From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Morton Subject: [patch 126/166] lib/dynamic_debug.c: use address-of operator on section symbols Date: Mon, 06 Apr 2020 20:10:45 -0700 Message-ID: <20200407031045.KqfxtQns2%akpm@linux-foundation.org> References: <20200406200254.a69ebd9e08c4074e41ddebaf@linux-foundation.org> Reply-To: linux-kernel@vger.kernel.org Return-path: Received: from mail.kernel.org ([198.145.29.99]:56402 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726331AbgDGDKr (ORCPT ); Mon, 6 Apr 2020 23:10:47 -0400 In-Reply-To: <20200406200254.a69ebd9e08c4074e41ddebaf@linux-foundation.org> Sender: mm-commits-owner@vger.kernel.org List-Id: mm-commits@vger.kernel.org To: akpm@linux-foundation.org, jbaron@akamai.com, linux-mm@kvack.org, mm-commits@vger.kernel.org, natechancellor@gmail.com, ndesaulniers@google.com, torvalds@linux-foundation.org From: Nathan Chancellor Subject: lib/dynamic_debug.c: use address-of operator on section symbols Clang warns: ../lib/dynamic_debug.c:1034:24: warning: array comparison always evaluates to false [-Wtautological-compare] if (__start___verbose == __stop___verbose) { ^ 1 warning generated. These are not true arrays, they are linker defined symbols, which are just addresses. Using the address of operator silences the warning and does not change the resulting assembly with either clang/ld.lld or gcc/ld (tested with diff + objdump -Dr). Link: https://github.com/ClangBuiltLinux/linux/issues/894 Link: http://lkml.kernel.org/r/20200220051320.10739-1-natechancellor@gmail.com Signed-off-by: Nathan Chancellor Suggested-by: Nick Desaulniers Acked-by: Jason Baron Signed-off-by: Andrew Morton --- lib/dynamic_debug.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/lib/dynamic_debug.c~dynamic_debug-use-address-of-operator-on-section-symbols +++ a/lib/dynamic_debug.c @@ -1031,7 +1031,7 @@ static int __init dynamic_debug_init(voi int n = 0, entries = 0, modct = 0; int verbose_bytes = 0; - if (__start___verbose == __stop___verbose) { + if (&__start___verbose == &__stop___verbose) { pr_warn("_ddebug table is empty in a CONFIG_DYNAMIC_DEBUG build\n"); return 1; } _