diff options
| -rw-r--r-- | arch/x86/mm/fault.c | 45 | ||||
| -rw-r--r-- | include/asm-x86/pgtable.h | 7 |
2 files changed, 23 insertions, 29 deletions
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 3f2b896..31e8730 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -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); diff --git a/include/asm-x86/pgtable.h b/include/asm-x86/pgtable.h index 182f9d4..88a53b1 100644 --- a/include/asm-x86/pgtable.h +++ b/include/asm-x86/pgtable.h @@ -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 |
