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

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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: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Pierre Gondois <pierre.gondois@arm.com>
Tested-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20230104183033.755668-4-pierre.gondois@arm.com
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
This commit is contained in:
Pierre Gondois 2023-01-04 19:30:26 +01:00 committed by Sudeep Holla
parent 8844c3df00
commit de0df442ee
1 changed files with 26 additions and 11 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

37
drivers/base/cacheinfo.c
View file

@ -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;
}