Pull video into test branch

[linux-drm-fsl-dcu.git] / arch / s390 / mm / fault.c

diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c
index 7cd82575813d1c7be34a85b109f75e1ff787b482..cd85e34d8703551bdb7fa640be56792bcf32eaf0 100644 (file)
--- a/arch/s390/mm/fault.c
+++ b/arch/s390/mm/fault.c
@@ -25,10 +25,13 @@
 #include <linux/console.h>
 #include <linux/module.h>
 #include <linux/hardirq.h>
+#include <linux/kprobes.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
 #define __FAIL_ADDR_MASK 0x7ffff000
@@ -48,6 +51,38 @@ extern int sysctl_userprocess_debug;
 
 extern void die(const char *,struct pt_regs *,long);
 
+#ifdef CONFIG_KPROBES
+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 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);
+}
+#else
+static inline int notify_page_fault(enum die_val val, const char *str,
+                       struct pt_regs *regs, long err, int trap, int sig)
+{
+       return NOTIFY_DONE;
+}
+#endif
+
 extern spinlock_t timerlist_lock;
 
 /*
@@ -159,7 +194,7 @@ static void do_sigsegv(struct pt_regs *regs, unsigned long error_code,
  *   11       Page translation     ->  Not present       (nullification)
  *   3b       Region third trans.  ->  Not present       (nullification)
  */
-static inline void
+static inline void __kprobes
 do_exception(struct pt_regs *regs, unsigned long error_code, int is_protection)
 {
         struct task_struct *tsk;
@@ -173,6 +208,10 @@ do_exception(struct pt_regs *regs, unsigned long error_code, int is_protection)
         tsk = current;
         mm = tsk->mm;
        
+       if (notify_page_fault(DIE_PAGE_FAULT, "page fault", regs, error_code, 14,
+                                       SIGSEGV) == NOTIFY_STOP)
+               return;
+
        /* 
          * Check for low-address protection.  This needs to be treated
         * as a special case because the translation exception code 
@@ -315,8 +354,9 @@ no_context:
 */
 out_of_memory:
        up_read(&mm->mmap_sem);
-       if (tsk->pid == 1) {
+       if (is_init(tsk)) {
                yield();
+               down_read(&mm->mmap_sem);
                goto survive;
        }
        printk("VM: killing process %s\n", tsk->comm);
@@ -355,6 +395,7 @@ void do_dat_exception(struct pt_regs *regs, unsigned long error_code)
 /*
  * 'pfault' pseudo page faults routines.
  */
+static ext_int_info_t ext_int_pfault;
 static int pfault_disable = 0;
 
 static int __init nopfault(char *str)
@@ -383,22 +424,15 @@ int pfault_init(void)
                  __PF_RES_FIELD };
         int rc;
 
-       if (pfault_disable)
+       if (!MACHINE_IS_VM || pfault_disable)
                return -1;
-        __asm__ __volatile__(
-                "    diag  %1,%0,0x258\n"
-               "0:  j     2f\n"
-               "1:  la    %0,8\n"
+       asm volatile(
+               "       diag    %1,%0,0x258\n"
+               "0:     j       2f\n"
+               "1:     la      %0,8\n"
                "2:\n"
-               ".section __ex_table,\"a\"\n"
-               "   .align 4\n"
-#ifndef CONFIG_64BIT
-               "   .long  0b,1b\n"
-#else /* CONFIG_64BIT */
-               "   .quad  0b,1b\n"
-#endif /* CONFIG_64BIT */
-               ".previous"
-                : "=d" (rc) : "a" (&refbk), "m" (refbk) : "cc" );
+               EX_TABLE(0b,1b)
+               : "=d" (rc) : "a" (&refbk), "m" (refbk) : "cc");
         __ctl_set_bit(0, 9);
         return rc;
 }
@@ -408,25 +442,18 @@ void pfault_fini(void)
        pfault_refbk_t refbk =
        { 0x258, 1, 5, 2, 0ULL, 0ULL, 0ULL, 0ULL };
 
-       if (pfault_disable)
+       if (!MACHINE_IS_VM || pfault_disable)
                return;
        __ctl_clear_bit(0,9);
-        __asm__ __volatile__(
-                "    diag  %0,0,0x258\n"
+       asm volatile(
+               "       diag    %0,0,0x258\n"
                "0:\n"
-               ".section __ex_table,\"a\"\n"
-               "   .align 4\n"
-#ifndef CONFIG_64BIT
-               "   .long  0b,0b\n"
-#else /* CONFIG_64BIT */
-               "   .quad  0b,0b\n"
-#endif /* CONFIG_64BIT */
-               ".previous"
-               : : "a" (&refbk), "m" (refbk) : "cc" );
+               EX_TABLE(0b,0b)
+               : : "a" (&refbk), "m" (refbk) : "cc");
 }
 
 asmlinkage void
-pfault_interrupt(struct pt_regs *regs, __u16 error_code)
+pfault_interrupt(__u16 error_code)
 {
        struct task_struct *tsk;
        __u16 subcode;
@@ -475,5 +502,25 @@ pfault_interrupt(struct pt_regs *regs, __u16 error_code)
                        set_tsk_need_resched(tsk);
        }
 }
-#endif
 
+void __init pfault_irq_init(void)
+{
+       if (!MACHINE_IS_VM)
+               return;
+
+       /*
+        * Try to get pfault pseudo page faults going.
+        */
+       if (register_early_external_interrupt(0x2603, pfault_interrupt,
+                                             &ext_int_pfault) != 0)
+               panic("Couldn't request external interrupt 0x2603");
+
+       if (pfault_init() == 0)
+               return;
+
+       /* Tough luck, no pfault. */
+       pfault_disable = 1;
+       unregister_early_external_interrupt(0x2603, pfault_interrupt,
+                                           &ext_int_pfault);
+}
+#endif