| Message ID | 1464702542-24394-3-git-send-email-mark.rutland@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, May 31, 2016 at 02:49:02PM +0100, Mark Rutland wrote: > 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 <mark.rutland@arm.com> > Cc: Catalin Marinas <catalin.marinas@arm.com> > Cc: Huang Shijie <shijie.huang@arm.com> Tested-by: Huang Shijie <shijie.huang@arm.com> thanks Huang Shijie IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
diff --git a/arch/arm64/mm/dump.c b/arch/arm64/mm/dump.c index a56a7ad..f94b80e 100644 --- a/arch/arm64/mm/dump.c +++ b/arch/arm64/mm/dump.c @@ -146,6 +146,7 @@ static const struct prot_bits pte_bits[] = { struct pg_level { const struct prot_bits *bits; + const char *name; size_t num; u64 mask; }; @@ -153,15 +154,19 @@ 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), }, @@ -210,7 +215,8 @@ 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);
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 <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Huang Shijie <shijie.huang@arm.com> Cc: Laura Abbott <labbott@fedoraproject.org> Cc: Steve Capper <steve.capper@arm.com> Cc: Will Deacon <will.deacon@arm.com> --- arch/arm64/mm/dump.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)