Merge tag 'fallthrough-fixes-clang-5.11-rc1' of git://git.kernel.org/…

…pub/scm/linux/kernel/git/gustavoars/linux

Pull fallthrough fixes from Gustavo A. R. Silva:
 "Fix many fall-through warnings when building with Clang 12.0.0
  using -Wimplicit-fallthrough.

   - powerpc: boot: include compiler_attributes.h (Nick Desaulniers)

   - Revert "lib: Revert use of fallthrough pseudo-keyword in lib/"
     (Nick Desaulniers)

   - powerpc: fix -Wimplicit-fallthrough (Nick Desaulniers)

   - lib: Fix fall-through warnings for Clang (Gustavo A. R. Silva)"

* tag 'fallthrough-fixes-clang-5.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux:
  lib: Fix fall-through warnings for Clang
  powerpc: fix -Wimplicit-fallthrough
  Revert "lib: Revert use of fallthrough pseudo-keyword in lib/"
  powerpc: boot: include compiler_attributes.h

arch/powerpc/boot/Makefile

@@ -31,6 +31,7 @@ endif
 BOOTCFLAGS    := -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \
 		 -fno-strict-aliasing -O2 -msoft-float -mno-altivec -mno-vsx \
 		 -pipe -fomit-frame-pointer -fno-builtin -fPIC -nostdinc \
+		 -include $(srctree)/include/linux/compiler_attributes.h \
 		 $(LINUXINCLUDE)
 
 ifdef CONFIG_PPC64_BOOT_WRAPPER

arch/powerpc/boot/decompress.c

@@ -21,7 +21,6 @@
 
 #define STATIC static
 #define INIT
-#define __always_inline inline
 
 /*
  * The build process will copy the required zlib source files and headers

arch/powerpc/kernel/prom_init.c

@@ -355,6 +355,7 @@ static int __init prom_strtobool(const char *s, bool *res)
 		default:
 			break;
 		}
+		break;
 	default:
 		break;
 	}

arch/powerpc/kernel/uprobes.c

@@ -141,6 +141,7 @@ int arch_uprobe_exception_notify(struct notifier_block *self,
 	case DIE_SSTEP:
 		if (uprobe_post_sstep_notifier(regs))
 			return NOTIFY_STOP;
+		break;
 	default:
 		break;
 	}

arch/powerpc/perf/imc-pmu.c

@@ -1500,6 +1500,7 @@ static int update_pmu_ops(struct imc_pmu *pmu)
 		pmu->pmu.stop = trace_imc_event_stop;
 		pmu->pmu.read = trace_imc_event_read;
 		pmu->attr_groups[IMC_FORMAT_ATTR] = &trace_imc_format_group;
+		break;
 	default:
 		break;
 	}

lib/asn1_decoder.c

@@ -381,7 +381,7 @@ int asn1_ber_decoder(const struct asn1_decoder *decoder,
 	case ASN1_OP_END_SET_ACT:
 		if (unlikely(!(flags & FLAG_MATCHED)))
 			goto tag_mismatch;
-		/* fall through */
+		fallthrough;
 
 	case ASN1_OP_END_SEQ:
 	case ASN1_OP_END_SET_OF:
@@ -448,7 +448,7 @@ int asn1_ber_decoder(const struct asn1_decoder *decoder,
 			pc += asn1_op_lengths[op];
 			goto next_op;
 		}
-		/* fall through */
+		fallthrough;
 
 	case ASN1_OP_ACT:
 		ret = actions[machine[pc + 1]](context, hdr, tag, data + tdp, len);

lib/assoc_array.c

@@ -1113,7 +1113,7 @@ struct assoc_array_edit *assoc_array_delete(struct assoc_array *array,
 						index_key))
 				goto found_leaf;
 		}
-		/* fall through */
+		fallthrough;
 	case assoc_array_walk_tree_empty:
 	case assoc_array_walk_found_wrong_shortcut:
 	default:

lib/bootconfig.c

@@ -827,7 +827,7 @@ int __init xbc_init(char *buf, const char **emsg, int *epos)
 							q - 2);
 				break;
 			}
-			/* fall through */
+			fallthrough;
 		case '=':
 			ret = xbc_parse_kv(&p, q, c);
 			break;
@@ -836,7 +836,7 @@ int __init xbc_init(char *buf, const char **emsg, int *epos)
 			break;
 		case '#':
 			q = skip_comment(q);
-			/* fall through */
+			fallthrough;
 		case ';':
 		case '\n':
 			ret = xbc_parse_key(&p, q);

