863 extern const void fault_vector_11;
864 initialize_ivt(&fault_vector_11);
867 initialize_ivt(&fault_vector_20);