Re: [PATCH 03/10] b43: Remove uninitialized_var() usage

From: Kalle Valo
Date: Fri Jun 05 2020 - 05:21:05 EST


Kees Cook <keescook@xxxxxxxxxxxx> writes:

> Using uninitialized_var() is dangerous as it papers over real bugs[1]
> (or can in the future), and suppresses unrelated compiler warnings (e.g.
> "unused variable"). If the compiler thinks it is uninitialized, either
> simply initialize the variable or make compiler changes. As a precursor
> to removing[2] this[3] macro[4], just initialize this variable to NULL,
> and make the (unreachable!) code do a conditional test.
>
> [1] https://lore.kernel.org/lkml/20200603174714.192027-1-glider@xxxxxxxxxx/
> [2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1TGqCR5vQkCzWJ0QxK6CernOU6eedsudAixw@xxxxxxxxxxxxxx/
> [3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz9knmPuXhOeg@xxxxxxxxxxxxxx/
> [4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@xxxxxxxxxxxxxx/
>
> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>

[...]

> @@ -4256,9 +4256,13 @@ static void b43_nphy_tx_gain_table_upload(struct b43_wldev *dev)
> pga_gain = (table[i] >> 24) & 0xf;
> pad_gain = (table[i] >> 19) & 0x1f;
> if (b43_current_band(dev->wl) == NL80211_BAND_2GHZ)
> - rfpwr_offset = rf_pwr_offset_table[pad_gain];
> + rfpwr_offset = rf_pwr_offset_table
> + ? rf_pwr_offset_table[pad_gain]
> + : 0;
> else
> - rfpwr_offset = rf_pwr_offset_table[pga_gain];
> + rfpwr_offset = rf_pwr_offset_table
> + ? rf_pwr_offset_table[pga_gain]
> + : 0;

To me this is ugly, isn't there a better way to fix this?

--
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