-Wflex-array-member-not-at-end was introduced in GCC-14, and we are
getting ready to enable it, globally.
So, in order to avoid ending up with a flexible-array member in the
middle of multiple other structs, we use the `struct_group_tagged()`
helper to create a new tagged `struct mt76_connac2_mcu_rxd_hdr`.
This structure groups together all the members of the flexible
`struct mt76_connac2_mcu_rxd` except the flexible array.
As a result, the array is effectively separated from the rest of the
members without modifying the memory layout of the flexible structure.
We then change the type of the middle struct members currently causing
trouble from `struct mt76_connac2_mcu_rxd` to `struct
mt76_connac2_mcu_rxd_hdr`.
We also want to ensure that when new members need to be added to the
flexible structure, they are always included within the newly created
tagged struct. For this, we use `static_assert()`. This ensures that the
memory layout for both the flexible structure and the new tagged struct
is the same after any changes.
This approach avoids having to implement `struct mt76_connac2_mcu_rxd_hdr`
as a completely separate structure, thus preventing having to maintain
two independent but basically identical structures, closing the door
to potential bugs in the future.
So, with these changes, fix the following warnings:
drivers/net/wireless/mediatek/mt76/mt7915/mcu.h:32:37: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
drivers/net/wireless/mediatek/mt76/mt7915/mcu.h:40:37: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
drivers/net/wireless/mediatek/mt76/mt7915/mcu.h:49:37: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
drivers/net/wireless/mediatek/mt76/mt7915/mcu.h:58:37: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
Signed-off-by: Gustavo A. R. Silva <[email protected]>
Link: https://patch.msgid.link/Zr5KsZugaEXrApQJ@elsanto
Signed-off-by: Felix Fietkau <[email protected]>
Transform zero-length arrays `rate`, `adm_stat` and `msdu_cnt` into
proper flexible-array members in anonymous union in `struct
mt7996_mcu_all_sta_info_event` via the DECLARE_FLEX_ARRAY()
helper; and fix multiple -Warray-bounds warnings:
drivers/net/wireless/mediatek/mt76/mt7996/mcu.c:544:61: warning: array subscript <unknown> is outside array bounds of 'struct <anonymous>[0]' [-Warray-bounds=]
drivers/net/wireless/mediatek/mt76/mt7996/mcu.c:551:58: warning: array subscript <unknown> is outside array bounds of 'struct <anonymous>[0]' [-Warray-bounds=]
drivers/net/wireless/mediatek/mt76/mt7996/mcu.c:553:58: warning: array subscript <unknown> is outside array bounds of 'struct <anonymous>[0]' [-Warray-bounds=]
drivers/net/wireless/mediatek/mt76/mt7996/mcu.c:530:61: warning: array subscript <unknown> is outside array bounds of 'struct <anonymous>[0]' [-Warray-bounds=]
drivers/net/wireless/mediatek/mt76/mt7996/mcu.c:538:66: warning: array subscript <unknown> is outside array bounds of 'struct <anonymous>[0]' [-Warray-bounds=]
drivers/net/wireless/mediatek/mt76/mt7996/mcu.c:540:66: warning: array subscript <unknown> is outside array bounds of 'struct <anonymous>[0]' [-Warray-bounds=]
drivers/net/wireless/mediatek/mt76/mt7996/mcu.c:520:57: warning: array subscript <unknown> is outside array bounds of 'struct all_sta_trx_rate[0]' [-Warray-bounds=]
drivers/net/wireless/mediatek/mt76/mt7996/mcu.c:526:76: warning: array subscript <unknown> is outside array bounds of 'struct all_sta_trx_rate[0]' [-Warray-bounds=]
drivers/net/wireless/mediatek/mt76/mt7996/mcu.c:526:76: warning: array subscript <unknown> is outside array bounds of 'struct all_sta_trx_rate[0]' [-Warray-bounds=]
drivers/net/wireless/mediatek/mt76/mt7996/mcu.c:526:76: warning: array subscript <unknown> is outside array bounds of 'struct all_sta_trx_rate[0]' [-Warray-bounds=]
drivers/net/wireless/mediatek/mt76/mt7996/mcu.c:526:76: warning: array subscript <unknown> is outside array bounds of 'struct all_sta_trx_rate[0]' [-Warray-bounds=]
This results in no differences in binary output, helps with the ongoing
efforts to globally enable -Warray-bounds.
Reviewed-by: Kees Cook <[email protected]>
Signed-off-by: Gustavo A. R. Silva <[email protected]>
Signed-off-by: Kalle Valo <[email protected]>
Link: https://msgid.link/ZXiU9ayVCslt3qiI@work
Zero-length arrays as fake flexible arrays are deprecated and we are
moving towards adopting C99 flexible-array members instead.
Address the following warnings found with GCC-13 and
-fstrict-flex-arrays=3 enabled:
drivers/net/wireless/mediatek/mt76/mt7921/acpi_sar.c:266:25: warning: array subscript 0 is outside array bounds of ‘struct mt7921_asar_dyn_limit_v2[0]’ [-Warray-bounds=]
drivers/net/wireless/mediatek/mt76/mt7921/acpi_sar.c:263:25: warning: array subscript 0 is outside array bounds of ‘struct mt7921_asar_dyn_limit[0]’ [-Warray-bounds=]
drivers/net/wireless/mediatek/mt76/mt7921/acpi_sar.c:223:28: warning: array subscript <unknown> is outside array bounds of ‘struct mt7921_asar_geo_limit_v2[0]’ [-Warray-bounds=]
drivers/net/wireless/mediatek/mt76/mt7921/acpi_sar.c:220:28: warning: array subscript <unknown> is outside array bounds of ‘struct mt7921_asar_geo_limit[0]’ [-Warray-bounds=]
drivers/net/wireless/mediatek/mt76/mt7921/acpi_sar.c:334:37: warning: array subscript i is outside array bounds of ‘u8[0]’ {aka ‘unsigned char[]’} [-Warray-bounds=]
Notice that the DECLARE_FLEX_ARRAY() helper allows for flexible-array
members in unions.
This helps with the ongoing efforts to tighten the FORTIFY_SOURCE
routines on memcpy() and help us make progress towards globally
enabling -fstrict-flex-arrays=3 [1].
Link: https://github.com/KSPP/linux/issues/21
Link: https://github.com/KSPP/linux/issues/272
Link: https://gcc.gnu.org/pipermail/gcc-patches/2022-October/602902.html [1]
Signed-off-by: Gustavo A. R. Silva <[email protected]>
Reviewed-by: Simon Horman <[email protected]>
Signed-off-by: Felix Fietkau <[email protected]>
In preparation to enable -Wimplicit-fallthrough for Clang, fix the
following warning by explicitly adding a break statement:
drivers/net/wireless/mediatek/mt76/mt7921/main.c:392:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
Link: https://github.com/KSPP/linux/issues/115
Signed-off-by: Gustavo A. R. Silva <[email protected]>
