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authorLi RongQing <lirongqing@baidu.com>2018-04-10 09:16:06 +0800
committerThomas Gleixner <tglx@linutronix.de>2018-04-10 16:46:39 +0200
commita774635db5c430cbf21fa5d2f2df3d23aaa8e782 (patch)
tree901a79ca1293a6ef62e57de71e74496347f1ad35 /arch/x86/xen
parentd94a155c59c98c19b98ee949eaab6a0312bbd6be (diff)
x86/apic: Fix signedness bug in APIC ID validity checks
The APIC ID as parsed from ACPI MADT is validity checked with the apic->apic_id_valid() callback, which depends on the selected APIC type. For non X2APIC types APIC IDs >= 0xFF are invalid, but values > 0x7FFFFFFF are detected as valid. This happens because the 'apicid' argument of the apic_id_valid() callback is type 'int'. So the resulting comparison apicid < 0xFF evaluates to true for all unsigned int values > 0x7FFFFFFF which are handed to default_apic_id_valid(). As a consequence, invalid APIC IDs in !X2APIC mode are considered valid and accounted as possible CPUs. Change the apicid argument type of the apic_id_valid() callback to u32 so the evaluation is unsigned and returns the correct result. [ tglx: Massaged changelog ] Signed-off-by: Li RongQing <lirongqing@baidu.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Cc: jgross@suse.com Cc: Dou Liyang <douly.fnst@cn.fujitsu.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: hpa@zytor.com Link: https://lkml.kernel.org/r/1523322966-10296-1-git-send-email-lirongqing@baidu.com
Diffstat (limited to 'arch/x86/xen')
-rw-r--r--arch/x86/xen/apic.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/xen/apic.c b/arch/x86/xen/apic.c
index de58533d3664..2fa79e2e73ea 100644
--- a/arch/x86/xen/apic.c
+++ b/arch/x86/xen/apic.c
@@ -112,7 +112,7 @@ static int xen_madt_oem_check(char *oem_id, char *oem_table_id)
return xen_pv_domain();
}
-static int xen_id_always_valid(int apicid)
+static int xen_id_always_valid(u32 apicid)
{
return 1;
}