[linux-block.git] / arch / sparc / mm / fault_64.c

// SPDX-License-Identifier: GPL-2.0
/*
 * arch/sparc64/mm/fault.c: Page fault handlers for the 64-bit Sparc.
 *
 * Copyright (C) 1996, 2008 David S. Miller (davem@davemloft.net)
 * Copyright (C) 1997, 1999 Jakub Jelinek (jj@ultra.linux.cz)
 */

#include <asm/head.h>

#include <linux/string.h>
#include <linux/types.h>
#include <linux/sched.h>
#include <linux/sched/debug.h>
#include <linux/ptrace.h>
#include <linux/mman.h>
#include <linux/signal.h>
#include <linux/mm.h>
#include <linux/extable.h>
#include <linux/init.h>
#include <linux/perf_event.h>
#include <linux/interrupt.h>
#include <linux/kprobes.h>
#include <linux/kdebug.h>
#include <linux/percpu.h>
#include <linux/context_tracking.h>
#include <linux/uaccess.h>

#include <asm/page.h>
#include <asm/openprom.h>
#include <asm/oplib.h>
#include <asm/asi.h>
#include <asm/lsu.h>
#include <asm/sections.h>
#include <asm/mmu_context.h>
#include <asm/setup.h>

int show_unhandled_signals = 1;

static void __kprobes unhandled_fault(unsigned long address,
				      struct task_struct *tsk,
				      struct pt_regs *regs)
{
	if ((unsigned long) address < PAGE_SIZE) {
		printk(KERN_ALERT "Unable to handle kernel NULL "
		       "pointer dereference\n");
	} else {
		printk(KERN_ALERT "Unable to handle kernel paging request "
		       "at virtual address %016lx\n", (unsigned long)address);
	}
	printk(KERN_ALERT "tsk->{mm,active_mm}->context = %016lx\n",
	       (tsk->mm ?
		CTX_HWBITS(tsk->mm->context) :
		CTX_HWBITS(tsk->active_mm->context)));
	printk(KERN_ALERT "tsk->{mm,active_mm}->pgd = %016lx\n",
	       (tsk->mm ? (unsigned long) tsk->mm->pgd :
		          (unsigned long) tsk->active_mm->pgd));
	die_if_kernel("Oops", regs);
}

static void __kprobes bad_kernel_pc(struct pt_regs *regs, unsigned long vaddr)
{
	printk(KERN_CRIT "OOPS: Bogus kernel PC [%016lx] in fault handler\n",
	       regs->tpc);
	printk(KERN_CRIT "OOPS: RPC [%016lx]\n", regs->u_regs[15]);
	printk("OOPS: RPC <%pS>\n", (void *) regs->u_regs[15]);
	printk(KERN_CRIT "OOPS: Fault was to vaddr[%lx]\n", vaddr);
	dump_stack();
	unhandled_fault(regs->tpc, current, regs);
}

/*
 * We now make sure that mmap_lock is held in all paths that call
 * this. Additionally, to prevent kswapd from ripping ptes from
 * under us, raise interrupts around the time that we look at the
 * pte, kswapd will have to wait to get his smp ipi response from
 * us. vmtruncate likewise. This saves us having to get pte lock.
 */
static unsigned int get_user_insn(unsigned long tpc)
{
	pgd_t *pgdp = pgd_offset(current->mm, tpc);
	p4d_t *p4dp;
	pud_t *pudp;
	pmd_t *pmdp;
	pte_t *ptep, pte;
	unsigned long pa;
	u32 insn = 0;

	if (pgd_none(*pgdp) || unlikely(pgd_bad(*pgdp)))
		goto out;
	p4dp = p4d_offset(pgdp, tpc);
	if (p4d_none(*p4dp) || unlikely(p4d_bad(*p4dp)))
		goto out;
	pudp = pud_offset(p4dp, tpc);
	if (pud_none(*pudp) || unlikely(pud_bad(*pudp)))
		goto out;

	/* This disables preemption for us as well. */
	local_irq_disable();

	pmdp = pmd_offset(pudp, tpc);
again:
	if (pmd_none(*pmdp) || unlikely(pmd_bad(*pmdp)))
		goto out_irq_enable;

#if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)
	if (is_hugetlb_pmd(*pmdp)) {
		pa  = pmd_pfn(*pmdp) << PAGE_SHIFT;
		pa += tpc & ~HPAGE_MASK;

		/* Use phys bypass so we don't pollute dtlb/dcache. */
		__asm__ __volatile__("lduwa [%1] %2, %0"
				     : "=r" (insn)
				     : "r" (pa), "i" (ASI_PHYS_USE_EC));
	} else
#endif
	{
		ptep = pte_offset_map(pmdp, tpc);
		if (!ptep)
			goto again;
		pte = *ptep;
		if (pte_present(pte)) {
			pa  = (pte_pfn(pte) << PAGE_SHIFT);
			pa += (tpc & ~PAGE_MASK);

			/* Use phys bypass so we don't pollute dtlb/dcache. */
			__asm__ __volatile__("lduwa [%1] %2, %0"
					     : "=r" (insn)
					     : "r" (pa), "i" (ASI_PHYS_USE_EC));
		}
		pte_unmap(ptep);
	}
out_irq_enable:
	local_irq_enable();
out:
	return insn;
}

static inline void
show_signal_msg(struct pt_regs *regs, int sig, int code,
		unsigned long address, struct task_struct *tsk)
{
	if (!unhandled_signal(tsk, sig))
		return;

	if (!printk_ratelimit())
		return;

	printk("%s%s[%d]: segfault at %lx ip %px (rpc %px) sp %px error %x",
	       task_pid_nr(tsk) > 1 ? KERN_INFO : KERN_EMERG,
	       tsk->comm, task_pid_nr(tsk), address,
	       (void *)regs->tpc, (void *)regs->u_regs[UREG_I7],
	       (void *)regs->u_regs[UREG_FP], code);

	print_vma_addr(KERN_CONT " in ", regs->tpc);

	printk(KERN_CONT "\n");
}

static void do_fault_siginfo(int code, int sig, struct pt_regs *regs,
			     unsigned long fault_addr, unsigned int insn,
			     int fault_code)
{
	unsigned long addr;

	if (fault_code & FAULT_CODE_ITLB) {
		addr = regs->tpc;
	} else {
		/* If we were able to probe the faulting instruction, use it
		 * to compute a precise fault address.  Otherwise use the fault
		 * time provided address which may only have page granularity.
		 */
		if (insn)
			addr = compute_effective_address(regs, insn, 0);
		else
			addr = fault_addr;
	}

	if (unlikely(show_unhandled_signals))
		show_signal_msg(regs, sig, code, addr, current);

	force_sig_fault(sig, code, (void __user *) addr);
}

static unsigned int get_fault_insn(struct pt_regs *regs, unsigned int insn)
{
	if (!insn) {
		if (!regs->tpc || (regs->tpc & 0x3))
			return 0;
		if (regs->tstate & TSTATE_PRIV) {
			insn = *(unsigned int *) regs->tpc;
		} else {
			insn = get_user_insn(regs->tpc);
		}
	}
	return insn;
}

static void __kprobes do_kernel_fault(struct pt_regs *regs, int si_code,
				      int fault_code, unsigned int insn,
				      unsigned long address)
{
	unsigned char asi = ASI_P;
 
	if ((!insn) && (regs->tstate & TSTATE_PRIV))
		goto cannot_handle;

	/* If user insn could be read (thus insn is zero), that
	 * is fine.  We will just gun down the process with a signal
	 * in that case.
	 */

	if (!(fault_code & (FAULT_CODE_WRITE|FAULT_CODE_ITLB)) &&
	    (insn & 0xc0800000) == 0xc0800000) {
		if (insn & 0x2000)
			asi = (regs->tstate >> 24);
		else
			asi = (insn >> 5);
		if ((asi & 0xf2) == 0x82) {
			if (insn & 0x1000000) {
				handle_ldf_stq(insn, regs);
			} else {
				/* This was a non-faulting load. Just clear the
				 * destination register(s) and continue with the next
				 * instruction. -jj
				 */
				handle_ld_nf(insn, regs);
			}
			return;
		}
	}
		
	/* Is this in ex_table? */
	if (regs->tstate & TSTATE_PRIV) {
		const struct exception_table_entry *entry;

		entry = search_exception_tables(regs->tpc);
		if (entry) {
			regs->tpc = entry->fixup;
			regs->tnpc = regs->tpc + 4;
			return;
		}
	} else {
		/* The si_code was set to make clear whether
		 * this was a SEGV_MAPERR or SEGV_ACCERR fault.
		 */
		do_fault_siginfo(si_code, SIGSEGV, regs, address, insn, fault_code);
		return;
	}

cannot_handle:
	unhandled_fault (address, current, regs);
}

static void noinline __kprobes bogus_32bit_fault_tpc(struct pt_regs *regs)
{
	static int times;

	if (times++ < 10)
		printk(KERN_ERR "FAULT[%s:%d]: 32-bit process reports "
		       "64-bit TPC [%lx]\n",
		       current->comm, current->pid,
		       regs->tpc);
	show_regs(regs);
}

asmlinkage void __kprobes do_sparc64_fault(struct pt_regs *regs)
{
	enum ctx_state prev_state = exception_enter();
	struct mm_struct *mm = current->mm;
	struct vm_area_struct *vma;
	unsigned int insn = 0;
	int si_code, fault_code;
	vm_fault_t fault;
	unsigned long address, mm_rss;
	unsigned int flags = FAULT_FLAG_DEFAULT;

	fault_code = get_thread_fault_code();

	if (kprobe_page_fault(regs, 0))
		goto exit_exception;

	si_code = SEGV_MAPERR;
	address = current_thread_info()->fault_address;

	if ((fault_code & FAULT_CODE_ITLB) &&
	    (fault_code & FAULT_CODE_DTLB))
		BUG();

	if (test_thread_flag(TIF_32BIT)) {
		if (!(regs->tstate & TSTATE_PRIV)) {
			if (unlikely((regs->tpc >> 32) != 0)) {
				bogus_32bit_fault_tpc(regs);
				goto intr_or_no_mm;
			}
		}
		if (unlikely((address >> 32) != 0))
			goto intr_or_no_mm;
	}

	if (regs->tstate & TSTATE_PRIV) {
		unsigned long tpc = regs->tpc;

		/* Sanity check the PC. */
		if ((tpc >= KERNBASE && tpc < (unsigned long) __init_end) ||
		    (tpc >= MODULES_VADDR && tpc < MODULES_END)) {
			/* Valid, no problems... */
		} else {
			bad_kernel_pc(regs, address);
			goto exit_exception;
		}
	} else
		flags |= FAULT_FLAG_USER;

