s390/numa: always use logical cpu and core ids (307b3114) · Commits · 戴 / test

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>

arch/s390/include/asm/smp.h

+6 −0

Original line number	Diff line number	Diff line
		@@ -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);

arch/s390/numa/mode_emu.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -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);

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