From nobody Wed Dec 31 00:39:03 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 D50FAC4332F for ; Mon, 13 Nov 2023 11:52:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230190AbjKMLwy (ORCPT ); Mon, 13 Nov 2023 06:52:54 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50558 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229956AbjKMLwu (ORCPT ); Mon, 13 Nov 2023 06:52:50 -0500 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 93F63D6D; Mon, 13 Nov 2023 03:52:46 -0800 (PST) Date: Mon, 13 Nov 2023 11:52:44 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1699876364; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Zi02sD89LPlH8uLlp7X1mPLBNiLp7U3VPX96M0xr2FU=; b=UEfCYzuuCupns2FPfK92kW94mFfK/+59IDtM9/2QPjEMajuwNLguSa9vOmUvpuxfojR4C0 ZcEk2zfrXT7tbhYX8n7gS0dXvt7pBnohdrTwuyW2BPotSgx+IHZapa1PJhQxR4nmk+odLY AfKTWpwyDhnAkufW+D7S+JLX7fTE5s3CUVvx1U0/VJ3ImgmS9wd/Ey8NPMjugC33Xh7zYI u1/2sbbGDYdHWT4hjAAZoVc3JDH84ZTHQFJ1FEm1O2YSe5EZO5+2lRxGeypIEU+TGSMJq5 5oWj2ehsC0BT21vwgY5C0Lg09hemmlvCxYb/V6mtAgzy/bhgk1nHOu5O7/WC0A== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1699876364; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Zi02sD89LPlH8uLlp7X1mPLBNiLp7U3VPX96M0xr2FU=; b=HrmgOVbPZZlhNAMUjAIZjnJBb3GDsunVrC4jgRMQY7MOxjlxiGemthgmGP2dAuMCQoWiM2 ovHiWb0By+SCX9BA== From: "tip-bot2 for Hou Wenlong" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: x86/paravirt] x86/paravirt: Use relative reference for the original instruction offset Cc: Hou Wenlong , "Borislav Petkov (AMD)" , Juergen Gross , x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: =?utf-8?q?=3C9e6053107fbaabc0d33e5d2865c5af2c67ec9925=2E16863?= =?utf-8?q?01237=2Egit=2Ehouwenlong=2Ehwl=40antgroup=2Ecom=3E?= References: =?utf-8?q?=3C9e6053107fbaabc0d33e5d2865c5af2c67ec9925=2E168630?= =?utf-8?q?1237=2Egit=2Ehouwenlong=2Ehwl=40antgroup=2Ecom=3E?= MIME-Version: 1.0 Message-ID: <169987636414.3135.6610650526442498008.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The following commit has been merged into the x86/paravirt branch of tip: Commit-ID: 5c22c4726e4a9c6b2e182c0b21c2d3dd63f608c4 Gitweb: https://git.kernel.org/tip/5c22c4726e4a9c6b2e182c0b21c2d3dd6= 3f608c4 Author: Hou Wenlong AuthorDate: Fri, 09 Jun 2023 17:45:31 +08:00 Committer: Borislav Petkov (AMD) CommitterDate: Mon, 13 Nov 2023 12:23:27 +01:00 x86/paravirt: Use relative reference for the original instruction offset Similar to the alternative patching, use a relative reference for original instruction offset rather than absolute one, which saves 8 bytes for one PARA_SITE entry on x86_64. As a result, a R_X86_64_PC32 relocation is generated instead of an R_X86_64_64 one, which also reduces relocation metadata on relocatable builds. Hardcode the alignment to 4 now. [ bp: Massage commit message. ] Signed-off-by: Hou Wenlong Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Juergen Gross Link: https://lore.kernel.org/r/9e6053107fbaabc0d33e5d2865c5af2c67ec9925.16= 86301237.git.houwenlong.hwl@antgroup.com --- arch/x86/include/asm/paravirt.h | 10 +++++----- arch/x86/include/asm/paravirt_types.h | 8 ++++---- arch/x86/kernel/alternative.c | 8 +++++--- arch/x86/kernel/callthunks.c | 2 +- 4 files changed, 15 insertions(+), 13 deletions(-) diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravir= t.h