Linux-2.6.12-rc2v2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 261 insertions, 0 deletions

diff --git a/arch/ia64/mm/fault.c b/arch/ia64/mm/fault.c
new file mode 100644
index 000000000000..da859125aaef
--- /dev/null
+++ b/arch/ia64/mm/fault.c
@@ -0,0 +1,261 @@
+/*
+ * MMU fault handling support.
+ *
+ * Copyright (C) 1998-2002 Hewlett-Packard Co
+ *      David Mosberger-Tang <davidm@hpl.hp.com>
+ */
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/smp_lock.h>
+#include <linux/interrupt.h>
+
+#include <asm/pgtable.h>
+#include <asm/processor.h>
+#include <asm/system.h>
+#include <asm/uaccess.h>
+
+extern void die (char *, struct pt_regs *, long);
+
+/*
+ * This routine is analogous to expand_stack() but instead grows the
+ * register backing store (which grows towards higher addresses).
+ * Since the register backing store is access sequentially, we
+ * disallow growing the RBS by more than a page at a time.  Note that
+ * the VM_GROWSUP flag can be set on any VM area but that's fine
+ * because the total process size is still limited by RLIMIT_STACK and
+ * RLIMIT_AS.
+ */
+static inline long
+expand_backing_store (struct vm_area_struct *vma, unsigned long address)
+{
+        unsigned long grow;
+
+        grow = PAGE_SIZE >> PAGE_SHIFT;
+        if (address - vma->vm_start > current->signal->rlim[RLIMIT_STACK].rlim_cur
+            || (((vma->vm_mm->total_vm + grow) << PAGE_SHIFT) > current->signal->rlim[RLIMIT_AS].rlim_cur))
+                return -ENOMEM;
+        vma->vm_end += PAGE_SIZE;
+        vma->vm_mm->total_vm += grow;
+        if (vma->vm_flags & VM_LOCKED)
+                vma->vm_mm->locked_vm += grow;
+        __vm_stat_account(vma->vm_mm, vma->vm_flags, vma->vm_file, grow);
+        return 0;
+}
+
+/*
+ * Return TRUE if ADDRESS points at a page in the kernel's mapped segment
+ * (inside region 5, on ia64) and that page is present.
+ */
+static int
+mapped_kernel_page_is_present (unsigned long address)
+{
+        pgd_t *pgd;
+        pud_t *pud;
+        pmd_t *pmd;
+        pte_t *ptep, pte;
+
+        pgd = pgd_offset_k(address);
+        if (pgd_none(*pgd) || pgd_bad(*pgd))
+                return 0;
+
+        pud = pud_offset(pgd, address);
+        if (pud_none(*pud) || pud_bad(*pud))
+                return 0;
+
+        pmd = pmd_offset(pud, address);
+        if (pmd_none(*pmd) || pmd_bad(*pmd))
+                return 0;
+
+        ptep = pte_offset_kernel(pmd, address);
+        if (!ptep)
+                return 0;
+
+        pte = *ptep;
+        return pte_present(pte);
+}
+
+void
+ia64_do_page_fault (unsigned long address, unsigned long isr, struct pt_regs *regs)
+{
+        int signal = SIGSEGV, code = SEGV_MAPERR;
+        struct vm_area_struct *vma, *prev_vma;
+        struct mm_struct *mm = current->mm;
+        struct siginfo si;
+        unsigned long mask;
+
+        /*
+         * If we're in an interrupt or have no user context, we must not take the fault..
+         */
+        if (in_atomic() || !mm)
+                goto no_context;
+
+#ifdef CONFIG_VIRTUAL_MEM_MAP
+        /*
+         * If fault is in region 5 and we are in the kernel, we may already
+         * have the mmap_sem (pfn_valid macro is called during mmap). There
+         * is no vma for region 5 addr's anyway, so skip getting the semaphore
+         * and go directly to the exception handling code.
+         */
+
+        if ((REGION_NUMBER(address) == 5) && !user_mode(regs))
+                goto bad_area_no_up;
+#endif
+
+        down_read(&mm->mmap_sem);
+
+        vma = find_vma_prev(mm, address, &prev_vma);
+        if (!vma)
+                goto bad_area;
+
+        /* find_vma_prev() returns vma such that address < vma->vm_end or NULL */
+        if (address < vma->vm_start)
+                goto check_expansion;
+
+  good_area:
+        code = SEGV_ACCERR;
+
+        /* OK, we've got a good vm_area for this memory area.  Check the access permissions: */
+
+#       define VM_READ_BIT      0
+#       define VM_WRITE_BIT     1
+#       define VM_EXEC_BIT      2
+
+#       if (((1 << VM_READ_BIT) != VM_READ || (1 << VM_WRITE_BIT) != VM_WRITE) \
+            || (1 << VM_EXEC_BIT) != VM_EXEC)
+#               error File is out of sync with <linux/mm.h>.  Please update.
