2 * linux/arch/frv/mm/fault.c
4 * Copyright (C) 2003 Red Hat, Inc. All Rights Reserved.
5 * - Written by David Howells (dhowells@redhat.com)
6 * - Derived from arch/m68knommu/mm/fault.c
7 * - Copyright (C) 1998 D. Jeff Dionne <jeff@lineo.ca>,
8 * - Copyright (C) 2000 Lineo, Inc. (www.lineo.com)
12 * linux/arch/m68k/mm/fault.c
14 * Copyright (C) 1995 Hamish Macdonald
17 #include <linux/mman.h>
19 #include <linux/kernel.h>
20 #include <linux/ptrace.h>
21 #include <linux/hardirq.h>
23 #include <asm/system.h>
24 #include <asm/pgtable.h>
25 #include <asm/uaccess.h>
26 #include <asm/gdb-stub.h>
28 /*****************************************************************************/
30 * This routine handles page faults. It determines the problem, and
31 * then passes it off to one of the appropriate routines.
33 asmlinkage void do_page_fault(int datammu, unsigned long esr0, unsigned long ear0)
35 struct vm_area_struct *vma;
37 unsigned long _pme, lrai, lrad, fixup;
46 const char *atxc[16] = {
47 [0x0] = "mmu-miss", [0x8] = "multi-dat", [0x9] = "multi-sat",
48 [0xa] = "tlb-miss", [0xc] = "privilege", [0xd] = "write-prot",
51 printk("do_page_fault(%d,%lx [%s],%lx)\n",
52 datammu, esr0, atxc[esr0 >> 20 & 0xf], ear0);
58 * We fault-in kernel-space virtual memory on-demand. The
59 * 'reference' page table is init_mm.pgd.
61 * NOTE! We MUST NOT take any locks for this case. We may
62 * be in an interrupt or a critical region, and should
63 * only copy the information from the master page table,
66 * This verifies that the fault happens in kernel space
67 * and that the fault was a page not present (invalid) error
69 if (!user_mode(__frame) && (esr0 & ESR0_ATXC) == ESR0_ATXC_AMRTLB_MISS) {
70 if (ear0 >= VMALLOC_START && ear0 < VMALLOC_END)
71 goto kernel_pte_fault;
72 if (ear0 >= PKMAP_BASE && ear0 < PKMAP_END)
73 goto kernel_pte_fault;
76 info.si_code = SEGV_MAPERR;
79 * If we're in an interrupt or have no user
80 * context, we must not take the fault..
82 if (in_atomic() || !mm)
85 down_read(&mm->mmap_sem);
87 vma = find_vma(mm, ear0);
90 if (vma->vm_start <= ear0)
92 if (!(vma->vm_flags & VM_GROWSDOWN))
95 if (user_mode(__frame)) {
97 * accessing the stack below %esp is always a bug.
98 * The "+ 32" is there due to some instructions (like
99 * pusha) doing post-decrement on the stack and that
100 * doesn't show up until later..
102 if ((ear0 & PAGE_MASK) + 2 * PAGE_SIZE < __frame->sp) {
104 printk("[%d] ### Access below stack @%lx (sp=%lx)\n",
105 current->pid, ear0, __frame->sp);
106 show_registers(__frame);
107 printk("[%d] ### Code: [%08lx] %02x %02x %02x %02x %02x %02x %02x %02x\n",
110 ((u8*)__frame->pc)[0],
111 ((u8*)__frame->pc)[1],
112 ((u8*)__frame->pc)[2],
113 ((u8*)__frame->pc)[3],
114 ((u8*)__frame->pc)[4],
115 ((u8*)__frame->pc)[5],
116 ((u8*)__frame->pc)[6],
117 ((u8*)__frame->pc)[7]
124 if (expand_stack(vma, ear0))
128 * Ok, we have a good vm_area for this memory access, so
132 info.si_code = SEGV_ACCERR;
134 switch (esr0 & ESR0_ATXC) {
136 /* handle write to write protected page */
137 case ESR0_ATXC_WP_EXCEP:
138 #ifdef TEST_VERIFY_AREA
139 if (!(user_mode(__frame)))
140 printk("WP fault at %08lx\n", __frame->pc);
142 if (!(vma->vm_flags & VM_WRITE))
147 /* handle read from protected page */
148 case ESR0_ATXC_PRIV_EXCEP:
151 /* handle read, write or exec on absent page
152 * - can't support write without permitting read
153 * - don't support execute without permitting read and vice-versa
155 case ESR0_ATXC_AMRTLB_MISS:
156 if (!(vma->vm_flags & (VM_READ | VM_WRITE | VM_EXEC)))
162 * If for any reason at all we couldn't handle the fault,
163 * make sure we exit gracefully rather than endlessly redo
166 fault = handle_mm_fault(mm, vma, ear0, write ? FAULT_FLAG_WRITE : 0);
167 if (unlikely(fault & VM_FAULT_ERROR)) {
168 if (fault & VM_FAULT_OOM)
170 else if (fault & VM_FAULT_SIGBUS)
174 if (fault & VM_FAULT_MAJOR)
179 up_read(&mm->mmap_sem);
183 * Something tried to access memory that isn't in our memory map..
