From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wm1-f47.google.com (mail-wm1-f47.google.com [209.85.128.47]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E39AF54CF68 for ; Tue, 13 Oct 2026 20:31:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.47 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791923521; cv=none; b=bD8zmg/Sh5fxHlDg38UIDPy/BQlJ3bm+Li1gOBYlhm2PtU7TfyvAUoGipV0Clt8FMuUhQLMofH5o9tLQV6lYe0AFdL/yQh2rnkdDNU8G/fTSObH1oEmiQoA2v8Hhu9Y93oPtN+DGnSxd053TSQEQ3ipKOJTqnPb43ms8pmvx70o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791923521; c=relaxed/simple; bh=f9EkJkO0/YdEpyV9iZEvDv1BUADI4zTrdrfFh5OACE4=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=VUPZLWM3jA87LqSnXY+fkHDo3fhMb1oahKjtYHG5mkU93Z5K2+nWmCCcVMOLB4YdCMR2sfnUKEXYaEEpwwGo7GfaTlDH/2vmFO621lsQPw4rbXkI0HMUO4GHse66pzGJ0oXlw/AZtmK77gevFDwQXRo1nNdwluLuFUEPB3r/imQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=JvyU9O+b; arc=none smtp.client-ip=209.85.128.47 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="JvyU9O+b" Received: by mail-wm1-f47.google.com with SMTP id 5b1f17b1804b1-4a02718da81so27260275e9.1 for ; Tue, 13 Oct 2026 13:31:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1791923517; x=1792528317; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to:content-type; bh=dSRlsCJ/5tvpWWe5VR84qQBeBhF4B6Pki9zDFnj6lNc=; b=JvyU9O+b8TuhIDYebZB2p6HUdZtbELUnoGK7yeN5ZHwiV+nlqYvIoVtx16bs7pVbot IfI6xxihqrjxmEK5W0k6OobbVaSEkribya1boFMU+h4ZpHYKJDV1Ha1AaiKS/XNftIQ9 luZy2HPLZXVHViU9nEeiwjetwPTCj1izQtuL8Uv+oMVgZKXZqy8SIQbKMgwa5Li6cvEf WqBvNh/R9G9gQxiqLtCbBi3ocMqfRWPLm6ZlYXhBh08wkpJhDFs2TmjZ/w4H5L9Wgtzb cN/Kkwger4tfeU0PgWswN9j545gdUz5lCuL+fWncZ8x0Vkj9A48q8vIISLScfJEpo3Aj sHAA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1791923517; x=1792528317; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to:content-type; bh=dSRlsCJ/5tvpWWe5VR84qQBeBhF4B6Pki9zDFnj6lNc=; b=SXTz1c65PLhjDex7q5xflZN0JTCl7Dot5WKCYTFvMAIYtqWJM9etB8vG5tHVxG2d3q y5rkwpYeDEOtxlEE+aK3XWhyhxXWpP7f7U+teQmhTRuYeRhU4oOBdXTK9spsiNJgpfBl tWLnuRPsZ7XeHvrUom7nPXmzeuew0rCGdZEv3GTEPOW8/MMF6Um23Ful23ls3V0Uketu CcU5nW3KVP4pyLlp/dLTsL1rbSE8B9wsFzrVvqih8fnKQ7SmjEnFKsF1DqNCq9tMJ3/T ds/AltUQut9CLWYXg2vDrfyf/LikOtnO5lg7b+QziXQTVe/Q2fTcv/Nd69ymGcRbGaXD ax0w== X-Forwarded-Encrypted: i=1; AKwUvBzzM/Y6fkPoU2V3TQ2VZ379ajnlPy6u+Nczi3Iw2OCE2hUnWmodyCc78d1/vpITcBiOo+HLbb4ZSaKtAu8=@vger.kernel.org X-Gm-Message-State: AFq9FYJAxVxeFNqe6pW7/FwZV9NozsZIJfw2hL/tt63c0cqWX7XOQM5A RSWgw+OdbX4rl8QAm8wE/TW3NA1mkrTC7m6FRzPk/l3heAZitdSQzS02 X-Gm-Gg: AYBFou3Rtj1+NUaHVSTbyMQYlSQTw8CTnWUIdsHzPEkcXP0shOnGTnfshVni5AXbO+f VeqdbpVReHmKsUrIdM5LiZVR/11xg21p45FAIfcEa9hvq3qE0HVJa1tvQHHyOReKil+X/qZxQj2 /0D0OnmeA5nCVjIvWtE2Wbia4tTcu3wZRyIf91IHUOpP3DVeBhE8a4Z00LF7dYeLziWwionhcLq 17V/X6dAcIzYu3yFjSMPfSTK9DnxaI4cJ9r9NQ1LF4PLew8/tYo4woCUyoUD8uhRUcdH3nQi+hw Txl0QNwUMTV/yck/mLeT868dMxMXioqTdb4VRuyfhwnQraRe4AUoz9UusyKy9I6kSH2vrZI+ge0 TB7ueh8ZzwDNhWyCEkgBCpeMmEDCaKd4bRkJLMY7GNQeBd1GZ9A+nsPaIA+fdas7Tuw6ZzE7pNY eKQX/DSEmboHgDLVrrwo6GfDmyPGwC86EELVlWEIrKn3uHQkLK6C7i9f0x0D3kue3ymOp7r0xJ+ YSZx9eOElaS31SzOYLEWsFc2GK7IanRm95zM7k2qrplo1dKmfJrytF2CGEWJG7lAGfhDNQeOIG4 I/XgaKHzzCw2KTdZcMGn5uY7RL5ZnGhnPKyUMhH7h/fV4ph8TDX4SVK3ptVifwx7Ew8u6X7hNvE L6vhBK2+LEuBxC10v X-Received: by 2002:a05:600c:34d4:b0:4a0:108:3b54 with SMTP id 5b1f17b1804b1-4a18e4d67d6mr260625985e9.32.1791923516977; Tue, 13 Oct 2026 13:31:56 -0700 (PDT) Received: from localhost.localdomain (dynamic-2a02-3100-a189-2701-8c58-155a-0279-7389.310.pool.telefonica.de. [2a02:3100:a189:2701:8c58:155a:279:7389]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-4a1b481b7f8sm5237345e9.3.2026.10.13.13.31.49 (version=TLS1_3 cipher=TLS_CHACHA20_POLY1305_SHA256 bits=256/256); Tue, 13 Oct 2026 13:31:52 -0700 (PDT) From: Karl Mehltretter To: Russell King , Miguel Ojeda Cc: Karl Mehltretter , Boqun Feng , Gary Guo , =?UTF-8?q?Bj=C3=B6rn=20Roy=20Baron?