linux-kernel - [PATCH v16 24/25] arm64: mm: Display non-present entries in ptdump

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Message-Id: <20191206135316.47703-25-steven.price@arm.com>
Date:   Fri,  6 Dec 2019 13:53:15 +0000
From:   Steven Price <steven.price@....com>
To:     Andrew Morton <akpm@...ux-foundation.org>, linux-mm@...ck.org
Cc:     Steven Price <steven.price@....com>,
        Andy Lutomirski <luto@...nel.org>,
        Ard Biesheuvel <ard.biesheuvel@...aro.org>,
        Arnd Bergmann <arnd@...db.de>, Borislav Petkov <bp@...en8.de>,
        Catalin Marinas <catalin.marinas@....com>,
        Dave Hansen <dave.hansen@...ux.intel.com>,
        Ingo Molnar <mingo@...hat.com>,
        James Morse <james.morse@....com>,
        Jérôme Glisse <jglisse@...hat.com>,
        Peter Zijlstra <peterz@...radead.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        Will Deacon <will@...nel.org>, x86@...nel.org,
        "H. Peter Anvin" <hpa@...or.com>,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
        Mark Rutland <Mark.Rutland@....com>,
        "Liang, Kan" <kan.liang@...ux.intel.com>
Subject: [PATCH v16 24/25] 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.

Acked-by: Catalin Marinas <catalin.marinas@....com>
Signed-off-by: Steven Price <steven.price@....com>
---
 arch/arm64/mm/dump.c | 25 +++++++++++++------------
 1 file changed, 13 insertions(+), 12 deletions(-)

diff --git a/arch/arm64/mm/dump.c b/arch/arm64/mm/dump.c
index 9d9b740a86d2..3203dd8e6d0a 100644
--- a/arch/arm64/mm/dump.c
+++ b/arch/arm64/mm/dump.c
@@ -269,21 +269,22 @@ 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   ",
+		}
+
+		pt_dump_seq_printf(st->seq, "0x%016lx-0x%016lx   ",
 				   st->start_address, addr);
 
-			delta = (addr - st->start_address) >> 10;
-			while (!(delta & 1023) && unit[1]) {
-				delta >>= 10;
-				unit++;
-			}
-			pt_dump_seq_printf(st->seq, "%9lu%c %s", delta, *unit,
-				   pg_level[st->level].name);
-			if (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");
+		delta = (addr - st->start_address) >> 10;
+		while (!(delta & 1023) && unit[1]) {
+			delta >>= 10;
+			unit++;
 		}
+		pt_dump_seq_printf(st->seq, "%9lu%c %s", delta, *unit,
+				   pg_level[st->level].name);
+		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++;
-- 
2.20.1