Messages in this thread | | | Date | Fri, 30 Sep 2016 01:36:28 +0100 | From | Mark Rutland <> | Subject | Re: [PATCH 2/3] arm64: dump: Make the page table dumping seq_file optional |
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On Thu, Sep 29, 2016 at 02:32:56PM -0700, Laura Abbott wrote: > The page table dumping code always assumes it will be dumping to a > seq_file to userspace. The dumping code is useful in other situations. > Let the seq_file be optional. > > Signed-off-by: Laura Abbott <labbott@redhat.com>
It might be worth elaborating on those other situations, e.g. that for those we'll have some additional logic that will only run in the absence of a seq_file.
The NOPing out of logic in the !seq_file case does feel a bit like spaghetti code, but it's not obvious to me that adding finer-grained callbacks is much better, and I guess we can reconsider that if and when we need to add more logic.
Regardless of the above:
Acked-by: Mark Rutland <mark.rutland@arm.com>
Thanks, Mark.
> --- > arch/arm64/mm/dump.c | 26 +++++++++++++++++++------- > 1 file changed, 19 insertions(+), 7 deletions(-) > > diff --git a/arch/arm64/mm/dump.c b/arch/arm64/mm/dump.c > index 29e0838..e318f3d 100644 > --- a/arch/arm64/mm/dump.c > +++ b/arch/arm64/mm/dump.c > @@ -50,6 +50,18 @@ static const struct addr_marker address_markers[] = { > { -1, NULL }, > }; > > +#define pt_dump_seq_printf(m, fmt, args...) \ > +({ \ > + if (m) \ > + seq_printf(m, fmt, ##args); \ > +}) > + > +#define pt_dump_seq_puts(m, fmt) \ > +({ \ > + if (m) \ > + seq_printf(m, fmt); \ > +}) > + > /* > * The page dumper groups page table entries of the same type into a single > * description. It uses pg_state to track the range information while > @@ -186,7 +198,7 @@ static void dump_prot(struct pg_state *st, const struct prot_bits *bits, > s = bits->clear; > > if (s) > - seq_printf(st->seq, " %s", s); > + pt_dump_seq_printf(st->seq, " %s", s); > } > } > > @@ -200,14 +212,14 @@ static void note_page(struct pg_state *st, unsigned long addr, unsigned level, > st->level = level; > st->current_prot = prot; > st->start_address = addr; > - seq_printf(st->seq, "---[ %s ]---\n", st->marker->name); > + pt_dump_seq_printf(st->seq, "---[ %s ]---\n", st->marker->name); > } else if (prot != st->current_prot || level != st->level || > addr >= st->marker[1].start_address) { > const char *unit = units; > unsigned long delta; > > if (st->current_prot) { > - 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; > @@ -215,17 +227,17 @@ static void note_page(struct pg_state *st, unsigned long addr, unsigned level, > delta >>= 10; > unit++; > } > - seq_printf(st->seq, "%9lu%c %s", delta, *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); > - seq_puts(st->seq, "\n"); > + pt_dump_seq_puts(st->seq, "\n"); > } > > if (addr >= st->marker[1].start_address) { > st->marker++; > - seq_printf(st->seq, "---[ %s ]---\n", st->marker->name); > + pt_dump_seq_printf(st->seq, "---[ %s ]---\n", st->marker->name); > } > > st->start_address = addr; > @@ -235,7 +247,7 @@ static void note_page(struct pg_state *st, unsigned long addr, unsigned level, > > if (addr >= st->marker[1].start_address) { > st->marker++; > - seq_printf(st->seq, "---[ %s ]---\n", st->marker->name); > + pt_dump_seq_printf(st->seq, "---[ %s ]---\n", st->marker->name); > } > > } > -- > 2.10.0 >
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