aboutsummaryrefslogtreecommitdiffstats
path: root/mm
diff options
authorSeongJae Park <sj@kernel.org>2026-05-22 08:40:19 -0700
committerAndrew Morton <akpm@linux-foundation.org>2026-05-28 21:31:24 -0700
commitccc43738c1c7249a9b2a2affe4ca85650f647dbb (patch)
tree91368b8e778c2f72a83ce218fe35210067127f5d /mm
parent3b9da4bc52fead22ca01d3398d372180ecd8d1c7 (diff)
downloadlinux-next-history-ccc43738c1c7249a9b2a2affe4ca85650f647dbb.tar.gz
mm/damon/core: add kdamond_call() debug_sanity check
kdamond_call() is the place where DAMON API callers are allowed to access the DAMON context's public internal state including the monitoring results. Hence it is important to ensure it is called with the expected DAMON context state. Do the check under DAMON_DEBUG_SANITY. Link: https://lore.kernel.org/20260522154026.80546-9-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Brendan Higgins <brendan.higgins@linux.dev> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/damon/core.c33
1 files changed, 33 insertions, 0 deletions
diff --git a/mm/damon/core.c b/mm/damon/core.c
index d816679dd7020..00e2997524ece 100644
--- a/mm/damon/core.c
+++ b/mm/damon/core.c
@@ -3329,6 +3329,37 @@ static void kdamond_usleep(unsigned long usecs)
usleep_range_idle(usecs, usecs + 1);
}
+#ifdef CONFIG_DAMON_DEBUG_SANITY
+static void damon_verify_ctx(struct damon_ctx *c)
+{
+ struct damon_target *t;
+ struct damon_region *r;
+
+ damon_for_each_target(t, c) {
+ struct damon_region *prev_r = NULL;
+ unsigned int nr_regions = 0;
+
+ damon_for_each_region(r, t) {
+ WARN_ONCE(r->ar.start >= r->ar.end,
+ "region start (%lu) >= end (%lu)\n",
+ r->ar.start, r->ar.end);
+ WARN_ONCE(prev_r && prev_r->ar.end > r->ar.start,
+ "region overlap (%lu > %lu)\n",
+ prev_r->ar.end, r->ar.start);
+ prev_r = r;
+ nr_regions++;
+ }
+ WARN_ONCE(damon_nr_regions(t) != nr_regions,
+ "nr_regions mismatch: %u != %u\n",
+ damon_nr_regions(t), nr_regions);
+ }
+}
+#else
+static void damon_verify_ctx(struct damon_ctx *c)
+{
+}
+#endif
+
/*
* kdamond_call() - handle damon_call_control objects.
* @ctx: The &struct damon_ctx of the kdamond.
@@ -3344,6 +3375,8 @@ static void kdamond_call(struct damon_ctx *ctx, bool cancel)
struct damon_call_control *control, *next;
LIST_HEAD(controls);
+ damon_verify_ctx(ctx);
+
mutex_lock(&ctx->call_controls_lock);
list_splice_tail_init(&ctx->call_controls, &controls);
mutex_unlock(&ctx->call_controls_lock);