diff options
| author | Simon Horman <horms@kernel.org> | 2025-04-25 16:50:47 +0100 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2025-04-29 11:50:38 -0700 |
| commit | e7e5ae71831c44d58627a991e603845a2fed2cab (patch) | |
| tree | 00279f5f846dbe2fd6b8318b332d914673e1c2d8 | |
| parent | d4cb1ecc22908ef46f2885ee2978a4f22e90f365 (diff) | |
net: dlink: Correct endianness handling of led_mode
As it's name suggests, parse_eeprom() parses EEPROM data.
This is done by reading data, 16 bits at a time as follows:
for (i = 0; i < 128; i++)
((__le16 *) sromdata)[i] = cpu_to_le16(read_eeprom(np, i));
sromdata is at the same memory location as psrom.
And the type of psrom is a pointer to struct t_SROM.
As can be seen in the loop above, data is stored in sromdata, and thus psrom,
as 16-bit little-endian values.
However, the integer fields of t_SROM are host byte order integers.
And in the case of led_mode this leads to a little endian value
being incorrectly treated as host byte order.
Looking at rio_set_led_mode, this does appear to be a bug as that code
masks led_mode with 0x1, 0x2 and 0x8. Logic that would be effected by a
reversed byte order.
This problem would only manifest on big endian hosts.
Found by inspection while investigating a sparse warning
regarding the crc field of t_SROM.
I believe that warning is a false positive. And although I plan
to send a follow-up to use little-endian types for other the integer
fields of PSROM_t I do not believe that will involve any bug fixes.
Compile tested only.
Fixes: c3f45d322cbd ("dl2k: Add support for IP1000A-based cards")
Signed-off-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250425-dlink-led-mode-v1-1-6bae3c36e736@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | drivers/net/ethernet/dlink/dl2k.c | 2 | ||||
| -rw-r--r-- | drivers/net/ethernet/dlink/dl2k.h | 2 |
2 files changed, 2 insertions, 2 deletions
diff --git a/drivers/net/ethernet/dlink/dl2k.c b/drivers/net/ethernet/dlink/dl2k.c index d88fbecdab4b..232e839a9d07 100644 --- a/drivers/net/ethernet/dlink/dl2k.c +++ b/drivers/net/ethernet/dlink/dl2k.c @@ -352,7 +352,7 @@ parse_eeprom (struct net_device *dev) eth_hw_addr_set(dev, psrom->mac_addr); if (np->chip_id == CHIP_IP1000A) { - np->led_mode = psrom->led_mode; + np->led_mode = le16_to_cpu(psrom->led_mode); return 0; } diff --git a/drivers/net/ethernet/dlink/dl2k.h b/drivers/net/ethernet/dlink/dl2k.h index 195dc6cfd895..0e33e2eaae96 100644 --- a/drivers/net/ethernet/dlink/dl2k.h +++ b/drivers/net/ethernet/dlink/dl2k.h @@ -335,7 +335,7 @@ typedef struct t_SROM { u16 sub_system_id; /* 0x06 */ u16 pci_base_1; /* 0x08 (IP1000A only) */ u16 pci_base_2; /* 0x0a (IP1000A only) */ - u16 led_mode; /* 0x0c (IP1000A only) */ + __le16 led_mode; /* 0x0c (IP1000A only) */ u16 reserved1[9]; /* 0x0e-0x1f */ u8 mac_addr[6]; /* 0x20-0x25 */ u8 reserved2[10]; /* 0x26-0x2f */ |