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signal: Mark expected switch fall-throughs

PATCH In review Gustavo A. R. Silva 3 participants 4 messages Oct 13, 2018 – Oct 16, 2018

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Gustavo A. R. Silva

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#0 lore raw

PATCH 1/1 signal: Mark expected switch fall-throughs

In preparation to enabling -Wimplicit-fallthrough, mark switch cases where we are expecting to fall through.

Signed-off-by Gustavo A. R. Silva <[email protected]>
---
 include/linux/signal.h | 6 ++++++
 1 file changed, 6 insertions(+)
include/linux/signal.h +6 -0
index 200ed96..f428e86 100644
@@ -129,9 +129,11 @@ static inline void name(sigset_t *r, const sigset_t *a, const sigset_t *b) \
 		b3 = b->sig[3]; b2 = b->sig[2];				\
 		r->sig[3] = op(a3, b3);					\
 		r->sig[2] = op(a2, b2);					\
+		/* fall through */					\
 	case 2:								\
 		a1 = a->sig[1]; b1 = b->sig[1];				\
 		r->sig[1] = op(a1, b1);					\
+		/* fall through */					\
 	case 1:								\
 		a0 = a->sig[0]; b0 = b->sig[0];				\
 		r->sig[0] = op(a0, b0);					\

@@ -161,7 +163,9 @@ static inline void name(sigset_t *set)					\
 	switch (_NSIG_WORDS) {						\
 	case 4:	set->sig[3] = op(set->sig[3]);				\
 		set->sig[2] = op(set->sig[2]);				\
+		/* fall through */					\
 	case 2:	set->sig[1] = op(set->sig[1]);				\
+		/* fall through */					\
 	case 1:	set->sig[0] = op(set->sig[0]);				\
 		    break;						\
 	default:							\

@@ -182,6 +186,7 @@ static inline void sigemptyset(sigset_t *set)
 		memset(set, 0, sizeof(sigset_t));
 		break;
 	case 2: set->sig[1] = 0;
+		/* fall through */
 	case 1:	set->sig[0] = 0;
 		break;
 	}

@@ -194,6 +199,7 @@ static inline void sigfillset(sigset_t *set)
 		memset(set, -1, sizeof(sigset_t));
 		break;
 	case 2: set->sig[1] = -1;
+		/* fall through */
 	case 1:	set->sig[0] = -1;
 		break;
 	}
Signature · 1 line
2.7.4
Acked-by on v1 1/1
#1 lore raw
Quoted 4 lines · Gustavo A. R. Silva

In preparation to enabling -Wimplicit-fallthrough, mark switch cases where we are expecting to fall through.

Signed-off-by Gustavo A. R. Silva <[email protected]>

Yes, please. :) I love every step closer we get to being able to use -Wimplicit-fallthrough.

Acked-by Kees Cook <[email protected]>

-Kees

Quoted 49 lines
---
 include/linux/signal.h | 6 ++++++
 1 file changed, 6 insertions(+)
include/linux/signal.h +6 -1
index 200ed96..f428e86 100644
@@ -129,9 +129,11 @@ static inline void name(sigset_t *r, const sigset_t *a, const sigset_t *b) \
                b3 = b->sig[3]; b2 = b->sig[2];                         \
                r->sig[3] = op(a3, b3);                                 \
                r->sig[2] = op(a2, b2);                                 \
+               /* fall through */                                      \
        case 2:                                                         \
                a1 = a->sig[1]; b1 = b->sig[1];                         \
                r->sig[1] = op(a1, b1);                                 \
+               /* fall through */                                      \
        case 1:                                                         \
                a0 = a->sig[0]; b0 = b->sig[0];                         \
                r->sig[0] = op(a0, b0);                                 \

@@ -161,7 +163,9 @@ static inline void name(sigset_t *set)                                      \
        switch (_NSIG_WORDS) {                                          \
        case 4: set->sig[3] = op(set->sig[3]);                          \
                set->sig[2] = op(set->sig[2]);                          \
+               /* fall through */                                      \
        case 2: set->sig[1] = op(set->sig[1]);                          \
+               /* fall through */                                      \
        case 1: set->sig[0] = op(set->sig[0]);                          \
                    break;                                              \
        default:                                                        \

