From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 214651FE47B; Sun, 7 Jun 2026 10:32:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780828355; cv=none; b=uJbrfwRYZG3PINhO0754Zvt1FgCl3ECTgRV48QD9gur1fW1npIoqGCfo4Yfvkc1bVh1rs9W7ZDkH3bj8P5RkQFwllXHHlKDIifCMbVU2xicagombHPFcRc+jWlJLbXKcI3RezO7mgP4Z5uM72Q4NX+4YeITiHx5qeFMhZwqIhyI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780828355; c=relaxed/simple; bh=sVq3wJAw7CTzFqEp2vUDQpkuhJOUHkaKIBNhmoHqDeI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Lz5mkZqqdH/AQIjmS7XC9RWhg5Y1kY24jkgAh5w/H1oRbnaaYWh1DK+3uaKrIgtk+MNGhR4Ysane0Oqsk4cRug09SzMOJrOsuZEFy3ta5IkbHiMoJ+rwIn2oivxizmMrzGnD+Vy4flMXXTtnC5i4SQ8tZz7ldJhLPQae9CUPFcY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Tsjcuku5; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="Tsjcuku5" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1DD8F1F00893; Sun, 7 Jun 2026 10:32:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1780828353; bh=P6dbCCIGK3NZP0qtF+EUf08NuwpHsLSrhG/Hi+cHqv0=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Tsjcuku51CDKdxN6QiPUqPS0NXDRcqUf9nNNK6TzmQbW4rfmQKVYZl+wYLDIHnv5u qeNyx6FzoCs6l8fw9dUUBV6H6rO0irhhOnPlr5VzoU1/LX2+g7c+YoXvrrWFXacH2u 7O6PG1LqwiaGbMvsltL4AmoEgN3v+plFHEucMNGU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Nathan Chancellor Subject: [PATCH 6.18 152/315] Disable -Wattribute-alias for clang-23 and newer Date: Sun, 7 Jun 2026 11:58:59 +0200 Message-ID: <20260607095733.189792177@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260607095727.528828913@linuxfoundation.org> References: <20260607095727.528828913@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Nathan Chancellor commit 175db11786bde9061db526bf1ac5107d915f5163 upstream. Clang recently added support for -Wattribute-alias [1], which results in the same warnings that necessitated commit bee20031772a ("disable -Wattribute-alias warning for SYSCALL_DEFINEx()") for GCC. kernel/time/itimer.c:325:1: error: alias and aliasee have different types 'long (unsigned int)' and 'long (typeof (__builtin_choose_expr((__builtin_types_compatible_p(typeof ((unsigned int)0), typeof (0LL)) || __builtin_types_compatible_p(typeof ((unsigned int)0), typeof (0ULL))), 0LL, 0L)))' (aka 'long (long)') [-Werror,-Wattribute-alias] 325 | SYSCALL_DEFINE1(alarm, unsigned int, seconds) | ^ include/linux/syscalls.h:225:36: note: expanded from macro 'SYSCALL_DEFINE1' 225 | #define SYSCALL_DEFINE1(name, ...) SYSCALL_DEFINEx(1, _##name, __VA_ARGS__) | ^ include/linux/syscalls.h:236:2: note: expanded from macro 'SYSCALL_DEFINEx' 236 | __SYSCALL_DEFINEx(x, sname, __VA_ARGS__) | ^ include/linux/syscalls.h:251:18: note: expanded from macro '__SYSCALL_DEFINEx' 251 | __attribute__((alias(__stringify(__se_sys##name)))); \ | ^ kernel/time/itimer.c:325:1: note: aliasee is declared here include/linux/syscalls.h:225:36: note: expanded from macro 'SYSCALL_DEFINE1' 225 | #define SYSCALL_DEFINE1(name, ...) SYSCALL_DEFINEx(1, _##name, __VA_ARGS__) | ^ include/linux/syscalls.h:236:2: note: expanded from macro 'SYSCALL_DEFINEx' 236 | __SYSCALL_DEFINEx(x, sname, __VA_ARGS__) | ^ include/linux/syscalls.h:255:18: note: expanded from macro '__SYSCALL_DEFINEx' 255 | asmlinkage long __se_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__)) \ | ^ :16:1: note: expanded from here 16 | __se_sys_alarm | ^ Disable the warnings in the same way for clang-23 and newer. Disable the warning about unknown