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 1AB39284696; Wed, 23 Apr 2025 14:47:24 +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=1745419645; cv=none; b=MD5Zk7qeh4NWR+chyV6cMioO2F2zfXwkRduvNzGij+1WvlmngFFjHLJmUf1QQScPJJsP4qhNMKwwKGTwoxjUO3OSHz8+Y7b483AhJ/fmaju/7fOT0bmANRjMQzKqb4w81apJ2ylOAmcS+c1OLklBWP9XtSL5xR8TbAOJ2fiGR6I= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745419645; c=relaxed/simple; bh=B7fIaIyJjcypiNPWO2naV0JMFOtELoj0eEO6EMSc9dw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=iU8jNmAnGt53vxT6Qn1PqSS1uhdnKP3N9y8qqxxZmEQ/OUX2wPHqrMKLgjtDQxQoDeKvbFxvBxCQojSycPmmKlr9eyUcvjP+8Aef1FSMYjdoSuR6KmWTXVrMNn9CDbvml9M2Umj+IWGzZd89Phwp8/70Shvs0nq5SUGY+dnyMhc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=xyq3Kski; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="xyq3Kski" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4925CC4CEE3; Wed, 23 Apr 2025 14:47:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1745419644; bh=B7fIaIyJjcypiNPWO2naV0JMFOtELoj0eEO6EMSc9dw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=xyq3Kski+pOveOTY2w+rJ5rH5gKP8dBWJRbKXJVg7/U86aZIDpLxvnEsBcTg8xhV7 DbIWgg704bsXLHWEZ1o03AdZgFwntL6qp1+zzaxozoyQOtbOWB9CYIrKiCEOcbGACs 9V38RkNozAydyYBvaQK+2At/jAHMScdDCQ91XXaw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Borislav Petkov , Boris Ostrovsky , Juergen Gross , Sasha Levin Subject: [PATCH 6.12 031/223] xen: fix multicall debug feature Date: Wed, 23 Apr 2025 16:41:43 +0200 Message-ID: <20250423142618.380739469@linuxfoundation.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250423142617.120834124@linuxfoundation.org> References: <20250423142617.120834124@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Juergen Gross [ Upstream commit 715ad3e0ec2b13c27335749f27a5c9f0c0e84064 ] Initializing a percpu variable with the address of a struct tagged as .initdata is breaking the build with CONFIG_SECTION_MISMATCH_WARN_ONLY not set to "y". Fix that by using an access function instead returning the .initdata struct address if the percpu space of the struct hasn't been allocated yet. Fixes: 368990a7fe30 ("xen: fix multicall debug data referencing") Reported-by: Borislav Petkov Reviewed-by: Boris Ostrovsky Acked-by: "Borislav Petkov (AMD)" Tested-by: "Borislav Petkov (AMD)" Signed-off-by: Juergen Gross Message-ID: <20250327190602.26015-1-jgross@suse.com> Signed-off-by: Sasha Levin --- arch/x86/xen/multicalls.c | 26 ++++++++++++++------------ arch/x86/xen/smp_pv.c | 1 - arch/x86/xen/xen-ops.h | 3 --- 3 files changed, 14 insertions(+), 16 deletions(-) diff --git a/arch/x86/xen/multicalls.c b/arch/x86/xen/multicalls.c index 10c660fae8b30..7237d56a9d3f0 100644 --- a/arch/x86/xen/multicalls.c +++ b/arch/x86/xen/multicalls.c @@ -54,14 +54,20 @@ struct mc_debug_data { static DEFINE_PER_CPU(struct mc_buffer, mc_buffer); static struct mc_debug_data mc_debug_data_early __initdata; -static DEFINE_PER_CPU(struct mc_debug_data *, mc_debug_data) = - &mc_debug_data_early; static struct mc_debug_data __percpu *mc_debug_data_ptr; DEFINE_PER_CPU(unsigned long, xen_mc_irq_flags); static struct static_key mc_debug __ro_after_init; static bool mc_debug_enabled __initdata; +static struct mc_debug_data * __ref get_mc_debug(void) +{ + if (!mc_debug_data_ptr) + return &mc_debug_data_early; + + return this_cpu_ptr(mc_debug_data_ptr); +} + static int __init xen_parse_mc_debug(char *arg) { mc_debug_enabled = true; @@ -71,20 +77,16 @@ static int __init xen_parse_mc_debug(char *arg) } early_param("xen_mc_debug", xen_parse_mc_debug); -void mc_percpu_init(unsigned int cpu) -{ - per_cpu(mc_debug_data, cpu) = per_cpu_ptr(mc_debug_data_ptr, cpu); -} - static int __init mc_debug_enable(void) { unsigned long flags; + struct mc_debug_data __percpu *mcdb; if (!mc_debug_enabled) return 0; - mc_debug_data_ptr = alloc_percpu(struct mc_debug_data); - if (!mc_debug_data_ptr) { + mcdb = alloc_percpu(struct mc_debug_data); + if (!mcdb) { pr_err("xen_mc_debug inactive\n"); static_key_slow_dec(&mc_debug); return -ENOMEM; @@ -93,7 +95,7 @@ static int __init mc_debug_enable(void) /* Be careful when switching to percpu debug data. */ local_irq_save(flags); xen_mc_flush(); - mc_percpu_init(0); + mc_debug_data_ptr = mcdb; local_irq_restore(flags); pr_info("xen_mc_debug active\n"); @@ -155,7 +157,7 @@ void xen_mc_flush(void) trace_xen_mc_flush(b->mcidx, b->argidx, b->cbidx); if (static_key_false(&mc_debug)) { - mcdb = __this_cpu_read(mc_debug_data); + mcdb = get_mc_debug(); memcpy(mcdb->entries, b->entries, b->mcidx * sizeof(struct multicall_entry)); } @@ -235,7 +237,7 @@ struct multicall_space __xen_mc_entry(size_t args) ret.mc = &b->entries[b->mcidx]; if (static_key_false(&mc_debug)) { - struct mc_debug_data *mcdb = __this_cpu_read(mc_debug_data); + struct mc_debug_data *mcdb = get_mc_debug(); mcdb->caller[b->mcidx] = __builtin_return_address(0); mcdb->argsz[b->mcidx] = args; diff --git a/arch/x86/xen/smp_pv.c b/arch/x86/xen/smp_pv.c index 6863d3da7decf..7ea57f728b89d 100644 --- a/arch/x86/xen/smp_pv.c +++ b/arch/x86/xen/smp_pv.c @@ -305,7 +305,6 @@ static int xen_pv_kick_ap(unsigned int cpu, struct task_struct *idle) return rc; xen_pmu_init(cpu); - mc_percpu_init(cpu); /* * Why is this a BUG? If the hypercall fails then everything can be diff --git a/arch/x86/xen/xen-ops.h b/arch/x86/xen/xen-ops.h index 63c13a2ccf556..25e318ef27d6b 100644 --- a/arch/x86/xen/xen-ops.h +++ b/arch/x86/xen/xen-ops.h @@ -261,9 +261,6 @@ void xen_mc_callback(void (*fn)(void *), void *data); */ struct multicall_space xen_mc_extend_args(unsigned long op, size_t arg_size); -/* Do percpu data initialization for multicalls. */ -void mc_percpu_init(unsigned int cpu); - extern bool is_xen_pmu; irqreturn_t xen_pmu_irq_handler(int irq, void *dev_id); -- 2.39.5