@@ -182,6 +186,7 @@ static inline void sigemptyset(sigset_t *set)
                memset(set, 0, sizeof(sigset_t));
                break;
        case 2: set->sig[1] = 0;
+               /* fall through */
        case 1: set->sig[0] = 0;
                break;
        }

@@ -194,6 +199,7 @@ static inline void sigfillset(sigset_t *set)
                memset(set, -1, sizeof(sigset_t));
                break;
        case 2: set->sig[1] = -1;
+               /* fall through */
        case 1: set->sig[0] = -1;
                break;
        }
--

2.7.4

Signature · 2 lines
Kees Cook
Pixel Security
Reviewed-by on v1 1/1
#3 lore raw
In reply to Gustavo A. R. Silva

[ Cc += [email protected] ]

Quoted 7 lines · Gustavo A. R. Silva

In preparation to enabling -Wimplicit-fallthrough, mark switch cases where we are expecting to fall through.

Signed-off-by Gustavo A. R. Silva <[email protected]>
---
 include/linux/signal.h | 6 ++++++
 1 file changed, 6 insertions(+)

These all look correct to me.

Reviewed-by Michael Ellerman <[email protected]>
Quoted 35 lines
include/linux/signal.h +5 -0
index 200ed96..f428e86 100644
@@ -129,9 +129,11 @@ static inline void name(sigset_t *r, const sigset_t *a, const sigset_t *b) \
 		b3 = b->sig[3]; b2 = b->sig[2];				\
 		r->sig[3] = op(a3, b3);					\
 		r->sig[2] = op(a2, b2);					\
+		/* fall through */					\
 	case 2:								\
 		a1 = a->sig[1]; b1 = b->sig[1];				\
 		r->sig[1] = op(a1, b1);					\
+		/* fall through */					\
 	case 1:								\
 		a0 = a->sig[0]; b0 = b->sig[0];				\
 		r->sig[0] = op(a0, b0);					\

@@ -161,7 +163,9 @@ static inline void name(sigset_t *set)					\
 	switch (_NSIG_WORDS) {						\
 	case 4:	set->sig[3] = op(set->sig[3]);				\
 		set->sig[2] = op(set->sig[2]);				\
+		/* fall through */					\
 	case 2:	set->sig[1] = op(set->sig[1]);				\
+		/* fall through */					\
 	case 1:	set->sig[0] = op(set->sig[0]);				\
 		    break;						\
 	default:							\

@@ -182,6 +186,7 @@ static inline void sigemptyset(sigset_t *set)
 		memset(set, 0, sizeof(sigset_t));
 		break;
 	case 2: set->sig[1] = 0;
+		/* fall through */
 	case 1:	set->sig[0] = 0;
 		break;
 	}

include/linux/signal.h static inline void sigfillset(sigset_t *set) · line 205

Quoted 7 lines
include/linux/signal.h +1 -0
@@ -194,6 +199,7 @@ static inline void sigfillset(sigset_t *set)
 		memset(set, -1, sizeof(sigset_t));
 		break;
 	case 2: set->sig[1] = -1;
+		/* fall through */
 	case 1:	set->sig[0] = -1;
 		break;
 	}

I think _NSIG_WORDS is always constant. So these last two seem like they could just be replaced with memset() and a modern compiler would do the right thing.

cheers

author
#2 lore raw
In reply to Kees Cook
Quoted 10 lines · Kees Cook
Quoted 4 lines · Gustavo A. R. Silva

In preparation to enabling -Wimplicit-fallthrough, mark switch cases where we are expecting to fall through.

Signed-off-by Gustavo A. R. Silva <[email protected]>

Yes, please. :) I love every step closer we get to being able to use -Wimplicit-fallthrough.

Yep. We are getting there. :D

Quoted 2 lines
Acked-by Kees Cook <[email protected]>

Thanks
--
Gustavo