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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
This commit is contained in:
Linus Torvalds 2008-10-16 15:08:45 -07:00
parent 70a3075d40 f61f1b5717
commit 0999d978dc
2 changed files with 23 additions and 29 deletions
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45
arch/x86/mm/fault.c
View File

@ -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 @@ 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
@ -874,12 +864,11 @@ out_of_memory:
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);

7
include/asm-x86/pgtable.h
View File

@ -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