[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);
	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);
		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, 0);
}

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;
		}
	}
	if (expand_stack(vma, address))
		goto bad_area;
	/*
	 * 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);

	if (fault_signal_pending(fault, regs))
		goto exit_exception;

	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 (flags & FAULT_FLAG_ALLOW_RETRY) {
		if (fault & VM_FAULT_MAJOR) {
			current->maj_flt++;
			perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ,
				      1, regs, address);
		} else {
			current->min_flt++;
			perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN,
				      1, regs, address);
		}
		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);

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

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 DM	101	pmdp = pmd_offset(pudp, tpc);
	102	if (pmd_none(pmdp) \|\| unlikely(pmd_bad(pmdp)))
	103	goto out_irq_enable;
	104
7bc3777c NG	105	#if defined(CONFIG_HUGETLB_PAGE) \|\| defined(CONFIG_TRANSPARENT_HUGEPAGE)
7bc3777c NG	106	if (is_hugetlb_pmd(*pmdp)) {
70ffc6eb DM	107	pa = pmd_pfn(*pmdp) << PAGE_SHIFT;
70ffc6eb DM	108	pa += tpc & ~HPAGE_MASK;
1da177e4	109
70ffc6eb DM	110	/* Use phys bypass so we don't pollute dtlb/dcache. */
	111	__asm__ __volatile__("lduwa [%1] %2, %0"
	112	: "=r" (insn)
	113	: "r" (pa), "i" (ASI_PHYS_USE_EC));
	114	} else
	115	#endif
	116	{
	117	ptep = pte_offset_map(pmdp, tpc);
	118	pte = *ptep;
	119	if (pte_present(pte)) {
	120	pa = (pte_pfn(pte) << PAGE_SHIFT);
	121	pa += (tpc & ~PAGE_MASK);
	122
	123	/* Use phys bypass so we don't pollute dtlb/dcache. */
	124	__asm__ __volatile__("lduwa [%1] %2, %0"
	125	: "=r" (insn)
	126	: "r" (pa), "i" (ASI_PHYS_USE_EC));
	127	}
	128	pte_unmap(ptep);
	129	}
	130	out_irq_enable:
	131	local_irq_enable();
1da177e4	132	out:
1da177e4 LT	133	return insn;
	134	}
	135
4b177647 DM	136	static inline void
	137	show_signal_msg(struct pt_regs *regs, int sig, int code,
	138	unsigned long address, struct task_struct *tsk)
	139	{
	140	if (!unhandled_signal(tsk, sig))
	141	return;
	142
	143	if (!printk_ratelimit())
	144	return;
	145
10a7e9d8	146	printk("%s%s[%d]: segfault at %lx ip %px (rpc %px) sp %px error %x",
4b177647 DM	147	task_pid_nr(tsk) > 1 ? KERN_INFO : KERN_EMERG,
	148	tsk->comm, task_pid_nr(tsk), address,
	149	(void )regs->tpc, (void )regs->u_regs[UREG_I7],
	150	(void *)regs->u_regs[UREG_FP], code);
	151
	152	print_vma_addr(KERN_CONT " in ", regs->tpc);
	153
	154	printk(KERN_CONT "\n");
	155	}
	156
1da177e4	157	static void do_fault_siginfo(int code, int sig, struct pt_regs *regs,
70ffc6eb DM	158	unsigned long fault_addr, unsigned int insn,
70ffc6eb DM	159	int fault_code)
1da177e4	160	{
4b177647	161	unsigned long addr;
1da177e4	162
70ffc6eb	163	if (fault_code & FAULT_CODE_ITLB) {
4b177647	164	addr = regs->tpc;
70ffc6eb DM	165	} else {
	166	/* If we were able to probe the faulting instruction, use it
	167	* to compute a precise fault address. Otherwise use the fault
	168	* time provided address which may only have page granularity.
