@@ -719,18 +719,22 @@ 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)
+static void sanitize_error_code(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;
+ *error_code |= X86_PF_PROT;
+}
+
+static void set_signal_archinfo(unsigned long address,
+ unsigned long error_code)
+{
+ struct task_struct *tsk = current;
tsk->thread.trap_nr = X86_TRAP_PF;
tsk->thread.error_code = error_code | X86_PF_USER;
@@ -771,6 +775,8 @@ no_context(struct pt_regs *regs, unsigned long error_code,
* faulting through the emulate_vsyscall() logic.
*/
if (current->thread.sig_on_uaccess_err && signal) {
+ sanitize_error_code(address, &error_code);
+
set_signal_archinfo(address, error_code);
/* XXX: hwpoison faults will set the wrong code. */
@@ -920,13 +926,7 @@ __bad_area_nosemaphore(struct pt_regs *regs, unsigned long error_code,
if (is_errata100(regs, address))
return;
- /*
- * 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;
+ sanitize_error_code(address, &error_code);
if (likely(show_unhandled_signals))
show_signal_msg(regs, error_code, address, tsk);
@@ -1045,6 +1045,8 @@ do_sigbus(struct pt_regs *regs, unsigned long error_code, unsigned long address,
if (is_prefetch(regs, error_code, address))
return;
+ sanitize_error_code(address, &error_code);
+
set_signal_archinfo(address, error_code);
#ifdef CONFIG_MEMORY_FAILURE
...to prepare for vDSO exception fixup, which will expose the error code to userspace and runs before set_signal_archinfo(), i.e. squashes the signal when fixup is successful. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> --- arch/x86/mm/fault.c | 26 ++++++++++++++------------ 1 file changed, 14 insertions(+), 12 deletions(-)