From nobody Mon Sep 15 18:02:39 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 BFF46C54EBC for ; Wed, 11 Jan 2023 17:21:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238685AbjAKRVx (ORCPT ); Wed, 11 Jan 2023 12:21:53 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49704 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238487AbjAKRVR (ORCPT ); Wed, 11 Jan 2023 12:21:17 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 52D66164B7; Wed, 11 Jan 2023 09:21:17 -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 E2D0661D7C; Wed, 11 Jan 2023 17:21:16 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C8A27C433EF; Wed, 11 Jan 2023 17:21:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1673457676; bh=ANC1L0wfy1/P0+f7TDcL1iJdITEJZEnzKGu3tEgjcsI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=MA/U+XhExNf+fuYB7IqjgrugfJkHiRS6aw7i1XlatIvpnKCSUmj6NEGFRa4rsthPS jibd7VDhON/0KD0gFuDXjtZan8MrILnJmpnAMuTh/rSWgJ2AcKE2tI5sdgCc8moT4f v+3yvhyOXIMQR4tICFtxQGH9Np12dsL6SmUJWfMuMNMaaO5MMLP5udx1IxRU9ThKBf kCmQZl6al1ZA/R2wcVbu3pn/iTeARnAWCG5fwRdKcTnf+ZYfroqVygo63+ZuDF6vdK NWtOvwlG31jA98tq69Wcz8B1VGGA5UZ4PvA1m90xxAt+F6KG312mh/yMMoWvJRlYfR Nt6rC9358gCXA== From: Jisheng Zhang To: Paul Walmsley , Palmer Dabbelt , Albert Ou , Anup Patel , Atish Patra , Heiko Stuebner Cc: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, kvm-riscv@lists.infradead.org, Guo Ren , Andrew Jones Subject: [PATCH v3 10/13] riscv: alternative: patch alternatives in the vDSO Date: Thu, 12 Jan 2023 01:10:24 +0800 Message-Id: <20230111171027.2392-11-jszhang@kernel.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20230111171027.2392-1-jszhang@kernel.org> References: <20230111171027.2392-1-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 | 25 +++++++++++++++++++++++++ arch/riscv/kernel/vdso.c | 5 ----- arch/riscv/kernel/vdso/vdso.lds.S | 7 +++++++ 4 files changed, 36 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..a883a309139f 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 +162,27 @@ static void __init_or_module _apply_alternatives(struc= t alt_entry *begin, stage); } =20 +static void __init apply_vdso_alternatives(void) +{ + const struct elf64_hdr *hdr; + const struct elf64_shdr *shdr; + const struct elf64_shdr *alt; + struct alt_entry *begin, *end; + + hdr =3D (struct elf64_hdr *)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); +} + void __init apply_boot_alternatives(void) { /* If called on non-boot cpu things could go wrong */ @@ -168,6 +191,8 @@ 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