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Commit 0999d978 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'x86-fixes-for-linus' of... 

Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86: fix compat-vdso
  x86/mm: unify init task OOM handling
  x86/mm: do not trigger a kernel warning if user-space disables interrupts and generates a page fault
parents 70a3075d f61f1b57

arch/x86/mm/fault.c

+17 −28
Original line number Diff line number Diff line
@@ -640,24 +640,23 @@ void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code) 
	}





#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 | X86_VM_MASK))

		local_irq_enable();



	/*

	 * 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
@@ -666,15 +665,9 @@ void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code) 
	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:

#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
@@ -737,9 +730,6 @@ void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code) 
			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
@@ -874,12 +864,11 @@ void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code) 
	up_read(&mm->mmap_sem);

	if (is_global_init(tsk)) {

		yield();

#ifdef CONFIG_X86_32

		down_read(&mm->mmap_sem);

		goto survive;

#else

		/*

		 * Re-lookup the vma - in theory the vma tree might

		 * have changed:

		 */

		goto again;

#endif

	}



	printk("VM: killing process %s\n", tsk->comm);

include/asm-x86/pgtable.h

+6 −1
Original line number Diff line number Diff line
@@ -148,8 +148,13 @@ 
#ifdef CONFIG_X86_64

#define __PAGE_KERNEL_IDENT_LARGE_EXEC	__PAGE_KERNEL_LARGE_EXEC

#else

/*

 * For PDE_IDENT_ATTR include USER bit. As the PDE and PTE protection

 * bits are combined, this will alow user to access the high address mapped

 * VDSO in the presence of CONFIG_COMPAT_VDSO

 */

#define PTE_IDENT_ATTR	 0x003		/* PRESENT+RW */

#define PDE_IDENT_ATTR	 0x063		/* PRESENT+RW+DIRTY+ACCESSED */

#define PDE_IDENT_ATTR	 0x067		/* PRESENT+RW+USER+DIRTY+ACCESSED */

#define PGD_IDENT_ATTR	 0x001		/* PRESENT (no other attributes) */

#endif