184 * Fix it, but check if it's kernel or user first..
187 up_read(&mm->mmap_sem);
189 /* User mode accesses just cause a SIGSEGV */
190 if (user_mode(__frame)) {
191 info.si_signo = SIGSEGV;
193 /* info.si_code has been set above */
194 info.si_addr = (void *) ear0;
195 force_sig_info(SIGSEGV, &info, current);
200 /* are we prepared to handle this kernel fault? */
201 if ((fixup = search_exception_table(__frame->pc)) != 0) {
207 * Oops. The kernel tried to access some bad page. We'll have to
208 * terminate things with extreme prejudice.
213 if (ear0 < PAGE_SIZE)
214 printk(KERN_ALERT "Unable to handle kernel NULL pointer dereference");
216 printk(KERN_ALERT "Unable to handle kernel paging request");
217 printk(" at virtual addr %08lx\n", ear0);
218 printk(" PC : %08lx\n", __frame->pc);
219 printk(" EXC : esr0=%08lx ear0=%08lx\n", esr0, ear0);
221 asm("lrai %1,%0,#1,#0,#0" : "=&r"(lrai) : "r"(ear0));
222 asm("lrad %1,%0,#1,#0,#0" : "=&r"(lrad) : "r"(ear0));
224 printk(KERN_ALERT " LRAI: %08lx\n", lrai);
225 printk(KERN_ALERT " LRAD: %08lx\n", lrad);
227 __break_hijack_kernel_event();
229 pge = pgd_offset(current->mm, ear0);
230 pue = pud_offset(pge, ear0);
231 _pme = pue->pue[0].ste[0];
233 printk(KERN_ALERT " PGE : %8p { PME %08lx }\n", pge, _pme);
235 if (_pme & xAMPRx_V) {
236 unsigned long dampr, damlr, val;
238 asm volatile("movsg dampr2,%0 ! movgs %2,dampr2 ! movsg damlr2,%1"
239 : "=&r"(dampr), "=r"(damlr)
240 : "r" (_pme | xAMPRx_L|xAMPRx_SS_16Kb|xAMPRx_S|xAMPRx_C|xAMPRx_V)
243 pte = (pte_t *) damlr + __pte_index(ear0);
246 asm volatile("movgs %0,dampr2" :: "r" (dampr));
248 printk(KERN_ALERT " PTE : %8p { %08lx }\n", pte, val);
251 die_if_kernel("Oops\n");
255 * We ran out of memory, or some other thing happened to us that made
256 * us unable to handle the page fault gracefully.
259 up_read(&mm->mmap_sem);
260 printk("VM: killing process %s\n", current->comm);
261 if (user_mode(__frame))
262 do_group_exit(SIGKILL);
266 up_read(&mm->mmap_sem);
269 * Send a sigbus, regardless of whether we were in kernel
272 info.si_signo = SIGBUS;
274 info.si_code = BUS_ADRERR;
275 info.si_addr = (void *) ear0;
276 force_sig_info(SIGBUS, &info, current);
278 /* Kernel mode? Handle exceptions or die */
279 if (!user_mode(__frame))
284 * The fault was caused by a kernel PTE (such as installed by vmalloc or kmap)
289 * Synchronize this task's top level page-table
290 * with the 'reference' page table.
292 * Do _not_ use "tsk" here. We might be inside
293 * an interrupt in the middle of a task switch..
295 int index = pgd_index(ear0);
301 pgd = (pgd_t *) __get_TTBR();
302 pgd = (pgd_t *)__va(pgd) + index;
303 pgd_k = ((pgd_t *)(init_mm.pgd)) + index;
305 if (!pgd_present(*pgd_k))
307 //set_pgd(pgd, *pgd_k); /////// gcc ICE's on this line
309 pud_k = pud_offset(pgd_k, ear0);
310 if (!pud_present(*pud_k))
313 pmd_k = pmd_offset(pud_k, ear0);
314 if (!pmd_present(*pmd_k))
317 pud = pud_offset(pgd, ear0);
318 pmd = pmd_offset(pud, ear0);
319 set_pmd(pmd, *pmd_k);
321 pte_k = pte_offset_kernel(pmd_k, ear0);
322 if (!pte_present(*pte_k))
326 } /* end do_page_fault() */