From d550d63d0082268a31e93a10c64cbc2476b98b24 Mon Sep 17 00:00:00 2001 From: Pei Xiao Date: Tue, 21 Oct 2025 17:42:27 +0800 Subject: [PATCH] eth: fbnic: fix integer overflow warning in TLV_MAX_DATA definition The TLV_MAX_DATA macro calculates (PAGE_SIZE - 512) which can exceed the maximum value of a 16-bit unsigned integer on architectures with large page sizes, causing compiler warnings: drivers/net/ethernet/meta/fbnic/fbnic_tlv.h:83:24: warning: conversion from 'long unsigned int' to 'short unsigned int' changes value from '261632' to '65024' [-Woverflow] Fix this by explicitly masking the result to 16 bits using bitwise AND with 0xFFFF, ensuring the value fits within the expected data type while maintaining the intended behavior for normal page sizes. This preserves the existing functionality while eliminating the compiler warning and potential undefined behavior from integer truncation. Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202510190832.3SQkTCHe-lkp@intel.com/ Signed-off-by: Pei Xiao Link: https://patch.msgid.link/182b9d0235d044d69d7a57c1296cc6f46e395beb.1761039651.git.xiaopei01@kylinos.cn Signed-off-by: Jakub Kicinski --- drivers/net/ethernet/meta/fbnic/fbnic_tlv.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_tlv.h b/drivers/net/ethernet/meta/fbnic/fbnic_tlv.h index c34bf87eeec95..3508b46ebdd00 100644 --- a/drivers/net/ethernet/meta/fbnic/fbnic_tlv.h +++ b/drivers/net/ethernet/meta/fbnic/fbnic_tlv.h @@ -80,7 +80,7 @@ struct fbnic_tlv_index { enum fbnic_tlv_type type; }; -#define TLV_MAX_DATA (PAGE_SIZE - 512) +#define TLV_MAX_DATA ((PAGE_SIZE - 512) & 0xFFFF) #define FBNIC_TLV_ATTR_ID_UNKNOWN USHRT_MAX #define FBNIC_TLV_ATTR_STRING(id, len) { id, len, FBNIC_TLV_STRING } #define FBNIC_TLV_ATTR_FLAG(id) { id, 0, FBNIC_TLV_FLAG } -- 2.47.3