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cacheinfo: Fix shared_cpu_map to handle shared caches at different levels 

[ Upstream commit 198102c910 ]

The cacheinfo sets up the shared_cpu_map by checking whether the caches
with the same index are shared between CPUs. However, this will trigger
slab-out-of-bounds access if the CPUs do not have the same cache hierarchy.
Another problem is the mismatched shared_cpu_map when the shared cache does
not have the same index between CPUs.

CPU0	I	D	L3
index	0	1	2	x
	^	^	^	^
index	0	1	2	3
CPU1	I	D	L2	L3

This patch checks each cache is shared with all caches on other CPUs.

Reviewed-by: Pierre Gondois <pierre.gondois@arm.com>
Signed-off-by: Yong-Xuan Wang <yongxuan.wang@sifive.com>
Link: https://lore.kernel.org/r/20230117105133.4445-2-yongxuan.wang@sifive.com
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Yong-Xuan Wang 2023-01-17 10:51:33 +00:00 committed by Greg Kroah-Hartman
parent c68ece7baf
commit 2f588d0345
1 changed files with 17 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

27
drivers/base/cacheinfo.c
View File

@ -251,7 +251,7 @@ static int cache_shared_cpu_map_setup(unsigned int cpu)
{
struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
struct cacheinfo *this_leaf, *sib_leaf;
unsigned int index;
unsigned int index, sib_index;
int ret = 0;
if (this_cpu_ci->cpu_map_populated)
@ -279,11 +279,13 @@ static int cache_shared_cpu_map_setup(unsigned int cpu)
if (i == cpu || !sib_cpu_ci->info_list)
continue;/* skip if itself or no cacheinfo */
sib_leaf = per_cpu_cacheinfo_idx(i, index);
if (cache_leaves_are_shared(this_leaf, sib_leaf)) {
cpumask_set_cpu(cpu, &sib_leaf->shared_cpu_map);
cpumask_set_cpu(i, &this_leaf->shared_cpu_map);
for (sib_index = 0; sib_index < cache_leaves(i); sib_index++) {
sib_leaf = per_cpu_cacheinfo_idx(i, sib_index);
if (cache_leaves_are_shared(this_leaf, sib_leaf)) {
cpumask_set_cpu(cpu, &sib_leaf->shared_cpu_map);
cpumask_set_cpu(i, &this_leaf->shared_cpu_map);
break;
}
}
}
/* record the maximum cache line size */
@ -297,7 +299,7 @@ static int cache_shared_cpu_map_setup(unsigned int cpu)
static void cache_shared_cpu_map_remove(unsigned int cpu)
{
struct cacheinfo *this_leaf, *sib_leaf;
unsigned int sibling, index;
unsigned int sibling, index, sib_index;
for (index = 0; index < cache_leaves(cpu); index++) {
this_leaf = per_cpu_cacheinfo_idx(cpu, index);
@ -308,9 +310,14 @@ static void cache_shared_cpu_map_remove(unsigned int cpu)
if (sibling == cpu || !sib_cpu_ci->info_list)
continue;/* skip if itself or no cacheinfo */
sib_leaf = per_cpu_cacheinfo_idx(sibling, index);
cpumask_clear_cpu(cpu, &sib_leaf->shared_cpu_map);
cpumask_clear_cpu(sibling, &this_leaf->shared_cpu_map);
for (sib_index = 0; sib_index < cache_leaves(sibling); sib_index++) {
sib_leaf = per_cpu_cacheinfo_idx(sibling, sib_index);
if (cache_leaves_are_shared(this_leaf, sib_leaf)) {
cpumask_clear_cpu(cpu, &sib_leaf->shared_cpu_map);
cpumask_clear_cpu(sibling, &this_leaf->shared_cpu_map);
break;
}
}
}
if (of_have_populated_dt())
of_node_put(this_leaf->fw_token);