]>
git.proxmox.com Git - mirror_ubuntu-bionic-kernel.git/blob - arch/mn10300/mm/fault.c
1 /* MN10300 MMU Fault handler
3 * Copyright (C) 2007 Matsushita Electric Industrial Co., Ltd.
4 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
5 * Modified by David Howells (dhowells@redhat.com)
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public Licence
9 * as published by the Free Software Foundation; either version
10 * 2 of the Licence, or (at your option) any later version.
13 #include <linux/signal.h>
14 #include <linux/sched.h>
15 #include <linux/kernel.h>
16 #include <linux/errno.h>
17 #include <linux/string.h>
18 #include <linux/types.h>
19 #include <linux/ptrace.h>
20 #include <linux/mman.h>
22 #include <linux/smp.h>
23 #include <linux/smp_lock.h>
24 #include <linux/interrupt.h>
25 #include <linux/init.h>
26 #include <linux/vt_kern.h> /* For unblank_screen() */
28 #include <asm/system.h>
29 #include <asm/uaccess.h>
30 #include <asm/pgalloc.h>
31 #include <asm/hardirq.h>
32 #include <asm/gdb-stub.h>
33 #include <asm/cpu-regs.h>
36 * Unlock any spinlocks which will prevent us from getting the
39 void bust_spinlocks(int yes
)
44 /* Many serial drivers do __global_cli() */
48 int loglevel_save
= console_loglevel
;
54 * OK, the message is on the console. Now we call printk()
55 * without oops_in_progress set so that printk will give klogd
56 * a poke. Hold onto your hats...
58 console_loglevel
= 15; /* NMI oopser may have shut the console
61 console_loglevel
= loglevel_save
;
65 void do_BUG(const char *file
, int line
)
68 printk(KERN_EMERG
"------------[ cut here ]------------\n");
69 printk(KERN_EMERG
"kernel BUG at %s:%d!\n", file
, line
);
73 static void print_pagetable_entries(pgd_t
*pgdir
, unsigned long address
)
79 pgd
= pgdir
+ __pgd_offset(address
);
80 printk(KERN_DEBUG
"pgd entry %p: %016Lx\n",
81 pgd
, (long long) pgd_val(*pgd
));
83 if (!pgd_present(*pgd
)) {
84 printk(KERN_DEBUG
"... pgd not present!\n");
87 pmd
= pmd_offset(pgd
, address
);
88 printk(KERN_DEBUG
"pmd entry %p: %016Lx\n",
89 pmd
, (long long)pmd_val(*pmd
));
91 if (!pmd_present(*pmd
)) {
92 printk(KERN_DEBUG
"... pmd not present!\n");
95 pte
= pte_offset(pmd
, address
);
96 printk(KERN_DEBUG
"pte entry %p: %016Lx\n",
97 pte
, (long long) pte_val(*pte
));
99 if (!pte_present(*pte
))
100 printk(KERN_DEBUG
"... pte not present!\n");
104 asmlinkage
void monitor_signal(struct pt_regs
*);
107 * This routine handles page faults. It determines the address,
108 * and the problem, and then passes it off to one of the appropriate
112 * - LSW: either MMUFCR_IFC or MMUFCR_DFC as appropriate
113 * - MSW: 0 if data access, 1 if instruction access
114 * - bit 0: TLB miss flag
115 * - bit 1: initial write
116 * - bit 2: page invalid
117 * - bit 3: protection violation
118 * - bit 4: accessor (0=user 1=kernel)
119 * - bit 5: 0=read 1=write
120 * - bit 6-8: page protection spec
121 * - bit 9: illegal address
122 * - bit 16: 0=data 1=ins
125 asmlinkage
void do_page_fault(struct pt_regs
*regs
, unsigned long fault_code
,
126 unsigned long address
)
128 struct vm_area_struct
*vma
;
129 struct task_struct
*tsk
;
130 struct mm_struct
*mm
;
135 #ifdef CONFIG_GDBSTUB
136 /* handle GDB stub causing a fault */
138 gdbstub_exception(regs
, TBR
& TBR_INT_CODE
);
144 printk(KERN_DEBUG
"--- do_page_fault(%p,%s:%04lx,%08lx)\n",
146 fault_code
& 0x10000 ? "ins" : "data",
147 fault_code
& 0xffff, address
);
153 * We fault-in kernel-space virtual memory on-demand. The
154 * 'reference' page table is init_mm.pgd.
