From 1c3bea0e71892ef9100c01d3799cdae8cac273ef Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Mon, 13 Oct 2014 15:53:33 -0700 Subject: [PATCH] signal: use BUILD_BUG() instead of _NSIG_WORDS_is_unsupported_size() Kill _NSIG_WORDS_is_unsupported_size(), use BUILD_BUG() instead. This simplifies the code, avoids the nested-externs warnings, and this way we do not defer the problem to linker. Also, fix the indentation in _SIG_SET_BINOP() and _SIG_SET_OP(). Note: this patch assumes that the code like "if (0) BUILD_BUG();" is valid. If not (say __compiletime_error() is not defined and thus __compiletime_error_fallback() uses a negative array) we should fix BUILD_BUG() and/or BUILD_BUG_ON_MSG(). This code should be fine by definition, this is the documented purpose of BUILD_BUG(). [sfr@canb.auug.org.au: fix powerpc build failures] Signed-off-by: Oleg Nesterov Reported-by: Jeff Kirsher Reviewed-by: Josh Triplett Signed-off-by: Stephen Rothwell Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/signal.h | 29 +++++++++++++---------------- 1 file changed, 13 insertions(+), 16 deletions(-) diff --git a/include/linux/signal.h b/include/linux/signal.h index 750196fcc0a..ab1e0392b5a 100644 --- a/include/linux/signal.h +++ b/include/linux/signal.h @@ -2,6 +2,7 @@ #define _LINUX_SIGNAL_H #include +#include #include struct task_struct; @@ -67,7 +68,6 @@ static inline int sigismember(sigset_t *set, int _sig) static inline int sigisemptyset(sigset_t *set) { - extern void _NSIG_WORDS_is_unsupported_size(void); switch (_NSIG_WORDS) { case 4: return (set->sig[3] | set->sig[2] | @@ -77,7 +77,7 @@ static inline int sigisemptyset(sigset_t *set) case 1: return set->sig[0] == 0; default: - _NSIG_WORDS_is_unsupported_size(); + BUILD_BUG(); return 0; } } @@ -90,24 +90,23 @@ static inline int sigisemptyset(sigset_t *set) #define _SIG_SET_BINOP(name, op) \ static inline void name(sigset_t *r, const sigset_t *a, const sigset_t *b) \ { \ - extern void _NSIG_WORDS_is_unsupported_size(void); \ unsigned long a0, a1, a2, a3, b0, b1, b2, b3; \ \ switch (_NSIG_WORDS) { \ - case 4: \ + case 4: \ a3 = a->sig[3]; a2 = a->sig[2]; \ b3 = b->sig[3]; b2 = b->sig[2]; \ r->sig[3] = op(a3, b3); \ r->sig[2] = op(a2, b2); \ - case 2: \ + case 2: \ a1 = a->sig[1]; b1 = b->sig[1]; \ r->sig[1] = op(a1, b1); \ - case 1: \ + case 1: \ a0 = a->sig[0]; b0 = b->sig[0]; \ r->sig[0] = op(a0, b0); \ break; \ - default: \ - _NSIG_WORDS_is_unsupported_size(); \ + default: \ + BUILD_BUG(); \ } \ } @@ -128,16 +127,14 @@ _SIG_SET_BINOP(sigandnsets, _sig_andn) #define _SIG_SET_OP(name, op) \ static inline void name(sigset_t *set) \ { \ - extern void _NSIG_WORDS_is_unsupported_size(void); \ - \ switch (_NSIG_WORDS) { \ - case 4: set->sig[3] = op(set->sig[3]); \ - set->sig[2] = op(set->sig[2]); \ - case 2: set->sig[1] = op(set->sig[1]); \ - case 1: set->sig[0] = op(set->sig[0]); \ + case 4: set->sig[3] = op(set->sig[3]); \ + set->sig[2] = op(set->sig[2]); \ + case 2: set->sig[1] = op(set->sig[1]); \ + case 1: set->sig[0] = op(set->sig[0]); \ break; \ - default: \ - _NSIG_WORDS_is_unsupported_size(); \ + default: \ + BUILD_BUG(); \ } \ } -- 2.46.0