x86/mm: Clean up the printk()s in show_fault_oops()

- Remove 'nx_warning' and 'smep_warning', which are just pointless obfuscation.
- Also convert to pr_crit().

Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20180627090715.28076-1-dvyukov@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index ee85766e632935c5bd9882793fce8053cc1701e8..2aafa6ab6103d150ad26e097221a972f5d16363f 100644 (file)
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -641,11 +641,6 @@ static int is_f00f_bug(struct pt_regs *regs, unsigned long address)
        return 0;
 }
 
-static const char nx_warning[] = KERN_CRIT
-"kernel tried to execute NX-protected page - exploit attempt? (uid: %d)\n";
-static const char smep_warning[] = KERN_CRIT
-"unable to execute userspace code (SMEP?) (uid: %d)\n";
-
 static void
 show_fault_oops(struct pt_regs *regs, unsigned long error_code,
                unsigned long address)
@@ -664,11 +659,13 @@ show_fault_oops(struct pt_regs *regs, unsigned long error_code,
                pte = lookup_address_in_pgd(pgd, address, &level);
 
                if (pte && pte_present(*pte) && !pte_exec(*pte))
-                       printk(nx_warning, from_kuid(&init_user_ns, current_uid()));
+                       pr_crit("kernel tried to execute NX-protected page - exploit attempt? (uid: %d)\n",
+                               from_kuid(&init_user_ns, current_uid()));
                if (pte && pte_present(*pte) && pte_exec(*pte) &&
                                (pgd_flags(*pgd) & _PAGE_USER) &&
                                (__read_cr4() & X86_CR4_SMEP))
-                       printk(smep_warning, from_kuid(&init_user_ns, current_uid()));
+                       pr_crit("unable to execute userspace code (SMEP?) (uid: %d)\n",
+                               from_kuid(&init_user_ns, current_uid()));
        }
 
        pr_alert("BUG: unable to handle kernel %s at %px\n",