Commit 810e41ce authored by Dmitry Antipov's avatar Dmitry Antipov Committed by Kalle Valo
Browse files

wifi: ath9k: fix fortify warnings 



When compiling with gcc 13.1 and CONFIG_FORTIFY_SOURCE=y,
I've noticed the following:

In function ‘fortify_memcpy_chk’,
    inlined from ‘ath_tx_complete_aggr’ at drivers/net/wireless/ath/ath9k/xmit.c:556:4,
    inlined from ‘ath_tx_process_buffer’ at drivers/net/wireless/ath/ath9k/xmit.c:773:3:
./include/linux/fortify-string.h:529:25: warning: call to ‘__read_overflow2_field’
declared with attribute warning: detected read beyond size of field (2nd parameter);
maybe use struct_group()? [-Wattribute-warning]
  529 |                         __read_overflow2_field(q_size_field, size);
      |                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

In function ‘fortify_memcpy_chk’,
    inlined from ‘ath_tx_count_frames’ at drivers/net/wireless/ath/ath9k/xmit.c:473:3,
    inlined from ‘ath_tx_complete_aggr’ at drivers/net/wireless/ath/ath9k/xmit.c:572:2,
    inlined from ‘ath_tx_process_buffer’ at drivers/net/wireless/ath/ath9k/xmit.c:773:3:
./include/linux/fortify-string.h:529:25: warning: call to ‘__read_overflow2_field’
declared with attribute warning: detected read beyond size of field (2nd parameter);
maybe use struct_group()? [-Wattribute-warning]
  529 |                         __read_overflow2_field(q_size_field, size);
      |                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

In both cases, the compiler complains on:

memcpy(ba, &ts->ba_low, WME_BA_BMP_SIZE >> 3);

which is the legal way to copy both 'ba_low' and following 'ba_high'
members of 'struct ath_tx_status' at once (that is, issue one 8-byte
'memcpy()' for two 4-byte fields). Since the fortification logic seems
interprets this trick as an attempt to overread 4-byte 'ba_low', silence
relevant warnings by using the convenient 'struct_group()' quirk.

Suggested-by: default avatarJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: default avatarDmitry Antipov <dmantipov@yandex.ru>
Acked-by: default avatarToke Høiland-Jørgensen <toke@toke.dk>
Signed-off-by: default avatarKalle Valo <quic_kvalo@quicinc.com>
Link: https://lore.kernel.org/r/20230620080855.396851-2-dmantipov@yandex.ru
parent 90f2ba48

drivers/net/wireless/ath/ath9k/mac.h

+4 −2
Original line number Diff line number Diff line
@@ -115,8 +115,10 @@ struct ath_tx_status { 
	u8 qid;

	u16 desc_id;

	u8 tid;

	struct_group(ba,

		u32 ba_low;

		u32 ba_high;

	);

	u32 evm0;

	u32 evm1;

	u32 evm2;

drivers/net/wireless/ath/ath9k/xmit.c

+2 −2
Original line number Diff line number Diff line
@@ -470,7 +470,7 @@ static void ath_tx_count_frames(struct ath_softc *sc, struct ath_buf *bf, 


	if (isaggr) {

		seq_st = ts->ts_seqnum;

		memcpy(ba, &ts->ba_low, WME_BA_BMP_SIZE >> 3);

		memcpy(ba, &ts->ba, WME_BA_BMP_SIZE >> 3);

	}



	while (bf) {
@@ -553,7 +553,7 @@ static void ath_tx_complete_aggr(struct ath_softc *sc, struct ath_txq *txq, 
	if (isaggr && txok) {

		if (ts->ts_flags & ATH9K_TX_BA) {

			seq_st = ts->ts_seqnum;

			memcpy(ba, &ts->ba_low, WME_BA_BMP_SIZE >> 3);

			memcpy(ba, &ts->ba, WME_BA_BMP_SIZE >> 3);

		} else {

			/*

			 * AR5416 can become deaf/mute when BA