From nobody Sun Apr 12 12:39:08 2026 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 D3380C6FD1D for ; Wed, 15 Mar 2023 22:44:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232358AbjCOWoo (ORCPT ); Wed, 15 Mar 2023 18:44:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36846 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229751AbjCOWom (ORCPT ); Wed, 15 Mar 2023 18:44:42 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7361714EA3; Wed, 15 Mar 2023 15:44:40 -0700 (PDT) Date: Wed, 15 Mar 2023 22:44:37 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1678920278; 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; bh=GjmlrFQTqGturbIE+fgewqog6NLlHfnD7mWRE0jhQv8=; b=nMhDrjSJUw9bqF/tIXTVi8+ftXNoYlgUXzLg72prueoXkTzqyzT0ERLkgWMYQ7r4oq7HIx 1P5vFoy8rUjxIRRsj/xrP4ULAoGaTqrDsw3gO9HYg3e1yu55btoptvYSPMJzeqA8Or/ohC 9bsWRn4zVqqjOWdCbJMfB7yGrte8lqVGadGi6UPcSZVtLJNBIC2K0JOeaRFhLgCiPmeaWp RlzpZn2gkBZzg8vNGO8xKFBPY7cc+LAWHv+jDGXgvT+b8WInzTYlwF0BCdK+8xl7FY5V2+ Mkcjvhh8Qfv+tWhTnDNe/vHkfY/fbrGmOrSOpWeT3WzH7XhotL4xA84H6hSV+A== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1678920278; 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; bh=GjmlrFQTqGturbIE+fgewqog6NLlHfnD7mWRE0jhQv8=; b=zIgROjbG15WKCvx1h/VK2V7yaE7w7oTHNpC3HVSHpo9lWHh55jYYk57rKZhc1hfRot8PTY ingboI/CmGYG28CQ== From: "tip-bot2 for Shawn Wang" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: x86/urgent] x86/resctrl: Clear staged_config[] before and after it is used Cc: Xin Hao , Shawn Wang , Reinette Chatre , Dave Hansen , stable@vger.kernel.org, x86@kernel.org, linux-kernel@vger.kernel.org MIME-Version: 1.0 Message-ID: <167892027751.5837.1271275229889484859.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/urgent branch of tip: Commit-ID: 0424a7dfe9129b93f29b277511a60e87f052ac6b Gitweb: https://git.kernel.org/tip/0424a7dfe9129b93f29b277511a60e87f= 052ac6b Author: Shawn Wang AuthorDate: Tue, 17 Jan 2023 13:14:50 -08:00 Committer: Dave Hansen CommitterDate: Wed, 15 Mar 2023 15:19:43 -07:00 x86/resctrl: Clear staged_config[] before and after it is used As a temporary storage, staged_config[] in rdt_domain should be cleared before and after it is used. The stale value in staged_config[] could cause an MSR access error. Here is a reproducer on a system with 16 usable CLOSIDs for a 15-way L3 Cache (MBA should be disabled if the number of CLOSIDs for MB is less than 16.) : mount -t resctrl resctrl -o cdp /sys/fs/resctrl mkdir /sys/fs/resctrl/p{1..7} umount /sys/fs/resctrl/ mount -t resctrl resctrl /sys/fs/resctrl mkdir /sys/fs/resctrl/p{1..8} An error occurs when creating resource group named p8: unchecked MSR access error: WRMSR to 0xca0 (tried to write 0x0000000000= 0007ff) at rIP: 0xffffffff82249142 (cat_wrmsr+0x32/0x60) Call Trace: __flush_smp_call_function_queue+0x11d/0x170 __sysvec_call_function+0x24/0xd0 sysvec_call_function+0x89/0xc0 asm_sysvec_call_function+0x16/0x20 When creating a new resource control group, hardware will be configured by the following process: rdtgroup_mkdir() rdtgroup_mkdir_ctrl_mon() rdtgroup_init_alloc() resctrl_arch_update_domains() resctrl_arch_update_domains() iterates and updates all resctrl_conf_type whose have_new_ctrl is true. Since staged_config[] holds the same values as when CDP was enabled, it will continue to update the CDP_CODE and CDP_DATA configurations. When group p8 is created, get_config_index() called in resctrl_arch_update_domains() will return 16 and 17 as the CLOSIDs for CDP_CODE and CDP_DATA, which will be translated to an invalid register - 0xca0 in this scenario. Fix it by clearing staged_config[] before and after it is used. [reinette: re-order commit tags] Fixes: 75408e43509e ("x86/resctrl: Allow different CODE/DATA configurations= to be staged") Suggested-by: Xin Hao Signed-off-by: Shawn Wang Signed-off-by: Reinette Chatre Signed-off-by: Dave Hansen Tested-by: Reinette Chatre Cc:stable@vger.kernel.org Link: https://lore.kernel.org/all/2fad13f49fbe89687fc40e9a5a61f23a28d1507a.