pcmcia: add locking to set_mem_map()

Protect the pccard_operations callback "set_mem_map" by a new
mutex ops_mutex. This mutex also protects the following values
in struct pcmcia_socket:

        pccard_mem_map          win[]
        pccard_mem_map          cis_mem
        void __iomem            *cis_virt

Tested-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>

1 files changed, 8 insertions, 0 deletions

diff --git a/drivers/pcmcia/rsrc_nonstatic.c b/drivers/pcmcia/rsrc_nonstatic.c
index 91626c17f97b..1de46cf2772f 100644
--- a/drivers/pcmcia/rsrc_nonstatic.c
+++ b/drivers/pcmcia/rsrc_nonstatic.c
@@ -274,17 +274,21 @@ static int readable(struct pcmcia_socket *s, struct resource *res,
 {
         int ret = -EINVAL;
 
+        mutex_lock(&s->ops_mutex);
         s->cis_mem.res = res;
         s->cis_virt = ioremap(res->start, s->map_size);
         if (s->cis_virt) {
+                mutex_unlock(&s->ops_mutex);
                 /* as we're only called from pcmcia.c, we're safe */
                 if (s->callback->validate)
                         ret = s->callback->validate(s, count);
                 /* invalidate mapping */
+                mutex_lock(&s->ops_mutex);
                 iounmap(s->cis_virt);
                 s->cis_virt = NULL;
         }
         s->cis_mem.res = NULL;
+        mutex_unlock(&s->ops_mutex);
         if ((ret) || (*count == 0))
                 return -EINVAL;
         return 0;
@@ -300,6 +304,8 @@ static int checksum(struct pcmcia_socket *s, struct resource *res,
         int i, a = 0, b = -1, d;
         void __iomem *virt;
 
+        mutex_lock(&s->ops_mutex);
+
         virt = ioremap(res->start, s->map_size);
         if (virt) {
                 map.map = 0;
@@ -322,6 +328,8 @@ static int checksum(struct pcmcia_socket *s, struct resource *res,
                 iounmap(virt);
         }
 
+        mutex_unlock(&s->ops_mutex);
+
         if (b == -1)
                 return -EINVAL;