lib/cmdline.c

@@ -144,27 +144,28 @@ unsigned long long memparse(const char *ptr, char **retptr)
 	case 'E':
 	case 'e':
 		ret <<= 10;
-		/* fall through */
+		fallthrough;
 	case 'P':
 	case 'p':
 		ret <<= 10;
-		/* fall through */
+		fallthrough;
 	case 'T':
 	case 't':
 		ret <<= 10;
-		/* fall through */
+		fallthrough;
 	case 'G':
 	case 'g':
 		ret <<= 10;
-		/* fall through */
+		fallthrough;
 	case 'M':
 	case 'm':
 		ret <<= 10;
-		/* fall through */
+		fallthrough;
 	case 'K':
 	case 'k':
 		ret <<= 10;
 		endptr++;
+		fallthrough;
 	default:
 		break;
 	}

lib/dim/net_dim.c

@@ -233,7 +233,7 @@ void net_dim(struct dim *dim, struct dim_sample end_sample)
 			schedule_work(&dim->work);
 			break;
 		}
-		/* fall through */
+		fallthrough;
 	case DIM_START_MEASURE:
 		dim_update_sample(end_sample.event_ctr, end_sample.pkt_ctr,
 				  end_sample.byte_ctr, &dim->start_sample);

lib/dim/rdma_dim.c

@@ -59,7 +59,7 @@ static bool rdma_dim_decision(struct dim_stats *curr_stats, struct dim *dim)
 			break;
 		case DIM_STATS_WORSE:
 			dim_turn(dim);
-			/* fall through */
+			fallthrough;
 		case DIM_STATS_BETTER:
 			step_res = rdma_dim_step(dim);
 			if (step_res == DIM_ON_EDGE)
@@ -94,7 +94,7 @@ void rdma_dim(struct dim *dim, u64 completions)
 			schedule_work(&dim->work);
 			break;
 		}
-		/* fall through */
+		fallthrough;
 	case DIM_START_MEASURE:
 		dim->state = DIM_MEASURE_IN_PROGRESS;
 		dim_update_sample_with_comps(curr_sample->event_ctr, 0, 0,

lib/glob.c

@@ -102,7 +102,7 @@ bool __pure glob_match(char const *pat, char const *str)
 			break;
 		case '\\':
 			d = *pat++;
-			/* fall through */
+			fallthrough;
 		default:	/* Literal character */
 literal:
 			if (c == d) {

lib/kstrtox.c

@@ -355,6 +355,7 @@ int kstrtobool(const char *s, bool *res)
 		default:
 			break;
 		}
+		break;
 	default:
 		break;
 	}

lib/nlattr.c

@@ -432,7 +432,7 @@ static int validate_nla(const struct nlattr *nla, int maxtype,
 			err = -EINVAL;
 			goto out_err;
 		}
-		/* fall through */
+		fallthrough;
 
 	case NLA_STRING:
 		if (attrlen < 1)

lib/siphash.c

@@ -68,11 +68,11 @@ 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; /* fall through */
-	case 6: b |= ((u64)end[5]) << 40; /* fall through */
-	case 5: b |= ((u64)end[4]) << 32; /* fall through */
+	case 7: b |= ((u64)end[6]) << 48; fallthrough;
+	case 6: b |= ((u64)end[5]) << 40; fallthrough;
+	case 5: b |= ((u64)end[4]) << 32; fallthrough;
 	case 4: b |= le32_to_cpup(data); break;
-	case 3: b |= ((u64)end[2]) << 16; /* fall through */
+	case 3: b |= ((u64)end[2]) << 16; fallthrough;
 	case 2: b |= le16_to_cpup(data); break;
 	case 1: b |= end[0];
 	}
@@ -101,11 +101,11 @@ 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; /* fall through */
-	case 6: b |= ((u64)end[5]) << 40; /* fall through */
-	case 5: b |= ((u64)end[4]) << 32; /* fall through */
+	case 7: b |= ((u64)end[6]) << 48; fallthrough;
+	case 6: b |= ((u64)end[5]) << 40; fallthrough;
+	case 5: b |= ((u64)end[4]) << 32; fallthrough;
 	case 4: b |= get_unaligned_le32(end); break;
-	case 3: b |= ((u64)end[2]) << 16; /* fall through */
+	case 3: b |= ((u64)end[2]) << 16; fallthrough;
 	case 2: b |= get_unaligned_le16(end); break;
 	case 1: b |= end[0];
 	}
@@ -268,11 +268,11 @@ u32 __hsiphash_aligned(const void *data, size_t len, const hsiphash_key_t *key)
 						  bytemask_from_count(left)));
 #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 7: b |= ((u64)end[6]) << 48; fallthrough;
+	case 6: b |= ((u64)end[5]) << 40; fallthrough;
+	case 5: b |= ((u64)end[4]) << 32; fallthrough;
 	case 4: b |= le32_to_cpup(data); break;
-	case 3: b |= ((u64)end[2]) << 16; /* fall through */
+	case 3: b |= ((u64)end[2]) << 16; fallthrough;
 	case 2: b |= le16_to_cpup(data); break;
 	case 1: b |= end[0];
 	}
@@ -301,11 +301,11 @@ u32 __hsiphash_unaligned(const void *data, size_t len,
 						  bytemask_from_count(left)));
 #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 7: b |= ((u64)end[6]) << 48; fallthrough;
+	case 6: b |= ((u64)end[5]) << 40; fallthrough;
+	case 5: b |= ((u64)end[4]) << 32; fallthrough;
 	case 4: b |= get_unaligned_le32(end); break;
-	case 3: b |= ((u64)end[2]) << 16; /* fall through */
+	case 3: b |= ((u64)end[2]) << 16; fallthrough;
 	case 2: b |= get_unaligned_le16(end); break;
 	case 1: b |= end[0];
 	}
@@ -431,7 +431,7 @@ 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; /* fall through */
+	case 3: b |= ((u32)end[2]) << 16; fallthrough;
 	case 2: b |= le16_to_cpup(data); break;
 	case 1: b |= end[0];
 	}
@@ -454,7 +454,7 @@ u32 __hsiphash_unaligned(const void *data, size_t len,
 		v0 ^= m;
 	}
 	switch (left) {
-	case 3: b |= ((u32)end[2]) << 16; /* fall through */
+	case 3: b |= ((u32)end[2]) << 16; fallthrough;
 	case 2: b |= get_unaligned_le16(end); break;
 	case 1: b |= end[0];
 	}

