[PATCH v3] lib/siphash.c: annotate implicit fall throughs

From: Mathieu Malaterre
Date: Wed Mar 13 2019 - 17:12:57 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=]

Move the break statement onto the next line to match the fall-through
comment pattern. Also move the trailing statement onto the next line to
pass checkpatch verification.

Acked-by: "Gustavo A. R. Silva" <gustavo@xxxxxxxxxxxxxx>
Signed-off-by: Mathieu Malaterre <malat@xxxxxxxxxx>
---
v3: move break statements onto next line and please checkpatch
v2: some cases were missed in v1, update missing ones

lib/siphash.c | 76 +++++++++++++++++++++++++++++++++++++--------------
1 file changed, 56 insertions(+), 20 deletions(-)

diff --git a/lib/siphash.c b/lib/siphash.c
index 3ae58b4edad6..f459e0f4a14e 100644
--- a/lib/siphash.c
+++ b/lib/siphash.c
@@ -68,13 +68,26 @@ u64 __siphash_aligned(const void *data, size_t len, const siphash_key_t *key)
bytemask_from_count(left)));
#else
switch (left) {
- case 7: b |= ((u64)end[6]) << 48;
- case 6: b |= ((u64)end[5]) << 40;
- case 5: b |= ((u64)end[4]) << 32;
- case 4: b |= le32_to_cpup(data); break;
- case 3: b |= ((u64)end[2]) << 16;
- case 2: b |= le16_to_cpup(data); break;
- case 1: b |= end[0];
+ 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];
}
#endif
POSTAMBLE
@@ -101,13 +114,26 @@ u64 __siphash_unaligned(const void *data, size_t len, const siphash_key_t *key)
bytemask_from_count(left)));
#else
switch (left) {
- case 7: b |= ((u64)end[6]) << 48;
- case 6: b |= ((u64)end[5]) << 40;
- case 5: b |= ((u64)end[4]) << 32;
- case 4: b |= get_unaligned_le32(end); break;
- case 3: b |= ((u64)end[2]) << 16;
- case 2: b |= get_unaligned_le16(end); break;
- case 1: b |= end[0];
+ 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];
}
#endif
POSTAMBLE
@@ -431,9 +457,14 @@ u32 __hsiphash_aligned(const void *data, size_t len, const hsiphash_key_t *key)
v0 ^= m;
}
switch (left) {
- case 3: b |= ((u32)end[2]) << 16;
- case 2: b |= le16_to_cpup(data); break;
- case 1: b |= end[0];
+ case 3:
+ b |= ((u32)end[2]) << 16;
+ /* fall through */
+ case 2:
+ b |= le16_to_cpup(data);
+ break;
+ case 1:
+ b |= end[0];
}
HPOSTAMBLE
}
@@ -454,9 +485,14 @@ u32 __hsiphash_unaligned(const void *data, size_t len,
v0 ^= m;
}
switch (left) {
- case 3: b |= ((u32)end[2]) << 16;
- case 2: b |= get_unaligned_le16(end); break;
- case 1: b |= end[0];
+ case 3:
+ b |= ((u32)end[2]) << 16;
+ /* fall through */
+ case 2:
+ b |= get_unaligned_le16(end);
+ break;
+ case 1:
+ b |= end[0];
}
HPOSTAMBLE
}
--
2.20.1