diff options
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/mm/fault.c | 30 |
1 files changed, 21 insertions, 9 deletions
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 3c9aed03d18e..b5ec1ca2f4a0 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -631,6 +631,24 @@ pgtable_bad(struct pt_regs *regs, unsigned long error_code, oops_end(flags, regs, sig); } +static void set_signal_archinfo(unsigned long address, + unsigned long error_code) +{ + struct task_struct *tsk = current; + + /* + * To avoid leaking information about the kernel page + * table layout, pretend that user-mode accesses to + * kernel addresses are always protection faults. + */ + if (address >= TASK_SIZE_MAX) + error_code |= X86_PF_PROT; + + tsk->thread.trap_nr = X86_TRAP_PF; + tsk->thread.error_code = error_code | X86_PF_USER; + tsk->thread.cr2 = address; +} + static noinline void no_context(struct pt_regs *regs, unsigned long error_code, unsigned long address, int signal, int si_code) @@ -656,9 +674,7 @@ no_context(struct pt_regs *regs, unsigned long error_code, * faulting through the emulate_vsyscall() logic. */ if (current->thread.sig_on_uaccess_err && signal) { - tsk->thread.trap_nr = X86_TRAP_PF; - tsk->thread.error_code = error_code | X86_PF_USER; - tsk->thread.cr2 = address; + set_signal_archinfo(address, error_code); /* XXX: hwpoison faults will set the wrong code. */ force_sig_fault(signal, si_code, (void __user *)address, @@ -821,9 +837,7 @@ __bad_area_nosemaphore(struct pt_regs *regs, unsigned long error_code, if (likely(show_unhandled_signals)) show_signal_msg(regs, error_code, address, tsk); - tsk->thread.cr2 = address; - tsk->thread.error_code = error_code; - tsk->thread.trap_nr = X86_TRAP_PF; + set_signal_archinfo(address, error_code); if (si_code == SEGV_PKUERR) force_sig_pkuerr((void __user *)address, pkey); @@ -937,9 +951,7 @@ do_sigbus(struct pt_regs *regs, unsigned long error_code, unsigned long address, if (is_prefetch(regs, error_code, address)) return; - tsk->thread.cr2 = address; - tsk->thread.error_code = error_code; - tsk->thread.trap_nr = X86_TRAP_PF; + set_signal_archinfo(address, error_code); #ifdef CONFIG_MEMORY_FAILURE if (fault & (VM_FAULT_HWPOISON|VM_FAULT_HWPOISON_LARGE)) { |