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| author | Li RongQing <lirongqing@baidu.com> | 2018-04-10 04:16:06 +0300 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2018-04-10 17:46:39 +0300 |
| commit | a774635db5c430cbf21fa5d2f2df3d23aaa8e782 (patch) | |
| tree | 901a79ca1293a6ef62e57de71e74496347f1ad35 /arch/x86/include/asm/apic.h | |
| parent | d94a155c59c98c19b98ee949eaab6a0312bbd6be (diff) | |
| download | linux-a774635db5c430cbf21fa5d2f2df3d23aaa8e782.tar.xz | |
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/include/asm/apic.h')
| -rw-r--r-- | arch/x86/include/asm/apic.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h index 98722773391d..f01eef8b392e 100644 --- a/arch/x86/include/asm/apic.h +++ b/arch/x86/include/asm/apic.h @@ -319,7 +319,7 @@ struct apic { /* Probe, setup and smpboot functions */ int (*probe)(void); int (*acpi_madt_oem_check)(char *oem_id, char *oem_table_id); - int (*apic_id_valid)(int apicid); + int (*apic_id_valid)(u32 apicid); int (*apic_id_registered)(void); bool (*check_apicid_used)(physid_mask_t *map, int apicid); @@ -492,7 +492,7 @@ static inline unsigned int read_apic_id(void) return apic->get_apic_id(reg); } -extern int default_apic_id_valid(int apicid); +extern int default_apic_id_valid(u32 apicid); extern int default_acpi_madt_oem_check(char *, char *); extern void default_setup_apic_routing(void); |