/*
* linux/arch/cris/mm/fault.c
*
- * Copyright (C) 2000, 2001 Axis Communications AB
- *
- * Authors: Bjorn Wesen
- *
- * $Log: fault.c,v $
- * Revision 1.11 2004/05/14 07:58:05 starvik
- * Merge of changes from 2.4
- *
- * Revision 1.10 2003/10/27 14:51:24 starvik
- * Removed debugcode
- *
- * Revision 1.9 2003/10/27 14:50:42 starvik
- * Changed do_page_fault signature
- *
- * Revision 1.8 2003/07/04 13:02:48 tobiasa
- * Moved code snippet from arch/cris/mm/fault.c that searches for fixup code
- * to seperate function in arch-specific files.
- *
- * Revision 1.7 2003/01/22 06:48:38 starvik
- * Fixed warnings issued by GCC 3.2.1
- *
- * Revision 1.6 2003/01/09 14:42:52 starvik
- * Merge of Linux 2.5.55
- *
- * Revision 1.5 2002/12/11 14:44:48 starvik
- * Extracted v10 (ETRAX 100LX) specific stuff to arch/cris/arch-v10/mm
- *
- * Revision 1.4 2002/11/13 15:10:28 starvik
- * pte_offset has been renamed to pte_offset_kernel
- *
- * Revision 1.3 2002/11/05 06:45:13 starvik
- * Merge of Linux 2.5.45
- *
- * Revision 1.2 2001/12/18 13:35:22 bjornw
- * Applied the 2.4.13->2.4.16 CRIS patch to 2.5.1 (is a copy of 2.4.15).
- *
- * Revision 1.20 2001/11/22 13:34:06 bjornw
- * * Bug workaround (LX TR89): force a rerun of the whole of an interrupted
- * unaligned write, because the second half of the write will be corrupted
- * otherwise. Affected unaligned writes spanning not-yet mapped pages.
- * * Optimization: use the wr_rd bit in R_MMU_CAUSE to know whether a miss
- * was due to a read or a write (before we didn't know this until the next
- * restart of the interrupted instruction, thus wasting one fault-irq)
- *
- * Revision 1.19 2001/11/12 19:02:10 pkj
- * Fixed compiler warnings.
- *
- * Revision 1.18 2001/07/18 22:14:32 bjornw
- * Enable interrupts in the bulk of do_page_fault
- *
- * Revision 1.17 2001/07/18 13:07:23 bjornw
- * * Detect non-existant PTE's in vmalloc pmd synchronization
- * * Remove comment about fast-paths for VMALLOC_START etc, because all that
- * was totally bogus anyway it turned out :)
- * * Fix detection of vmalloc-area synchronization
- * * Add some comments
- *
- * Revision 1.16 2001/06/13 00:06:08 bjornw
- * current_pgd should be volatile
- *
- * Revision 1.15 2001/06/13 00:02:23 bjornw
- * Use a separate variable to store the current pgd to avoid races in schedule
- *
- * Revision 1.14 2001/05/16 17:41:07 hp
- * Last comment tweak further tweaked.
- *
- * Revision 1.13 2001/05/15 00:58:44 hp
- * Expand a bit on the comment why we compare address >= TASK_SIZE rather
- * than >= VMALLOC_START.
- *
- * Revision 1.12 2001/04/04 10:51:14 bjornw
- * mmap_sem is grabbed for reading
- *
- * Revision 1.11 2001/03/23 07:36:07 starvik
- * Corrected according to review remarks
- *
- * Revision 1.10 2001/03/21 16:10:11 bjornw
- * CRIS_FRAME_FIXUP not needed anymore, use FRAME_NORMAL
- *
- * Revision 1.9 2001/03/05 13:22:20 bjornw
- * Spell-fix and fix in vmalloc_fault handling
- *
- * Revision 1.8 2000/11/22 14:45:31 bjornw
- * * 2.4.0-test10 removed the set_pgdir instantaneous kernel global mapping
- * into all processes. Instead we fill in the missing PTE entries on demand.
- *
- * Revision 1.7 2000/11/21 16:39:09 bjornw
- * fixup switches frametype
- *
- * Revision 1.6 2000/11/17 16:54:08 bjornw
- * More detailed siginfo reporting
+ * Copyright (C) 2000-2006 Axis Communications AB
*
+ * Authors: Bjorn Wesen
*
*/
/* current active page directory */
-volatile pgd_t *current_pgd;
+volatile DEFINE_PER_CPU(pgd_t *,current_pgd);
+unsigned long cris_signal_return_page;
/*
* This routine handles page faults. It determines the address,
* address.
*
* error_code:
- * bit 0 == 0 means no page found, 1 means protection fault
- * bit 1 == 0 means read, 1 means write
+ * bit 0 == 0 means no page found, 1 means protection fault
+ * bit 1 == 0 means read, 1 means write
*
* If this routine detects a bad access, it returns 1, otherwise it
* returns 0.
struct mm_struct *mm;
struct vm_area_struct * vma;
siginfo_t info;
+ int fault;
- D(printk("Page fault for %X at %X, prot %d write %d\n",
- address, regs->erp, protection, writeaccess));
+ D(printk(KERN_DEBUG
+ "Page fault for %lX on %X at %lX, prot %d write %d\n",
+ address, smp_processor_id(), instruction_pointer(regs),
+ protection, writeaccess));
tsk = current;
!user_mode(regs))
goto vmalloc_fault;
+ /* When stack execution is not allowed we store the signal
+ * trampolines in the reserved cris_signal_return_page.