156 * NOTE! We MUST NOT take any locks for this case. We may
157 * be in an interrupt or a critical region, and should
158 * only copy the information from the master page table,
161 * This verifies that the fault happens in kernel space
162 * and that the fault was a page not present (invalid) error
164 if (address
>= VMALLOC_START
&& address
< VMALLOC_END
&&
165 (fault_code
& MMUFCR_xFC_ACCESS
) == MMUFCR_xFC_ACCESS_SR
&&
166 (fault_code
& MMUFCR_xFC_PGINVAL
) == MMUFCR_xFC_PGINVAL
171 info
.si_code
= SEGV_MAPERR
;
174 * If we're in an interrupt or have no user
175 * context, we must not take the fault..
177 if (in_atomic() || !mm
)
180 down_read(&mm
->mmap_sem
);
182 vma
= find_vma(mm
, address
);
185 if (vma
->vm_start
<= address
)
187 if (!(vma
->vm_flags
& VM_GROWSDOWN
))
190 if ((fault_code
& MMUFCR_xFC_ACCESS
) == MMUFCR_xFC_ACCESS_USR
) {
191 /* accessing the stack below the stack pointer is always a
193 if ((address
& PAGE_MASK
) + 2 * PAGE_SIZE
< regs
->sp
) {
196 "[%d] ### Access below stack @%lx (sp=%lx)\n",
197 current
->pid
, address
, regs
->sp
);
199 "vma [%08x - %08x]\n",
200 vma
->vm_start
, vma
->vm_end
);
201 show_registers(regs
);
203 "[%d] ### Code: [%08lx]"
204 " %02x %02x %02x %02x %02x %02x %02x %02x\n",
207 ((u8
*) regs
->pc
)[0],
208 ((u8
*) regs
->pc
)[1],
209 ((u8
*) regs
->pc
)[2],
210 ((u8
*) regs
->pc
)[3],
211 ((u8
*) regs
->pc
)[4],
212 ((u8
*) regs
->pc
)[5],
213 ((u8
*) regs
->pc
)[6],
221 if (expand_stack(vma
, address
))
225 * Ok, we have a good vm_area for this memory access, so
229 info
.si_code
= SEGV_ACCERR
;
231 switch (fault_code
& (MMUFCR_xFC_PGINVAL
|MMUFCR_xFC_TYPE
)) {
232 default: /* 3: write, present */
233 case MMUFCR_xFC_TYPE_WRITE
:
234 #ifdef TEST_VERIFY_AREA
235 if ((fault_code
& MMUFCR_xFC_ACCESS
) == MMUFCR_xFC_ACCESS_SR
)
236 printk(KERN_DEBUG
"WP fault at %08lx\n", regs
->pc
);
238 /* write to absent page */
239 case MMUFCR_xFC_PGINVAL
| MMUFCR_xFC_TYPE_WRITE
:
240 if (!(vma
->vm_flags
& VM_WRITE
))
245 /* read from protected page */
246 case MMUFCR_xFC_TYPE_READ
:
249 /* read from absent page present */
250 case MMUFCR_xFC_PGINVAL
| MMUFCR_xFC_TYPE_READ
:
251 if (!(vma
->vm_flags
& (VM_READ
| VM_EXEC
)))
257 * If for any reason at all we couldn't handle the fault,
258 * make sure we exit gracefully rather than endlessly redo
261 fault
= handle_mm_fault(mm
, vma
, address
, write
? FAULT_FLAG_WRITE
: 0);
262 if (unlikely(fault
& VM_FAULT_ERROR
)) {
263 if (fault
& VM_FAULT_OOM
)
265 else if (fault
& VM_FAULT_SIGBUS
)
269 if (fault
& VM_FAULT_MAJOR
)
274 up_read(&mm
->mmap_sem
);
278 * Something tried to access memory that isn't in our memory map..