	/*
	 * If we're in an interrupt or have no user
	 * context, we must not take the fault..
	 */
	if (faulthandler_disabled() || !mm)
		goto intr_or_no_mm;

	perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);

	if (!mmap_read_trylock(mm)) {
		if ((regs->tstate & TSTATE_PRIV) &&
		    !search_exception_tables(regs->tpc)) {
			insn = get_fault_insn(regs, insn);
			goto handle_kernel_fault;
		}

retry:
		mmap_read_lock(mm);
	}

	if (fault_code & FAULT_CODE_BAD_RA)
		goto do_sigbus;

	vma = find_vma(mm, address);
	if (!vma)
		goto bad_area;

	/* Pure DTLB misses do not tell us whether the fault causing
	 * load/store/atomic was a write or not, it only says that there
	 * was no match.  So in such a case we (carefully) read the
	 * instruction to try and figure this out.  It's an optimization
	 * so it's ok if we can't do this.
	 *
	 * Special hack, window spill/fill knows the exact fault type.
	 */
	if (((fault_code &
	      (FAULT_CODE_DTLB | FAULT_CODE_WRITE | FAULT_CODE_WINFIXUP)) == FAULT_CODE_DTLB) &&
	    (vma->vm_flags & VM_WRITE) != 0) {
		insn = get_fault_insn(regs, 0);
		if (!insn)
			goto continue_fault;
		/* All loads, stores and atomics have bits 30 and 31 both set
		 * in the instruction.  Bit 21 is set in all stores, but we
		 * have to avoid prefetches which also have bit 21 set.
		 */
		if ((insn & 0xc0200000) == 0xc0200000 &&
		    (insn & 0x01780000) != 0x01680000) {
			/* Don't bother updating thread struct value,
			 * because update_mmu_cache only cares which tlb
			 * the access came from.
			 */
			fault_code |= FAULT_CODE_WRITE;
		}
	}
continue_fault:

	if (vma->vm_start <= address)
		goto good_area;
	if (!(vma->vm_flags & VM_GROWSDOWN))
		goto bad_area;
	if (!(fault_code & FAULT_CODE_WRITE)) {
		/* Non-faulting loads shouldn't expand stack. */
		insn = get_fault_insn(regs, insn);
		if ((insn & 0xc0800000) == 0xc0800000) {
			unsigned char asi;

			if (insn & 0x2000)
				asi = (regs->tstate >> 24);
			else
				asi = (insn >> 5);
			if ((asi & 0xf2) == 0x82)
				goto bad_area;
		}
	}
	vma = expand_stack(mm, address);
	if (!vma)
		goto bad_area_nosemaphore;
	/*
	 * Ok, we have a good vm_area for this memory access, so
	 * we can handle it..
	 */
good_area:
	si_code = SEGV_ACCERR;

	/* If we took a ITLB miss on a non-executable page, catch
	 * that here.
	 */
	if ((fault_code & FAULT_CODE_ITLB) && !(vma->vm_flags & VM_EXEC)) {
		WARN(address != regs->tpc,
		     "address (%lx) != regs->tpc (%lx)\n", address, regs->tpc);
		WARN_ON(regs->tstate & TSTATE_PRIV);
		goto bad_area;
	}

	if (fault_code & FAULT_CODE_WRITE) {
		if (!(vma->vm_flags & VM_WRITE))
			goto bad_area;

		/* Spitfire has an icache which does not snoop
		 * processor stores.  Later processors do...
		 */
		if (tlb_type == spitfire &&
		    (vma->vm_flags & VM_EXEC) != 0 &&
		    vma->vm_file != NULL)
			set_thread_fault_code(fault_code |
					      FAULT_CODE_BLKCOMMIT);

		flags |= FAULT_FLAG_WRITE;
	} else {
		/* Allow reads even for write-only mappings */
		if (!(vma->vm_flags & (VM_READ | VM_EXEC)))
			goto bad_area;
	}

	fault = handle_mm_fault(vma, address, flags, regs);

	if (fault_signal_pending(fault, regs)) {
		if (regs->tstate & TSTATE_PRIV) {
			insn = get_fault_insn(regs, insn);
			goto handle_kernel_fault;
		}
		goto exit_exception;
	}

	/* The fault is fully completed (including releasing mmap lock) */
	if (fault & VM_FAULT_COMPLETED)
		goto lock_released;

	if (unlikely(fault & VM_FAULT_ERROR)) {
		if (fault & VM_FAULT_OOM)
			goto out_of_memory;
		else if (fault & VM_FAULT_SIGSEGV)
			goto bad_area;
		else if (fault & VM_FAULT_SIGBUS)
			goto do_sigbus;
		BUG();
	}

	if (fault & VM_FAULT_RETRY) {
		flags |= FAULT_FLAG_TRIED;

		/* No need to mmap_read_unlock(mm) as we would
		 * have already released it in __lock_page_or_retry
		 * in mm/filemap.c.
		 */

		goto retry;
	}
	mmap_read_unlock(mm);

lock_released:
	mm_rss = get_mm_rss(mm);
#if defined(CONFIG_TRANSPARENT_HUGEPAGE)
	mm_rss -= (mm->context.thp_pte_count * (HPAGE_SIZE / PAGE_SIZE));
#endif
	if (unlikely(mm_rss >
		     mm->context.tsb_block[MM_TSB_BASE].tsb_rss_limit))
		tsb_grow(mm, MM_TSB_BASE, mm_rss);
#if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)
	mm_rss = mm->context.hugetlb_pte_count + mm->context.thp_pte_count;
	mm_rss *= REAL_HPAGE_PER_HPAGE;
	if (unlikely(mm_rss >
		     mm->context.tsb_block[MM_TSB_HUGE].tsb_rss_limit)) {
		if (mm->context.tsb_block[MM_TSB_HUGE].tsb)
			tsb_grow(mm, MM_TSB_HUGE, mm_rss);
		else
			hugetlb_setup(regs);

