arm64: mm: display non-present entries in ptdump

Previously the /sys/kernel/debug/kernel_page_tables file would only show
lines for entries present in the page tables.  However it is useful to
also show non-present entries as this makes the size and level of the
holes more visible.  This aligns the behaviour with x86 which also shows
holes.

Link: http://lkml.kernel.org/r/20191218162402.45610-23-steven.price@arm.comSigned-off-by: Steven Price <steven.price@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Hogan <jhogan@kernel.org>
Cc: James Morse <james.morse@arm.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: "Liang, Kan" <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will@kernel.org>
Cc: Zong Li <zong.li@sifive.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/arm64/mm/dump.c

@@ -270,6 +270,8 @@ static void note_page(struct ptdump_state *pt_st, unsigned long addr, int level,
 		if (st->current_prot) {
 			note_prot_uxn(st, addr);
 			note_prot_wx(st, addr);
+		}
+
 		pt_dump_seq_printf(st->seq, "0x%016lx-0x%016lx   ",
 				   st->start_address, addr);
 
@@ -280,11 +282,10 @@ static void note_page(struct ptdump_state *pt_st, unsigned long addr, int level,
 		}
 		pt_dump_seq_printf(st->seq, "%9lu%c %s", delta, *unit,
 				   pg_level[st->level].name);
-			if (pg_level[st->level].bits)
+		if (st->current_prot && pg_level[st->level].bits)
 			dump_prot(st, pg_level[st->level].bits,
 				  pg_level[st->level].num);
 		pt_dump_seq_puts(st->seq, "\n");
-		}
 
 		if (addr >= st->marker[1].start_address) {
 			st->marker++;