index 6c8ff12..d9384e9 100644 --- a/arch/x86/include/asm/paravirt.h +++ b/arch/x86/include/asm/paravirt.h @@ -743,16 +743,16 @@ void native_pv_lock_init(void) __init; =20 #else /* __ASSEMBLY__ */ =20 -#define _PVSITE(ptype, ops, word, algn) \ +#define _PVSITE(ptype, ops) \ 771:; \ ops; \ 772:; \ .pushsection .parainstructions,"a"; \ - .align algn; \ - word 771b; \ + .align 4; \ + .long 771b-.; \ .byte ptype; \ .byte 772b-771b; \ - _ASM_ALIGN; \ + .align 4; \ .popsection =20 =20 @@ -760,7 +760,7 @@ void native_pv_lock_init(void) __init; #ifdef CONFIG_PARAVIRT_XXL =20 #define PARA_PATCH(off) ((off) / 8) -#define PARA_SITE(ptype, ops) _PVSITE(ptype, ops, .quad, 8) +#define PARA_SITE(ptype, ops) _PVSITE(ptype, ops) #define PARA_INDIRECT(addr) *addr(%rip) =20 #ifdef CONFIG_DEBUG_ENTRY diff --git a/arch/x86/include/asm/paravirt_types.h b/arch/x86/include/asm/p= aravirt_types.h index 772d034..e1bfb71 100644 --- a/arch/x86/include/asm/paravirt_types.h +++ b/arch/x86/include/asm/paravirt_types.h @@ -5,7 +5,7 @@ #ifndef __ASSEMBLY__ /* These all sit in the .parainstructions section to tell us what to patch= . */ struct paravirt_patch_site { - u8 *instr; /* original instructions */ + s32 instr_offset; /* original instructions */ u8 type; /* type of this instruction */ u8 len; /* length of original instruction */ }; @@ -263,11 +263,11 @@ extern struct paravirt_patch_template pv_ops; #define _paravirt_alt(insn_string, type) \ "771:\n\t" insn_string "\n" "772:\n" \ ".pushsection .parainstructions,\"a\"\n" \ - _ASM_ALIGN "\n" \ - _ASM_PTR " 771b\n" \ + " .align 4\n" \ + " .long 771b-.\n" \ " .byte " type "\n" \ " .byte 772b-771b\n" \ - _ASM_ALIGN "\n" \ + " .align 4\n" \ ".popsection\n" =20 /* Generate patchable code, with the default asm parameters. */ diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c index 73be393..be35c8c 100644 --- a/arch/x86/kernel/alternative.c +++ b/arch/x86/kernel/alternative.c @@ -1431,20 +1431,22 @@ void __init_or_module apply_paravirt(struct paravir= t_patch_site *start, { struct paravirt_patch_site *p; char insn_buff[MAX_PATCH_LEN]; + u8 *instr; =20 for (p =3D start; p < end; p++) { unsigned int used; =20 + instr =3D (u8 *)&p->instr_offset + p->instr_offset; BUG_ON(p->len > MAX_PATCH_LEN); /* prep the buffer with the original instructions */ - memcpy(insn_buff, p->instr, p->len); - used =3D paravirt_patch(p->type, insn_buff, (unsigned long)p->instr, p->= len); + memcpy(insn_buff, instr, p->len); + used =3D paravirt_patch(p->type, insn_buff, (unsigned long)instr, p->len= ); =20 BUG_ON(used > p->len); =20 /* Pad the rest with nops */ add_nops(insn_buff + used, p->len - used); - text_poke_early(p->instr, insn_buff, p->len); + text_poke_early(instr, insn_buff, p->len); } } extern struct paravirt_patch_site __start_parainstructions[], diff --git a/arch/x86/kernel/callthunks.c b/arch/x86/kernel/callthunks.c index e9ad518..57e5c2e 100644 --- a/arch/x86/kernel/callthunks.c +++ b/arch/x86/kernel/callthunks.c @@ -240,7 +240,7 @@ patch_paravirt_call_sites(struct paravirt_patch_site *s= tart, struct paravirt_patch_site *p; =20 for (p =3D start; p < end; p++) - patch_call(p->instr, ct); + patch_call((void *)&p->instr_offset + p->instr_offset, ct); } =20 static __init_or_module void