= , Benno Lossin , Andreas Hindborg , Alice Ryhl , Trevor Gross , Danilo Krummrich , Daniel Almeida , Tamir Duberstein , Alexandre Courbot , =?UTF-8?q?Onur=20=C3=96zkan?= , Arnd Bergmann , Linus Walleij , Christian Schrefl , Bradley Morgan , "Paul E . McKenney" , Peter Zijlstra , FUJITA Tomonori , Nathan Chancellor , Nick Desaulniers , Bill Wendling , Justin Stitt , linux-arm-kernel@lists.infradead.org, rust-for-linux@vger.kernel.org, llvm@lists.linux.dev, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v3 1/6] ARM: cmpxchg: always inline __arch_xchg() and __cmpxchg() Date: Tue, 13 Oct 2026 22:31:35 +0200 Message-Id: <20261013203140.31741-2-kmehltretter@gmail.com> X-Mailer: git-send-email 2.39.5 (Apple Git-154) In-Reply-To: <20261013203140.31741-1-kmehltretter@gmail.com> References: <20261013203140.31741-1-kmehltretter@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit __arch_xchg(), __cmpxchg() and __cmpxchg_local() rely on inlining to remove their undefined-function calls for unsupported sizes. With gcc 8.1.0 and CC_OPTIMIZE_FOR_SIZE, bcm2835_defconfig with RUST=y fails to link. The compiler emits out-of-line copies for the many callers in rust/helpers/helpers.c, retaining those calls: helpers.c:(.text+0x424): undefined reference to `__bad_xchg' helpers.c:(.text+0x4ac): undefined reference to `__bad_cmpxchg' Mark the functions __always_inline so the compiler can remove the unsupported-size path for each caller's constant size. Fixes: ab717dd98bee ("rust: helpers: Add i8/i16 atomic xchg_acquire helpers") Fixes: ac8f06ade38a ("rust: sync: atomic: Add Atomic<*{mut,const} T> support") Cc: stable@vger.kernel.org Reviewed-by: Bradley Morgan Reviewed-by: Gary Guo Assisted-by: LLM Signed-off-by: Karl Mehltretter --- arch/arm/include/asm/cmpxchg.h | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/arch/arm/include/asm/cmpxchg.h b/arch/arm/include/asm/cmpxchg.h index 9beb64d30586..0ce5225af442 100644 --- a/arch/arm/include/asm/cmpxchg.h +++ b/arch/arm/include/asm/cmpxchg.h @@ -26,7 +26,7 @@ #define swp_is_buggy #endif -static inline unsigned long +static __always_inline unsigned long __arch_xchg(unsigned long x, volatile void *ptr, int size) { extern void __bad_xchg(volatile void *, int); @@ -155,8 +155,8 @@ extern void __bad_cmpxchg(volatile void *ptr, int size); * cmpxchg only support 32-bits operands on ARMv6. */ -static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old, - unsigned long new, int size) +static __always_inline unsigned long +__cmpxchg(volatile void *ptr, unsigned long old, unsigned long new, int size) { unsigned long oldval, res; @@ -220,9 +220,9 @@ static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old, sizeof(*(ptr))); \ }) -static inline unsigned long __cmpxchg_local(volatile void *ptr, - unsigned long old, - unsigned long new, int size) +static __always_inline unsigned long +__cmpxchg_local(volatile void *ptr, unsigned long old, unsigned long new, + int size) { unsigned long ret; -- 2.39.5 (Apple Git-154)