Merge git://oss.sgi.com:8090/xfs/xfs-2.6

[linux-2.6] / arch / s390 / mm / fault.c

diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c
index 8bc35183db5943a62ae6c4ff9b552b3059210c18..8b924b359774a40abb9042c2737b5ac9f6c637a2 100644 (file)
--- a/arch/s390/mm/fault.c
+++ b/arch/s390/mm/fault.c
@@ -20,17 +20,17 @@
 #include <linux/mman.h>
 #include <linux/mm.h>
 #include <linux/smp.h>
+#include <linux/kdebug.h>
 #include <linux/smp_lock.h>
 #include <linux/init.h>
 #include <linux/console.h>
 #include <linux/module.h>
 #include <linux/hardirq.h>
 #include <linux/kprobes.h>
+#include <linux/uaccess.h>
 
 #include <asm/system.h>
-#include <asm/uaccess.h>
 #include <asm/pgtable.h>
-#include <asm/kdebug.h>
 #include <asm/s390_ext.h>
 
 #ifndef CONFIG_64BIT
@@ -52,38 +52,24 @@ extern int sysctl_userprocess_debug;
 extern void die(const char *,struct pt_regs *,long);
 
 #ifdef CONFIG_KPROBES
-static ATOMIC_NOTIFIER_HEAD(notify_page_fault_chain);
-int register_page_fault_notifier(struct notifier_block *nb)
-{
-       return atomic_notifier_chain_register(&notify_page_fault_chain, nb);
-}
-
-int unregister_page_fault_notifier(struct notifier_block *nb)
-{
-       return atomic_notifier_chain_unregister(&notify_page_fault_chain, nb);
-}
-
-static int __kprobes __notify_page_fault(struct pt_regs *regs, long err)
-{
-       struct die_args args = { .str = "page fault",
-                                .trapnr = 14,
-                                .signr = SIGSEGV };
-       args.regs = regs;
-       args.err = err;
-       return atomic_notifier_call_chain(&notify_page_fault_chain,
-                                         DIE_PAGE_FAULT, &args);
-}
-
 static inline int notify_page_fault(struct pt_regs *regs, long err)
 {
-       if (unlikely(kprobe_running()))
-               return __notify_page_fault(regs, err);
-       return NOTIFY_DONE;
+       int ret = 0;
+
+       /* kprobe_running() needs smp_processor_id() */
+       if (!user_mode(regs)) {
+               preempt_disable();
+               if (kprobe_running() && kprobe_fault_handler(regs, 14))
+                       ret = 1;
+               preempt_enable();
+       }
+
+       return ret;
 }
 #else
 static inline int notify_page_fault(struct pt_regs *regs, long err)
 {
-       return NOTIFY_DONE;
+       return 0;
 }
 #endif
 
@@ -263,68 +249,38 @@ extern long sys_rt_sigreturn(struct pt_regs *regs);
 extern long sys32_sigreturn(struct pt_regs *regs);
 extern long sys32_rt_sigreturn(struct pt_regs *regs);
 
-static inline void do_sigreturn(struct mm_struct *mm, struct pt_regs *regs,
-                               int rt)
+static int signal_return(struct mm_struct *mm, struct pt_regs *regs,
+                        unsigned long address, unsigned long error_code)
 {
+       u16 instruction;
+       int rc, compat;
+
+       pagefault_disable();
+       rc = __get_user(instruction, (u16 __user *) regs->psw.addr);
+       pagefault_enable();
+       if (rc)
+               return -EFAULT;
+
        up_read(&mm->mmap_sem);
        clear_tsk_thread_flag(current, TIF_SINGLE_STEP);
 #ifdef CONFIG_COMPAT
-       if (test_tsk_thread_flag(current, TIF_31BIT)) {
-               if (rt)
-                       sys32_rt_sigreturn(regs);
-               else
-                       sys32_sigreturn(regs);
-               return;
-       }
-#endif /* CONFIG_COMPAT */
-       if (rt)
-               sys_rt_sigreturn(regs);
+       compat = test_tsk_thread_flag(current, TIF_31BIT);
+       if (compat && instruction == 0x0a77)
+               sys32_sigreturn(regs);
+       else if (compat && instruction == 0x0aad)
+               sys32_rt_sigreturn(regs);
        else
+#endif
+       if (instruction == 0x0a77)
                sys_sigreturn(regs);
-       return;
-}
-
-static int signal_return(struct mm_struct *mm, struct pt_regs *regs,
-                        unsigned long address, unsigned long error_code)
-{
-       pgd_t *pgd;
-       pmd_t *pmd;
-       pte_t *pte;
-       u16 *instruction;
-       unsigned long pfn, uaddr = regs->psw.addr;
-
-       spin_lock(&mm->page_table_lock);
-       pgd = pgd_offset(mm, uaddr);
-       if (pgd_none(*pgd) || unlikely(pgd_bad(*pgd)))
-               goto out_fault;
-       pmd = pmd_offset(pgd, uaddr);
-       if (pmd_none(*pmd) || unlikely(pmd_bad(*pmd)))
-               goto out_fault;
-       pte = pte_offset_map(pmd_offset(pgd_offset(mm, uaddr), uaddr), uaddr);
-       if (!pte || !pte_present(*pte))
-               goto out_fault;
-       pfn = pte_pfn(*pte);
-       if (!pfn_valid(pfn))
-               goto out_fault;
-       spin_unlock(&mm->page_table_lock);
-
-       instruction = (u16 *) ((pfn << PAGE_SHIFT) + (uaddr & (PAGE_SIZE-1)));
-       if (*instruction == 0x0a77)
-               do_sigreturn(mm, regs, 0);
-       else if (*instruction == 0x0aad)
-               do_sigreturn(mm, regs, 1);
+       else if (instruction == 0x0aad)
+               sys_rt_sigreturn(regs);
        else {
-               printk("- XXX - do_exception: task = %s, primary, NO EXEC "
-                      "-> SIGSEGV\n", current->comm);
-               up_read(&mm->mmap_sem);
                current->thread.prot_addr = address;
                current->thread.trap_no = error_code;
                do_sigsegv(regs, error_code, SEGV_MAPERR, address);
        }
        return 0;
-out_fault:
-       spin_unlock(&mm->page_table_lock);
-       return -EFAULT;
 }
 #endif /* CONFIG_S390_EXEC_PROTECT */
 
@@ -349,7 +305,7 @@ do_exception(struct pt_regs *regs, unsigned long error_code, int write)
        int space;
        int si_code;
 
-       if (notify_page_fault(regs, error_code) == NOTIFY_STOP)
+       if (notify_page_fault(regs, error_code))
                return;
 
        tsk = current;