Commit de0df442 authored by Pierre Gondois's avatar Pierre Gondois Committed by Sudeep Holla
Browse files

cacheinfo: Check 'cache-unified' property to count cache leaves 

The DeviceTree Specification v0.3 specifies that the cache node
'[d-|i-|]cache-size' property is required. The 'cache-unified'
property is specifies whether the cache level is separate
or unified.

If the cache-size property is missing, no cache leaves is accounted.
This can lead to a 'BUG: KASAN: slab-out-of-bounds' [1] bug.

Check 'cache-unified' property and always account for at least
one cache leaf when parsing the device tree.

[1] https://lore.kernel.org/all/0f19cb3f-d6cf-4032-66d2-dedc9d09a0e3@linaro.org/



Reported-by: default avatarKrzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: default avatarPierre Gondois <pierre.gondois@arm.com>
Tested-by: default avatarKrzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20230104183033.755668-4-pierre.gondois@arm.com


Signed-off-by: default avatarSudeep Holla <sudeep.holla@arm.com>
parent 8844c3df

drivers/base/cacheinfo.c

+26 −11
Original line number Diff line number Diff line
@@ -230,12 +230,9 @@ static int cache_setup_of_node(unsigned int cpu) 
	return 0;

}



int init_of_cache_level(unsigned int cpu)

static int of_count_cache_leaves(struct device_node *np)

{

	struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);

	struct device_node *np = of_cpu_device_node_get(cpu);

	struct device_node *prev = NULL;

	unsigned int levels = 0, leaves = 0, level;

	unsigned int leaves = 0;



	if (of_property_read_bool(np, "cache-size"))

		++leaves;
@@ -243,6 +240,28 @@ int init_of_cache_level(unsigned int cpu) 
		++leaves;

	if (of_property_read_bool(np, "d-cache-size"))

		++leaves;



	if (!leaves) {

		/* The '[i-|d-|]cache-size' property is required, but

		 * if absent, fallback on the 'cache-unified' property.

		 */

		if (of_property_read_bool(np, "cache-unified"))

			return 1;

		else

			return 2;

	}



	return leaves;

}



int init_of_cache_level(unsigned int cpu)

{

	struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);

	struct device_node *np = of_cpu_device_node_get(cpu);

	struct device_node *prev = NULL;

	unsigned int levels = 0, leaves, level;



	leaves = of_count_cache_leaves(np);

	if (leaves > 0)

		levels = 1;
@@ -256,12 +275,8 @@ int init_of_cache_level(unsigned int cpu) 
			goto err_out;

		if (level <= levels)

			goto err_out;

		if (of_property_read_bool(np, "cache-size"))

			++leaves;

		if (of_property_read_bool(np, "i-cache-size"))

			++leaves;

		if (of_property_read_bool(np, "d-cache-size"))

			++leaves;



		leaves += of_count_cache_leaves(np);

		levels = level;

	}