diff options
| -rw-r--r-- | arch/x86/mm/fault.c | 21 |
1 files changed, 16 insertions, 5 deletions
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 2a9ea3aee49..94c4e726219 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -782,6 +782,15 @@ static inline int access_error(unsigned long error_code, int write, return 0; } +static int fault_in_kernel_space(unsigned long address) +{ +#ifdef CONFIG_X86_32 + return address >= TASK_SIZE; +#else /* !CONFIG_X86_32 */ + return address >= TASK_SIZE64; +#endif /* CONFIG_X86_32 */ +} + /* * This routine handles page faults. It determines the address, * and the problem, and then passes it off to one of the appropriate @@ -822,11 +831,7 @@ void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code) * (error_code & 4) == 0, and that the fault was not a * protection error (error_code & 9) == 0. */ -#ifdef CONFIG_X86_32 - if (unlikely(address >= TASK_SIZE)) { -#else - if (unlikely(address >= TASK_SIZE64)) { -#endif + if (unlikely(fault_in_kernel_space(address))) { if (!(error_code & (PF_RSVD|PF_USER|PF_PROT)) && vmalloc_fault(address) >= 0) return; @@ -898,6 +903,12 @@ void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code) return; } down_read(&mm->mmap_sem); + } else { + /* + * The above down_read_trylock() might have succeeded in which + * case we'll have missed the might_sleep() from down_read(). + */ + might_sleep(); } vma = find_vma(mm, address); |