Patch "mac80211: Fix clang warning about constant operand in logical operation" has been added to the 4.9-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    mac80211: Fix clang warning about constant operand in logical operation

to the 4.9-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     mac80211-fix-clang-warning-about-constant-operand-in-logical-operation.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 93f56de259376d7e4fff2b2d104082e1fa66e237 Mon Sep 17 00:00:00 2001
From: Matthias Kaehlcke <mka@chromium.org>
Date: Thu, 6 Apr 2017 16:31:41 -0700
Subject: mac80211: Fix clang warning about constant operand in logical operation

From: Matthias Kaehlcke <mka@chromium.org>

commit 93f56de259376d7e4fff2b2d104082e1fa66e237 upstream.

When clang detects a non-boolean constant in a logical operation it
generates a 'constant-logical-operand' warning. In
ieee80211_try_rate_control_ops_get() the result of strlen(<const str>)
is used in a logical operation, clang resolves the expression to an
(integer) constant at compile time when clang's builtin strlen function
is used.

Change the condition to check for strlen() > 0 to make the constant
operand boolean and thus avoid the warning.

Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Cc: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 net/mac80211/rate.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

--- a/net/mac80211/rate.c
+++ b/net/mac80211/rate.c
@@ -173,9 +173,11 @@ ieee80211_rate_control_ops_get(const cha
 		/* try default if specific alg requested but not found */
 		ops = ieee80211_try_rate_control_ops_get(ieee80211_default_rc_algo);
 
-	/* try built-in one if specific alg requested but not found */
-	if (!ops && strlen(CONFIG_MAC80211_RC_DEFAULT))
+	/* Note: check for > 0 is intentional to avoid clang warning */
+	if (!ops && (strlen(CONFIG_MAC80211_RC_DEFAULT) > 0))
+		/* try built-in one if specific alg requested but not found */
 		ops = ieee80211_try_rate_control_ops_get(CONFIG_MAC80211_RC_DEFAULT);
+
 	kernel_param_unlock(THIS_MODULE);
 
 	return ops;


Patches currently in stable-queue which might be from mka@chromium.org are

queue-4.9/dm-ioctl-remove-double-parentheses.patch
queue-4.9/arm64-avoid-overflow-in-va_start-and-page_offset.patch
queue-4.9/btrfs-remove-extra-parentheses-from-condition-in-copy_items.patch
queue-4.9/genirq-use-cpumask_available-for-check-of-cpumask-variable.patch
queue-4.9/nl80211-fix-enum-type-of-variable-in-nl80211_put_sta_rate.patch
queue-4.9/selinux-remove-redundant-check-for-unknown-labeling-behavior.patch
queue-4.9/fs-compat-remove-warning-from-compatible_ioctl.patch
queue-4.9/jiffies.h-declare-jiffies-and-jiffies_64-with-____cacheline_aligned_in_smp.patch
queue-4.9/selinux-remove-unnecessary-check-of-array-base-in-selinux_set_mapping.patch
queue-4.9/pci-make-pci_rom_address_mask-a-32-bit-constant.patch
queue-4.9/frv-declare-jiffies-to-be-located-in-the-.data-section.patch
queue-4.9/mac80211-ibss-fix-channel-type-enum-in-ieee80211_sta_join_ibss.patch
queue-4.9/cfg80211-fix-array-bounds-warning-in-fragment-copy.patch
queue-4.9/netfilter-ctnetlink-make-some-parameters-integer-to-avoid-enum-mismatch.patch
queue-4.9/mac80211-fix-clang-warning-about-constant-operand-in-logical-operation.patch
queue-4.9/cpumask-add-helper-cpumask_available.patch