	}
#endif
exit_exception:
	exception_exit(prev_state);
	return;

	/*
	 * Something tried to access memory that isn't in our memory map..
	 * Fix it, but check if it's kernel or user first..
	 */
bad_area:
	mmap_read_unlock(mm);
bad_area_nosemaphore:
	insn = get_fault_insn(regs, insn);

handle_kernel_fault:
	do_kernel_fault(regs, si_code, fault_code, insn, address);
	goto exit_exception;

/*
 * We ran out of memory, or some other thing happened to us that made
 * us unable to handle the page fault gracefully.
 */
out_of_memory:
	insn = get_fault_insn(regs, insn);
	mmap_read_unlock(mm);
	if (!(regs->tstate & TSTATE_PRIV)) {
		pagefault_out_of_memory();
		goto exit_exception;
	}
	goto handle_kernel_fault;

intr_or_no_mm:
	insn = get_fault_insn(regs, 0);
	goto handle_kernel_fault;

do_sigbus:
	insn = get_fault_insn(regs, insn);
	mmap_read_unlock(mm);

	/*
	 * Send a sigbus, regardless of whether we were in kernel
	 * or user mode.
	 */
	do_fault_siginfo(BUS_ADRERR, SIGBUS, regs, address, insn, fault_code);

	/* Kernel mode? Handle exceptions or die */
	if (regs->tstate & TSTATE_PRIV)
		goto handle_kernel_fault;
}
Commit	Line	Data
b2441318	1	// SPDX-License-Identifier: GPL-2.0
b00dc837	2	/*
1da177e4 LT	3	* arch/sparc64/mm/fault.c: Page fault handlers for the 64-bit Sparc.
1da177e4 LT	4	*
4fe3ebec	5	* Copyright (C) 1996, 2008 David S. Miller (davem@davemloft.net)
1da177e4 LT	6	* Copyright (C) 1997, 1999 Jakub Jelinek (jj@ultra.linux.cz)
	7	*/
	8
	9	#include <asm/head.h>
	10
	11	#include <linux/string.h>
	12	#include <linux/types.h>
	13	#include <linux/sched.h>
b17b0153	14	#include <linux/sched/debug.h>
1da177e4 LT	15	#include <linux/ptrace.h>
	16	#include <linux/mman.h>
	17	#include <linux/signal.h>
	18	#include <linux/mm.h>
cdd4f4c7	19	#include <linux/extable.h>
1da177e4	20	#include <linux/init.h>
a084b667	21	#include <linux/perf_event.h>
1da177e4	22	#include <linux/interrupt.h>
05e14cb3	23	#include <linux/kprobes.h>
1eeb66a1	24	#include <linux/kdebug.h>
eeabac73	25	#include <linux/percpu.h>
812cb83a	26	#include <linux/context_tracking.h>
70ffdb93	27	#include <linux/uaccess.h>
1da177e4 LT	28
1da177e4 LT	29	#include <asm/page.h>
1da177e4 LT	30	#include <asm/openprom.h>
1da177e4 LT	31	#include <asm/oplib.h>
1da177e4 LT	32	#include <asm/asi.h>
	33	#include <asm/lsu.h>
	34	#include <asm/sections.h>
7a1ac526	35	#include <asm/mmu_context.h>
8df52620	36	#include <asm/setup.h>
1da177e4	37
4b177647 DM	38	int show_unhandled_signals = 1;
4b177647 DM	39
05e14cb3 PP	40	static void __kprobes unhandled_fault(unsigned long address,
	41	struct task_struct *tsk,
	42	struct pt_regs *regs)
1da177e4 LT	43	{
	44	if ((unsigned long) address < PAGE_SIZE) {
	45	printk(KERN_ALERT "Unable to handle kernel NULL "
	46	"pointer dereference\n");
	47	} else {
	48	printk(KERN_ALERT "Unable to handle kernel paging request "
	49	"at virtual address %016lx\n", (unsigned long)address);
	50	}
	51	printk(KERN_ALERT "tsk->{mm,active_mm}->context = %016lx\n",
	52	(tsk->mm ?
	53	CTX_HWBITS(tsk->mm->context) :
	54	CTX_HWBITS(tsk->active_mm->context)));
	55	printk(KERN_ALERT "tsk->{mm,active_mm}->pgd = %016lx\n",
	56	(tsk->mm ? (unsigned long) tsk->mm->pgd :
	57	(unsigned long) tsk->active_mm->pgd));
1da177e4 LT	58	die_if_kernel("Oops", regs);
	59	}
	60
4ed5d5e4	61	static void __kprobes bad_kernel_pc(struct pt_regs *regs, unsigned long vaddr)
1da177e4	62	{
1da177e4 LT	63	printk(KERN_CRIT "OOPS: Bogus kernel PC [%016lx] in fault handler\n",
1da177e4 LT	64	regs->tpc);
eb398d10	65	printk(KERN_CRIT "OOPS: RPC [%016lx]\n", regs->u_regs[15]);
4fe3ebec	66	printk("OOPS: RPC <%pS>\n", (void *) regs->u_regs[15]);
bf941d6c	67	printk(KERN_CRIT "OOPS: Fault was to vaddr[%lx]\n", vaddr);
c1f193a7	68	dump_stack();
1da177e4 LT	69	unhandled_fault(regs->tpc, current, regs);
	70	}
	71
	72	/*
c1e8d7c6	73	* We now make sure that mmap_lock is held in all paths that call
1da177e4 LT	74	* this. Additionally, to prevent kswapd from ripping ptes from
	75	* under us, raise interrupts around the time that we look at the
	76	* pte, kswapd will have to wait to get his smp ipi response from
da160546	77	* us. vmtruncate likewise. This saves us having to get pte lock.
1da177e4 LT	78	*/
	79	static unsigned int get_user_insn(unsigned long tpc)
	80	{
	81	pgd_t *pgdp = pgd_offset(current->mm, tpc);
5637bc50	82	p4d_t *p4dp;
1da177e4 LT	83	pud_t *pudp;
	84	pmd_t *pmdp;
	85	pte_t *ptep, pte;
	86	unsigned long pa;
	87	u32 insn = 0;
1da177e4	88
70ffc6eb DM	89	if (pgd_none(pgdp) \|\| unlikely(pgd_bad(pgdp)))
70ffc6eb DM	90	goto out;
5637bc50 MR	91	p4dp = p4d_offset(pgdp, tpc);
	92	if (p4d_none(p4dp) \|\| unlikely(p4d_bad(p4dp)))
	93	goto out;
	94	pudp = pud_offset(p4dp, tpc);
70ffc6eb DM	95	if (pud_none(pudp) \|\| unlikely(pud_bad(pudp)))
70ffc6eb DM	96	goto out;
1da177e4 LT	97
1da177e4 LT	98	/* This disables preemption for us as well. */
70ffc6eb	99	local_irq_disable();
1da177e4	100
70ffc6eb	101	pmdp = pmd_offset(pudp, tpc);
4be14ec0	102	again:
70ffc6eb DM	103	if (pmd_none(pmdp) \|\| unlikely(pmd_bad(pmdp)))
	104	goto out_irq_enable;
	105
7bc3777c NG	106	#if defined(CONFIG_HUGETLB_PAGE) \|\| defined(CONFIG_TRANSPARENT_HUGEPAGE)
7bc3777c NG	107	if (is_hugetlb_pmd(*pmdp)) {
70ffc6eb DM	108	pa = pmd_pfn(*pmdp) << PAGE_SHIFT;
70ffc6eb DM	109	pa += tpc & ~HPAGE_MASK;
1da177e4	110
70ffc6eb DM	111	/* Use phys bypass so we don't pollute dtlb/dcache. */
	112	__asm__ __volatile__("lduwa [%1] %2, %0"
	113	: "=r" (insn)
	114	: "r" (pa), "i" (ASI_PHYS_USE_EC));
	115	} else
	116	#endif
	117	{
	118	ptep = pte_offset_map(pmdp, tpc);
4be14ec0 HD	119	if (!ptep)
4be14ec0 HD	120	goto again;
70ffc6eb DM	121	pte = *ptep;
	122	if (pte_present(pte)) {
	123	pa = (pte_pfn(pte) << PAGE_SHIFT);
	124	pa += (tpc & ~PAGE_MASK);
	125
	126	/* Use phys bypass so we don't pollute dtlb/dcache. */
	127	__asm__ __volatile__("lduwa [%1] %2, %0"
	128	: "=r" (insn)
	129	: "r" (pa), "i" (ASI_PHYS_USE_EC));
	130	}
	131	pte_unmap(ptep);
	132	}
	133	out_irq_enable:
	134	local_irq_enable();
1da177e4	135	out:
1da177e4 LT	136	return insn;
	137	}
	138
4b177647 DM	139	static inline void
	140	show_signal_msg(struct pt_regs *regs, int sig, int code,
	141	unsigned long address, struct task_struct *tsk)
	142	{
	143	if (!unhandled_signal(tsk, sig))
	144	return;
	145
	146	if (!printk_ratelimit())
	147	return;
	148
10a7e9d8	149	printk("%s%s[%d]: segfault at %lx ip %px (rpc %px) sp %px error %x",
4b177647 DM	150	task_pid_nr(tsk) > 1 ? KERN_INFO : KERN_EMERG,
	151	tsk->comm, task_pid_nr(tsk), address,
	152	(void )regs->tpc, (void )regs->u_regs[UREG_I7],
	153	(void *)regs->u_regs[UREG_FP], code);
	154
	155	print_vma_addr(KERN_CONT " in ", regs->tpc);
	156
	157	printk(KERN_CONT "\n");
	158	}
	159
1da177e4	160	static void do_fault_siginfo(int code, int sig, struct pt_regs *regs,
70ffc6eb DM	161	unsigned long fault_addr, unsigned int insn,
70ffc6eb DM	162	int fault_code)
1da177e4	163	{
4b177647	164	unsigned long addr;
1da177e4	165
70ffc6eb	166	if (fault_code & FAULT_CODE_ITLB) {
4b177647	167	addr = regs->tpc;
70ffc6eb DM	168	} else {
	169	/* If we were able to probe the faulting instruction, use it
	170	* to compute a precise fault address. Otherwise use the fault
	171	* time provided address which may only have page granularity.
	172	*/
	173	if (insn)
	174	addr = compute_effective_address(regs, insn, 0);
	175	else
	176	addr = fault_addr;
	177	}
4b177647 DM	178
	179	if (unlikely(show_unhandled_signals))
	180	show_signal_msg(regs, sig, code, addr, current);
	181
