From 48dd73c55d45d60037ea8d73eab60f2033d90721 Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Tue, 31 May 2016 14:49:02 +0100 Subject: [PATCH] arm64: mm: dump: log span level The page table dump code logs spans of entries at the same level (pgd/pud/pmd/pte) which have the same attributes. While we log the (decoded) attributes, we don't log the level, which leaves the output ambiguous and/or confusing in some cases. For example: 0xffff800800000000-0xffff800980000000 6G RW NX SHD AF BLK UXN MEM/NORMAL If using 4K pages, this may describe a span of 6 1G block entries at the PGD/PUD level, or 3072 2M block entries at the PMD level. This patch adds the page table level to each output line, removing this ambiguity. For the example above, this will produce: 0xffffffc800000000-0xffffffc980000000 6G PUD RW NX SHD AF BLK UXN MEM/NORMAL When 3 level tables are in use, and we use the asm-generic/nopud.h definitions, the dump code treats each entry in the PGD as a 1 element table at the PUD level, and logs spans as being PUDs, which can be confusing. To counteract this, the "PUD" mnemonic is replaced with "PGD" when CONFIG_PGTABLE_LEVELS <= 3. Likewise for "PMD" when CONFIG_PGTABLE_LEVELS <= 2. Signed-off-by: Mark Rutland Cc: Catalin Marinas Cc: Huang Shijie Cc: Laura Abbott Cc: Steve Capper Cc: Will Deacon Signed-off-by: Will Deacon --- arch/arm64/mm/dump.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/arch/arm64/mm/dump.c b/arch/arm64/mm/dump.c index 8404190fe2bd..ccfde237d6e6 100644 --- a/arch/arm64/mm/dump.c +++ b/arch/arm64/mm/dump.c @@ -150,6 +150,7 @@ static const struct prot_bits pte_bits[] = { struct pg_level { const struct prot_bits *bits; + const char *name; size_t num; u64 mask; }; @@ -157,15 +158,19 @@ struct pg_level { static struct pg_level pg_level[] = { { }, { /* pgd */ + .name = "PGD", .bits = pte_bits, .num = ARRAY_SIZE(pte_bits), }, { /* pud */ + .name = (CONFIG_PGTABLE_LEVELS > 3) ? "PUD" : "PGD", .bits = pte_bits, .num = ARRAY_SIZE(pte_bits), }, { /* pmd */ + .name = (CONFIG_PGTABLE_LEVELS > 2) ? "PMD" : "PGD", .bits = pte_bits, .num = ARRAY_SIZE(pte_bits), }, { /* pte */ + .name = "PTE", .bits = pte_bits, .num = ARRAY_SIZE(pte_bits), }, @@ -214,7 +219,8 @@ static void note_page(struct pg_state *st, unsigned long addr, unsigned level, delta >>= 10; unit++; } - seq_printf(st->seq, "%9lu%c", delta, *unit); + 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);