+#       endif
+
+        mask = (  (((isr >> IA64_ISR_X_BIT) & 1UL) << VM_EXEC_BIT)
+                | (((isr >> IA64_ISR_W_BIT) & 1UL) << VM_WRITE_BIT)
+                | (((isr >> IA64_ISR_R_BIT) & 1UL) << VM_READ_BIT));
+
+        if ((vma->vm_flags & mask) != mask)
+                goto bad_area;
+
+  survive:
+        /*
+         * If for any reason at all we couldn't handle the fault, make
+         * sure we exit gracefully rather than endlessly redo the
+         * fault.
+         */
+        switch (handle_mm_fault(mm, vma, address, (mask & VM_WRITE) != 0)) {
+              case VM_FAULT_MINOR:
+                ++current->min_flt;
+                break;
+              case VM_FAULT_MAJOR:
+                ++current->maj_flt;
+                break;
+              case VM_FAULT_SIGBUS:
+                /*
+                 * We ran out of memory, or some other thing happened
+                 * to us that made us unable to handle the page fault
+                 * gracefully.
+                 */
+                signal = SIGBUS;
+                goto bad_area;
+              case VM_FAULT_OOM:
+                goto out_of_memory;
+              default:
+                BUG();
+        }
+        up_read(&mm->mmap_sem);
+        return;
+
+  check_expansion:
+        if (!(prev_vma && (prev_vma->vm_flags & VM_GROWSUP) && (address == prev_vma->vm_end))) {
+                if (!(vma->vm_flags & VM_GROWSDOWN))
+                        goto bad_area;
+                if (REGION_NUMBER(address) != REGION_NUMBER(vma->vm_start)
+                    || REGION_OFFSET(address) >= RGN_MAP_LIMIT)
+                        goto bad_area;
+                if (expand_stack(vma, address))
+                        goto bad_area;
+        } else {
+                vma = prev_vma;
+                if (REGION_NUMBER(address) != REGION_NUMBER(vma->vm_start)
+                    || REGION_OFFSET(address) >= RGN_MAP_LIMIT)
+                        goto bad_area;
+                if (expand_backing_store(vma, address))
+                        goto bad_area;
+        }
+        goto good_area;
+
+  bad_area:
+        up_read(&mm->mmap_sem);
+#ifdef CONFIG_VIRTUAL_MEM_MAP
+  bad_area_no_up:
+#endif
+        if ((isr & IA64_ISR_SP)
+            || ((isr & IA64_ISR_NA) && (isr & IA64_ISR_CODE_MASK) == IA64_ISR_CODE_LFETCH))
+        {
+                /*
+                 * This fault was due to a speculative load or lfetch.fault, set the "ed"
+                 * bit in the psr to ensure forward progress.  (Target register will get a
+                 * NaT for ld.s, lfetch will be canceled.)
+                 */
+                ia64_psr(regs)->ed = 1;
+                return;
+        }
+        if (user_mode(regs)) {
+                si.si_signo = signal;
+                si.si_errno = 0;
+                si.si_code = code;
+                si.si_addr = (void __user *) address;
+                si.si_isr = isr;
+                si.si_flags = __ISR_VALID;
+                force_sig_info(signal, &si, current);
+                return;
+        }
+
+  no_context:
+        if (isr & IA64_ISR_SP) {
+                /*
+                 * This fault was due to a speculative load set the "ed" bit in the psr to
+                 * ensure forward progress (target register will get a NaT).
+                 */
+                ia64_psr(regs)->ed = 1;
+                return;
+        }
+
+        if (ia64_done_with_exception(regs))
+                return;
+
+        /*
+         * Since we have no vma's for region 5, we might get here even if the address is
+         * valid, due to the VHPT walker inserting a non present translation that becomes
+         * stale. If that happens, the non present fault handler already purged the stale
+         * translation, which fixed the problem. So, we check to see if the translation is
+         * valid, and return if it is.
+         */
+        if (REGION_NUMBER(address) == 5 && mapped_kernel_page_is_present(address))
+                return;
+
+        /*
+         * Oops. The kernel tried to access some bad page. We'll have to terminate things
+         * with extreme prejudice.
+         */
+        bust_spinlocks(1);
+
+        if (address < PAGE_SIZE)
+                printk(KERN_ALERT "Unable to handle kernel NULL pointer dereference (address %016lx)\n", address);
+        else
+                printk(KERN_ALERT "Unable to handle kernel paging request at "
+                       "virtual address %016lx\n", address);
+        die("Oops", regs, isr);
+        bust_spinlocks(0);
+        do_exit(SIGKILL);
+        return;
+
+  out_of_memory:
+        up_read(&mm->mmap_sem);
+        if (current->pid == 1) {
+                yield();
+                down_read(&mm->mmap_sem);
+                goto survive;
+        }
+        printk(KERN_CRIT "VM: killing process %s\n", current->comm);
+        if (user_mode(regs))
+                do_exit(SIGKILL);
+        goto no_context;
+}