tg3_nvram_write_block_unbuffered() is reading data from nvram into
allocated buffer before overwriting a part of it with user-supplied
data. Then it feeds the entire page back to nvram. It should be
storing the words it had read as little-endian, not as host-endian.
Note that tg3_set_eeprom() does exactly that for padding the same
data to full words before it gets passed down to tg3_nvram_write_block()
and then to tg3_nvram_write_block_unbuffered().
Moreover, when we get to sending the entire thing back to nvram, we
go through it word-by-word, doing essentially
writel(swab32(le32_to_cpu(word)), ...)
so if we want them to reach the card in host-independent endianness,
we'd better really have all that buffer filled with fixed-endian.
For user-supplied part we obviously do have that (it's an array of
octets memcpy'd in), ditto for padding of user-supplied part to word
boundaries (taken care of in tg3_set_eeprom()). The rest of the
buffer gets filled by tg3_nvram_write_block_unbuffered() and it would
damn better be consistent with that (and with tg3_get_eeprom(), while
we are at it - there we also convert the words read from nvram to
little-endian before returning the buffer to user).
The bug should get triggered on big-endian boxen when set_eeprom is done
for less than entire page. Then the words that should've been unaffected
at all will actually get byteswapped in place in nvram.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
Al Viro
286e310f94