	169	*/
	170	if (insn)
	171	addr = compute_effective_address(regs, insn, 0);
	172	else
	173	addr = fault_addr;
	174	}
4b177647 DM	175
	176	if (unlikely(show_unhandled_signals))
	177	show_signal_msg(regs, sig, code, addr, current);
	178
2e1661d2	179	force_sig_fault(sig, code, (void __user *) addr, 0);
1da177e4 LT	180	}
1da177e4 LT	181
1da177e4 LT	182	static unsigned int get_fault_insn(struct pt_regs *regs, unsigned int insn)
	183	{
	184	if (!insn) {
	185	if (!regs->tpc \|\| (regs->tpc & 0x3))
	186	return 0;
	187	if (regs->tstate & TSTATE_PRIV) {
	188	insn = (unsigned int ) regs->tpc;
	189	} else {
	190	insn = get_user_insn(regs->tpc);
	191	}
	192	}
	193	return insn;
	194	}
	195
4ed5d5e4 DM	196	static void __kprobes do_kernel_fault(struct pt_regs *regs, int si_code,
	197	int fault_code, unsigned int insn,
	198	unsigned long address)
1da177e4	199	{
1da177e4 LT	200	unsigned char asi = ASI_P;
	201
	202	if ((!insn) && (regs->tstate & TSTATE_PRIV))
	203	goto cannot_handle;
	204
	205	/* If user insn could be read (thus insn is zero), that
	206	* is fine. We will just gun down the process with a signal
	207	* in that case.
	208	*/
	209
	210	if (!(fault_code & (FAULT_CODE_WRITE\|FAULT_CODE_ITLB)) &&
	211	(insn & 0xc0800000) == 0xc0800000) {
	212	if (insn & 0x2000)
	213	asi = (regs->tstate >> 24);
	214	else
	215	asi = (insn >> 5);
	216	if ((asi & 0xf2) == 0x82) {
	217	if (insn & 0x1000000) {
	218	handle_ldf_stq(insn, regs);
	219	} else {
	220	/* This was a non-faulting load. Just clear the
	221	* destination register(s) and continue with the next
	222	* instruction. -jj
	223	*/
	224	handle_ld_nf(insn, regs);
	225	}
	226	return;
	227	}
	228	}
	229
1da177e4 LT	230	/* Is this in ex_table? */
1da177e4 LT	231	if (regs->tstate & TSTATE_PRIV) {
8cf14af0	232	const struct exception_table_entry *entry;
1da177e4	233
622eaec6 DM	234	entry = search_exception_tables(regs->tpc);
622eaec6 DM	235	if (entry) {
8cf14af0	236	regs->tpc = entry->fixup;
1da177e4	237	regs->tnpc = regs->tpc + 4;
1da177e4 LT	238	return;
	239	}
	240	} else {
	241	/* The si_code was set to make clear whether
	242	* this was a SEGV_MAPERR or SEGV_ACCERR fault.
