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 56500332904; Fri, 21 Nov 2025 13:28:58 +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=1763731738; cv=none; b=TFW1egE1yqdQBNsR11XcSsPfCnAFzqtTUj1BgHLt40s/vzLPTj1+YQLB9ZZC1lVrWWP+Pxr5BLLi4OXIpBapCb5HkDuH+UsDNoPbFLd7KuYRrFqjGrAnAmcBxvqzIXv1XgvASD4guWtVZcaqVo9PvF3U6NYUQxCTAEvWOqBsr6w= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763731738; c=relaxed/simple; bh=lxeSOqo6sPnoFelYY038M5a/9Pi1WQinnx45NU8GKoc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=muF8wbKIf+8UVnoickVfww0Cmhq+NBgFskHbcYpPxd1wXTESRA8H9nV+iFtb41luD1SKPTOo/e52jUf58krg1OZuxq51Pm68I6dgfOSGiqz0ppOJVzwAjrZtB0dYIa1gWsAhbyouHcFxytDUYgn7t3tSVx4eiTCNdgDsqeRIJR8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=MclSZca9; 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="MclSZca9" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CBF72C4CEF1; Fri, 21 Nov 2025 13:28:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1763731738; bh=lxeSOqo6sPnoFelYY038M5a/9Pi1WQinnx45NU8GKoc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=MclSZca9AfGxS9hF2XAyhYaG3QDb/cOSvQA96WCO1InODSARKWLAMqRp4FBRudXTD Onxpb7J5+XFmV5tXi5WAQDMqQtrBjwpmdG+aA+CWalkdP8E2PIyJN8KiEE1wA5s8iX 6Wxff544TSqlgMDOsnuoaBKUrO0yhtefFbGZFknM= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, "Mario Limonciello (AMD) (kernel.org)" , "Gautham R. Shenoy" , "Rafael J. Wysocki" , Sasha Levin Subject: [PATCH 6.12 064/185] ACPI: CPPC: Perform fast check switch only for online CPUs Date: Fri, 21 Nov 2025 14:11:31 +0100 Message-ID: <20251121130146.186825980@linuxfoundation.org> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20251121130143.857798067@linuxfoundation.org> References: <20251121130143.857798067@linuxfoundation.org> User-Agent: quilt/0.69 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: Gautham R. Shenoy [ Upstream commit 8821c8e80a65bc4eb73daf63b34aac6b8ad69461 ] per_cpu(cpc_desc_ptr, cpu) object is initialized for only the online CPUs via acpi_soft_cpu_online() --> __acpi_processor_start() --> acpi_cppc_processor_probe(). However the function cppc_allow_fast_switch() checks for the validity of the _CPC object for all the present CPUs. This breaks when the kernel is booted with "nosmt=force". Check fast_switch capability only on online CPUs Fixes: 15eece6c5b05 ("ACPI: CPPC: Fix NULL pointer dereference when nosmp is used") Reviewed-by: "Mario Limonciello (AMD) (kernel.org)" Signed-off-by: Gautham R. Shenoy Link: https://patch.msgid.link/20251107074145.2340-4-gautham.shenoy@amd.com Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin --- drivers/acpi/cppc_acpi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c index 3ce5bb87d25b7..c4a1fee4b4873 100644 --- a/drivers/acpi/cppc_acpi.c +++ b/drivers/acpi/cppc_acpi.c @@ -463,7 +463,7 @@ bool cppc_allow_fast_switch(void) struct cpc_desc *cpc_ptr; int cpu; - for_each_present_cpu(cpu) { + for_each_online_cpu(cpu) { cpc_ptr = per_cpu(cpc_desc_ptr, cpu); desired_reg = &cpc_ptr->cpc_regs[DESIRED_PERF]; if (!CPC_IN_SYSTEM_MEMORY(desired_reg) && -- 2.51.0