netdev - [PATCH 1/2] iproute2: tc/m_pedit.c

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Message-Id: <1435222983-14661-1-git-send-email-zenczykowski@gmail.com>
Date:	Thu, 25 Jun 2015 02:03:02 -0700
From:	Maciej Żenczykowski <zenczykowski@...il.com>
To:	Maciej Żenczykowski <maze@...gle.com>,
	Stephen Hemminger <shemming@...cade.com>,
	Eric Dumazet <edumazet@...gle.com>
Cc:	netdev@...r.kernel.org
Subject: [PATCH 1/2] iproute2: tc/m_pedit.c - remove dead code

From: Maciej Żenczykowski <maze@...gle.com>

The initializers are simply not needed.

These if-blocks are outright dead code, because '0 > unsigned' is always
false, so only else clause triggers and regardless of which clause triggers
it only updates 'ind' which is later unconditionally written to before
being used anyway.

Otherwise we get errors from clang:

  m_pedit.c:166:8: error: comparison of 0 > unsigned expression is always false [-Werror,-Wtautological-compare]
    if (0 > tkey->off) {
        ~ ^ ~~~~~~~~~
  m_pedit.c:209:8: error: comparison of 0 > unsigned expression is always false [-Werror,-Wtautological-compare]
    if (0 > tkey->off) {
        ~ ^ ~~~~~~~~~
  2 errors generated.

Change-Id: I3c9e9092915088fc56f992e5df736851541a4458
---
 tc/m_pedit.c | 32 ++++++++------------------------
 1 file changed, 8 insertions(+), 24 deletions(-)

diff --git a/tc/m_pedit.c b/tc/m_pedit.c
index dfe9b2ebd6e0..4fdd189d7d9c 100644
--- a/tc/m_pedit.c
+++ b/tc/m_pedit.c
@@ -160,17 +160,9 @@ pack_key32(__u32 retain,struct tc_pedit_sel *sel,struct tc_pedit_key *tkey)
 int
 pack_key16(__u32 retain,struct tc_pedit_sel *sel,struct tc_pedit_key *tkey)
 {
-	int ind = 0, stride = 0;
+	int ind, stride;
 	__u32 m[4] = {0xFFFF0000,0xFF0000FF,0x0000FFFF};
 
-	if (0 > tkey->off) {
-		ind = tkey->off + 1;
-		if (0 > ind)
-			ind = -1*ind;
-	} else {
-		ind = tkey->off;
-	}
-
 	if (tkey->val > 0xFFFF || tkey->mask > 0xFFFF) {
 		fprintf(stderr, "pack_key16 bad value\n");
 		return -1;
@@ -178,18 +170,16 @@ pack_key16(__u32 retain,struct tc_pedit_sel *sel,struct tc_pedit_key *tkey)
 
 	ind = tkey->off & 3;
 
-	if (0 > ind || 2 < ind) {
+	if (ind == 3) {
 		fprintf(stderr, "pack_key16 bad index value %d\n",ind);
 		return -1;
 	}
 
 	stride = 8 * ind;
 	tkey->val = htons(tkey->val);
-	if (stride > 0) {
-		tkey->val <<= stride;
-		tkey->mask <<= stride;
-		retain <<= stride;
-	}
+	tkey->val <<= stride;
+	tkey->mask <<= stride;
+	retain <<= stride;
 	tkey->mask = retain|m[ind];
 
 	tkey->off &= ~3;
@@ -203,28 +193,22 @@ pack_key16(__u32 retain,struct tc_pedit_sel *sel,struct tc_pedit_key *tkey)
 int
 pack_key8(__u32 retain,struct tc_pedit_sel *sel,struct tc_pedit_key *tkey)
 {
-	int ind = 0, stride = 0;
+	int ind, stride;
 	__u32 m[4] = {0xFFFFFF00,0xFFFF00FF,0xFF00FFFF,0x00FFFFFF};
 
-	if (0 > tkey->off) {
-		ind = tkey->off + 1;
-		if (0 > ind)
-			ind = -1*ind;
-	} else {
-		ind = tkey->off;
-	}
-
 	if (tkey->val > 0xFF || tkey->mask > 0xFF) {
 		fprintf(stderr, "pack_key8 bad value (val %x mask %x\n", tkey->val, tkey->mask);
 		return -1;
 	}
 
 	ind = tkey->off & 3;
+
 	stride = 8 * ind;
 	tkey->val <<= stride;
 	tkey->mask <<= stride;
 	retain <<= stride;
 	tkey->mask = retain|m[ind];
+
 	tkey->off &= ~3;
 
 	if (pedit_debug)
-- 
2.4.3.573.g4eafbef

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