On 5/10/2021 6:04 PM, Wang, Haiyue wrote: >> -----Original Message----- >> From: dev <[email protected]> On Behalf Of Ferruh Yigit >> Sent: Monday, May 10, 2021 23:03 >> To: Yang, Qiming <[email protected]>; Zhang, Qi Z >> <[email protected]>; Stillwell Jr, Paul M >> <[email protected]>; Lu, Wenzhuo <[email protected]>; Rong, >> Leyi <[email protected]>; >> Shukla, Shivanshu <[email protected]> >> Cc: Yigit, Ferruh <[email protected]>; [email protected]; [email protected]; >> Kevin Traynor >> <[email protected]>; Ajit Khaparde <[email protected]> >> Subject: [dpdk-dev] [PATCH 3/4] net/ice/base: fix build with gcc11 >> >> Reproduced with '--buildtype=debugoptimized' config, >> compiler version: gcc (GCC) 12.0.0 20210509 (experimental) >> >> There are multiple build errors, like: >> ../drivers/net/ice/base/ice_switch.c: In function ‘ice_add_marker_act’: >> ../drivers/net/ice/base/ice_switch.c:3727:15: >> warning: array subscript ‘struct ice_aqc_sw_rules_elem[0]’ >> is partly outside array bounds of ‘unsigned char[52]’ >> [-Warray-bounds] >> 3727 | lg_act->type = CPU_TO_LE16(ICE_AQC_SW_RULES_T_LG_ACT); >> | ^~ >> In file included from ../drivers/net/ice/base/ice_type.h:52, >> from ../drivers/net/ice/base/ice_common.h:8, >> from ../drivers/net/ice/base/ice_switch.h:8, >> from ../drivers/net/ice/base/ice_switch.c:5: >> ../drivers/net/ice/base/ice_osdep.h:209:29: >> note: referencing an object of size 52 allocated by ‘rte_zmalloc’ >> 209 | #define ice_malloc(h, s) rte_zmalloc(NULL, s, 0) >> | ^~~~~~~~~~~~~~~~~~~~~~~ >> ../drivers/net/ice/base/ice_switch.c:3720:50: >> note: in expansion of macro ‘ice_malloc’ >> lg_act = (struct ice_aqc_sw_rules_elem *)ice_malloc(hw, rules_size); >> >> These errors are mainly because allocated memory is cast to >> "struct ice_aqc_sw_rules_elem *" but allocated size is less than the size >> of "struct ice_aqc_sw_rules_elem". >> >> "struct ice_aqc_sw_rules_elem" has multiple other structs has unions, >> based on which one is used allocated memory being less than the size of >> "struct ice_aqc_sw_rules_elem" is logically correct but compiler is >> complaining about it. >> >> As a solution making sure allocated memory size is at least size of >> "struct ice_aqc_sw_rules_elem". >> The function to use the struct is 'ice_aq_sw_rules()', and it already has >> parameter for size of the rule, allocating more than needed shouldn't >> cause any problem. >> >> Fixes: c7dd15931183 ("net/ice/base: add virtual switch code") >> Fixes: 02acdce2f553 ("net/ice/base: add MAC filter with marker and counter") >> Fixes: f89aa3affa9e ("net/ice/base: support removing advanced rule") >> Cc: [email protected] >> >> Signed-off-by: Ferruh Yigit <[email protected]> >> --- >> Cc: [email protected] >> Cc: [email protected] >> Cc: [email protected] >> Cc: Kevin Traynor <[email protected]> >> Cc: Ajit Khaparde <[email protected]> >> --- >> drivers/net/ice/base/ice_switch.c | 30 +++++++++++++++++++++++------- >> 1 file changed, 23 insertions(+), 7 deletions(-) > > GCC bug ? > > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98266 > > Bug 98266 - [11 Regression] bogus array subscript is partly outside array > bounds on virtual inheritance >
I am not sure if this is a gcc defect. Here there is a memory allocated and assigned to "struct ice_aqc_sw_rules_elem *", but allocated memory size is less than the struct size. As far as I understand this is the reason of compiler warning. For this case it may not be problem logically since both who allocates memory and who uses the memory follows a contract, but there is a mismatch between pointer type and object. If some other function wants to access all fields of the struct, it will be out of bound access.
