[PATCH v2 11/14] x86/fault: Rename no_context() to kernelmode_fixup_or_oops()

[Andy Lutomirski]

The name no_context() has never been very clear.  It's only called for
faults from kernel mode, so rename it and change the no-longer-useful
user_mode(regs) check to a WARN_ON_ONCE.

Cc: Dave Hansen <dave.han...@linux.intel.com>
Cc: Peter Zijlstra <pet...@infradead.org>
Signed-off-by: Andy Lutomirski <l...@kernel.org>
---
 arch/x86/mm/fault.c | 28 ++++++++++------------------
 1 file changed, 10 insertions(+), 18 deletions(-)

diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index f735639455a5..9fb636b2a3da 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -729,17 +729,10 @@ page_fault_oops(struct pt_regs *regs, unsigned long 
error_code,
 }
 
 static noinline void
-no_context(struct pt_regs *regs, unsigned long error_code,
-          unsigned long address, int signal, int si_code)
+kernelmode_fixup_or_oops(struct pt_regs *regs, unsigned long error_code,
+                        unsigned long address, int signal, int si_code)
 {
-       if (user_mode(regs)) {
-               /*
-                * This is an implicit supervisor-mode access from user
-                * mode.  Bypass all the kernel-mode recovery code and just
-                * OOPS.
-                */
-               goto oops;
-       }
+       WARN_ON_ONCE(user_mode(regs));
 
        /* Are we prepared to handle this kernel fault? */
        if (fixup_exception(regs, X86_TRAP_PF, error_code, address)) {
@@ -779,7 +772,6 @@ no_context(struct pt_regs *regs, unsigned long error_code,
        if (is_prefetch(regs, error_code, address))
                return;
 
-oops:
        page_fault_oops(regs, error_code, address);
 }
 
@@ -826,7 +818,7 @@ __bad_area_nosemaphore(struct pt_regs *regs, unsigned long 
error_code,
        struct task_struct *tsk = current;
 
        if (!user_mode(regs)) {
-               no_context(regs, error_code, address, pkey, si_code);
+               kernelmode_fixup_or_oops(regs, error_code, address, pkey, 
si_code);
                return;
        }
 
@@ -958,7 +950,7 @@ do_sigbus(struct pt_regs *regs, unsigned long error_code, 
unsigned long address,
 {
        /* Kernel mode? Handle exceptions or die: */
        if (!user_mode(regs)) {
-               no_context(regs, error_code, address, SIGBUS, BUS_ADRERR);
+               kernelmode_fixup_or_oops(regs, error_code, address, SIGBUS, 
BUS_ADRERR);
                return;
        }
 
@@ -1420,8 +1412,8 @@ void do_user_addr_fault(struct pt_regs *regs,
                 * has unlocked the mm for us if we get here.
                 */
                if (!user_mode(regs))
-                       no_context(regs, error_code, address, SIGBUS,
-                                  BUS_ADRERR);
+                       kernelmode_fixup_or_oops(regs, error_code, address,
+                                                SIGBUS, BUS_ADRERR);
                return;
        }
 
@@ -1441,15 +1433,15 @@ void do_user_addr_fault(struct pt_regs *regs,
                return;
 
        if (fatal_signal_pending(current) && !user_mode(regs)) {
-               no_context(regs, error_code, address, 0, 0);
+               kernelmode_fixup_or_oops(regs, error_code, address, 0, 0);
                return;
        }
 
        if (fault & VM_FAULT_OOM) {
                /* Kernel mode? Handle exceptions or die: */
                if (!user_mode(regs)) {
-                       no_context(regs, error_code, address,
-                                  SIGSEGV, SEGV_MAPERR);
+                       kernelmode_fixup_or_oops(regs, error_code, address,
+                                                SIGSEGV, SEGV_MAPERR);
                        return;
                }
 
-- 
2.29.2