[PATCH] char/moxa.c: fix endianess and multiple-card issues

While testing Moxa C218T/PCI on PowerPC 405EP I found that loading firmware
using the linux kernel driver fails because calculation of the checksum is
not endianess independent in the original code.

After I fixed this I found that uploading firmware in a system with
multiple cards causes a kernel oops.  I had a look in the recent moxa
sources and found that they do some kind of locking there.  Applying this
lock fixed the problem.

Alan sayeth:

  Checksum changes are clearly correct.  Other changes is an improvement but
  not I think enough to handle malicious firmware attacks.  That said such an
  attacker has CAP_SYS_RAWIO anyway so that part is irrelevant except for
  neatness.

[akpm@osdl.org: cleanups]
Signed-off-by: Dirk Eibach <eibach@gdsys.de>
Acked-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 6 insertions, 2 deletions

diff --git a/drivers/char/moxa.c b/drivers/char/moxa.c
index 4ea7bd5f4f56..a369dd6877d8 100644
--- a/drivers/char/moxa.c
+++ b/drivers/char/moxa.c
@@ -142,6 +142,7 @@ typedef struct _moxa_board_conf {
 
 static moxa_board_conf moxa_boards[MAX_BOARDS];
 static void __iomem *moxaBaseAddr[MAX_BOARDS];
+static int loadstat[MAX_BOARDS];
 
 struct moxa_str {
         int type;
@@ -1688,6 +1689,8 @@ int MoxaDriverPoll(void)
         if (moxaCard == 0)
                 return (-1);
         for (card = 0; card < MAX_BOARDS; card++) {
+                if (loadstat[card] == 0)
+                        continue;
                 if ((ports = moxa_boards[card].numPorts) == 0)
                         continue;
                 if (readb(moxaIntPend[card]) == 0xff) {
@@ -2903,6 +2906,7 @@ static int moxaloadcode(int cardno, unsigned char __user *tmp, int len)
                 }
                 break;
         }
+        loadstat[cardno] = 1;
         return (0);
 }
 
@@ -2920,7 +2924,7 @@ static int moxaloadc218(int cardno, void __iomem *baseAddr, int len)
         len1 = len >> 1;
         ptr = (ushort *) moxaBuff;
         for (i = 0; i < len1; i++)
-                usum += *(ptr + i);
+                usum += le16_to_cpu(*(ptr + i));
         retry = 0;
         do {
                 len1 = len >> 1;
@@ -2992,7 +2996,7 @@ static int moxaloadc320(int cardno, void __iomem *baseAddr, int len, int *numPor
         wlen = len >> 1;
         uptr = (ushort *) moxaBuff;
         for (i = 0; i < wlen; i++)
-                usum += uptr[i];
+                usum += le16_to_cpu(uptr[i]);
         retry = 0;
         j = 0;
         do {