lib/ts_fsm.c

@@ -193,7 +193,7 @@ static unsigned int fsm_find(struct ts_config *conf, struct ts_state *state)
 				TOKEN_MISMATCH();
 
 			block_idx++;
-			/* fall through */
+			fallthrough;
 
 		case TS_FSM_ANY:
 			if (next == NULL)

lib/vsprintf.c

@@ -1265,7 +1265,7 @@ char *mac_address_string(char *buf, char *end, u8 *addr,
 
 	case 'R':
 		reversed = true;
-		/* fall through */
+		fallthrough;
 
 	default:
 		separator = ':';
@@ -1682,7 +1682,7 @@ char *uuid_string(char *buf, char *end, const u8 *addr,
 	switch (*(++fmt)) {
 	case 'L':
 		uc = true;
-		/* fall through */
+		fallthrough;
 	case 'l':
 		index = guid_index;
 		break;
@@ -2219,7 +2219,7 @@ char *pointer(const char *fmt, char *buf, char *end, void *ptr,
 	case 'S':
 	case 's':
 		ptr = dereference_symbol_descriptor(ptr);
-		/* fall through */
+		fallthrough;
 	case 'B':
 		return symbol_string(buf, end, ptr, spec, fmt);
 	case 'R':
@@ -2450,7 +2450,7 @@ int format_decode(const char *fmt, struct printf_spec *spec)
 
 	case 'x':
 		spec->flags |= SMALL;
-		/* fall through */
+		fallthrough;
 
 	case 'X':
 		spec->base = 16;
@@ -2459,6 +2459,7 @@ int format_decode(const char *fmt, struct printf_spec *spec)
 	case 'd':
 	case 'i':
 		spec->flags |= SIGN;
+		break;
 	case 'u':
 		break;
 
@@ -2468,7 +2469,7 @@ int format_decode(const char *fmt, struct printf_spec *spec)
 		 * utility, treat it as any other invalid or
 		 * unsupported format specifier.
 		 */
-		/* fall through */
+		fallthrough;
 
 	default:
 		WARN_ONCE(1, "Please remove unsupported %%%c in format string\n", *fmt);
@@ -3411,10 +3412,10 @@ int vsscanf(const char *buf, const char *fmt, va_list args)
 			break;
 		case 'i':
 			base = 0;
-			/* fall through */
+			fallthrough;
 		case 'd':
 			is_sign = true;
-			/* fall through */
+			fallthrough;
 		case 'u':
 			break;
 		case '%':

lib/xz/xz_dec_lzma2.c

@@ -1043,7 +1043,7 @@ XZ_EXTERN enum xz_ret xz_dec_lzma2_run(struct xz_dec_lzma2 *s,
 
 			s->lzma2.sequence = SEQ_LZMA_PREPARE;
 
-			/* fall through */
+			fallthrough;
 
 		case SEQ_LZMA_PREPARE:
 			if (s->lzma2.compressed < RC_INIT_BYTES)
@@ -1055,7 +1055,7 @@ XZ_EXTERN enum xz_ret xz_dec_lzma2_run(struct xz_dec_lzma2 *s,
 			s->lzma2.compressed -= RC_INIT_BYTES;
 			s->lzma2.sequence = SEQ_LZMA_RUN;
 
-			/* fall through */
+			fallthrough;
 
 		case SEQ_LZMA_RUN:
 			/*