sh: Prevent fixed slot PMB remapping from clobbering boot entries.

The PMB initialization code walks the entries and synchronizes the
software PMB state with the hardware mappings, preserving the slot index.
Unfortunately pmb_alloc() only tested the bit position in the entry map
and failed to set it, resulting in subsequent remaps being able to be
dynamically assigned a slot that trampled an existing boot mapping with
general badness ensuing.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

diff --git a/arch/sh/mm/pmb.c b/arch/sh/mm/pmb.c
index 3c9bf5b5c36fc1352ea4f5f625829fee44eec1a1..a06483076a41282e02c6cbf09ab97c0522986f8a 100644 (file)
--- a/arch/sh/mm/pmb.c
+++ b/arch/sh/mm/pmb.c
@@ -77,7 +77,7 @@ static struct pmb_entry *pmb_alloc(unsigned long vpn, unsigned long ppn,
                if (pos < 0)
                        return ERR_PTR(pos);
        } else {
-               if (test_bit(entry, &pmb_map))
+               if (test_and_set_bit(entry, &pmb_map))
                        return ERR_PTR(-ENOSPC);
                pos = entry;
        }