Merge branch 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
[safe/jmp/linux-2.6] / arch / x86 / mm / fault.c
index ec08d83..c76ef1d 100644 (file)
@@ -10,6 +10,7 @@
 #include <linux/string.h>
 #include <linux/types.h>
 #include <linux/ptrace.h>
+#include <linux/mmiotrace.h>
 #include <linux/mman.h>
 #include <linux/mm.h>
 #include <linux/smp.h>
@@ -34,6 +35,7 @@
 #include <asm/tlbflush.h>
 #include <asm/proto.h>
 #include <asm-generic/sections.h>
+#include <asm/traps.h>
 
 /*
  * Page fault error code bits
 #define PF_RSVD                (1<<3)
 #define PF_INSTR       (1<<4)
 
+static inline int kmmio_fault(struct pt_regs *regs, unsigned long addr)
+{
+#ifdef CONFIG_MMIOTRACE
+       if (unlikely(is_kmmio_active()))
+               if (kmmio_handler(regs, addr) == 1)
+                       return -1;
+#endif
+       return 0;
+}
+
 static inline int notify_page_fault(struct pt_regs *regs)
 {
 #ifdef CONFIG_KPROBES
        int ret = 0;
 
        /* kprobe_running() needs smp_processor_id() */
-#ifdef CONFIG_X86_32
        if (!user_mode_vm(regs)) {
-#else
-       if (!user_mode(regs)) {
-#endif
                preempt_disable();
                if (kprobe_running() && kprobe_fault_handler(regs, 14))
                        ret = 1;
@@ -350,8 +358,6 @@ static int is_errata100(struct pt_regs *regs, unsigned long address)
        return 0;
 }
 
-void do_invalid_op(struct pt_regs *, unsigned long);
-
 static int is_f00f_bug(struct pt_regs *regs, unsigned long address)
 {
 #ifdef CONFIG_X86_F00F_BUG
@@ -387,7 +393,7 @@ static void show_fault_oops(struct pt_regs *regs, unsigned long error_code,
                if (pte && pte_present(*pte) && !pte_exec(*pte))
                        printk(KERN_CRIT "kernel tried to execute "
                                "NX-protected page - exploit attempt? "
-                               "(uid: %d)\n", current->uid);
+                               "(uid: %d)\n", current_uid());
        }
 #endif
 
@@ -396,11 +402,7 @@ static void show_fault_oops(struct pt_regs *regs, unsigned long error_code,
                printk(KERN_CONT "NULL pointer dereference");
        else
                printk(KERN_CONT "paging request");
-#ifdef CONFIG_X86_32
-       printk(KERN_CONT " at %08lx\n", address);
-#else
-       printk(KERN_CONT " at %016lx\n", address);
-#endif
+       printk(KERN_CONT " at %p\n", (void *) address);
        printk(KERN_ALERT "IP:");
        printk_address(regs->ip, 1);
        dump_pagetable(address);
@@ -411,6 +413,7 @@ static noinline void pgtable_bad(unsigned long address, struct pt_regs *regs,
                                 unsigned long error_code)
 {
        unsigned long flags = oops_begin();
+       int sig = SIGKILL;
        struct task_struct *tsk;
 
        printk(KERN_ALERT "%s: Corrupted page table at address %lx\n",
@@ -421,8 +424,8 @@ static noinline void pgtable_bad(unsigned long address, struct pt_regs *regs,
        tsk->thread.trap_no = 14;
        tsk->thread.error_code = error_code;
        if (__die("Bad pagetable", regs, error_code))
-               regs = NULL;
-       oops_end(flags, regs, SIGKILL);
+               sig = 0;
+       oops_end(flags, regs, sig);
 }
 #endif
 
@@ -497,6 +500,11 @@ static int vmalloc_fault(unsigned long address)
        unsigned long pgd_paddr;
        pmd_t *pmd_k;
        pte_t *pte_k;
+
+       /* Make sure we are in vmalloc area */
+       if (!(address >= VMALLOC_START && address < VMALLOC_END))
+               return -1;
+
        /*
         * Synchronize this task's top level page-table
         * with the 'reference' page table.
@@ -526,7 +534,7 @@ static int vmalloc_fault(unsigned long address)
           happen within a race in page table update. In the later
           case just flush. */
 
-       pgd = pgd_offset(current->mm ?: &init_mm, address);
+       pgd = pgd_offset(current->active_mm, address);
        pgd_ref = pgd_offset_k(address);
        if (pgd_none(*pgd_ref))
                return -1;
@@ -583,13 +591,9 @@ void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code)
        int fault;
 #ifdef CONFIG_X86_64
        unsigned long flags;
+       int sig;
 #endif
 
-       /*
-        * We can fault from pretty much anywhere, with unknown IRQ state.
-        */
-       trace_hardirqs_fixup();
-
        tsk = current;
        mm = tsk->mm;
        prefetchw(&mm->mmap_sem);
@@ -599,7 +603,7 @@ void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code)
 
        si_code = SEGV_MAPERR;
 
