fedora core 6 1.2949 + vserver 2.2.0
[linux-2.6.git] / arch / x86_64 / mm / fault.c
index 80bb11c..9a46b46 100644 (file)
@@ -5,14 +5,13 @@
  *  Copyright (C) 2001,2002 Andi Kleen, SuSE Labs.
  */
 
-#include <linux/config.h>
 #include <linux/signal.h>
 #include <linux/sched.h>
 #include <linux/kernel.h>
 #include <linux/errno.h>
 #include <linux/string.h>
 #include <linux/types.h>
-#include <linux/ptrace.h>
+#include <linux/tracehook.h>
 #include <linux/mman.h>
 #include <linux/mm.h>
 #include <linux/smp.h>
@@ -24,9 +23,9 @@
 #include <linux/compiler.h>
 #include <linux/module.h>
 #include <linux/kprobes.h>
+#include <linux/uaccess.h>
 
 #include <asm/system.h>
-#include <asm/uaccess.h>
 #include <asm/pgalloc.h>
 #include <asm/smp.h>
 #include <asm/tlbflush.h>
 #define PF_RSVD        (1<<3)
 #define PF_INSTR       (1<<4)
 
+static ATOMIC_NOTIFIER_HEAD(notify_page_fault_chain);
+
+/* Hook to register for page fault notifications */
+int register_page_fault_notifier(struct notifier_block *nb)
+{
+       vmalloc_sync_all();
+       return atomic_notifier_chain_register(&notify_page_fault_chain, nb);
+}
+EXPORT_SYMBOL_GPL(register_page_fault_notifier);
+
+int unregister_page_fault_notifier(struct notifier_block *nb)
+{
+       return atomic_notifier_chain_unregister(&notify_page_fault_chain, nb);
+}
+EXPORT_SYMBOL_GPL(unregister_page_fault_notifier);
+
+static inline int notify_page_fault(enum die_val val, const char *str,
+                       struct pt_regs *regs, long err, int trap, int sig)
+{
+       struct die_args args = {
+               .regs = regs,
+               .str = str,
+               .err = err,
+               .trapnr = trap,
+               .signr = sig
+       };
+       return atomic_notifier_call_chain(&notify_page_fault_chain, val, &args);
+}
+
 void bust_spinlocks(int yes)
 {
        int loglevel_save = console_loglevel;
@@ -77,7 +105,7 @@ static noinline int is_prefetch(struct pt_regs *regs, unsigned long addr,
        if (error_code & PF_INSTR)
                return 0;
        
-       instr = (unsigned char *)convert_rip_to_linear(current, regs);
+       instr = (unsigned char __user *)convert_rip_to_linear(current, regs);
        max_instr = instr + 15;
 
        if (user_mode(regs) && instr >= (unsigned char *)TASK_SIZE64)
@@ -88,7 +116,7 @@ static noinline int is_prefetch(struct pt_regs *regs, unsigned long addr,
                unsigned char instr_hi;
                unsigned char instr_lo;
 
-               if (__get_user(opcode, instr))
+               if (probe_kernel_address(instr, opcode))
                        break; 
 
                instr_hi = opcode & 0xf0; 
@@ -126,7 +154,7 @@ static noinline int is_prefetch(struct pt_regs *regs, unsigned long addr,
                case 0x00:
                        /* Prefetch instruction is 0x0F0D or 0x0F18 */
                        scan_more = 0;
-                       if (__get_user(opcode, instr)) 
+                       if (probe_kernel_address(instr, opcode))
                                break;
                        prefetch = (instr_lo == 0xF) &&
                                (opcode == 0x0D || opcode == 0x18);
@@ -142,7 +170,7 @@ static noinline int is_prefetch(struct pt_regs *regs, unsigned long addr,
 static int bad_address(void *p) 
 { 
        unsigned long dummy;
-       return __get_user(dummy, (unsigned long *)p);
+       return probe_kernel_address((unsigned long *)p, dummy);
 } 
 
 void dump_pagetable(unsigned long address)
@@ -160,7 +188,7 @@ void dump_pagetable(unsigned long address)
        printk("PGD %lx ", pgd_val(*pgd));
        if (!pgd_present(*pgd)) goto ret; 
 
-       pud = __pud_offset_k((pud_t *)pgd_page(*pgd), address);
+       pud = pud_offset(pgd, address);
        if (bad_address(pud)) goto bad;
        printk("PUD %lx ", pud_val(*pud));
        if (!pud_present(*pud)) goto ret;
@@ -216,9 +244,9 @@ static int is_errata93(struct pt_regs *regs, unsigned long address)
 
 int unhandled_signal(struct task_struct *tsk, int sig)
 {
-       if (tsk->pid == 1)
+       if (is_init(tsk))
                return 1;
-       if (tsk->ptrace & PT_PTRACED)
+       if (tracehook_consider_fatal_signal(tsk, sig))
                return 0;
        return (tsk->sighand->action[sig-1].sa.sa_handler == SIG_IGN) ||
                (tsk->sighand->action[sig-1].sa.sa_handler == SIG_DFL);
@@ -265,7 +293,7 @@ static int vmalloc_fault(unsigned long address)
        if (pgd_none(*pgd))
                set_pgd(pgd, *pgd_ref);
        else
-               BUG_ON(pgd_page(*pgd) != pgd_page(*pgd_ref));
+               BUG_ON(pgd_page_vaddr(*pgd) != pgd_page_vaddr(*pgd_ref));
 
