From: Pierre Gondois pierre.gondois@arm.com
[ Upstream commit de0df442ee49cb1f6ee58f3fec5dcb5e5eb70aab ]
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 Signed-off-by: Wen Yang wen.yang@linux.dev --- drivers/base/cacheinfo.c | 37 ++++++++++++++++++++++++++----------- 1 file changed, 26 insertions(+), 11 deletions(-)
diff --git a/drivers/base/cacheinfo.c b/drivers/base/cacheinfo.c index 480007210bcc..ab99b0f0d010 100644 --- a/drivers/base/cacheinfo.c +++ b/drivers/base/cacheinfo.c @@ -224,12 +224,9 @@ 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; @@ -237,6 +234,28 @@ 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;
@@ -250,12 +269,8 @@ 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; }