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Commit d79d0d8a authored by Dmitry Vyukov's avatar Dmitry Vyukov Committed by Ingo Molnar
Browse files

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: default avatarJoe Perches <joe@perches.com>
Signed-off-by: default avatarDmitry 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: default avatarIngo Molnar <mingo@kernel.org>
parent b8c1e429

arch/x86/mm/fault.c

+4 −7
Original line number Diff line number Diff line
@@ -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",