warning options to avoid breaking the build for versions of clang-23 that do not have -Wattribute-alias, such as ones deployed by vendors like Android or CI systems or when bisecting LLVM between llvmorg-23-init and release/23.x. Cc: stable@vger.kernel.org Closes: https://github.com/ClangBuiltLinux/linux/issues/2163 Link: https://github.com/llvm/llvm-project/commit/40da6920a0d71d49dfa2392b09153600b0759f5e [1] Link: https://patch.msgid.link/20260515-syscall-disable-attribute-alias-for-clang-v1-1-9a9d95d41df6@kernel.org Signed-off-by: Nathan Chancellor Signed-off-by: Greg Kroah-Hartman --- arch/riscv/include/asm/syscall_wrapper.h | 4 ++++ include/linux/compat.h | 4 ++++ include/linux/compiler-clang.h | 6 ++++++ include/linux/compiler_types.h | 4 ++++ include/linux/syscalls.h | 4 ++++ 5 files changed, 22 insertions(+) --- a/arch/riscv/include/asm/syscall_wrapper.h +++ b/arch/riscv/include/asm/syscall_wrapper.h @@ -32,6 +32,10 @@ asmlinkage long __riscv_sys_ni_syscall(c __diag_push(); \ __diag_ignore(GCC, 8, "-Wattribute-alias", \ "Type aliasing is used to sanitize syscall arguments"); \ + __diag_ignore(clang, 23, "-Wunknown-warning-option", \ + "Avoid breaking versions without -Wattribute-alias"); \ + __diag_ignore(clang, 23, "-Wattribute-alias", \ + "Type aliasing is used to sanitize syscall arguments"); \ static long __se_##prefix##name(ulong, ulong, ulong, ulong, ulong, ulong, \ ulong) \ __attribute__((alias(__stringify(___se_##prefix##name)))); \ --- a/include/linux/compat.h +++ b/include/linux/compat.h @@ -72,6 +72,10 @@ __diag_push(); \ __diag_ignore(GCC, 8, "-Wattribute-alias", \ "Type aliasing is used to sanitize syscall arguments");\ + __diag_ignore(clang, 23, "-Wunknown-warning-option", \ + "Avoid breaking versions without -Wattribute-alias"); \ + __diag_ignore(clang, 23, "-Wattribute-alias", \ + "Type aliasing is used to sanitize syscall arguments"); \ asmlinkage long compat_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)) \ __attribute__((alias(__stringify(__se_compat_sys##name)))); \ ALLOW_ERROR_INJECTION(compat_sys##name, ERRNO); \ --- a/include/linux/compiler-clang.h +++ b/include/linux/compiler-clang.h @@ -131,6 +131,12 @@ #define __diag_str(s) __diag_str1(s) #define __diag(s) _Pragma(__diag_str(clang diagnostic s)) +#if CONFIG_CLANG_VERSION >= 230000 +#define __diag_clang_23(s) __diag(s) +#else +#define __diag_clang_23(s) +#endif + #define __diag_clang_13(s) __diag(s) #define __diag_ignore_all(option, comment) \ --- a/include/linux/compiler_types.h +++ b/include/linux/compiler_types.h @@ -636,6 +636,10 @@ struct ftrace_likely_data { #define __diag_GCC(version, severity, string) #endif +#ifndef __diag_clang +#define __diag_clang(version, severity, string) +#endif + #define __diag_push() __diag(push) #define __diag_pop() __diag(pop) --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -247,6 +247,10 @@ static inline int is_syscall_trace_event __diag_push(); \ __diag_ignore(GCC, 8, "-Wattribute-alias", \ "Type aliasing is used to sanitize syscall arguments");\ + __diag_ignore(clang, 23, "-Wunknown-warning-option", \ + "Avoid breaking versions without -Wattribute-alias");\ + __diag_ignore(clang, 23, "-Wattribute-alias", \ + "Type aliasing is used to sanitize syscall arguments");\ asmlinkage long sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)) \ __attribute__((alias(__stringify(__se_sys##name)))); \ ALLOW_ERROR_INJECTION(sys##name, ERRNO); \