+ * Handle this in the exact same way as vmalloc (we know
+ * that the mapping is there and is valid so no need to
+ * call handle_mm_fault).
+ */
+ if (cris_signal_return_page &&
+ address == cris_signal_return_page &&
+ !protection && user_mode(regs))
+ goto vmalloc_fault;
+
/* we can and should enable interrupts at this point */
- sti();
+ local_irq_enable();
mm = tsk->mm;
info.si_code = SEGV_MAPERR;
/* first do some preliminary protection checks */
- if (writeaccess) {
+ if (writeaccess == 2){
+ if (!(vma->vm_flags & VM_EXEC))
+ goto bad_area;
+ } else if (writeaccess == 1) {
if (!(vma->vm_flags & VM_WRITE))
goto bad_area;
} else {
* the fault.
*/
- switch (handle_mm_fault(mm, vma, address, writeaccess)) {
- case 1:
- tsk->min_flt++;
- break;
- case 2:
- tsk->maj_flt++;
- break;
- case 0:
- goto do_sigbus;
- default:
- goto out_of_memory;
+ fault = handle_mm_fault(mm, vma, address, writeaccess & 1);
+ if (unlikely(fault & VM_FAULT_ERROR)) {
+ if (fault & VM_FAULT_OOM)
+ goto out_of_memory;
+ else if (fault & VM_FAULT_SIGBUS)
+ goto do_sigbus;
+ BUG();
}
+ if (fault & VM_FAULT_MAJOR)
+ tsk->maj_flt++;
+ else
+ tsk->min_flt++;
up_read(&mm->mmap_sem);
return;
/* info.si_code has been set above */
info.si_addr = (void *)address;
force_sig_info(SIGSEGV, &info, tsk);
+ printk(KERN_NOTICE "%s (pid %d) segfaults for page "
+ "address %08lx at pc %08lx\n",
+ tsk->comm, tsk->pid, address, instruction_pointer(regs));
return;
}
/* Are we prepared to handle this kernel fault?
*
- * (The kernel has valid exception-points in the source
+ * (The kernel has valid exception-points in the source
* when it acesses user-memory. When it fails in one
* of those points, we find it in a table and do a jump
* to some fixup code that loads an appropriate error
* terminate things with extreme prejudice.
*/
- if ((unsigned long) (address) < PAGE_SIZE)
- printk(KERN_ALERT "Unable to handle kernel NULL pointer dereference");
- else
- printk(KERN_ALERT "Unable to handle kernel access");
- printk(" at virtual address %08lx\n",address);
-
- die_if_kernel("Oops", regs, (writeaccess << 1) | protection);
+ if (!oops_in_progress) {
+ oops_in_progress = 1;
+ if ((unsigned long) (address) < PAGE_SIZE)
+ printk(KERN_ALERT "Unable to handle kernel NULL "
+ "pointer dereference");
+ else
+ printk(KERN_ALERT "Unable to handle kernel access"
+ " at virtual address %08lx\n", address);
+
+ die_if_kernel("Oops", regs, (writeaccess << 1) | protection);
+ oops_in_progress = 0;
+ }
do_exit(SIGKILL);
int offset = pgd_index(address);
pgd_t *pgd, *pgd_k;
+ pud_t *pud, *pud_k;
pmd_t *pmd, *pmd_k;
pte_t *pte_k;
- pgd = (pgd_t *)current_pgd + offset;
+ pgd = (pgd_t *)per_cpu(current_pgd, smp_processor_id()) + offset;
pgd_k = init_mm.pgd + offset;
/* Since we're two-level, we don't need to do both
* set_pgd and set_pmd (they do the same thing). If
* we go three-level at some point, do the right thing
- * with pgd_present and set_pgd here.
- *
+ * with pgd_present and set_pgd here.
+ *
* Also, since the vmalloc area is global, we don't
* need to copy individual PTE's, it is enough to
* copy the pgd pointer into the pte page of the
* it exists.
*/
- pmd = pmd_offset(pgd, address);
- pmd_k = pmd_offset(pgd_k, address);
+ pud = pud_offset(pgd, address);
+ pud_k = pud_offset(pgd_k, address);
+ if (!pud_present(*pud_k))
+ goto no_context;
+
+ pmd = pmd_offset(pud, address);
+ pmd_k = pmd_offset(pud_k, address);
if (!pmd_present(*pmd_k))
goto bad_area_nosemaphore;
return;
}
}
+
+/* Find fixup code. */
+int
+find_fixup_code(struct pt_regs *regs)
+{
+ const struct exception_table_entry *fixup;
+
+ if ((fixup = search_exception_tables(instruction_pointer(regs))) != 0) {
+ /* Adjust the instruction pointer in the stackframe. */
+ instruction_pointer(regs) = fixup->fixup;
+ arch_fixup(regs);
+ return 1;
+ }
+
+ return 0;
+}
projects / linux-2.6.git / blobdiff