2009-03-31 23:31:07

by Chris Wright

[permalink] [raw]
Subject: [patch 21/45] ath5k: warn and correct rate for unknown hw rate indexes

-stable review patch. If anyone has any objections, please let us know.
---------------------

From: Bob Copeland <[email protected]>

upstream commit: b726604706ad88d8b28bc487e45e710f58cc19ee

ath5k sets up a mapping table from the hardware rate index to
the rate index used by mac80211; however, we have seen some
received frames with incorrect rate indexes. Such frames
normally get dropped with a warning in __ieee80211_rx(),
but it doesn't include enough information to track down the
error.

This patch adds a warning to hw_to_driver_rix for any lookups
that result in a rate index of -1, then returns a valid rate so
the frame can be processed.

Changes-licensed-under: 3-Clause-BSD

Signed-off-by: Bob Copeland <[email protected]>
Cc: [email protected]
Signed-off-by: John W. Linville <[email protected]>
[chrisw: add db5b4f7ae3901fdc48c5b988fc2a5e0cb4ec1870 to backport]
Signed-off-by: Chris Wright <[email protected]>
---
drivers/net/wireless/ath5k/base.c | 14 ++++++++++++--
drivers/net/wireless/ath5k/base.h | 2 +-
2 files changed, 13 insertions(+), 3 deletions(-)

--- a/drivers/net/wireless/ath5k/base.c
+++ b/drivers/net/wireless/ath5k/base.c
@@ -1090,8 +1090,18 @@ ath5k_mode_setup(struct ath5k_softc *sc)
static inline int
ath5k_hw_to_driver_rix(struct ath5k_softc *sc, int hw_rix)
{
- WARN_ON(hw_rix < 0 || hw_rix > AR5K_MAX_RATES);
- return sc->rate_idx[sc->curband->band][hw_rix];
+ int rix;
+
+ /* return base rate on errors */
+ if (WARN(hw_rix < 0 || hw_rix >= AR5K_MAX_RATES,
+ "hw_rix out of bounds: %x\n", hw_rix))
+ return 0;
+
+ rix = sc->rate_idx[sc->curband->band][hw_rix];
+ if (WARN(rix < 0, "invalid hw_rix: %x\n", hw_rix))
+ rix = 0;
+
+ return rix;
}

/***************\
--- a/drivers/net/wireless/ath5k/base.h
+++ b/drivers/net/wireless/ath5k/base.h
@@ -112,7 +112,7 @@ struct ath5k_softc {
struct ieee80211_supported_band sbands[IEEE80211_NUM_BANDS];
struct ieee80211_channel channels[ATH_CHAN_MAX];
struct ieee80211_rate rates[IEEE80211_NUM_BANDS][AR5K_MAX_RATES];
- u8 rate_idx[IEEE80211_NUM_BANDS][AR5K_MAX_RATES];
+ s8 rate_idx[IEEE80211_NUM_BANDS][AR5K_MAX_RATES];
enum nl80211_iftype opmode;
struct ath5k_hw *ah; /* Atheros HW */