mm/damon/lru_sort: adjust local variable to dynamic allocation

When KASAN is enabled and built with clang:
    mm/damon/lru_sort.c:199:12: error: stack frame size (2328) exceeds
limit (2048) in 'damon_lru_sort_apply_parameters' [-Werror,-Wframe-larger-than]
    static int damon_lru_sort_apply_parameters(void)
               ^
    1 error generated.

This is because damon_lru_sort_quota contains a large array, and
assigning this variable to a local variable causes a large amount of
stack space to be occupied.

So adjust local variable to dynamic allocation.

Link: https://lkml.kernel.org/r/20240723035513.20153-1-flyingpeng@tencent.com
Signed-off-by: Peng Hao <flyingpeng@tencent.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/damon/lru_sort.c b/mm/damon/lru_sort.c
index 4af8fd4a390b662b1ff5f05ce789c4794eee1277..0b35bd5fb6594488c780a8c89de8d6fadb9281c2 100644 (file)
--- a/mm/damon/lru_sort.c
+++ b/mm/damon/lru_sort.c
@@ -148,12 +148,17 @@ static struct damon_target *target;
 static struct damos *damon_lru_sort_new_scheme(
                struct damos_access_pattern *pattern, enum damos_action action)
 {
-       struct damos_quota quota = damon_lru_sort_quota;
+       struct damos *damos;
+       struct damos_quota *quota = kmemdup(&damon_lru_sort_quota,
+                                   sizeof(damon_lru_sort_quota), GFP_KERNEL);
+
+       if (!quota)
+               return NULL;
 
        /* Use half of total quota for hot/cold pages sorting */
-       quota.ms = quota.ms / 2;
+       quota->ms = quota->ms / 2;
 
-       return damon_new_scheme(
+       damos = damon_new_scheme(
                        /* find the pattern, and */
                        pattern,
                        /* (de)prioritize on LRU-lists */
@@ -161,10 +166,12 @@ static struct damos *damon_lru_sort_new_scheme(
                        /* for each aggregation interval */
                        0,
                        /* under the quota. */
-                       &quota,
+                       quota,
                        /* (De)activate this according to the watermarks. */
                        &damon_lru_sort_wmarks,
                        NUMA_NO_NODE);
+       kfree(quota);
+       return damos;
 }
 
 /* Create a DAMON-based operation scheme for hot memory regions */