The patch titled
Subject: wifi: rt2x00: use explicitly signed type for clamping
has been added to the -mm mm-nonmm-unstable branch. Its filename is
wifi-rt2x00-use-explicitly-signed-type-for-clamping.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/wifi-rt2x00-use-explicitly-signed-type-for-clamping.patch
This patch will later appear in the mm-nonmm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: "Jason A. Donenfeld" <Jason@xxxxxxxxx>
Subject: wifi: rt2x00: use explicitly signed type for clamping
Date: Tue, 18 Oct 2022 14:27:34 -0600
On some platforms, `char` is unsigned, which makes casting -7 to char
overflow, which in turn makes the clamping operation bogus. Instead, deal
with an explicit `s8` type, so that the comparison is always signed, and
return an s8 result from the function as well. Note that this function's
result is assigned to a `short`, which is always signed.
Link: https://lkml.kernel.org/r/20221018202734.140489-1-Jason@xxxxxxxxx
Signed-off-by: Jason A. Donenfeld <Jason@xxxxxxxxx>
Cc: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Cc: Stanislaw Gruszka <stf_xl@xxxxx>
Cc: Helmut Schaa <helmut.schaa@xxxxxxxxxxxxxx>
Cc: Kalle Valo <kvalo@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/net/wireless/ralink/rt2x00/rt2800lib.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
--- a/drivers/net/wireless/ralink/rt2x00/rt2800lib.c~wifi-rt2x00-use-explicitly-signed-type-for-clamping
+++ a/drivers/net/wireless/ralink/rt2x00/rt2800lib.c
@@ -4035,23 +4035,23 @@ static void rt2800_iq_calibrate(struct r
rt2800_bbp_write(rt2x00dev, 159, cal != 0xff ? cal : 0);
}
-static char rt2800_txpower_to_dev(struct rt2x00_dev *rt2x00dev,
+static s8 rt2800_txpower_to_dev(struct rt2x00_dev *rt2x00dev,
unsigned int channel,
- char txpower)
+ s8 txpower)
{
if (rt2x00_rt(rt2x00dev, RT3593) ||
rt2x00_rt(rt2x00dev, RT3883))
txpower = rt2x00_get_field8(txpower, EEPROM_TXPOWER_ALC);
if (channel <= 14)
- return clamp_t(char, txpower, MIN_G_TXPOWER, MAX_G_TXPOWER);
+ return clamp_t(s8, txpower, MIN_G_TXPOWER, MAX_G_TXPOWER);
if (rt2x00_rt(rt2x00dev, RT3593) ||
rt2x00_rt(rt2x00dev, RT3883))
- return clamp_t(char, txpower, MIN_A_TXPOWER_3593,
+ return clamp_t(s8, txpower, MIN_A_TXPOWER_3593,
MAX_A_TXPOWER_3593);
else
- return clamp_t(char, txpower, MIN_A_TXPOWER, MAX_A_TXPOWER);
+ return clamp_t(s8, txpower, MIN_A_TXPOWER, MAX_A_TXPOWER);
}
static void rt3883_bbp_adjust(struct rt2x00_dev *rt2x00dev,
_
Patches currently in -mm which might be from Jason@xxxxxxxxx are
wifi-rt2x00-use-explicitly-signed-type-for-clamping.patch
minmax-sanity-check-constant-bounds-when-clamping.patch
minmax-clamp-more-efficiently-by-avoiding-extra-comparison.patch
