1 files changed, 26 insertions, 29 deletions

diff --git a/arch/x86_64/mm/fault.c b/arch/x86_64/mm/fault.c
index 635e58d443d7..54816adb8e93 100644
--- a/arch/x86_64/mm/fault.c
+++ b/arch/x86_64/mm/fault.c
@@ -159,7 +159,7 @@ void dump_pagetable(unsigned long address)
 	pmd_t *pmd;
 	pte_t *pte;
 
-	asm("movq %%cr3,%0" : "=r" (pgd));
+	pgd = (pgd_t *)read_cr3();
 
 	pgd = __va((unsigned long)pgd & PHYSICAL_PAGE_MASK); 
 	pgd += pgd_index(address);
@@ -221,16 +221,6 @@ static int is_errata93(struct pt_regs *regs, unsigned long address)
 	return 0;
 } 
 
-int unhandled_signal(struct task_struct *tsk, int sig)
-{
-	if (is_init(tsk))
-		return 1;
-	if (tsk->ptrace & PT_PTRACED)
-		return 0;
-	return (tsk->sighand->action[sig-1].sa.sa_handler == SIG_IGN) ||
-		(tsk->sighand->action[sig-1].sa.sa_handler == SIG_DFL);
-}
-
 static noinline void pgtable_bad(unsigned long address, struct pt_regs *regs,
 				 unsigned long error_code)
 {
@@ -301,8 +291,8 @@ static int vmalloc_fault(unsigned long address)
 	return 0;
 }
 
-int page_fault_trace = 0;
-int exception_trace = 1;
+static int page_fault_trace;
+int show_unhandled_signals = 1;
 
 /*
  * This routine handles page faults.  It determines the address,
@@ -317,7 +307,7 @@ asmlinkage void __kprobes do_page_fault(struct pt_regs *regs,
 	struct vm_area_struct * vma;
 	unsigned long address;
 	const struct exception_table_entry *fixup;
-	int write;
+	int write, fault;
 	unsigned long flags;
 	siginfo_t info;
 
@@ -326,7 +316,7 @@ asmlinkage void __kprobes do_page_fault(struct pt_regs *regs,
 	prefetchw(&mm->mmap_sem);
 
 	/* get the address */
-	__asm__("movq %%cr2,%0":"=r" (address));
+	address = read_cr2();
 
 	info.si_code = SEGV_MAPERR;
 
@@ -384,6 +374,13 @@ asmlinkage void __kprobes do_page_fault(struct pt_regs *regs,
 	if (unlikely(in_atomic() || !mm))
 		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:
 	/* When running in the kernel we expect faults to occur only to
 	 * addresses in user space.  All other faults represent errors in the
@@ -450,19 +447,18 @@ good_area:
 	 * make sure we exit gracefully rather than endlessly redo
 	 * the fault.
 	 */
-	switch (handle_mm_fault(mm, vma, address, write)) {
-	case VM_FAULT_MINOR:
-		tsk->min_flt++;
-		break;
-	case VM_FAULT_MAJOR:
-		tsk->maj_flt++;
-		break;
-	case VM_FAULT_SIGBUS:
-		goto do_sigbus;
-	default:
-		goto out_of_memory;
+	fault = handle_mm_fault(mm, vma, address, write);
+	if (unlikely(fault & VM_FAULT_ERROR)) {
+		if (fault & VM_FAULT_OOM)
+			goto out_of_memory;
+		else if (fault & VM_FAULT_SIGBUS)
+			goto do_sigbus;
+		BUG();
 	}
-
+	if (fault & VM_FAULT_MAJOR)
+		tsk->maj_flt++;
+	else
+		tsk->min_flt++;
 	up_read(&mm->mmap_sem);
 	return;
 
@@ -495,7 +491,8 @@ bad_area_nosemaphore:
 		    (address >> 32))
 			return;
 
-		if (exception_trace && unhandled_signal(tsk, SIGSEGV)) {
+		if (show_unhandled_signals && unhandled_signal(tsk, SIGSEGV) &&
+		    printk_ratelimit()) {
 			printk(
 		       "%s%s[%d]: segfault at %016lx rip %016lx rsp %016lx error %lx\n",
 					tsk->pid > 1 ? KERN_INFO : KERN_EMERG,
@@ -569,7 +566,7 @@ out_of_memory:
 	}
 	printk("VM: killing process %s\n", tsk->comm);
 	if (error_code & 4)
-		do_exit(SIGKILL);
+		do_group_exit(SIGKILL);
 	goto no_context;
 
 do_sigbus: