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From: Thomas Gleixner <tglx@linutronix.de>
To: Dou Liyang <douly.fnst@cn.fujitsu.com>
Cc: cl@linux.com, tj@kernel.org, mika.j.penttila@gmail.com,
	mingo@redhat.com, akpm@linux-foundation.org, rjw@rjwysocki.net,
	hpa@zytor.com, yasu.isimatu@gmail.com,
	isimatu.yasuaki@jp.fujitsu.com, kamezawa.hiroyu@jp.fujitsu.com,
	izumi.taku@jp.fujitsu.com, gongzhaogang@inspur.com,
	len.brown@intel.com, lenb@kernel.org, chen.tang@easystack.cn,
	rafael@kernel.org, x86@kernel.org, linux-acpi@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-mm@kvack.org,
	Gu Zheng <guz.fnst@cn.fujitsu.com>,
	Tang Chen <tangchen@cn.fujitsu.com>,
	Zhu Guihua <zhugh.fnst@cn.fujitsu.com>
Subject: acpi: Fix broken error check in map_processor()
Date: Fri, 23 Sep 2016 17:08:04 +0200 (CEST)	[thread overview]
Message-ID: <alpine.DEB.2.20.1609231705570.5640@nanos> (raw)

map_processor() checks the cpuid value returned by acpi_map_cpuid() for -1
but acpi_map_cpuid() returns -EINVAL in case of error.

As a consequence the error is ignored and the following access into percpu
data with that negative cpuid results in a boot crash.

This happens always when NR_CPUS/nr_cpu_ids is smaller than the number of
processors listed in the ACPI tables.

Use a proper error check for id < 0 so the function returns instead of
trying to map CPU#(-EINVAL).

Reported-by: Ingo Molnar <mingo@kernel.org>
Fixes: dc6db24d2476 ("x86/acpi: Set persistent cpuid <-> nodeid mapping when booting")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 drivers/acpi/processor_core.c |    9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

--- a/drivers/acpi/processor_core.c
+++ b/drivers/acpi/processor_core.c
@@ -284,7 +284,7 @@ EXPORT_SYMBOL_GPL(acpi_get_cpuid);
 static bool __init
 map_processor(acpi_handle handle, phys_cpuid_t *phys_id, int *cpuid)
 {
-	int type;
+	int type, id;
 	u32 acpi_id;
 	acpi_status status;
 	acpi_object_type acpi_type;
@@ -320,10 +320,11 @@ map_processor(acpi_handle handle, phys_c
 	type = (acpi_type == ACPI_TYPE_DEVICE) ? 1 : 0;
 
 	*phys_id = __acpi_get_phys_id(handle, type, acpi_id, false);
-	*cpuid = acpi_map_cpuid(*phys_id, acpi_id);
-	if (*cpuid == -1)
-		return false;
+	id = acpi_map_cpuid(*phys_id, acpi_id);
 
+	if (id < 0)
+		return false;
+	*cpuid = id;
 	return true;
 }
 

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             reply	other threads:[~2016-09-23 15:12 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-09-23 15:08 Thomas Gleixner [this message]
2016-09-24  0:06 ` Rafael J. Wysocki

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