[dpdk-dev] [PATCH v2] librte_acl: fix undefined behavior

[Aaron Conole <aconole@redhat.com>]

Left-shift of an integer constant is represented as 'int' type, but a left
shift of 1 by 31 bits in 'int' is undefined.  Use the U suffix to force
a representation as unsigned.

Caught while running with ubsan under gcc.

Fixes: dc276b5780c2 ("acl: new library")
Cc: Konstantin Ananyev <konstantin.ananyev@intel.com>
Signed-off-by: Aaron Conole <aconole@redhat.com>
---
v2: correct one other place where I could have used CHAR_BIT

I could have changed the sizeof(bits_t) * 8 in the bitset.bits as well during
the cleanup, but chose not to to keep the change only to the lines I needed.

 lib/librte_acl/acl_bld.c | 6 +++---
 lib/librte_acl/acl_gen.c | 4 ++--
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/lib/librte_acl/acl_bld.c b/lib/librte_acl/acl_bld.c
index b82191f42..9d27c0a5a 100644
--- a/lib/librte_acl/acl_bld.c
+++ b/lib/librte_acl/acl_bld.c
@@ -320,7 +320,7 @@ acl_add_ptr_range(struct acl_build_context *context,
 	for (n = 0; n < UINT8_MAX + 1; n++)
 		if (n >= low && n <= high)
 			bitset.bits[n / (sizeof(bits_t) * 8)] |=
-				1 << (n % (sizeof(bits_t) * 8));
+				1U << (n % (sizeof(bits_t) * CHAR_BIT));
 
 	return acl_add_ptr(context, root, node, &bitset);
 }
@@ -343,7 +343,7 @@ acl_gen_mask(struct rte_acl_bitset *bitset, uint32_t value, uint32_t mask)
 		if ((n & mask) == value) {
 			range++;
 			bitset->bits[n / (sizeof(bits_t) * 8)] |=
-				1 << (n % (sizeof(bits_t) * 8));
+				1U << (n % (sizeof(bits_t) * CHAR_BIT));
 		}
 	}
 	return range;
@@ -972,7 +972,7 @@ build_trie(struct acl_build_context *context, struct rte_acl_build_rule *head,
 				sizeof(*end->mrt));
 
 		for (m = context->cfg.num_categories; 0 != m--; ) {
-			if (rule->f->data.category_mask & (1 << m)) {
+			if (rule->f->data.category_mask & (1U << m)) {
 				end->mrt->results[m] = rule->f->data.userdata;
 				end->mrt->priority[m] = rule->f->data.priority;
 			} else {
diff --git a/lib/librte_acl/acl_gen.c b/lib/librte_acl/acl_gen.c
index 35a0140b4..81dec3aa6 100644
--- a/lib/librte_acl/acl_gen.c
+++ b/lib/librte_acl/acl_gen.c
@@ -133,7 +133,7 @@ acl_node_fill_dfa(const struct rte_acl_node *node,
 		for (n = 0; n < RTE_ACL_DFA_SIZE; n++) {
 
 			if (bits->bits[n / (sizeof(bits_t) * CHAR_BIT)] &
-				(1 << (n % (sizeof(bits_t) * CHAR_BIT)))) {
+				(1U << (n % (sizeof(bits_t) * CHAR_BIT)))) {
 
 				dfa[n] = resolved ? child->node_index : x;
 				ranges += (last_bit == 0);
@@ -175,7 +175,7 @@ acl_count_sequential_groups(struct rte_acl_bitset *bits, int zero_one)
 	}
 	for (n = 0; n < QRANGE_MIN; n++) {
 		if (bits->bits[n / (sizeof(bits_t) * 8)] &
-				(1 << (n % (sizeof(bits_t) * 8)))) {
+				(1U << (n % (sizeof(bits_t) * CHAR_BIT)))) {
 			if (zero_one == 1 && last_bit != 1)
 				ranges++;
 			last_bit = 1;
-- 
2.21.0