From: Igor Mammedov <imammedo@redhat.com>
To: linux-kernel@vger.kernel.org
Cc: tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com,
x86@kernel.org, imammedo@redhat.com, bp@suse.de,
paul.gortmaker@windriver.com, JBeulich@suse.com,
prarit@redhat.com, drjones@redhat.com, toshi.kani@hp.com,
riel@redhat.com, gong.chen@linux.intel.com, andi@firstfloor.org,
lenb@kernel.org, rjw@rjwysocki.net, linux-acpi@vger.kernel.org
Subject: [PATCH v4 2/5] x86: fix memory corruption in acpi_unmap_lsapic()
Date: Mon, 14 Apr 2014 17:11:14 +0200 [thread overview]
Message-ID: <1397488277-14865-3-git-send-email-imammedo@redhat.com> (raw)
In-Reply-To: <1397488277-14865-1-git-send-email-imammedo@redhat.com>
if during CPU hotplug master CPU failed to wake up AP
it set percpu x86_cpu_to_apicid to BAD_APICID=0xFFFF for AP.
However following attempt to unplug that CPU will lead to
out of bound write access to __apicid_to_node[] which is
32768 items long on x86_64 kernel.
So drop setting x86_cpu_to_apicid to BAD_APICID in do_boot_cpu()
and allow acpi_processor_remove()->acpi_unmap_lsapic() cleanly
remove CPU.
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
---
arch/x86/kernel/smpboot.c | 2 --
1 files changed, 0 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 6124f15..2988f69 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -859,8 +859,6 @@ static int do_boot_cpu(int apicid, int cpu, struct task_struct *idle)
/* was set by cpu_init() */
cpumask_clear_cpu(cpu, cpu_initialized_mask);
-
- per_cpu(x86_cpu_to_apicid, cpu) = BAD_APICID;
}
/* mark "stuck" area as not stuck */
--
1.7.1
next prev parent reply other threads:[~2014-04-14 15:13 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-04-14 15:11 [PATCH v4 0/5] x86: fix hang when AP bringup is too slow Igor Mammedov
2014-04-14 15:11 ` [PATCH v4 1/5] x86: fix list corruption on CPU hotplug Igor Mammedov
2014-04-30 21:18 ` Toshi Kani
2014-04-14 15:11 ` Igor Mammedov [this message]
2014-04-14 15:11 ` [PATCH v4 3/5] acpi_processor: do not mark present at boot but not onlined CPU as onlined Igor Mammedov
2014-04-15 5:48 ` Rafael J. Wysocki
2014-04-15 6:00 ` Igor Mammedov
2014-04-15 6:04 ` Ingo Molnar
2014-04-15 15:48 ` Rafael J. Wysocki
2014-04-15 5:53 ` Rafael J. Wysocki
2014-04-30 21:25 ` Toshi Kani
2014-05-02 11:32 ` Igor Mammedov
2014-05-02 17:23 ` Toshi Kani
2014-04-14 15:11 ` [PATCH v4 4/5] x86: log error on secondary CPU wakeup failure at ERR level Igor Mammedov
2014-04-30 21:30 ` Toshi Kani
2014-04-14 15:11 ` [PATCH v4 5/5] x86: initialize secondary CPU only if master CPU will wait for it Igor Mammedov
2014-05-01 23:11 ` Toshi Kani
2014-05-02 8:21 ` Igor Mammedov
2014-05-02 14:52 ` Toshi Kani
2014-05-05 20:26 ` Igor Mammedov
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