	243	*/
70ffc6eb	244	do_fault_siginfo(si_code, SIGSEGV, regs, address, insn, fault_code);
1da177e4 LT	245	return;
	246	}
	247
	248	cannot_handle:
	249	unhandled_fault (address, current, regs);
	250	}
	251
4ed5d5e4	252	static void noinline __kprobes bogus_32bit_fault_tpc(struct pt_regs *regs)
9b026058 DM	253	{
	254	static int times;
	255
	256	if (times++ < 10)
	257	printk(KERN_ERR "FAULT[%s:%d]: 32-bit process reports "
	258	"64-bit TPC [%lx]\n",
	259	current->comm, current->pid,
	260	regs->tpc);
	261	show_regs(regs);
	262	}
	263
05e14cb3	264	asmlinkage void __kprobes do_sparc64_fault(struct pt_regs *regs)
1da177e4	265	{
812cb83a	266	enum ctx_state prev_state = exception_enter();
1da177e4 LT	267	struct mm_struct *mm = current->mm;
	268	struct vm_area_struct *vma;
	269	unsigned int insn = 0;
50a7ca3c SJ	270	int si_code, fault_code;
50a7ca3c SJ	271	vm_fault_t fault;
7a1ac526	272	unsigned long address, mm_rss;
dde16072	273	unsigned int flags = FAULT_FLAG_DEFAULT;
1da177e4 LT	274
	275	fault_code = get_thread_fault_code();
	276
b98cca44	277	if (kprobe_page_fault(regs, 0))
812cb83a	278	goto exit_exception;
1da177e4 LT	279
	280	si_code = SEGV_MAPERR;
	281	address = current_thread_info()->fault_address;
	282
	283	if ((fault_code & FAULT_CODE_ITLB) &&
	284	(fault_code & FAULT_CODE_DTLB))
	285	BUG();
	286
eeabac73	287	if (test_thread_flag(TIF_32BIT)) {
9b026058 DM	288	if (!(regs->tstate & TSTATE_PRIV)) {
	289	if (unlikely((regs->tpc >> 32) != 0)) {
	290	bogus_32bit_fault_tpc(regs);
	291	goto intr_or_no_mm;
	292	}
	293	}
e5c460f4	294	if (unlikely((address >> 32) != 0))
9b026058	295	goto intr_or_no_mm;
eeabac73 DM	296	}
eeabac73 DM	297
1da177e4	298	if (regs->tstate & TSTATE_PRIV) {
9b026058	299	unsigned long tpc = regs->tpc;
1da177e4 LT	300
1da177e4 LT	301	/* Sanity check the PC. */
be71716e	302	if ((tpc >= KERNBASE && tpc < (unsigned long) __init_end) \|\|
1da177e4 LT	303	(tpc >= MODULES_VADDR && tpc < MODULES_END)) {
	304	/* Valid, no problems... */
	305	} else {
bf941d6c	306	bad_kernel_pc(regs, address);
812cb83a	307	goto exit_exception;
1da177e4	308	}
759496ba JW	309	} else
759496ba JW	310	flags \|= FAULT_FLAG_USER;
1da177e4 LT	311
	312	/*
	313	* If we're in an interrupt or have no user
	314	* context, we must not take the fault..
	315	*/
70ffdb93	316	if (faulthandler_disabled() \|\| !mm)
1da177e4 LT	317	goto intr_or_no_mm;
1da177e4 LT	318
a8b0ca17	319	perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
a084b667	320
d8ed45c5	321	if (!mmap_read_trylock(mm)) {
1da177e4 LT	322	if ((regs->tstate & TSTATE_PRIV) &&
	323	!search_exception_tables(regs->tpc)) {
	324	insn = get_fault_insn(regs, insn);
	325	goto handle_kernel_fault;
	326	}
7358e510 KC	327
7358e510 KC	328	retry:
d8ed45c5	329	mmap_read_lock(mm);
1da177e4 LT	330	}
1da177e4 LT	331
4ccb9272	332	if (fault_code & FAULT_CODE_BAD_RA)
	333	goto do_sigbus;
	334
1da177e4 LT	335	vma = find_vma(mm, address);
	336	if (!vma)
	337	goto bad_area;
	338
	339	/* Pure DTLB misses do not tell us whether the fault causing
	340	* load/store/atomic was a write or not, it only says that there
	341	* was no match. So in such a case we (carefully) read the
	342	* instruction to try and figure this out. It's an optimization
	343	* so it's ok if we can't do this.
	344	*
	345	* Special hack, window spill/fill knows the exact fault type.
	346	*/
	347	if (((fault_code &
	348	(FAULT_CODE_DTLB \| FAULT_CODE_WRITE \| FAULT_CODE_WINFIXUP)) == FAULT_CODE_DTLB) &&
	349	(vma->vm_flags & VM_WRITE) != 0) {
	350	insn = get_fault_insn(regs, 0);
	351	if (!insn)
	352	goto continue_fault;
73c50a27 DM	353	/* All loads, stores and atomics have bits 30 and 31 both set
	354	* in the instruction. Bit 21 is set in all stores, but we
	355	* have to avoid prefetches which also have bit 21 set.
