diff options
Diffstat (limited to 'arch/tile/mm/fault.c')
| -rw-r--r-- | arch/tile/mm/fault.c | 22 |
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. */ |