powerpc/mm/ptdump: Wrap seq_printf() to handle NULL pointers

Lovingly borrowed from the arch/arm64 ptdump code.

This doesn't seem to be an issue in practice, but is necessary for my
upcoming commit.

Signed-off-by: Russell Currey <ruscur@russell.cc>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This commit is contained in:
Russell Currey 2019-05-02 17:39:46 +10:00 committed by Michael Ellerman
parent c9e0fc33b8
commit 5f18cbdbdd

View File

@ -108,6 +108,18 @@ static 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_putc(m, c) \
({ \
if (m) \
seq_putc(m, c); \
})
static void dump_flag_info(struct pg_state *st, const struct flag_info
*flag, u64 pte, int num)
{
@ -125,19 +137,19 @@ static void dump_flag_info(struct pg_state *st, const struct flag_info
val = pte & flag->val;
if (flag->shift)
val = val >> flag->shift;
seq_printf(st->seq, " %s:%llx", flag->set, val);
pt_dump_seq_printf(st->seq, " %s:%llx", flag->set, val);
} else {
if ((pte & flag->mask) == flag->val)
s = flag->set;
else
s = flag->clear;
if (s)
seq_printf(st->seq, " %s", s);
pt_dump_seq_printf(st->seq, " %s", s);
}
st->current_flags &= ~flag->mask;
}
if (st->current_flags != 0)
seq_printf(st->seq, " unknown flags:%llx", st->current_flags);
pt_dump_seq_printf(st->seq, " unknown flags:%llx", st->current_flags);
}
static void dump_addr(struct pg_state *st, unsigned long addr)
@ -152,12 +164,12 @@ static void dump_addr(struct pg_state *st, unsigned long addr)
#define REG "0x%08lx"
#endif
seq_printf(st->seq, REG "-" REG " ", st->start_address, addr - 1);
pt_dump_seq_printf(st->seq, REG "-" REG " ", st->start_address, addr - 1);
if (st->start_pa == st->last_pa && st->start_address + PAGE_SIZE != addr) {
seq_printf(st->seq, "[" REG "]", st->start_pa);
pt_dump_seq_printf(st->seq, "[" REG "]", st->start_pa);
delta = PAGE_SIZE >> 10;
} else {
seq_printf(st->seq, " " REG " ", st->start_pa);
pt_dump_seq_printf(st->seq, " " REG " ", st->start_pa);
delta = (addr - st->start_address) >> 10;
}
/* Work out what appropriate unit to use */
@ -165,7 +177,7 @@ static void dump_addr(struct pg_state *st, unsigned long addr)
delta >>= 10;
unit++;
}
seq_printf(st->seq, "%9lu%c", delta, *unit);
pt_dump_seq_printf(st->seq, "%9lu%c", delta, *unit);
}
@ -182,7 +194,7 @@ static void note_page(struct pg_state *st, unsigned long addr,
st->start_address = addr;
st->start_pa = pa;
st->last_pa = pa;
seq_printf(st->seq, "---[ %s ]---\n", st->marker->name);
pt_dump_seq_printf(st->seq, "---[ %s ]---\n", st->marker->name);
/*
* Dump the section of virtual memory when:
* - the PTE flags from one entry to the next differs.
@ -206,7 +218,7 @@ static void note_page(struct pg_state *st, unsigned long addr,
st->current_flags,
pg_level[st->level].num);
seq_putc(st->seq, '\n');
pt_dump_seq_putc(st->seq, '\n');
}
/*
@ -215,7 +227,7 @@ static void note_page(struct pg_state *st, unsigned long addr,
*/
while (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;
st->start_pa = pa;