Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc

[sfrench/cifs-2.6.git] / arch / powerpc / mm / fault.c

diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c
index 78a0d59903ee69d2b8ac96de20e18c17fd5f9206..bfe901353142f9d835eafa01cbf37b58868d0e10 100644 (file)
--- a/arch/powerpc/mm/fault.c
+++ b/arch/powerpc/mm/fault.c
@@ -28,6 +28,7 @@
 #include <linux/highmem.h>
 #include <linux/module.h>
 #include <linux/kprobes.h>
+#include <linux/kdebug.h>
 
 #include <asm/page.h>
 #include <asm/pgtable.h>
@@ -36,40 +37,28 @@
 #include <asm/system.h>
 #include <asm/uaccess.h>
 #include <asm/tlbflush.h>
-#include <asm/kdebug.h>
 #include <asm/siginfo.h>
 
-#ifdef CONFIG_KPROBES
-ATOMIC_NOTIFIER_HEAD(notify_page_fault_chain);
 
-/* Hook to register for page fault notifications */
-int register_page_fault_notifier(struct notifier_block *nb)
+#ifdef CONFIG_KPROBES
+static inline int notify_page_fault(struct pt_regs *regs)
 {
-       return atomic_notifier_chain_register(&notify_page_fault_chain, nb);
-}
+       int ret = 0;
+
+       /* kprobe_running() needs smp_processor_id() */
+       if (!user_mode(regs)) {
+               preempt_disable();
+               if (kprobe_running() && kprobe_fault_handler(regs, 11))
+                       ret = 1;
+               preempt_enable();
+       }
 
-int unregister_page_fault_notifier(struct notifier_block *nb)
-{
-       return atomic_notifier_chain_unregister(&notify_page_fault_chain, nb);
-}
-
-static inline int notify_page_fault(enum die_val val, const char *str,
-                       struct pt_regs *regs, long err, int trap, int sig)
-{
-       struct die_args args = {
-               .regs = regs,
-               .str = str,
-               .err = err,
-               .trapnr = trap,
-               .signr = sig
-       };
-       return atomic_notifier_call_chain(&notify_page_fault_chain, val, &args);
+       return ret;
 }
 #else
-static inline int notify_page_fault(enum die_val val, const char *str,
-                       struct pt_regs *regs, long err, int trap, int sig)
+static inline int notify_page_fault(struct pt_regs *regs)
 {
-       return NOTIFY_DONE;
+       return 0;
 }
 #endif
 
@@ -175,8 +164,7 @@ int __kprobes do_page_fault(struct pt_regs *regs, unsigned long address,
        is_write = error_code & ESR_DST;
 #endif /* CONFIG_4xx || CONFIG_BOOKE */
 
-       if (notify_page_fault(DIE_PAGE_FAULT, "page_fault", regs, error_code,
-                               11, SIGSEGV) == NOTIFY_STOP)
+       if (notify_page_fault(regs))
                return 0;
 
        if (trap == 0x300) {
@@ -333,7 +321,7 @@ good_area:
                /* protection fault */
                if (error_code & 0x08000000)
                        goto bad_area;
-               if (!(vma->vm_flags & (VM_READ | VM_EXEC)))
+               if (!(vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE)))
                        goto bad_area;
        }
 
@@ -386,7 +374,7 @@ bad_area_nosemaphore:
  */
 out_of_memory:
        up_read(&mm->mmap_sem);
-       if (current->pid == 1) {
+       if (is_init(current)) {
                yield();
                down_read(&mm->mmap_sem);
                goto survive;
@@ -426,18 +414,21 @@ void bad_page_fault(struct pt_regs *regs, unsigned long address, int sig)
 
        /* kernel has accessed a bad area */
 
-       printk(KERN_ALERT "Unable to handle kernel paging request for ");
        switch (regs->trap) {
-               case 0x300:
-               case 0x380:
-                       printk("data at address 0x%08lx\n", regs->dar);
-                       break;
-               case 0x400:
-               case 0x480:
-                       printk("instruction fetch\n");
-                       break;
-               default:
-                       printk("unknown fault\n");
+       case 0x300:
+       case 0x380:
+               printk(KERN_ALERT "Unable to handle kernel paging request for "
+                       "data at address 0x%08lx\n", regs->dar);
+               break;
+       case 0x400:
+       case 0x480:
+               printk(KERN_ALERT "Unable to handle kernel paging request for "
+                       "instruction fetch\n");
+               break;
+       default:
+               printk(KERN_ALERT "Unable to handle kernel paging request for "
+                       "unknown fault\n");
+               break;
        }
        printk(KERN_ALERT "Faulting instruction address: 0x%08lx\n",
                regs->nip);