[PATCH v2] lib/siphash.c: annotate implicit fall throughs

From: Mathieu Malaterre
Date: Wed Mar 13 2019 - 16:24:48 EST


There is a plan to build the kernel with -Wimplicit-fallthrough and
these places in the code produced warnings (W=1). Fix them up.

This commit remove the following warnings:

lib/siphash.c:71:12: warning: this statement may fall through [-Wimplicit-fallthrough=]
lib/siphash.c:72:12: warning: this statement may fall through [-Wimplicit-fallthrough=]
lib/siphash.c:73:12: warning: this statement may fall through [-Wimplicit-fallthrough=]
lib/siphash.c:75:12: warning: this statement may fall through [-Wimplicit-fallthrough=]
lib/siphash.c:108:12: warning: this statement may fall through [-Wimplicit-fallthrough=]
lib/siphash.c:109:12: warning: this statement may fall through [-Wimplicit-fallthrough=]
lib/siphash.c:110:12: warning: this statement may fall through [-Wimplicit-fallthrough=]
lib/siphash.c:112:12: warning: this statement may fall through [-Wimplicit-fallthrough=]
lib/siphash.c:434:12: warning: this statement may fall through [-Wimplicit-fallthrough=]
lib/siphash.c:462:12: warning: this statement may fall through [-Wimplicit-fallthrough=]

Cc: "Gustavo A. R. Silva" <gustavo@xxxxxxxxxxxxxx>
Signed-off-by: Mathieu Malaterre <malat@xxxxxxxxxx>
---
v2: some cases were missed in v1, update missing ones

lib/siphash.c | 10 ++++++++++
1 file changed, 10 insertions(+)

diff --git a/lib/siphash.c b/lib/siphash.c
index 3ae58b4edad6..f4f778d28660 100644
--- a/lib/siphash.c
+++ b/lib/siphash.c
@@ -69,10 +69,14 @@ u64 __siphash_aligned(const void *data, size_t len, const siphash_key_t *key)
#else
switch (left) {
case 7: b |= ((u64)end[6]) << 48;
+ /* fall through */
case 6: b |= ((u64)end[5]) << 40;
+ /* fall through */
case 5: b |= ((u64)end[4]) << 32;
+ /* fall through */
case 4: b |= le32_to_cpup(data); break;
case 3: b |= ((u64)end[2]) << 16;
+ /* fall through */
case 2: b |= le16_to_cpup(data); break;
case 1: b |= end[0];
}
@@ -102,10 +106,14 @@ u64 __siphash_unaligned(const void *data, size_t len, const siphash_key_t *key)
#else
switch (left) {
case 7: b |= ((u64)end[6]) << 48;
+ /* fall through */
case 6: b |= ((u64)end[5]) << 40;
+ /* fall through */
case 5: b |= ((u64)end[4]) << 32;
+ /* fall through */
case 4: b |= get_unaligned_le32(end); break;
case 3: b |= ((u64)end[2]) << 16;
+ /* fall through */
case 2: b |= get_unaligned_le16(end); break;
case 1: b |= end[0];
}
@@ -432,6 +440,7 @@ u32 __hsiphash_aligned(const void *data, size_t len, const hsiphash_key_t *key)
}
switch (left) {
case 3: b |= ((u32)end[2]) << 16;
+ /* fall through */
case 2: b |= le16_to_cpup(data); break;
case 1: b |= end[0];
}
@@ -455,6 +464,7 @@ u32 __hsiphash_unaligned(const void *data, size_t len,
}
switch (left) {
case 3: b |= ((u32)end[2]) << 16;
+ /* fall through */
case 2: b |= get_unaligned_le16(end); break;
case 1: b |= end[0];
}
--
2.20.1