From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 C229D152DE4; Thu, 29 Feb 2024 15:49:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709221745; cv=none; b=hWUpghG5Gh3bv+YPoCgTzOyC5leAPBx2xonbZaHLJVf91oPuSRyQp86f1n3t0kJrO3ZNyf5PokX2sh3ycZfgKVH49a1P/t90RBqQlX3UQSZ957GQ08lysTOESGolYVfPDNUl63clX261V928iFoIr9L7o7JISRTFoC6x6TTvIk4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709221745; c=relaxed/simple; bh=KcTNPiFwNY84hKxY/REFym2TAOMI7OjhJJXCHAPfAWI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=MJvdq36yk36iUevndfeXWOpR9cXMLotf+uChWgDV8CkfGyhT4WfJpjEr+6Xg4vdNu72ggzCNJ+hLEhJz8f3rpZI9Ekn9UWddoxmoGhslO7ubRYDMNtUj5zYV6eetkehsT6VnUKSIpHGyaveY+Cbf8Tx0w2tW3MhT3wkP3Ow5+0k= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=NPL5cAnS; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="NPL5cAnS" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 00E29C433F1; Thu, 29 Feb 2024 15:49:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1709221745; bh=KcTNPiFwNY84hKxY/REFym2TAOMI7OjhJJXCHAPfAWI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NPL5cAnSlK8E2JmD1bx2QsnCuYOR1JQPep15hbh+cu6yUGvJr9VZs9BZl/BFRwGyM SSWYXfOlHl88iK9BGNw0jBVOxeJ97PINYPFUtHBHu9Eght+yoY8H2StUNCRnhoCOzy azdNqvh9YGLXCAgGvDEfDZREgctXCkoqTCVM2ecZHS+5c29sn+S++Y4fbMhRFUD0vD 7ipV6CPZZWqqIbUAUo46ktrB/uOnU1gLk+/Cir9XI+4i35U458lGzslc2VKH4YooXf A4d1aypOT9KKV1lc+KEyrxQZUelqcrlN/FU7Entch2eMxx3O27bssM+qIFfMOq1AGC cUsmaSthPAtOQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Fangrui Song , Ard Biesheuvel , Mark Rutland , Will Deacon , Sasha Levin , peterz@infradead.org, jpoimboe@kernel.org, jbaron@akamai.com, catalin.marinas@arm.com, nathan@kernel.org, linux-arm-kernel@lists.infradead.org, llvm@lists.linux.dev Subject: [PATCH AUTOSEL 6.7 07/26] arm64: jump_label: use constraints "Si" instead of "i" Date: Thu, 29 Feb 2024 10:48:26 -0500 Message-ID: <20240229154851.2849367-7-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240229154851.2849367-1-sashal@kernel.org> References: <20240229154851.2849367-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: llvm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.7.6 Content-Transfer-Encoding: 8bit From: Fangrui Song [ Upstream commit f9daab0ad01cf9d165dbbbf106ca4e61d06e7fe8 ] The generic constraint "i" seems to be copied from x86 or arm (and with a redundant generic operand modifier "c"). It works with -fno-PIE but not with -fPIE/-fPIC in GCC's aarch64 port. The machine constraint "S", which denotes a symbol or label reference with a constant offset, supports PIC and has been available in GCC since 2012 and in Clang since 7.0. However, Clang before 19 does not support "S" on a symbol with a constant offset [1] (e.g. `static_key_false(&nf_hooks_needed[pf][hook])` in include/linux/netfilter.h), so we use "i" as a fallback. Suggested-by: Ard Biesheuvel Signed-off-by: Fangrui Song Link: https://github.com/llvm/llvm-project/pull/80255 [1] Acked-by: Mark Rutland Link: https://lore.kernel.org/r/20240206074552.541154-1-maskray@google.com Signed-off-by: Will Deacon Signed-off-by: Sasha Levin --- arch/arm64/include/asm/jump_label.h | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/arch/arm64/include/asm/jump_label.h b/arch/arm64/include/asm/jump_label.h index 48ddc0f45d228..b7716b215f91a 100644 --- a/arch/arm64/include/asm/jump_label.h +++ b/arch/arm64/include/asm/jump_label.h @@ -15,6 +15,10 @@ #define JUMP_LABEL_NOP_SIZE AARCH64_INSN_SIZE +/* + * Prefer the constraint "S" to support PIC with GCC. Clang before 19 does not + * support "S" on a symbol with a constant offset, so we use "i" as a fallback. + */ static __always_inline bool arch_static_branch(struct static_key * const key, const bool branch) { @@ -23,9 +27,9 @@ static __always_inline bool arch_static_branch(struct static_key * const key, " .pushsection __jump_table, \"aw\" \n\t" " .align 3 \n\t" " .long 1b - ., %l[l_yes] - . \n\t" - " .quad %c0 - . \n\t" + " .quad (%[key] - .) + %[bit0] \n\t" " .popsection \n\t" - : : "i"(&((char *)key)[branch]) : : l_yes); + : : [key]"Si"(key), [bit0]"i"(branch) : : l_yes); return false; l_yes: @@ -40,9 +44,9 @@ static __always_inline bool arch_static_branch_jump(struct static_key * const ke " .pushsection __jump_table, \"aw\" \n\t" " .align 3 \n\t" " .long 1b - ., %l[l_yes] - . \n\t" - " .quad %c0 - . \n\t" + " .quad (%[key] - .) + %[bit0] \n\t" " .popsection \n\t" - : : "i"(&((char *)key)[branch]) : : l_yes); + : : [key]"Si"(key), [bit0]"i"(branch) : : l_yes); return false; l_yes: -- 2.43.0 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id D6BDFC48BF6 for ; 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Thu, 29 Feb 2024 15:49:20 +0000 Received: from dfw.source.kernel.org ([2604:1380:4641:c500::1]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1rfieg-0000000E75f-2KAW for linux-arm-kernel@lists.infradead.org; Thu, 29 Feb 2024 15:49:08 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id DDB6B611D2; Thu, 29 Feb 2024 15:49:05 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 00E29C433F1; Thu, 29 Feb 2024 15:49:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1709221745; bh=KcTNPiFwNY84hKxY/REFym2TAOMI7OjhJJXCHAPfAWI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NPL5cAnSlK8E2JmD1bx2QsnCuYOR1JQPep15hbh+cu6yUGvJr9VZs9BZl/BFRwGyM SSWYXfOlHl88iK9BGNw0jBVOxeJ97PINYPFUtHBHu9Eght+yoY8H2StUNCRnhoCOzy azdNqvh9YGLXCAgGvDEfDZREgctXCkoqTCVM2ecZHS+5c29sn+S++Y4fbMhRFUD0vD 7ipV6CPZZWqqIbUAUo46ktrB/uOnU1gLk+/Cir9XI+4i35U458lGzslc2VKH4YooXf A4d1aypOT9KKV1lc+KEyrxQZUelqcrlN/FU7Entch2eMxx3O27bssM+qIFfMOq1AGC cUsmaSthPAtOQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Fangrui Song , Ard Biesheuvel , Mark Rutland , Will Deacon , Sasha Levin , peterz@infradead.org, jpoimboe@kernel.org, jbaron@akamai.com, catalin.marinas@arm.com, nathan@kernel.org, linux-arm-kernel@lists.infradead.org, llvm@lists.linux.dev Subject: [PATCH AUTOSEL 6.7 07/26] arm64: jump_label: use constraints "Si" instead of "i" Date: Thu, 29 Feb 2024 10:48:26 -0500 Message-ID: <20240229154851.2849367-7-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240229154851.2849367-1-sashal@kernel.org> References: <20240229154851.2849367-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.7.6 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240229_074906_865668_FFA53215 X-CRM114-Status: GOOD ( 11.40 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org From: Fangrui Song [ Upstream commit f9daab0ad01cf9d165dbbbf106ca4e61d06e7fe8 ] The generic constraint "i" seems to be copied from x86 or arm (and with a redundant generic operand modifier "c"). It works with -fno-PIE but not with -fPIE/-fPIC in GCC's aarch64 port. The machine constraint "S", which denotes a symbol or label reference with a constant offset, supports PIC and has been available in GCC since 2012 and in Clang since 7.0. However, Clang before 19 does not support "S" on a symbol with a constant offset [1] (e.g. `static_key_false(&nf_hooks_needed[pf][hook])` in include/linux/netfilter.h), so we use "i" as a fallback. Suggested-by: Ard Biesheuvel Signed-off-by: Fangrui Song Link: https://github.com/llvm/llvm-project/pull/80255 [1] Acked-by: Mark Rutland Link: https://lore.kernel.org/r/20240206074552.541154-1-maskray@google.com Signed-off-by: Will Deacon Signed-off-by: Sasha Levin --- arch/arm64/include/asm/jump_label.h | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/arch/arm64/include/asm/jump_label.h b/arch/arm64/include/asm/jump_label.h index 48ddc0f45d228..b7716b215f91a 100644 --- a/arch/arm64/include/asm/jump_label.h +++ b/arch/arm64/include/asm/jump_label.h @@ -15,6 +15,10 @@ #define JUMP_LABEL_NOP_SIZE AARCH64_INSN_SIZE +/* + * Prefer the constraint "S" to support PIC with GCC. Clang before 19 does not + * support "S" on a symbol with a constant offset, so we use "i" as a fallback. + */ static __always_inline bool arch_static_branch(struct static_key * const key, const bool branch) { @@ -23,9 +27,9 @@ static __always_inline bool arch_static_branch(struct static_key * const key, " .pushsection __jump_table, \"aw\" \n\t" " .align 3 \n\t" " .long 1b - ., %l[l_yes] - . \n\t" - " .quad %c0 - . \n\t" + " .quad (%[key] - .) + %[bit0] \n\t" " .popsection \n\t" - : : "i"(&((char *)key)[branch]) : : l_yes); + : : [key]"Si"(key), [bit0]"i"(branch) : : l_yes); return false; l_yes: @@ -40,9 +44,9 @@ static __always_inline bool arch_static_branch_jump(struct static_key * const ke " .pushsection __jump_table, \"aw\" \n\t" " .align 3 \n\t" " .long 1b - ., %l[l_yes] - . \n\t" - " .quad %c0 - . \n\t" + " .quad (%[key] - .) + %[bit0] \n\t" " .popsection \n\t" - : : "i"(&((char *)key)[branch]) : : l_yes); + : : [key]"Si"(key), [bit0]"i"(branch) : : l_yes); return false; l_yes: -- 2.43.0 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel