arm64: dump: Make the page table dumping seq_file optional

The page table dumping code always assumes it will be dumping to a
seq_file to userspace. Future code will be taking advantage of
the page table dumping code but will not need the seq_file. Make
the seq_file optional for these cases.

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Laura Abbott <labbott@redhat.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

diff --git a/arch/arm64/mm/dump.c b/arch/arm64/mm/dump.c
index f0f0be74d8e7bda2eda8d6dcb9d7031bc489e9d8..bb366490c5f70a53884714229f659b6df2e46bd5 100644 (file)
--- 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);
        }
 
 }