Fedora kernel-2.6.17-1.2142_FC4 patched with stable patch-2.6.17.4-vs2.0.2-rc26.diff

[linux-2.6.git] / arch / ia64 / mm / fault.c

diff --git a/arch/ia64/mm/fault.c b/arch/ia64/mm/fault.c
index ac29954..08de598 100644 (file)
--- a/arch/ia64/mm/fault.c
+++ b/arch/ia64/mm/fault.c
@@ -9,46 +9,17 @@
 #include <linux/mm.h>
 #include <linux/smp_lock.h>
 #include <linux/interrupt.h>
+#include <linux/kprobes.h>
 #include <linux/vs_memory.h>
 
 #include <asm/pgtable.h>
 #include <asm/processor.h>
 #include <asm/system.h>
 #include <asm/uaccess.h>
+#include <asm/kdebug.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;
-       if (!vx_vmpages_avail(vma->vm_mm, grow) ||
-               ((vma->vm_flags & VM_LOCKED) &&
-               !vx_vmlocked_avail(vma->vm_mm, grow)))
-               return -ENOMEM;
-       vma->vm_end += PAGE_SIZE;
-       vx_vmpages_add(vma->vm_mm, grow);
-       if (vma->vm_flags & VM_LOCKED)
-               vx_vmlocked_add(vma->vm_mm, 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.
@@ -81,7 +52,7 @@ mapped_kernel_page_is_present (unsigned long address)
        return pte_present(pte);
 }
 
-void
+void __kprobes
 ia64_do_page_fault (unsigned long address, unsigned long isr, struct pt_regs *regs)
 {
        int signal = SIGSEGV, code = SEGV_MAPERR;
@@ -90,6 +61,9 @@ ia64_do_page_fault (unsigned long address, unsigned long isr, struct pt_regs *re
        struct siginfo si;
        unsigned long mask;
 
+       /* mmap_sem is performance critical.... */
+       prefetchw(&mm->mmap_sem);
+
        /*
         * If we're in an interrupt or have no user context, we must not take the fault..
         */
@@ -108,6 +82,13 @@ ia64_do_page_fault (unsigned long address, unsigned long isr, struct pt_regs *re
                goto bad_area_no_up;
 #endif
 
+       /*
+        * This is to handle the kprobes on user space access instructions
+        */
+       if (notify_die(DIE_PAGE_FAULT, "page fault", regs, code, TRAP_BRKPT,
+                                       SIGSEGV) == NOTIFY_STOP)
+               return;
+
        down_read(&mm->mmap_sem);
 
        vma = find_vma_prev(mm, address, &prev_vma);
@@ -182,7 +163,13 @@ ia64_do_page_fault (unsigned long address, unsigned long isr, struct pt_regs *re
                if (REGION_NUMBER(address) != REGION_NUMBER(vma->vm_start)
                    || REGION_OFFSET(address) >= RGN_MAP_LIMIT)
                        goto bad_area;
-               if (expand_backing_store(vma, address))
+               /*
+                * Since the register backing store is accessed sequentially,
+                * we disallow growing it by more than a page at a time.
+                */
+               if (address > vma->vm_end + PAGE_SIZE - sizeof(long))
+                       goto bad_area;
+               if (expand_upwards(vma, address))
                        goto bad_area;
        }
        goto good_area;
@@ -227,9 +214,6 @@ ia64_do_page_fault (unsigned long address, unsigned long isr, struct pt_regs *re
                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
@@ -240,6 +224,9 @@ ia64_do_page_fault (unsigned long address, unsigned long isr, struct pt_regs *re
        if (REGION_NUMBER(address) == 5 && mapped_kernel_page_is_present(address))
                return;
 
+       if (ia64_done_with_exception(regs))
+               return;
+
        /*
         * Oops. The kernel tried to access some bad page. We'll have to terminate things
         * with extreme prejudice.