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Diffstat (limited to 'arch/tile/mm/fault.c')
-rw-r--r--arch/tile/mm/fault.c22
1 files changed, 16 insertions, 6 deletions
diff --git a/arch/tile/mm/fault.c b/arch/tile/mm/fault.c
index cba30e9547b4..22e58f51ed23 100644
--- a/arch/tile/mm/fault.c
+++ b/arch/tile/mm/fault.c
@@ -130,7 +130,7 @@ static inline pmd_t *vmalloc_sync_one(pgd_t *pgd, unsigned long address)
}
/*
- * Handle a fault on the vmalloc or module mapping area
+ * Handle a fault on the vmalloc area.
*/
static inline int vmalloc_fault(pgd_t *pgd, unsigned long address)
{
@@ -203,9 +203,14 @@ static pgd_t *get_current_pgd(void)
* interrupt or a critical region, and must do as little as possible.
* Similarly, we can't use atomic ops here, since we may be handling a
* fault caused by an atomic op access.
+ *
+ * If we find a migrating PTE while we're in an NMI context, and we're
+ * at a PC that has a registered exception handler, we don't wait,
+ * since this thread may (e.g.) have been interrupted while migrating
+ * its own stack, which would then cause us to self-deadlock.
*/
static int handle_migrating_pte(pgd_t *pgd, int fault_num,
- unsigned long address,
+ unsigned long address, unsigned long pc,
int is_kernel_mode, int write)
{
pud_t *pud;
@@ -227,6 +232,8 @@ static int handle_migrating_pte(pgd_t *pgd, int fault_num,
pte_offset_kernel(pmd, address);
pteval = *pte;
if (pte_migrating(pteval)) {
+ if (in_nmi() && search_exception_tables(pc))
+ return 0;
wait_for_migration(pte);
return 1;
}
@@ -300,7 +307,7 @@ static int handle_page_fault(struct pt_regs *regs,
* rather than trying to patch up the existing PTE.
*/
pgd = get_current_pgd();
- if (handle_migrating_pte(pgd, fault_num, address,
+ if (handle_migrating_pte(pgd, fault_num, address, regs->pc,
is_kernel_mode, write))
return 1;
@@ -335,9 +342,12 @@ static int handle_page_fault(struct pt_regs *regs,
/*
* If we're trying to touch user-space addresses, we must
* be either at PL0, or else with interrupts enabled in the
- * kernel, so either way we can re-enable interrupts here.
+ * kernel, so either way we can re-enable interrupts here
+ * unless we are doing atomic access to user space with
+ * interrupts disabled.
*/
- local_irq_enable();
+ if (!(regs->flags & PT_FLAGS_DISABLE_IRQ))
+ local_irq_enable();
mm = tsk->mm;
@@ -665,7 +675,7 @@ struct intvec_state do_page_fault_ics(struct pt_regs *regs, int fault_num,
*/
if (fault_num == INT_DTLB_ACCESS)
write = 1;
- if (handle_migrating_pte(pgd, fault_num, address, 1, write))
+ if (handle_migrating_pte(pgd, fault_num, address, pc, 1, write))
return state;
/* Return zero so that we continue on with normal fault handling. */