From 209261c019f56d77f6a0cc38048e9a6f25867589 Mon Sep 17 00:00:00 2001 From: Grant Grundler Date: Sun, 23 Mar 2008 23:23:10 -0600 Subject: [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 Signed-off-by: Jeff Garzik --- drivers/net/tulip/eeprom.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'drivers/net/tulip/eeprom.c') 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); -- cgit v1.2.3