Merge tag 'ecryptfs-3.6-rc1-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git...

[karo-tx-linux.git] / arch / s390 / mm / fault.c

diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c
index 72cec9ecd96c7304486fc49b732764edcf4cb0f3..6c013f544146d8bf92d6143378c8f1fbf5631b02 100644 (file)
--- a/arch/s390/mm/fault.c
+++ b/arch/s390/mm/fault.c
@@ -1,8 +1,6 @@
 /*
- *  arch/s390/mm/fault.c
- *
  *  S390 version
- *    Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation
+ *    Copyright IBM Corp. 1999
  *    Author(s): Hartmut Penner (hp@de.ibm.com)
  *               Ulrich Weigand (uweigand@de.ibm.com)
  *
@@ -51,6 +49,7 @@
 #define VM_FAULT_BADCONTEXT    0x010000
 #define VM_FAULT_BADMAP                0x020000
 #define VM_FAULT_BADACCESS     0x040000
+#define VM_FAULT_SIGNAL        0x080000
 
 static unsigned long store_indication;
 
@@ -112,7 +111,7 @@ static inline int user_space_fault(unsigned long trans_exc_code)
        if (trans_exc_code == 2)
                /* Access via secondary space, set_fs setting decides */
                return current->thread.mm_segment.ar4;
-       if (user_mode == HOME_SPACE_MODE)
+       if (addressing_mode == HOME_SPACE_MODE)
                /* User space if the access has been done via home space. */
                return trans_exc_code == 3;
        /*
@@ -221,7 +220,7 @@ static noinline void do_fault_error(struct pt_regs *regs, int fault)
        case VM_FAULT_BADACCESS:
        case VM_FAULT_BADMAP:
                /* Bad memory access. Check if it is kernel or user space. */
-               if (regs->psw.mask & PSW_MASK_PSTATE) {
+               if (user_mode(regs)) {
                        /* User mode accesses just cause a SIGSEGV */
                        si_code = (fault == VM_FAULT_BADMAP) ?
                                SEGV_MAPERR : SEGV_ACCERR;
@@ -231,15 +230,19 @@ static noinline void do_fault_error(struct pt_regs *regs, int fault)
        case VM_FAULT_BADCONTEXT:
                do_no_context(regs);
                break;
+       case VM_FAULT_SIGNAL:
+               if (!user_mode(regs))
+                       do_no_context(regs);
+               break;
        default: /* fault & VM_FAULT_ERROR */
                if (fault & VM_FAULT_OOM) {
-                       if (!(regs->psw.mask & PSW_MASK_PSTATE))
+                       if (!user_mode(regs))
                                do_no_context(regs);
                        else
                                pagefault_out_of_memory();
                } else if (fault & VM_FAULT_SIGBUS) {
                        /* Kernel mode? Handle exceptions or die */
-                       if (!(regs->psw.mask & PSW_MASK_PSTATE))
+                       if (!user_mode(regs))
                                do_no_context(regs);
                        else
                                do_sigbus(regs);
@@ -288,7 +291,7 @@ static inline int do_exception(struct pt_regs *regs, int access)
 
        address = trans_exc_code & __FAIL_ADDR_MASK;
        perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
-       flags = FAULT_FLAG_ALLOW_RETRY;
+       flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
        if (access == VM_WRITE || (trans_exc_code & store_indication) == 0x400)
                flags |= FAULT_FLAG_WRITE;
        down_read(&mm->mmap_sem);
@@ -337,6 +340,11 @@ retry:
         * the fault.
         */
        fault = handle_mm_fault(mm, vma, address, flags);
+       /* No reason to continue if interrupted by SIGKILL. */
+       if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current)) {
+               fault = VM_FAULT_SIGNAL;
+               goto out;
+       }
        if (unlikely(fault & VM_FAULT_ERROR))
                goto out_up;
 
@@ -428,7 +436,7 @@ void __kprobes do_asce_exception(struct pt_regs *regs)
        }
 
        /* User mode accesses just cause a SIGSEGV */
-       if (regs->psw.mask & PSW_MASK_PSTATE) {
+       if (user_mode(regs)) {
                do_sigsegv(regs, SEGV_MAPERR);
                return;
        }
@@ -443,6 +451,7 @@ int __handle_fault(unsigned long uaddr, unsigned long pgm_int_code, int write)
        struct pt_regs regs;
        int access, fault;
 
+       /* Emulate a uaccess fault from kernel mode. */
        regs.psw.mask = psw_kernel_bits | PSW_MASK_DAT | PSW_MASK_MCHECK;
        if (!irqs_disabled())
                regs.psw.mask |= PSW_MASK_IO | PSW_MASK_EXT;
@@ -452,12 +461,12 @@ int __handle_fault(unsigned long uaddr, unsigned long pgm_int_code, int write)
        regs.int_parm_long = (uaddr & PAGE_MASK) | 2;
        access = write ? VM_WRITE : VM_READ;
        fault = do_exception(&regs, access);
-       if (unlikely(fault)) {
-               if (fault & VM_FAULT_OOM)
-                       return -EFAULT;
-               else if (fault & VM_FAULT_SIGBUS)
-                       do_sigbus(&regs);
-       }
+       /*
+        * Since the fault happened in kernel mode while performing a uaccess
+        * all we need to do now is emulating a fixup in case "fault" is not
+        * zero.
+        * For the calling uaccess functions this results always in -EFAULT.
+        */
        return fault ? -EFAULT : 0;
 }