diff options
Diffstat (limited to 'arch/ia64/mm/fault.c')
| -rw-r--r-- | arch/ia64/mm/fault.c | 74 |
1 files changed, 47 insertions, 27 deletions
diff --git a/arch/ia64/mm/fault.c b/arch/ia64/mm/fault.c index 9150ffaff9e..7225dad8709 100644 --- a/arch/ia64/mm/fault.c +++ b/arch/ia64/mm/fault.c @@ -10,13 +10,13 @@ #include <linux/interrupt.h> #include <linux/kprobes.h> #include <linux/kdebug.h> +#include <linux/prefetch.h> #include <asm/pgtable.h> #include <asm/processor.h> -#include <asm/system.h> #include <asm/uaccess.h> -extern void die (char *, struct pt_regs *, long); +extern int die(char *, struct pt_regs *, long); #ifdef CONFIG_KPROBES static inline int notify_page_fault(struct pt_regs *regs, int trap) @@ -26,7 +26,7 @@ static inline int notify_page_fault(struct pt_regs *regs, int trap) if (!user_mode(regs)) { /* kprobe_running() needs smp_processor_id() */ preempt_disable(); - if (kprobe_running() && kprobes_fault_handler(regs, trap)) + if (kprobe_running() && kprobe_fault_handler(regs, trap)) ret = 1; preempt_enable(); } @@ -72,6 +72,10 @@ mapped_kernel_page_is_present (unsigned long address) return pte_present(pte); } +# define VM_READ_BIT 0 +# define VM_WRITE_BIT 1 +# define VM_EXEC_BIT 2 + void __kprobes ia64_do_page_fault (unsigned long address, unsigned long isr, struct pt_regs *regs) { @@ -81,6 +85,10 @@ ia64_do_page_fault (unsigned long address, unsigned long isr, struct pt_regs *re struct siginfo si; unsigned long mask; int fault; + unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE; + + mask = ((((isr >> IA64_ISR_X_BIT) & 1UL) << VM_EXEC_BIT) + | (((isr >> IA64_ISR_W_BIT) & 1UL) << VM_WRITE_BIT)); /* mmap_sem is performance critical.... */ prefetchw(&mm->mmap_sem); @@ -109,6 +117,11 @@ ia64_do_page_fault (unsigned long address, unsigned long isr, struct pt_regs *re if (notify_page_fault(regs, TRAP_BRKPT)) return; + if (user_mode(regs)) + flags |= FAULT_FLAG_USER; + if (mask & VM_WRITE) + flags |= FAULT_FLAG_WRITE; +retry: down_read(&mm->mmap_sem); vma = find_vma_prev(mm, address, &prev_vma); @@ -130,10 +143,6 @@ ia64_do_page_fault (unsigned long address, unsigned long isr, struct pt_regs *re /* OK, we've got a good vm_area for this memory area. Check the access permissions: */ -# define VM_READ_BIT 0 -# define VM_WRITE_BIT 1 -# define VM_EXEC_BIT 2 - # if (((1 << VM_READ_BIT) != VM_READ || (1 << VM_WRITE_BIT) != VM_WRITE) \ || (1 << VM_EXEC_BIT) != VM_EXEC) # error File is out of sync with <linux/mm.h>. Please update. @@ -142,19 +151,19 @@ ia64_do_page_fault (unsigned long address, unsigned long isr, struct pt_regs *re if (((isr >> IA64_ISR_R_BIT) & 1UL) && (!(vma->vm_flags & (VM_READ | VM_WRITE)))) goto bad_area; - mask = ( (((isr >> IA64_ISR_X_BIT) & 1UL) << VM_EXEC_BIT) - | (((isr >> IA64_ISR_W_BIT) & 1UL) << VM_WRITE_BIT)); - if ((vma->vm_flags & mask) != mask) goto bad_area; - survive: /* * 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(mm, vma, address, (mask & VM_WRITE) != 0); + fault = handle_mm_fault(mm, vma, address, flags); + + if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current)) + return; + if (unlikely(fault & VM_FAULT_ERROR)) { /* * We ran out of memory, or some other thing happened @@ -169,10 +178,25 @@ ia64_do_page_fault (unsigned long address, unsigned long isr, struct pt_regs *re } BUG(); } - if (fault & VM_FAULT_MAJOR) - current->maj_flt++; - else - current->min_flt++; + + if (flags & FAULT_FLAG_ALLOW_RETRY) { + if (fault & VM_FAULT_MAJOR) + current->maj_flt++; + else + current->min_flt++; + if (fault & VM_FAULT_RETRY) { + flags &= ~FAULT_FLAG_ALLOW_RETRY; + flags |= FAULT_FLAG_TRIED; + + /* No need to up_read(&mm->mmap_sem) as we would + * have already released it in __lock_page_or_retry + * in mm/filemap.c. + */ + + goto retry; + } + } + up_read(&mm->mmap_sem); return; @@ -267,20 +291,16 @@ ia64_do_page_fault (unsigned long address, unsigned long isr, struct pt_regs *re else printk(KERN_ALERT "Unable to handle kernel paging request at " "virtual address %016lx\n", address); - die("Oops", regs, isr); + if (die("Oops", regs, isr)) + regs = NULL; bust_spinlocks(0); - do_exit(SIGKILL); + if (regs) + do_exit(SIGKILL); return; out_of_memory: up_read(&mm->mmap_sem); - if (is_init(current)) { - yield(); - down_read(&mm->mmap_sem); - goto survive; - } - printk(KERN_CRIT "VM: killing process %s\n", current->comm); - if (user_mode(regs)) - do_exit(SIGKILL); - goto no_context; + if (!user_mode(regs)) + goto no_context; + pagefault_out_of_memory(); } |