From nobody Mon Sep 15 06:20:51 2025 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1BC6AC677F1 for ; Sun, 15 Jan 2023 16:02:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231659AbjAOQCz (ORCPT ); Sun, 15 Jan 2023 11:02:55 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33194 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231512AbjAOQCU (ORCPT ); Sun, 15 Jan 2023 11:02:20 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 401A63A83; Sun, 15 Jan 2023 08:00:55 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 6384260D45; Sun, 15 Jan 2023 16:00:44 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A453DC433F2; Sun, 15 Jan 2023 16:00:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1673798443; bh=6Eu0jHWRD+88REC096NM3n9cVsx1NdyvP+EwuRbaOno=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=tFgh1aNBWX7PtMPjbNtcRfuhQJMNDt6Yh8ERb7riW2cXH8DUWHTL5KHn1PUsWXW5u zHpnaJXHRJdrfnmERwaDap8260Qsscd2JCjEhwYF3v8eZeIzOfZzvQILQWEvCgFepm p96715md/KsEJQ9yaTMRVkLr/Kuqm2kMm19vqpTvVb4C25T7E/mm903BiLeG9Qmi96 /DCFv1FazPVCqU+Di9lmrcZgNNgOL48cp1knIaF4O48AkH3CGyX64lUMMWMCFIAQyk LNflr8UMl8pJTZn0r3YjVQKDzfyyWwF6UyKdqPJu0JqIkvICEhLq2MNH1xRRgrlXNq pBOSJRaokHLrQ== From: Jisheng Zhang To: Paul Walmsley , Palmer Dabbelt , Albert Ou , Anup Patel , Atish Patra , Heiko Stuebner , Conor Dooley , Andrew Jones Cc: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, kvm-riscv@lists.infradead.org, Guo Ren Subject: [PATCH v4 10/13] riscv: alternative: patch alternatives in the vDSO Date: Sun, 15 Jan 2023 23:49:50 +0800 Message-Id: <20230115154953.831-11-jszhang@kernel.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20230115154953.831-1-jszhang@kernel.org> References: <20230115154953.831-1-jszhang@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Make it possible to use alternatives in the vDSO, so that better implementations can be used if possible. Signed-off-by: Jisheng Zhang Reviewed-by: Guo Ren Reviewed-by: Andrew Jones --- arch/riscv/include/asm/vdso.h | 4 ++++ arch/riscv/kernel/alternative.c | 29 +++++++++++++++++++++++++++++ arch/riscv/kernel/vdso.c | 5 ----- arch/riscv/kernel/vdso/vdso.lds.S | 7 +++++++ 4 files changed, 40 insertions(+), 5 deletions(-) diff --git a/arch/riscv/include/asm/vdso.h b/arch/riscv/include/asm/vdso.h index a7644f46d0e5..f891478829a5 100644 --- a/arch/riscv/include/asm/vdso.h +++ b/arch/riscv/include/asm/vdso.h @@ -28,8 +28,12 @@ #define COMPAT_VDSO_SYMBOL(base, name) \ (void __user *)((unsigned long)(base) + compat__vdso_##name##_offset) =20 +extern char compat_vdso_start[], compat_vdso_end[]; + #endif /* CONFIG_COMPAT */ =20 +extern char vdso_start[], vdso_end[]; + #endif /* !__ASSEMBLY__ */ =20 #endif /* CONFIG_MMU */ diff --git a/arch/riscv/kernel/alternative.c b/arch/riscv/kernel/alternativ= e.c index 3d4f1f32c7f6..fc341b69bf62 100644 --- a/arch/riscv/kernel/alternative.c +++ b/arch/riscv/kernel/alternative.c @@ -11,7 +11,9 @@ #include #include #include +#include #include +#include #include #include #include @@ -160,6 +162,31 @@ static void __init_or_module _apply_alternatives(struc= t alt_entry *begin, stage); } =20 +#ifdef CONFIG_MMU +static void __init apply_vdso_alternatives(void) +{ + const Elf_Ehdr *hdr; + const Elf_Shdr *shdr; + const Elf_Shdr *alt; + struct alt_entry *begin, *end; + + hdr =3D (Elf_Ehdr *)vdso_start; + shdr =3D (void *)hdr + hdr->e_shoff; + alt =3D find_section(hdr, shdr, ".alternative"); + if (!alt) + return; + + begin =3D (void *)hdr + alt->sh_offset, + end =3D (void *)hdr + alt->sh_offset + alt->sh_size, + + _apply_alternatives((struct alt_entry *)begin, + (struct alt_entry *)end, + RISCV_ALTERNATIVES_BOOT); +} +#else +static void __init apply_vdso_alternatives(void) { } +#endif + void __init apply_boot_alternatives(void) { /* If called on non-boot cpu things could go wrong */ @@ -168,6 +195,8 @@ void __init apply_boot_alternatives(void) _apply_alternatives((struct alt_entry *)__alt_start, (struct alt_entry *)__alt_end, RISCV_ALTERNATIVES_BOOT); + + apply_vdso_alternatives(); } =20 /* diff --git a/arch/riscv/kernel/vdso.c b/arch/riscv/kernel/vdso.c index e410275918ac..4e631c098f4d 100644 --- a/arch/riscv/kernel/vdso.c +++ b/arch/riscv/kernel/vdso.c @@ -22,11 +22,6 @@ struct vdso_data { }; #endif =20 -extern char vdso_start[], vdso_end[]; -#ifdef CONFIG_COMPAT -extern char compat_vdso_start[], compat_vdso_end[]; -#endif - enum vvar_pages { VVAR_DATA_PAGE_OFFSET, VVAR_TIMENS_PAGE_OFFSET, diff --git a/arch/riscv/kernel/vdso/vdso.lds.S b/arch/riscv/kernel/vdso/vds= o.lds.S index 150b1a572e61..4a0606633290 100644 --- a/arch/riscv/kernel/vdso/vdso.lds.S +++ b/arch/riscv/kernel/vdso/vdso.lds.S @@ -40,6 +40,13 @@ SECTIONS . =3D 0x800; .text : { *(.text .text.*) } :text =20 + . =3D ALIGN(4); + .alternative : { + __alt_start =3D .; + *(.alternative) + __alt_end =3D .; + } + .data : { *(.got.plt) *(.got) *(.data .data.* .gnu.linkonce.d.*) --=20 2.38.1