	356	*/
1da177e4	357	if ((insn & 0xc0200000) == 0xc0200000 &&
73c50a27	358	(insn & 0x01780000) != 0x01680000) {
1da177e4 LT	359	/* Don't bother updating thread struct value,
	360	* because update_mmu_cache only cares which tlb
	361	* the access came from.
	362	*/
	363	fault_code \|= FAULT_CODE_WRITE;
	364	}
	365	}
	366	continue_fault:
	367
	368	if (vma->vm_start <= address)
	369	goto good_area;
	370	if (!(vma->vm_flags & VM_GROWSDOWN))
	371	goto bad_area;
	372	if (!(fault_code & FAULT_CODE_WRITE)) {
	373	/* Non-faulting loads shouldn't expand stack. */
	374	insn = get_fault_insn(regs, insn);
	375	if ((insn & 0xc0800000) == 0xc0800000) {
	376	unsigned char asi;
	377
	378	if (insn & 0x2000)
	379	asi = (regs->tstate >> 24);
	380	else
	381	asi = (insn >> 5);
	382	if ((asi & 0xf2) == 0x82)
	383	goto bad_area;
	384	}
	385	}
	386	if (expand_stack(vma, address))
	387	goto bad_area;
	388	/*
	389	* Ok, we have a good vm_area for this memory access, so
	390	* we can handle it..
	391	*/
	392	good_area:
	393	si_code = SEGV_ACCERR;
	394
	395	/* If we took a ITLB miss on a non-executable page, catch
	396	* that here.
	397	*/
	398	if ((fault_code & FAULT_CODE_ITLB) && !(vma->vm_flags & VM_EXEC)) {
2bf7c3ef DA	399	WARN(address != regs->tpc,
	400	"address (%lx) != regs->tpc (%lx)\n", address, regs->tpc);
	401	WARN_ON(regs->tstate & TSTATE_PRIV);
1da177e4 LT	402	goto bad_area;
	403	}
	404
	405	if (fault_code & FAULT_CODE_WRITE) {
	406	if (!(vma->vm_flags & VM_WRITE))
	407	goto bad_area;
	408
	409	/* Spitfire has an icache which does not snoop
	410	* processor stores. Later processors do...
	411	*/
	412	if (tlb_type == spitfire &&
	413	(vma->vm_flags & VM_EXEC) != 0 &&
	414	vma->vm_file != NULL)
	415	set_thread_fault_code(fault_code \|
	416	FAULT_CODE_BLKCOMMIT);
759496ba JW	417
759496ba JW	418	flags \|= FAULT_FLAG_WRITE;
1da177e4 LT	419	} else {
	420	/* Allow reads even for write-only mappings */
	421	if (!(vma->vm_flags & (VM_READ \| VM_EXEC)))
	422	goto bad_area;
	423	}
	424
dcddffd4	425	fault = handle_mm_fault(vma, address, flags);
7358e510	426
4ef87322	427	if (fault_signal_pending(fault, regs))
812cb83a	428	goto exit_exception;
7358e510	429
83c54070 NP	430	if (unlikely(fault & VM_FAULT_ERROR)) {
	431	if (fault & VM_FAULT_OOM)
	432	goto out_of_memory;
33692f27 LT	433	else if (fault & VM_FAULT_SIGSEGV)
33692f27 LT	434	goto bad_area;
83c54070 NP	435	else if (fault & VM_FAULT_SIGBUS)
83c54070 NP	436	goto do_sigbus;
1da177e4 LT	437	BUG();
1da177e4 LT	438	}
7358e510 KC	439
	440	if (flags & FAULT_FLAG_ALLOW_RETRY) {
	441	if (fault & VM_FAULT_MAJOR) {
	442	current->maj_flt++;
	443	perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ,
	444	1, regs, address);
	445	} else {
	446	current->min_flt++;
	447	perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN,
	448	1, regs, address);
	449	}
	450	if (fault & VM_FAULT_RETRY) {
45cac65b	451	flags \|= FAULT_FLAG_TRIED;
7358e510	452
3e4e28c5	453	/* No need to mmap_read_unlock(mm) as we would
7358e510 KC	454	* have already released it in __lock_page_or_retry
	455	* in mm/filemap.c.