2c9f7eaf	182	force_sig_fault(sig, code, (void __user *) addr);
1da177e4 LT	183	}
1da177e4 LT	184
1da177e4 LT	185	static unsigned int get_fault_insn(struct pt_regs *regs, unsigned int insn)
	186	{
	187	if (!insn) {
	188	if (!regs->tpc \|\| (regs->tpc & 0x3))
	189	return 0;
	190	if (regs->tstate & TSTATE_PRIV) {
	191	insn = (unsigned int ) regs->tpc;
	192	} else {
	193	insn = get_user_insn(regs->tpc);
	194	}
	195	}
	196	return insn;
	197	}
	198
4ed5d5e4 DM	199	static void __kprobes do_kernel_fault(struct pt_regs *regs, int si_code,
	200	int fault_code, unsigned int insn,
	201	unsigned long address)
1da177e4	202	{
1da177e4 LT	203	unsigned char asi = ASI_P;
	204
	205	if ((!insn) && (regs->tstate & TSTATE_PRIV))
	206	goto cannot_handle;
	207
	208	/* If user insn could be read (thus insn is zero), that
	209	* is fine. We will just gun down the process with a signal
	210	* in that case.
	211	*/
	212
	213	if (!(fault_code & (FAULT_CODE_WRITE\|FAULT_CODE_ITLB)) &&
	214	(insn & 0xc0800000) == 0xc0800000) {
	215	if (insn & 0x2000)
	216	asi = (regs->tstate >> 24);
	217	else
	218	asi = (insn >> 5);
	219	if ((asi & 0xf2) == 0x82) {
	220	if (insn & 0x1000000) {
	221	handle_ldf_stq(insn, regs);
	222	} else {
	223	/* This was a non-faulting load. Just clear the
	224	* destination register(s) and continue with the next
	225	* instruction. -jj
	226	*/
	227	handle_ld_nf(insn, regs);
	228	}
	229	return;
	230	}
	231	}
	232
1da177e4 LT	233	/* Is this in ex_table? */
1da177e4 LT	234	if (regs->tstate & TSTATE_PRIV) {
8cf14af0	235	const struct exception_table_entry *entry;
1da177e4	236
622eaec6 DM	237	entry = search_exception_tables(regs->tpc);
622eaec6 DM	238	if (entry) {
8cf14af0	239	regs->tpc = entry->fixup;
1da177e4	240	regs->tnpc = regs->tpc + 4;
1da177e4 LT	241	return;
	242	}
	243	} else {
	244	/* The si_code was set to make clear whether
	245	* this was a SEGV_MAPERR or SEGV_ACCERR fault.
	246	*/
70ffc6eb	247	do_fault_siginfo(si_code, SIGSEGV, regs, address, insn, fault_code);
1da177e4 LT	248	return;
	249	}
	250
	251	cannot_handle:
	252	unhandled_fault (address, current, regs);
	253	}
	254
4ed5d5e4	255	static void noinline __kprobes bogus_32bit_fault_tpc(struct pt_regs *regs)
9b026058 DM	256	{
	257	static int times;
	258
	259	if (times++ < 10)
	260	printk(KERN_ERR "FAULT[%s:%d]: 32-bit process reports "
	261	"64-bit TPC [%lx]\n",
	262	current->comm, current->pid,
	263	regs->tpc);
	264	show_regs(regs);
	265	}
	266
05e14cb3	267	asmlinkage void __kprobes do_sparc64_fault(struct pt_regs *regs)
1da177e4	268	{
812cb83a	269	enum ctx_state prev_state = exception_enter();
1da177e4 LT	270	struct mm_struct *mm = current->mm;
	271	struct vm_area_struct *vma;
	272	unsigned int insn = 0;
50a7ca3c SJ	273	int si_code, fault_code;
50a7ca3c SJ	274	vm_fault_t fault;
7a1ac526	275	unsigned long address, mm_rss;
dde16072	276	unsigned int flags = FAULT_FLAG_DEFAULT;
1da177e4 LT	277
	278	fault_code = get_thread_fault_code();
	279
b98cca44	280	if (kprobe_page_fault(regs, 0))
812cb83a	281	goto exit_exception;
1da177e4 LT	282
	283	si_code = SEGV_MAPERR;
	284	address = current_thread_info()->fault_address;
	285
	286	if ((fault_code & FAULT_CODE_ITLB) &&
	287	(fault_code & FAULT_CODE_DTLB))
	288	BUG();
	289
eeabac73	290	if (test_thread_flag(TIF_32BIT)) {
9b026058 DM	291	if (!(regs->tstate & TSTATE_PRIV)) {
	292	if (unlikely((regs->tpc >> 32) != 0)) {
	293	bogus_32bit_fault_tpc(regs);
	294	goto intr_or_no_mm;
	295	}
	296	}
e5c460f4	297	if (unlikely((address >> 32) != 0))
9b026058	298	goto intr_or_no_mm;
eeabac73 DM	299	}
eeabac73 DM	300
1da177e4	301	if (regs->tstate & TSTATE_PRIV) {
9b026058	302	unsigned long tpc = regs->tpc;
1da177e4 LT	303
1da177e4 LT	304	/* Sanity check the PC. */
be71716e	305	if ((tpc >= KERNBASE && tpc < (unsigned long) __init_end) \|\|
