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s390/numa: always use logical cpu and core ids 

The toptree algorithm uses the physical core ids to create a mapping
between cores and nodes (to_node_id array within emu_cores structure).
The core ids are used as an index into an array which size depends on
CONFIG_NR_CPUS. If the physical core ids are larger, this will result
in out-of-bounds write accesses.

Generate logical core ids instead to avoid this.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Heiko Carstens 2016-12-02 13:16:02 +01:00 committed by Martin Schwidefsky
parent 11a247e376
commit 307b3114ef
2 changed files with 7 additions and 1 deletions
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6
arch/s390/include/asm/smp.h
View File

@ -69,6 +69,12 @@ static inline void smp_stop_cpu(void)
}
}
/* Return thread 0 CPU number as base CPU */
static inline int smp_get_base_cpu(int cpu)
{
return cpu - (cpu % (smp_cpu_mtid + 1));
}
#ifdef CONFIG_HOTPLUG_CPU
extern int smp_rescan_cpus(void);
extern void __noreturn cpu_die(void);

2
arch/s390/numa/mode_emu.c
View File

@ -360,7 +360,7 @@ static struct toptree *toptree_from_topology(void)
drawer = toptree_get_child(node, top->drawer_id);
book = toptree_get_child(drawer, top->book_id);
mc = toptree_get_child(book, top->socket_id);
core = toptree_get_child(mc, top->core_id);
core = toptree_get_child(mc, smp_get_base_cpu(cpu));
if (!drawer || !book || !mc || !core)
panic("NUMA emulation could not allocate memory");
cpumask_set_cpu(cpu, &core->mask);