4.14-stable review patch. If anyone has any objections, please let me know.
------------------
From: Thomas Gleixner tglx@linutronix.de
commit c05344947b37f7cda726e802457370bc6eac4d26 upstream.
The check for a present page in printk_prot():
if (!pgprot_val(prot)) { /* Not present */
is bogus. If a PTE is set to PAGE_NONE then the pgprot_val is not zero and the entry is decoded in bogus ways, e.g. as RX GLB. That is confusing when analyzing mapping correctness. Check for the present bit to make an informed decision.
Signed-off-by: Thomas Gleixner tglx@linutronix.de Cc: Andy Lutomirski luto@kernel.org Cc: Borislav Petkov bp@alien8.de Cc: Dave Hansen dave.hansen@linux.intel.com Cc: H. Peter Anvin hpa@zytor.com Cc: Josh Poimboeuf jpoimboe@redhat.com Cc: Juergen Gross jgross@suse.com Cc: Linus Torvalds torvalds@linux-foundation.org Cc: Peter Zijlstra peterz@infradead.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar mingo@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/x86/mm/dump_pagetables.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/arch/x86/mm/dump_pagetables.c +++ b/arch/x86/mm/dump_pagetables.c @@ -140,7 +140,7 @@ static void printk_prot(struct seq_file static const char * const level_name[] = { "cr3", "pgd", "p4d", "pud", "pmd", "pte" };
- if (!pgprot_val(prot)) { + if (!(pr & _PAGE_PRESENT)) { /* Not present */ pt_dump_cont_printf(m, dmsg, " "); } else {