	456	*/
	457
	458	goto retry;
	459	}
a084b667	460	}
d8ed45c5	461	mmap_read_unlock(mm);
7a1ac526 DM	462
7a1ac526 DM	463	mm_rss = get_mm_rss(mm);
af1b1a9b MK	464	#if defined(CONFIG_TRANSPARENT_HUGEPAGE)
af1b1a9b MK	465	mm_rss -= (mm->context.thp_pte_count * (HPAGE_SIZE / PAGE_SIZE));
dcc1e8dd	466	#endif
7bebd83d	467	if (unlikely(mm_rss >
dcc1e8dd DM	468	mm->context.tsb_block[MM_TSB_BASE].tsb_rss_limit))
dcc1e8dd DM	469	tsb_grow(mm, MM_TSB_BASE, mm_rss);
9e695d2e	470	#if defined(CONFIG_HUGETLB_PAGE) \|\| defined(CONFIG_TRANSPARENT_HUGEPAGE)
af1b1a9b	471	mm_rss = mm->context.hugetlb_pte_count + mm->context.thp_pte_count;
1e953d84	472	mm_rss *= REAL_HPAGE_PER_HPAGE;
7bebd83d	473	if (unlikely(mm_rss >
0fbebed6 DM	474	mm->context.tsb_block[MM_TSB_HUGE].tsb_rss_limit)) {
	475	if (mm->context.tsb_block[MM_TSB_HUGE].tsb)
	476	tsb_grow(mm, MM_TSB_HUGE, mm_rss);
	477	else
	478	hugetlb_setup(regs);
	479
	480	}
dcc1e8dd	481	#endif
812cb83a KT	482	exit_exception:
812cb83a KT	483	exception_exit(prev_state);
efdc1e20	484	return;
1da177e4 LT	485
	486	/*
	487	* Something tried to access memory that isn't in our memory map..
	488	* Fix it, but check if it's kernel or user first..
	489	*/
	490	bad_area:
	491	insn = get_fault_insn(regs, insn);
d8ed45c5	492	mmap_read_unlock(mm);
1da177e4 LT	493
	494	handle_kernel_fault:
	495	do_kernel_fault(regs, si_code, fault_code, insn, address);
812cb83a	496	goto exit_exception;
1da177e4 LT	497
	498	/*
	499	* We ran out of memory, or some other thing happened to us that made
	500	* us unable to handle the page fault gracefully.
	501	*/
	502	out_of_memory:
	503	insn = get_fault_insn(regs, insn);
d8ed45c5	504	mmap_read_unlock(mm);
a923c28f DM	505	if (!(regs->tstate & TSTATE_PRIV)) {
a923c28f DM	506	pagefault_out_of_memory();
812cb83a	507	goto exit_exception;
a923c28f	508	}
1da177e4 LT	509	goto handle_kernel_fault;
	510
	511	intr_or_no_mm:
	512	insn = get_fault_insn(regs, 0);
	513	goto handle_kernel_fault;
	514
	515	do_sigbus:
	516	insn = get_fault_insn(regs, insn);
d8ed45c5	517	mmap_read_unlock(mm);
1da177e4 LT	518
	519	/*
	520	* Send a sigbus, regardless of whether we were in kernel
	521	* or user mode.
	522	*/
70ffc6eb	523	do_fault_siginfo(BUS_ADRERR, SIGBUS, regs, address, insn, fault_code);
1da177e4 LT	524
	525	/* Kernel mode? Handle exceptions or die */
	526	if (regs->tstate & TSTATE_PRIV)
	527	goto handle_kernel_fault;
1da177e4	528	}