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authorGrant Grundler <grundler@parisc-linux.org>2008-03-23 23:23:10 -0600
committerJeff Garzik <jeff@garzik.org>2008-03-28 21:52:14 -0400
commit209261c019f56d77f6a0cc38048e9a6f25867589 (patch)
tree36824a55e62c33e4ae4c24ce824d2948a83924de
parent3480c63bdf008e9289aab94418f43b9592978fff (diff)
[netdrvr] tulip_read_eeprom fixes for BUG 4420
If "location" is > "addr_len" bits, the high bits of location would interfere with the READ_CMD sent to the eeprom controller. A patch was submitted to bug: http://bugzilla.kernel.org/show_bug.cgi?id=4420 which simply truncated the "location", read whatever was in "location modulo addr_len", and returned that value. That avoids confusing the eeprom but seems like the wrong solution to me. Correct would be to not read beyond "1 << addr_len" address of the eeprom. I am submitting two changes to implement this: 1) tulip_read_eeprom will return zero (since we can't return -EINVAL) if this is attempted (defensive programming). 2) In tulip_core.c, fix the tulip_read_eeprom caller so they don't iterate past addr_len bits and make sure the entire tp->eeprom[] array is cleared. I konw we don't strictly need both. I would prefer both in the tree since it documents the issue and provides a second "defense" from the bug from creeping back in. Signed-off-by: Grant Grundler <grundler@parisc-linux.org> Signed-off-by: Jeff Garzik <jeff@garzik.org>
-rw-r--r--drivers/net/tulip/eeprom.c6
-rw-r--r--drivers/net/tulip/tulip_core.c7
2 files changed, 12 insertions, 1 deletions
diff --git a/drivers/net/tulip/eeprom.c b/drivers/net/tulip/eeprom.c
index 206918bad53..da2206f6021 100644
--- a/drivers/net/tulip/eeprom.c
+++ b/drivers/net/tulip/eeprom.c
@@ -343,6 +343,12 @@ int __devinit tulip_read_eeprom(struct net_device *dev, int location, int addr_l
void __iomem *ee_addr = tp->base_addr + CSR9;
int read_cmd = location | (EE_READ_CMD << addr_len);
+ /* If location is past the end of what we can address, don't
+ * read some other location (ie truncate). Just return zero.
+ */
+ if (location > (1 << addr_len) - 1)
+ return 0;
+
iowrite32(EE_ENB & ~EE_CS, ee_addr);
iowrite32(EE_ENB, ee_addr);
diff --git a/drivers/net/tulip/tulip_core.c b/drivers/net/tulip/tulip_core.c
index ed600bf56e7..82f404b76d8 100644
--- a/drivers/net/tulip/tulip_core.c
+++ b/drivers/net/tulip/tulip_core.c
@@ -1437,6 +1437,7 @@ static int __devinit tulip_init_one (struct pci_dev *pdev,
EEPROM.
*/
ee_data = tp->eeprom;
+ memset(ee_data, 0, sizeof(tp->eeprom));
sum = 0;
if (chip_idx == LC82C168) {
for (i = 0; i < 3; i++) {
@@ -1458,8 +1459,12 @@ static int __devinit tulip_init_one (struct pci_dev *pdev,
/* A serial EEPROM interface, we read now and sort it out later. */
int sa_offset = 0;
int ee_addr_size = tulip_read_eeprom(dev, 0xff, 8) & 0x40000 ? 8 : 6;
+ int ee_max_addr = ((1 << ee_addr_size) - 1) * sizeof(u16);
- for (i = 0; i < sizeof(tp->eeprom); i+=2) {
+ if (ee_max_addr > sizeof(tp->eeprom))
+ ee_max_addr = sizeof(tp->eeprom);
+
+ for (i = 0; i < ee_max_addr ; i += sizeof(u16)) {
u16 data = tulip_read_eeprom(dev, i/2, ee_addr_size);
ee_data[i] = data & 0xff;
ee_data[i + 1] = data >> 8;