Commit d550d63d authored by Pei Xiao's avatar Pei Xiao Committed by Jakub Kicinski
Browse files

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: default avatarkernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202510190832.3SQkTCHe-lkp@intel.com/


Signed-off-by: default avatarPei Xiao <xiaopei01@kylinos.cn>
Link: https://patch.msgid.link/182b9d0235d044d69d7a57c1296cc6f46e395beb.1761039651.git.xiaopei01@kylinos.cn


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 11457396

drivers/net/ethernet/meta/fbnic/fbnic_tlv.h

+1 −1
Original line number Diff line number Diff line
@@ -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 }