= 1673988935.git.reinette.chatre%40intel.com --- arch/x86/kernel/cpu/resctrl/ctrlmondata.c | 7 +----- arch/x86/kernel/cpu/resctrl/internal.h | 1 +- arch/x86/kernel/cpu/resctrl/rdtgroup.c | 25 ++++++++++++++++++---- 3 files changed, 24 insertions(+), 9 deletions(-) diff --git a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c b/arch/x86/kernel/cp= u/resctrl/ctrlmondata.c index eb07d44..b44c487 100644 --- a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c +++ b/arch/x86/kernel/cpu/resctrl/ctrlmondata.c @@ -368,7 +368,6 @@ ssize_t rdtgroup_schemata_write(struct kernfs_open_file= *of, { struct resctrl_schema *s; struct rdtgroup *rdtgrp; - struct rdt_domain *dom; struct rdt_resource *r; char *tok, *resname; int ret =3D 0; @@ -397,10 +396,7 @@ ssize_t rdtgroup_schemata_write(struct kernfs_open_fil= e *of, goto out; } =20 - list_for_each_entry(s, &resctrl_schema_all, list) { - list_for_each_entry(dom, &s->res->domains, list) - memset(dom->staged_config, 0, sizeof(dom->staged_config)); - } + rdt_staged_configs_clear(); =20 while ((tok =3D strsep(&buf, "\n")) !=3D NULL) { resname =3D strim(strsep(&tok, ":")); @@ -445,6 +441,7 @@ ssize_t rdtgroup_schemata_write(struct kernfs_open_file= *of, } =20 out: + rdt_staged_configs_clear(); rdtgroup_kn_unlock(of->kn); cpus_read_unlock(); return ret ?: nbytes; diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/r= esctrl/internal.h index 8edecc5..85ceaf9 100644 --- a/arch/x86/kernel/cpu/resctrl/internal.h +++ b/arch/x86/kernel/cpu/resctrl/internal.h @@ -555,5 +555,6 @@ void __check_limbo(struct rdt_domain *d, bool force_fre= e); void rdt_domain_reconfigure_cdp(struct rdt_resource *r); void __init thread_throttle_mode_init(void); void __init mbm_config_rftype_init(const char *config); +void rdt_staged_configs_clear(void); =20 #endif /* _ASM_X86_RESCTRL_INTERNAL_H */ diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/r= esctrl/rdtgroup.c index 884b6e9..6ad33f3 100644 --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c @@ -78,6 +78,19 @@ void rdt_last_cmd_printf(const char *fmt, ...) va_end(ap); } =20 +void rdt_staged_configs_clear(void) +{ + struct rdt_resource *r; + struct rdt_domain *dom; + + lockdep_assert_held(&rdtgroup_mutex); + + for_each_alloc_capable_rdt_resource(r) { + list_for_each_entry(dom, &r->domains, list) + memset(dom->staged_config, 0, sizeof(dom->staged_config)); + } +} + /* * Trivial allocator for CLOSIDs. Since h/w only supports a small number, * we can keep a bitmap of free CLOSIDs in a single integer. @@ -3107,7 +3120,9 @@ static int rdtgroup_init_alloc(struct rdtgroup *rdtgr= p) { struct resctrl_schema *s; struct rdt_resource *r; - int ret; + int ret =3D 0; + + rdt_staged_configs_clear(); =20 list_for_each_entry(s, &resctrl_schema_all, list) { r =3D s->res; @@ -3119,20 +3134,22 @@ static int rdtgroup_init_alloc(struct rdtgroup *rdt= grp) } else { ret =3D rdtgroup_init_cat(s, rdtgrp->closid); if (ret < 0) - return ret; + goto out; } =20 ret =3D resctrl_arch_update_domains(r, rdtgrp->closid); if (ret < 0) { rdt_last_cmd_puts("Failed to initialize allocations\n"); - return ret; + goto out; } =20 } =20 rdtgrp->mode =3D RDT_MODE_SHAREABLE; =20 - return 0; +out: + rdt_staged_configs_clear(); + return ret; } =20 static int mkdir_rdt_prepare(struct kernfs_node *parent_kn,