-       if (notify_page_fault(regs))
+       if (unlikely(kmmio_fault(regs, address)))
                return;
 
        /*
@@ -628,6 +632,9 @@ void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code)
                if (spurious_fault(address, error_code))
                        return;
 
+               /* kprobes don't want to hook the spurious faults. */
+               if (notify_page_fault(regs))
+                       return;
                /*
                 * Don't take the mm semaphore here. If we fixup a prefetch
                 * fault we could otherwise deadlock.
@@ -635,25 +642,27 @@ void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code)
                goto bad_area_nosemaphore;
        }
 
-
-#ifdef CONFIG_X86_32
-       /* It's safe to allow irq's after cr2 has been saved and the vmalloc
-          fault has been handled. */
-       if (regs->flags & (X86_EFLAGS_IF|VM_MASK))
-               local_irq_enable();
+       /* kprobes don't want to hook the spurious faults. */
+       if (notify_page_fault(regs))
+               return;
 
        /*
-        * If we're in an interrupt, have no user context or are running in an
-        * atomic region then we must not take the fault.
+        * It's safe to allow irq's after cr2 has been saved and the
+        * vmalloc fault has been handled.
+        *
+        * User-mode registers count as a user access even for any
+        * potential system fault or CPU buglet.
         */
-       if (in_atomic() || !mm)
-               goto bad_area_nosemaphore;
-#else /* CONFIG_X86_64 */
-       if (likely(regs->flags & X86_EFLAGS_IF))
+       if (user_mode_vm(regs)) {
+               local_irq_enable();
+               error_code |= PF_USER;
+       } else if (regs->flags & X86_EFLAGS_IF)
                local_irq_enable();
 
+#ifdef CONFIG_X86_64
        if (unlikely(error_code & PF_RSVD))
                pgtable_bad(address, regs, error_code);
+#endif
 
        /*
         * If we're in an interrupt, have no user context or are running in an
@@ -663,14 +672,7 @@ void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code)
                goto bad_area_nosemaphore;
 
        /*
-        * User-mode registers count as a user access even for any
-        * potential system fault or CPU buglet.
-        */
-       if (user_mode_vm(regs))
-               error_code |= PF_USER;
-again:
-#endif
-       /* When running in the kernel we expect faults to occur only to
+        * When running in the kernel we expect faults to occur only to
         * addresses in user space.  All other faults represent errors in the
         * kernel and should generate an OOPS.  Unfortunately, in the case of an
         * erroneous fault occurring in a code path which already holds mmap_sem
@@ -733,9 +735,6 @@ good_area:
                        goto bad_area;
        }
 
-#ifdef CONFIG_X86_32
-survive:
-#endif
        /*
         * If for any reason at all we couldn't handle the fault,
         * make sure we exit gracefully rather than endlessly redo
@@ -795,14 +794,10 @@ bad_area_nosemaphore:
                if (show_unhandled_signals && unhandled_signal(tsk, SIGSEGV) &&
                    printk_ratelimit()) {
                        printk(
-#ifdef CONFIG_X86_32
-                       "%s%s[%d]: segfault at %lx ip %08lx sp %08lx error %lx",
-#else
-                       "%s%s[%d]: segfault at %lx ip %lx sp %lx error %lx",
-#endif
+                       "%s%s[%d]: segfault at %lx ip %p sp %p error %lx",
                        task_pid_nr(tsk) > 1 ? KERN_INFO : KERN_EMERG,
-                       tsk->comm, task_pid_nr(tsk), address, regs->ip,
-                       regs->sp, error_code);
+                       tsk->comm, task_pid_nr(tsk), address,
+                       (void *) regs->ip, (void *) regs->sp, error_code);
                        print_vma_addr(" in ", regs->ip);
                        printk("\n");
                }
@@ -859,33 +854,22 @@ no_context:
        bust_spinlocks(0);
        do_exit(SIGKILL);
 #else
+       sig = SIGKILL;
        if (__die("Oops", regs, error_code))
-               regs = NULL;
+               sig = 0;
        /* Executive summary in case the body of the oops scrolled away */
        printk(KERN_EMERG "CR2: %016lx\n", address);
-       oops_end(flags, regs, SIGKILL);
+       oops_end(flags, regs, sig);
 #endif
 