1da177e4 LT	306	(tpc >= MODULES_VADDR && tpc < MODULES_END)) {
	307	/* Valid, no problems... */
	308	} else {
bf941d6c	309	bad_kernel_pc(regs, address);
812cb83a	310	goto exit_exception;
1da177e4	311	}
759496ba JW	312	} else
759496ba JW	313	flags \|= FAULT_FLAG_USER;
1da177e4 LT	314
	315	/*
	316	* If we're in an interrupt or have no user
	317	* context, we must not take the fault..
	318	*/
70ffdb93	319	if (faulthandler_disabled() \|\| !mm)
1da177e4 LT	320	goto intr_or_no_mm;
1da177e4 LT	321
a8b0ca17	322	perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
a084b667	323
d8ed45c5	324	if (!mmap_read_trylock(mm)) {
1da177e4 LT	325	if ((regs->tstate & TSTATE_PRIV) &&
	326	!search_exception_tables(regs->tpc)) {
	327	insn = get_fault_insn(regs, insn);
	328	goto handle_kernel_fault;
	329	}
7358e510 KC	330
7358e510 KC	331	retry:
d8ed45c5	332	mmap_read_lock(mm);
1da177e4 LT	333	}
1da177e4 LT	334
4ccb9272	335	if (fault_code & FAULT_CODE_BAD_RA)
	336	goto do_sigbus;
	337
1da177e4 LT	338	vma = find_vma(mm, address);
	339	if (!vma)
	340	goto bad_area;
	341
	342	/* Pure DTLB misses do not tell us whether the fault causing
	343	* load/store/atomic was a write or not, it only says that there
	344	* was no match. So in such a case we (carefully) read the
	345	* instruction to try and figure this out. It's an optimization
	346	* so it's ok if we can't do this.
	347	*
	348	* Special hack, window spill/fill knows the exact fault type.
	349	*/
	350	if (((fault_code &
	351	(FAULT_CODE_DTLB \| FAULT_CODE_WRITE \| FAULT_CODE_WINFIXUP)) == FAULT_CODE_DTLB) &&
	352	(vma->vm_flags & VM_WRITE) != 0) {
	353	insn = get_fault_insn(regs, 0);
	354	if (!insn)
	355	goto continue_fault;
73c50a27 DM	356	/* All loads, stores and atomics have bits 30 and 31 both set
	357	* in the instruction. Bit 21 is set in all stores, but we
	358	* have to avoid prefetches which also have bit 21 set.
	359	*/
1da177e4	360	if ((insn & 0xc0200000) == 0xc0200000 &&
73c50a27	361	(insn & 0x01780000) != 0x01680000) {
1da177e4 LT	362	/* Don't bother updating thread struct value,
	363	* because update_mmu_cache only cares which tlb
	364	* the access came from.
	365	*/
	366	fault_code \|= FAULT_CODE_WRITE;
	367	}
	368	}
	369	continue_fault:
	370
	371	if (vma->vm_start <= address)
	372	goto good_area;
	373	if (!(vma->vm_flags & VM_GROWSDOWN))
	374	goto bad_area;
	375	if (!(fault_code & FAULT_CODE_WRITE)) {
	376	/* Non-faulting loads shouldn't expand stack. */
	377	insn = get_fault_insn(regs, insn);
	378	if ((insn & 0xc0800000) == 0xc0800000) {
	379	unsigned char asi;
	380
	381	if (insn & 0x2000)
	382	asi = (regs->tstate >> 24);
	383	else
	384	asi = (insn >> 5);
	385	if ((asi & 0xf2) == 0x82)
	386	goto bad_area;
	387	}
	388	}
8d7071af LT	389	vma = expand_stack(mm, address);
	390	if (!vma)
	391	goto bad_area_nosemaphore;
1da177e4 LT	392	/*
	393	* Ok, we have a good vm_area for this memory access, so
	394	* we can handle it..
	395	*/
	396	good_area:
	397	si_code = SEGV_ACCERR;
	398
	399	/* If we took a ITLB miss on a non-executable page, catch
	400	* that here.
	401	*/
	402	if ((fault_code & FAULT_CODE_ITLB) && !(vma->vm_flags & VM_EXEC)) {
2bf7c3ef DA	403	WARN(address != regs->tpc,
	404	"address (%lx) != regs->tpc (%lx)\n", address, regs->tpc);
	405	WARN_ON(regs->tstate & TSTATE_PRIV);
1da177e4 LT	406	goto bad_area;
	407	}
	408
	409	if (fault_code & FAULT_CODE_WRITE) {
	410	if (!(vma->vm_flags & VM_WRITE))
	411	goto bad_area;
	412
	413	/* Spitfire has an icache which does not snoop
	414	* processor stores. Later processors do...
	415	*/
	416	if (tlb_type == spitfire &&
	417	(vma->vm_flags & VM_EXEC) != 0 &&
	418	vma->vm_file != NULL)
	419	set_thread_fault_code(fault_code \|
	420	FAULT_CODE_BLKCOMMIT);
