* S390 version
* Copyright IBM Corp. 1999
* Author(s): Hartmut Penner (hp@de.ibm.com)
- * Ulrich Weigand (uweigand@de.ibm.com)
+ * Ulrich Weigand (uweigand@de.ibm.com)
*
* Derived from "arch/i386/mm/fault.c"
* Copyright (C) 1995 Linus Torvalds
#define __FAIL_ADDR_MASK -4096L
/*
- * Allocate private vm_fault_reason from top. Please make sure it won't
- * collide with vm_fault_reason.
+ * Allocate private vm_fault_reason from top.
+ * Please make sure it won't collide with vm_fault_reason.
*/
#define VM_FAULT_BADCONTEXT ((__force vm_fault_t)0x80000000)
#define VM_FAULT_BADMAP ((__force vm_fault_t)0x40000000)
unsigned long trans_exc_code;
trans_exc_code = regs->int_parm_long & 3;
+ /* Primary address space */
if (likely(trans_exc_code == 0)) {
- /* primary space exception */
if (user_mode(regs))
return USER_FAULT;
if (!IS_ENABLED(CONFIG_PGSTE))
}
if (trans_exc_code == 2)
return USER_FAULT;
+ /* Access register mode, not used in the kernel */
if (trans_exc_code == 1) {
- /* access register mode, not used in the kernel */
return USER_FAULT;
}
- /* home space exception -> access via kernel ASCE */
+ /* Home space -> access via kernel ASCE */
return KERNEL_FAULT;
}
show_regs(regs);
}
-/*
- * Send SIGSEGV to task. This is an external routine
- * to keep the stack usage of do_page_fault small.
- */
static noinline void do_sigsegv(struct pt_regs *regs, int si_code)
{
report_user_fault(regs, SIGSEGV, 1);
if (kfence_handle_page_fault(address, is_write, regs))
return;
}
- /*
- * Oops. The kernel tried to access some bad page. We'll have to
- * terminate things with extreme prejudice.
- */
if (fault_type == KERNEL_FAULT)
printk(KERN_ALERT "Unable to handle kernel pointer dereference"
" in virtual kernel address space\n");
static noinline void do_low_address(struct pt_regs *regs)
{
- /* Low-address protection hit in kernel mode means
- NULL pointer write access in kernel mode. */
+ /*
+ * Low-address protection hit in kernel mode means
+ * NULL pointer write access in kernel mode.
+ */
if (regs->psw.mask & PSW_MASK_PSTATE) {
- /* Low-address protection hit in user mode 'cannot happen'. */
+ /* Low-address protection hit in user mode: 'cannot happen' */
die (regs, "Low-address protection");
}
static noinline void do_sigbus(struct pt_regs *regs)
{
- /*
- * Send a sigbus, regardless of whether we were in kernel
- * or user mode.
- */
force_sig_fault(SIGBUS, BUS_ADRERR,
(void __user *)(regs->int_parm_long & __FAIL_ADDR_MASK));
}
* routines.
*
* interruption code (int_code):
- * 04 Protection -> Write-Protection (suppression)
- * 10 Segment translation -> Not present (nullification)
- * 11 Page translation -> Not present (nullification)
- * 3b Region third trans. -> Not present (nullification)
+ * 04 Protection -> Write-Protection (suppression)
+ * 10 Segment translation -> Not present (nullification)
+ * 11 Page translation -> Not present (nullification)
+ * 3b Region third trans. -> Not present (nullification)
*/
static inline vm_fault_t do_exception(struct pt_regs *regs, int access)
{
* been nullified. Don't signal single step via SIGTRAP.
*/
clear_thread_flag(TIF_PER_TRAP);
-
if (kprobe_page_fault(regs, 14))
return 0;
-
mm = tsk->mm;
address = get_fault_address(regs);
is_write = fault_is_write(regs);
-
- /*
- * Verify that the fault happened in user space, that
- * we are not in an interrupt and that there is a
- * user context.
- */
fault = VM_FAULT_BADCONTEXT;
type = get_fault_type(regs);
switch (type) {
goto out;
break;
}
-
perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
flags = FAULT_FLAG_DEFAULT;
if (user_mode(regs))
}
lock_mmap:
mmap_read_lock(mm);
-
gmap = NULL;
if (IS_ENABLED(CONFIG_PGSTE) && type == GMAP_FAULT) {
gmap = (struct gmap *) S390_lowcore.gmap;
if (gmap->pfault_enabled)
flags |= FAULT_FLAG_RETRY_NOWAIT;
}
-
retry:
fault = VM_FAULT_BADMAP;
vma = find_vma(mm, address);
if (!vma)
goto out_up;
-
if (unlikely(vma->vm_start > address)) {
if (!(vma->vm_flags & VM_GROWSDOWN))
goto out_up;
if (!vma)
goto out;
}
-
- /*
- * Ok, we have a good vm_area for this memory access, so
- * we can handle it..
- */
fault = VM_FAULT_BADACCESS;
if (unlikely(!(vma->vm_flags & access)))
goto out_up;
-
- /*
- * If for any reason at all we couldn't handle the fault,
- * make sure we exit gracefully rather than endlessly redo
- * the fault.
- */
fault = handle_mm_fault(vma, address, flags, regs);
if (fault_signal_pending(fault, regs)) {
fault = VM_FAULT_SIGNAL;
goto out_up;
goto out;
}
-
/* The fault is fully completed (including releasing mmap lock) */
if (fault & VM_FAULT_COMPLETED) {
if (gmap) {
fault = 0;
goto out;
}
-
if (unlikely(fault & VM_FAULT_ERROR))
goto out_up;
-
if (fault & VM_FAULT_RETRY) {
if (IS_ENABLED(CONFIG_PGSTE) && gmap &&
(flags & FAULT_FLAG_RETRY_NOWAIT)) {
/*
- * FAULT_FLAG_RETRY_NOWAIT has been set, mmap_lock has
- * not been released
+ * FAULT_FLAG_RETRY_NOWAIT has been set,
+ * mmap_lock has not been released
*/
current->thread.gmap_pfault = 1;
fault = VM_FAULT_PFAULT;
int rc;
/*
- * bit 61 tells us if the address is valid, if it's not we
- * have a major problem and should stop the kernel or send a
- * SIGSEGV to the process. Unfortunately bit 61 is not
- * reliable without the misc UV feature so we need to check
- * for that as well.
+ * Bit 61 indicates if the address is valid, if it is not the
+ * kernel should be stopped or SIGSEGV should be sent to the
+ * process. Bit 61 is not reliable without the misc UV feature,
+ * therefore this needs to be checked too.
*/
if (uv_has_feature(BIT_UV_FEAT_MISC) &&
!test_bit_inv(61, ®s->int_parm_long)) {
send_sig(SIGSEGV, current, 0);
return;
}
-
/*
- * The kernel should never run into this case and we
- * have no way out of this situation.
+ * The kernel should never run into this case and
+ * there is no way out of this situation.
*/
panic("Unexpected PGM 0x3d with TEID bit 61=0");
}
-
switch (get_fault_type(regs)) {
case GMAP_FAULT:
mm = current->mm;
WARN_ON_ONCE(1);
return;
}
-
if (gmap_convert_to_secure(gmap, gaddr) == -EINVAL)
send_sig(SIGSEGV, current, 0);
}
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