279 * Fix it, but check if it's kernel or user first..
282 up_read(&mm
->mmap_sem
);
283 monitor_signal(regs
);
285 /* User mode accesses just cause a SIGSEGV */
286 if ((fault_code
& MMUFCR_xFC_ACCESS
) == MMUFCR_xFC_ACCESS_USR
) {
287 info
.si_signo
= SIGSEGV
;
289 /* info.si_code has been set above */
290 info
.si_addr
= (void *)address
;
291 force_sig_info(SIGSEGV
, &info
, tsk
);
296 monitor_signal(regs
);
297 /* Are we prepared to handle this kernel fault? */
298 if (fixup_exception(regs
))
302 * Oops. The kernel tried to access some bad page. We'll have to
303 * terminate things with extreme prejudice.
308 if (address
< PAGE_SIZE
)
310 "Unable to handle kernel NULL pointer dereference");
313 "Unable to handle kernel paging request");
314 printk(" at virtual address %08lx\n", address
);
315 printk(" printing pc:\n");
316 printk(KERN_ALERT
"%08lx\n", regs
->pc
);
318 #ifdef CONFIG_GDBSTUB
320 regs
, fault_code
& 0x00010000 ? EXCEP_IAERROR
: EXCEP_DAERROR
);
324 page
= ((unsigned long *) __va(page
))[address
>> 22];
325 printk(KERN_ALERT
"*pde = %08lx\n", page
);
328 address
&= 0x003ff000;
329 page
= ((unsigned long *) __va(page
))[address
>> PAGE_SHIFT
];
330 printk(KERN_ALERT
"*pte = %08lx\n", page
);
333 die("Oops", regs
, fault_code
);
337 * We ran out of memory, or some other thing happened to us that made
338 * us unable to handle the page fault gracefully.
341 up_read(&mm
->mmap_sem
);
342 monitor_signal(regs
);
343 printk(KERN_ALERT
"VM: killing process %s\n", tsk
->comm
);
344 if ((fault_code
& MMUFCR_xFC_ACCESS
) == MMUFCR_xFC_ACCESS_USR
)
349 up_read(&mm
->mmap_sem
);
350 monitor_signal(regs
);
353 * Send a sigbus, regardless of whether we were in kernel
356 info
.si_signo
= SIGBUS
;
358 info
.si_code
= BUS_ADRERR
;
359 info
.si_addr
= (void *)address
;
360 force_sig_info(SIGBUS
, &info
, tsk
);
362 /* Kernel mode? Handle exceptions or die */
363 if ((fault_code
& MMUFCR_xFC_ACCESS
) == MMUFCR_xFC_ACCESS_SR
)
370 * Synchronize this task's top level page-table
371 * with the 'reference' page table.
373 * Do _not_ use "tsk" here. We might be inside
374 * an interrupt in the middle of a task switch..
376 int index
= pgd_index(address
);
382 pgd_k
= init_mm
.pgd
+ index
;
384 if (!pgd_present(*pgd_k
))
387 pud_k
= pud_offset(pgd_k
, address
);
388 if (!pud_present(*pud_k
))
391 pmd_k
= pmd_offset(pud_k
, address
);
392 if (!pmd_present(*pmd_k
))
395 pgd
= (pgd_t
*) PTBR
+ index
;
396 pud
= pud_offset(pgd
, address
);
397 pmd
= pmd_offset(pud
, address
);
398 set_pmd(pmd
, *pmd_k
);
400 pte_k
= pte_offset_kernel(pmd_k
, address
);
401 if (!pte_present(*pte_k
))