Hello Ping-Ke Shih,
The patch e3ec7017f6a2: "rtw89: add Realtek 802.11ax driver" from Oct
11, 2021, leads to the following Smatch static checker warning:
drivers/net/wireless/realtek/rtw89/mac.c:586 hfc_ch_ctrl()
warn: array off by one? 'cfg[ch]'
drivers/net/wireless/realtek/rtw89/mac.c
568 static int hfc_ch_ctrl(struct rtw89_dev *rtwdev, u8 ch)
569 {
570 struct rtw89_hfc_param *param = &rtwdev->mac.hfc_param;
571 const struct rtw89_hfc_ch_cfg *cfg = param->ch_cfg;
572 int ret = 0;
573 u32 val = 0;
574
575 ret = rtw89_mac_check_mac_en(rtwdev, RTW89_MAC_0, RTW89_DMAC_SEL);
576 if (ret)
577 return ret;
578
579 ret = hfc_ch_cfg_chk(rtwdev, ch);
580 if (ret)
581 return ret;
582
583 if (ch > RTW89_DMA_B1HI)
^^^^^^^^^^^^^^^^^^^
584 return -EINVAL;
585
--> 586 val = u32_encode_bits(cfg[ch].min, B_AX_MIN_PG_MASK) |
587 u32_encode_bits(cfg[ch].max, B_AX_MAX_PG_MASK) |
588 (cfg[ch].grp ? B_AX_GRP : 0);
This is an unpublished Smatch warning which uses an "assume every >
comparison should be >= wrong until proven otherwise" approach. In
this case, Smatch can't tell the size of the cfg[] array.
Manually it looks like cfg can only be rtw8852a_hfc_chcfg_pcie[] which
has RTW89_DMA_CH_NUM (13) elements. Is there a reason why we don't use
the last element? Also it's puzzling that the last element is
FWCMDQ instead of H2C. So maybe that's the reason?
589 rtw89_write32(rtwdev, R_AX_ACH0_PAGE_CTRL + ch * 4, val);
590
591 return 0;
592 }
regards,
dan carpenter