-/*
- * We ran out of memory, or some other thing happened to us that made
- * us unable to handle the page fault gracefully.
- */
 out_of_memory:
+       /*
+        * We ran out of memory, call the OOM killer, and return the userspace
+        * (which will retry the fault, or kill us if we got oom-killed).
+        */
        up_read(&mm->mmap_sem);
-       if (is_global_init(tsk)) {
-               yield();
-#ifdef CONFIG_X86_32
-               down_read(&mm->mmap_sem);
-               goto survive;
-#else
-               goto again;
-#endif
-       }
-
-       printk("VM: killing process %s\n", tsk->comm);
-       if (error_code & PF_USER)
-               do_group_exit(SIGKILL);
-       goto no_context;
+       pagefault_out_of_memory();
+       return;
 
 do_sigbus:
        up_read(&mm->mmap_sem);
@@ -909,76 +893,45 @@ LIST_HEAD(pgd_list);
 
 void vmalloc_sync_all(void)
 {
-#ifdef CONFIG_X86_32
-       /*
-        * Note that races in the updates of insync and start aren't
-        * problematic: insync can only get set bits added, and updates to
-        * start are only improving performance (without affecting correctness
-        * if undone).
-        */
-       static DECLARE_BITMAP(insync, PTRS_PER_PGD);
-       static unsigned long start = TASK_SIZE;
        unsigned long address;
 
+#ifdef CONFIG_X86_32
        if (SHARED_KERNEL_PMD)
                return;
 
-       BUILD_BUG_ON(TASK_SIZE & ~PGDIR_MASK);
-       for (address = start; address >= TASK_SIZE; address += PGDIR_SIZE) {
-               if (!test_bit(pgd_index(address), insync)) {
-                       unsigned long flags;
-                       struct page *page;
-
-                       spin_lock_irqsave(&pgd_lock, flags);
-                       list_for_each_entry(page, &pgd_list, lru) {
-                               if (!vmalloc_sync_one(page_address(page),
-                                                     address))
-                                       break;
-                       }
-                       spin_unlock_irqrestore(&pgd_lock, flags);
-                       if (!page)
-                               set_bit(pgd_index(address), insync);
+       for (address = VMALLOC_START & PMD_MASK;
+            address >= TASK_SIZE && address < FIXADDR_TOP;
+            address += PMD_SIZE) {
+               unsigned long flags;
+               struct page *page;
+
+               spin_lock_irqsave(&pgd_lock, flags);
+               list_for_each_entry(page, &pgd_list, lru) {
+                       if (!vmalloc_sync_one(page_address(page),
+                                             address))
+                               break;
                }
-               if (address == start && test_bit(pgd_index(address), insync))
-                       start = address + PGDIR_SIZE;
+               spin_unlock_irqrestore(&pgd_lock, flags);
        }
 #else /* CONFIG_X86_64 */
-       /*
-        * Note that races in the updates of insync and start aren't
-        * problematic: insync can only get set bits added, and updates to
-        * start are only improving performance (without affecting correctness
-        * if undone).
-        */
-       static DECLARE_BITMAP(insync, PTRS_PER_PGD);
-       static unsigned long start = VMALLOC_START & PGDIR_MASK;
-       unsigned long address;
-
-       for (address = start; address <= VMALLOC_END; address += PGDIR_SIZE) {
-               if (!test_bit(pgd_index(address), insync)) {
-                       const pgd_t *pgd_ref = pgd_offset_k(address);
-                       unsigned long flags;
-                       struct page *page;
-
-                       if (pgd_none(*pgd_ref))
-                               continue;
-                       spin_lock_irqsave(&pgd_lock, flags);
-                       list_for_each_entry(page, &pgd_list, lru) {
-                               pgd_t *pgd;
-                               pgd = (pgd_t *)page_address(page) + pgd_index(address);
-                               if (pgd_none(*pgd))
-                                       set_pgd(pgd, *pgd_ref);
-                               else
-                                       BUG_ON(pgd_page_vaddr(*pgd) != pgd_page_vaddr(*pgd_ref));
-                       }
-                       spin_unlock_irqrestore(&pgd_lock, flags);
-                       set_bit(pgd_index(address), insync);
+       for (address = VMALLOC_START & PGDIR_MASK; address <= VMALLOC_END;
+            address += PGDIR_SIZE) {
+               const pgd_t *pgd_ref = pgd_offset_k(address);
+               unsigned long flags;
+               struct page *page;
+
+               if (pgd_none(*pgd_ref))
+                       continue;
+               spin_lock_irqsave(&pgd_lock, flags);
+               list_for_each_entry(page, &pgd_list, lru) {
+                       pgd_t *pgd;
+                       pgd = (pgd_t *)page_address(page) + pgd_index(address);
+                       if (pgd_none(*pgd))
+                               set_pgd(pgd, *pgd_ref);
+                       else
+                               BUG_ON(pgd_page_vaddr(*pgd) != pgd_page_vaddr(*pgd_ref));
                }
-               if (address == start)
-                       start = address + PGDIR_SIZE;
+               spin_unlock_irqrestore(&pgd_lock, flags);
        }
-       /* Check that there is no need to do the same for the modules area. */
-       BUILD_BUG_ON(!(MODULES_VADDR > __START_KERNEL));
-       BUILD_BUG_ON(!(((MODULES_END - 1) & PGDIR_MASK) ==
-                               (__START_KERNEL & PGDIR_MASK)));
 #endif
 }