Re: [PATCH 1/2] staging: wilc1000: fix some endianness sparse warnings

From: Dan Carpenter
Date: Wed May 30 2018 - 07:18:09 EST


On Tue, May 29, 2018 at 09:11:43PM +0200, Thibaut Robert wrote:
> diff --git a/drivers/staging/wilc1000/wilc_wfi_cfgoperations.c b/drivers/staging/wilc1000/wilc_wfi_cfgoperations.c
> index e248702ee519..745bf5ca2622 100644
> --- a/drivers/staging/wilc1000/wilc_wfi_cfgoperations.c
> +++ b/drivers/staging/wilc1000/wilc_wfi_cfgoperations.c
> @@ -1431,7 +1431,7 @@ void wilc_wfi_p2p_rx(struct net_device *dev, u8 *buff, u32 size)
>
> freq = ieee80211_channel_to_frequency(curr_channel, NL80211_BAND_2GHZ);
>
> - if (!ieee80211_is_action(buff[FRAME_TYPE_ID])) {
> + if (!ieee80211_is_action(cpu_to_le16(buff[FRAME_TYPE_ID]))) {

"buff" comes from the network, it's going to be little endian, not cpu
endian. The rest of the function treats it as CPU endian but I'm pretty
sure it's wrong...

> cfg80211_rx_mgmt(priv->wdev, freq, 0, buff, size, 0);
> return;
> }


> diff --git a/drivers/staging/wilc1000/wilc_wlan.c b/drivers/staging/wilc1000/wilc_wlan.c
> index 28c93f3f846e..a5ac1d26590b 100644
> --- a/drivers/staging/wilc1000/wilc_wlan.c
> +++ b/drivers/staging/wilc1000/wilc_wlan.c
> @@ -560,7 +560,8 @@ int wilc_wlan_handle_txq(struct net_device *dev, u32 *txq_count)
> int ret = 0;
> int counter;
> int timeout;
> - u32 vmm_table[WILC_VMM_TBL_SIZE];
> + __le32 vmm_table[WILC_VMM_TBL_SIZE];
> + u32 table_entry;
> struct wilc_vif *vif;
> struct wilc *wilc;
> const struct wilc_hif_func *func;
> @@ -598,10 +599,10 @@ int wilc_wlan_handle_txq(struct net_device *dev, u32 *txq_count)
> if ((sum + vmm_sz) > LINUX_TX_SIZE)
> break;
>
> - vmm_table[i] = vmm_sz / 4;
> + table_entry = vmm_sz / 4;
> if (tqe->type == WILC_CFG_PKT)
> - vmm_table[i] |= BIT(10);
> - vmm_table[i] = cpu_to_le32(vmm_table[i]);
> + table_entry |= BIT(10);
> + vmm_table[i] = cpu_to_le32(table_entry);
>
> i++;
> sum += vmm_sz;
> @@ -704,8 +705,7 @@ int wilc_wlan_handle_txq(struct net_device *dev, u32 *txq_count)
> if (vmm_table[i] == 0)
> break;
>
> - vmm_table[i] = cpu_to_le32(vmm_table[i]);
> - vmm_sz = (vmm_table[i] & 0x3ff);
> + vmm_sz = (le32_to_cpu(vmm_table[i]) & 0x3ff);
> vmm_sz *= 4;
> header = (tqe->type << 31) |
> (tqe->buffer_size << 15) |
> @@ -715,8 +715,7 @@ int wilc_wlan_handle_txq(struct net_device *dev, u32 *txq_count)
> else
> header &= ~BIT(30);
>
> - header = cpu_to_le32(header);
> - memcpy(&txb[offset], &header, 4);
> + *((__le32 *)&txb[offset]) = cpu_to_le32(header);

I worry about alignment issues here. That might be the reason for the
memcpy(). (I'm reading as fast as I can and don't the code so I may
be wrong).

> if (tqe->type == WILC_CFG_PKT) {
> buffer_offset = ETH_CONFIG_PKT_HDR_OFFSET;
> } else if (tqe->type == WILC_NET_PKT) {
> @@ -770,8 +769,7 @@ static void wilc_wlan_handle_rx_buff(struct wilc *wilc, u8 *buffer, int size)
>
> do {
> buff_ptr = buffer + offset;
> - memcpy(&header, buff_ptr, 4);
> - header = cpu_to_le32(header);
> + header = le32_to_cpup((__le32 *)buff_ptr);

Maybe the same, whenever you see a memcpy().

>
> is_cfg_packet = (header >> 31) & 0x1;
> pkt_offset = (header >> 22) & 0x1ff;
> @@ -942,6 +940,7 @@ int wilc_wlan_firmware_download(struct wilc *wilc, const u8 *buffer,
> u32 offset;
> u32 addr, size, size2, blksz;
> u8 *dma_buffer;
> + const __le32 *header;
> int ret = 0;
>
> blksz = BIT(12);
> @@ -952,10 +951,9 @@ int wilc_wlan_firmware_download(struct wilc *wilc, const u8 *buffer,
>
> offset = 0;
> do {
> - memcpy(&addr, &buffer[offset], 4);
> - memcpy(&size, &buffer[offset + 4], 4);
> - addr = cpu_to_le32(addr);
> - size = cpu_to_le32(size);
> + header = (__le32 *)buffer + offset;
> + addr = le32_to_cpu(header[0]);
> + size = le32_to_cpu(header[1]);
> acquire_bus(wilc, ACQUIRE_ONLY);
> offset += 8;
> while (((int)size) && (offset < buffer_size)) {
> diff --git a/drivers/staging/wilc1000/wilc_wlan_cfg.c b/drivers/staging/wilc1000/wilc_wlan_cfg.c
> index c0b9b700f4d7..4a914d8572aa 100644
> --- a/drivers/staging/wilc1000/wilc_wlan_cfg.c
> +++ b/drivers/staging/wilc1000/wilc_wlan_cfg.c
> @@ -275,14 +275,14 @@ static int wilc_wlan_cfg_set_bin(u8 *frame, u32 offset, u16 id, u8 *b, u32 size)
>
> static void wilc_wlan_parse_response_frame(u8 *info, int size)
> {
> - u32 wid, len = 0, i = 0;
> + u32 wid;
> + int len = 0, i = 0;

Why did we make these int now?

>
> while (size > 0) {
> i = 0;
> - wid = info[0] | (info[1] << 8);
> - wid = cpu_to_le32(wid);
> + wid = le16_to_cpup((__le16 *)info);
>
> - switch ((wid >> 12) & 0x7) {
> + switch (info[1] >> 4) {

Why do we not need to mask by 0x7? Anyway, I feel like this isn't
beautiful. We should be using a macro and "wid" instead of magically
poking into info[1].

switch(SOME_MACRO(wid)) {


regards,
dan carpenter