        /* Below here mismatches are bugs because these lower tables
           are shared */
@@ -274,7 +302,7 @@ static int vmalloc_fault(unsigned long address)
        pud_ref = pud_offset(pgd_ref, address);
        if (pud_none(*pud_ref))
                return -1;
-       if (pud_none(*pud) || pud_page(*pud) != pud_page(*pud_ref))
+       if (pud_none(*pud) || pud_page_vaddr(*pud) != pud_page_vaddr(*pud_ref))
                BUG();
        pmd = pmd_offset(pud, address);
        pmd_ref = pmd_offset(pud_ref, address);
@@ -348,7 +376,7 @@ asmlinkage void __kprobes do_page_fault(struct pt_regs *regs,
                        if (vmalloc_fault(address) >= 0)
                                return;
                }
-               if (notify_die(DIE_PAGE_FAULT, "page fault", regs, error_code, 14,
+               if (notify_page_fault(DIE_PAGE_FAULT, "page fault", regs, error_code, 14,
                                                SIGSEGV) == NOTIFY_STOP)
                        return;
                /*
@@ -358,7 +386,7 @@ asmlinkage void __kprobes do_page_fault(struct pt_regs *regs,
                goto bad_area_nosemaphore;
        }
 
-       if (notify_die(DIE_PAGE_FAULT, "page fault", regs, error_code, 14,
+       if (notify_page_fault(DIE_PAGE_FAULT, "page fault", regs, error_code, 14,
                                        SIGSEGV) == NOTIFY_STOP)
                return;
 
@@ -383,7 +411,7 @@ asmlinkage void __kprobes do_page_fault(struct pt_regs *regs,
        /* 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.  Unfortunatly, in the case of an
-        * erroneous fault occuring in a code path which already holds mmap_sem
+        * erroneous fault occurring in a code path which already holds mmap_sem
         * we will deadlock attempting to validate the fault against the
         * address space.  Luckily the kernel only validly references user
         * space from well defined areas of code, which are listed in the
@@ -410,8 +438,10 @@ asmlinkage void __kprobes do_page_fault(struct pt_regs *regs,
        if (!(vma->vm_flags & VM_GROWSDOWN))
                goto bad_area;
        if (error_code & 4) {
-               // XXX: align red zone size with ABI 
-               if (address + 128 < regs->rsp)
+               /* Allow userspace just enough access below the stack pointer
+                * to let the 'enter' instruction work.
+                */
+               if (address + 65536 + 32 * sizeof(unsigned long) < regs->rsp)
                        goto bad_area;
        }
        if (expand_stack(vma, address))
@@ -434,7 +464,7 @@ good_area:
                case PF_PROT:           /* read, present */
                        goto bad_area;
                case 0:                 /* read, not present */
-                       if (!(vma->vm_flags & (VM_READ | VM_EXEC)))
+                       if (!(vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE)))
                                goto bad_area;
        }
 
@@ -484,10 +514,10 @@ bad_area_nosemaphore:
 
                if (exception_trace && unhandled_signal(tsk, SIGSEGV)) {
                        printk(
-                      "%s%s[%d]: segfault at %016lx rip %016lx rsp %016lx error %lx\n",
+                      "%s%s[%d:#%u]: segfault at %016lx rip %016lx rsp %016lx error %lx\n",
                                        tsk->pid > 1 ? KERN_INFO : KERN_EMERG,
-                                       tsk->comm, tsk->pid, address, regs->rip,
-                                       regs->rsp, error_code);
+                                       tsk->comm, tsk->pid, tsk->xid, address,
+                                       regs->rip, regs->rsp, error_code);
                }
        
                tsk->thread.cr2 = address;
@@ -534,7 +564,6 @@ no_context:
                printk(KERN_ALERT "Unable to handle kernel paging request");
        printk(" at %016lx RIP: \n" KERN_ALERT,address);
        printk_address(regs->rip);
-       printk("\n");
        dump_pagetable(address);
        tsk->thread.cr2 = address;
        tsk->thread.trap_no = 14;
@@ -551,11 +580,12 @@ no_context:
  */
 out_of_memory:
        up_read(&mm->mmap_sem);
-       if (current->pid == 1) { 
+       if (is_init(current)) {
                yield();
                goto again;
        }
-       printk("VM: killing process %s\n", tsk->comm);
+       printk("VM: killing process %s(%d:#%u)\n",
+               tsk->comm, tsk->pid, tsk->xid);
        if (error_code & 4)
                do_exit(SIGKILL);
        goto no_context;
@@ -606,7 +636,7 @@ void vmalloc_sync_all(void)
                                if (pgd_none(*pgd))
                                        set_pgd(pgd, *pgd_ref);
                                else
-                                       BUG_ON(pgd_page(*pgd) != pgd_page(*pgd_ref));
+                                       BUG_ON(pgd_page_vaddr(*pgd) != pgd_page_vaddr(*pgd_ref));
                        }
                        spin_unlock(&pgd_lock);
                        set_bit(pgd_index(address), insync);