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Diffstat (limited to 'arch/s390/mm/fault.c')
-rw-r--r--arch/s390/mm/fault.c39
1 files changed, 24 insertions, 15 deletions
diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c
index 72cec9ecd96..6c013f54414 100644
--- 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;
}