Re: [PATCH v2 2/5] staging: r8188eu: cast to restricted __be32
From: Larry Finger <hidden>
Date: 2021-08-20 21:44:55
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On 8/19/21 3:17 AM, Aakash Hemadri wrote:
quoted hunk ↗ jump to hunk
Fix sparse warning:quoted
rtw_br_ext.c:836:54: warning: cast to restricted __be32Unnecessary double cast, remove them. Signed-off-by: Aakash Hemadri <redacted> --- drivers/staging/r8188eu/core/rtw_br_ext.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)diff --git a/drivers/staging/r8188eu/core/rtw_br_ext.c b/drivers/staging/r8188eu/core/rtw_br_ext.c index 404fa8904e47..6a0462ce6230 100644 --- a/drivers/staging/r8188eu/core/rtw_br_ext.c +++ b/drivers/staging/r8188eu/core/rtw_br_ext.c@@ -671,7 +671,7 @@ void dhcp_flag_bcast(struct adapter *priv, struct sk_buff *skb) (udph->dest == __constant_htons(SERVER_PORT))) { /* DHCP request */ struct dhcpMessage *dhcph = (struct dhcpMessage *)((size_t)udph + sizeof(struct udphdr)); - u32 cookie = be32_to_cpu((__be32)dhcph->cookie); + u32 cookie = dhcph->cookie; if (cookie == DHCP_MAGIC) { /* match magic word */ if (!(dhcph->flags & htons(BROADCAST_FLAG))) {
This patch is wrong. All the documentation I could find tells me that the multi-byte entries in dhcph are big-endian, thus the new line should read: u32 cookie = be32_to_cpu(dhcph->cookie); combined with:
@@ -649,7 +650,7 @@ struct dhcpMessage { u_int8_t chaddr[16]; u_int8_t sname[64]; u_int8_t file[128]; - u_int32_t cookie; + __be32 cookie; u_int8_t options[308]; /* 312 - cookie */ };
The old code was, in fact, correct, but not in a way that satisfied Sparse. Larry