759496ba JW	421
759496ba JW	422	flags \|= FAULT_FLAG_WRITE;
1da177e4 LT	423	} else {
	424	/* Allow reads even for write-only mappings */
	425	if (!(vma->vm_flags & (VM_READ \| VM_EXEC)))
	426	goto bad_area;
	427	}
	428
f08147df	429	fault = handle_mm_fault(vma, address, flags, regs);
7358e510	430
79c54c97 AV	431	if (fault_signal_pending(fault, regs)) {
	432	if (regs->tstate & TSTATE_PRIV) {
	433	insn = get_fault_insn(regs, insn);
	434	goto handle_kernel_fault;
	435	}
812cb83a	436	goto exit_exception;
79c54c97	437	}
7358e510	438
d9272525 PX	439	/* The fault is fully completed (including releasing mmap lock) */
	440	if (fault & VM_FAULT_COMPLETED)
	441	goto lock_released;
	442
83c54070 NP	443	if (unlikely(fault & VM_FAULT_ERROR)) {
	444	if (fault & VM_FAULT_OOM)
	445	goto out_of_memory;
33692f27 LT	446	else if (fault & VM_FAULT_SIGSEGV)
33692f27 LT	447	goto bad_area;
83c54070 NP	448	else if (fault & VM_FAULT_SIGBUS)
83c54070 NP	449	goto do_sigbus;
1da177e4 LT	450	BUG();
1da177e4 LT	451	}
7358e510	452
36ef159f QZ	453	if (fault & VM_FAULT_RETRY) {
36ef159f QZ	454	flags \|= FAULT_FLAG_TRIED;
7358e510	455
36ef159f QZ	456	/* No need to mmap_read_unlock(mm) as we would
	457	* have already released it in __lock_page_or_retry
	458	* in mm/filemap.c.
	459	*/
7358e510	460
36ef159f	461	goto retry;
a084b667	462	}
d8ed45c5	463	mmap_read_unlock(mm);
7a1ac526	464
d9272525	465	lock_released:
7a1ac526	466	mm_rss = get_mm_rss(mm);
af1b1a9b MK	467	#if defined(CONFIG_TRANSPARENT_HUGEPAGE)
af1b1a9b MK	468	mm_rss -= (mm->context.thp_pte_count * (HPAGE_SIZE / PAGE_SIZE));
dcc1e8dd	469	#endif
7bebd83d	470	if (unlikely(mm_rss >
dcc1e8dd DM	471	mm->context.tsb_block[MM_TSB_BASE].tsb_rss_limit))
dcc1e8dd DM	472	tsb_grow(mm, MM_TSB_BASE, mm_rss);
9e695d2e	473	#if defined(CONFIG_HUGETLB_PAGE) \|\| defined(CONFIG_TRANSPARENT_HUGEPAGE)
af1b1a9b	474	mm_rss = mm->context.hugetlb_pte_count + mm->context.thp_pte_count;
1e953d84	475	mm_rss *= REAL_HPAGE_PER_HPAGE;
7bebd83d	476	if (unlikely(mm_rss >
0fbebed6 DM	477	mm->context.tsb_block[MM_TSB_HUGE].tsb_rss_limit)) {
	478	if (mm->context.tsb_block[MM_TSB_HUGE].tsb)
	479	tsb_grow(mm, MM_TSB_HUGE, mm_rss);
	480	else
	481	hugetlb_setup(regs);
	482
	483	}
dcc1e8dd	484	#endif
812cb83a KT	485	exit_exception:
812cb83a KT	486	exception_exit(prev_state);
efdc1e20	487	return;
1da177e4 LT	488
	489	/*
	490	* Something tried to access memory that isn't in our memory map..
	491	* Fix it, but check if it's kernel or user first..
	492	*/
	493	bad_area:
d8ed45c5	494	mmap_read_unlock(mm);
8d7071af LT	495	bad_area_nosemaphore:
8d7071af LT	496	insn = get_fault_insn(regs, insn);
1da177e4 LT	497
	498	handle_kernel_fault:
	499	do_kernel_fault(regs, si_code, fault_code, insn, address);
812cb83a	500	goto exit_exception;
1da177e4 LT	501
	502	/*
	503	* We ran out of memory, or some other thing happened to us that made
	504	* us unable to handle the page fault gracefully.
	505	*/
	506	out_of_memory:
	507	insn = get_fault_insn(regs, insn);
d8ed45c5	508	mmap_read_unlock(mm);
a923c28f DM	509	if (!(regs->tstate & TSTATE_PRIV)) {
a923c28f DM	510	pagefault_out_of_memory();
812cb83a	511	goto exit_exception;
a923c28f	512	}
1da177e4 LT	513	goto handle_kernel_fault;
	514
	515	intr_or_no_mm:
	516	insn = get_fault_insn(regs, 0);
	517	goto handle_kernel_fault;
	518
	519	do_sigbus:
	520	insn = get_fault_insn(regs, insn);
d8ed45c5	521	mmap_read_unlock(mm);
1da177e4 LT	522
	523	/*
	524	* Send a sigbus, regardless of whether we were in kernel
	525	* or user mode.
	526	*/
70ffc6eb	527	do_fault_siginfo(BUS_ADRERR, SIGBUS, regs, address, insn, fault_code);
1da177e4 LT	528
	529	/* Kernel mode? Handle exceptions or die */
	530	if (regs->tstate & TSTATE_PRIV)
	531	goto handle_kernel_fault;
1da177e4	532	}