From: "Liam R. Howlett (Google)" <liam@infradead.org>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
maple-tree@lists.infradead.org, Lorenzo Stoakes <ljs@kernel.org>,
Chris Mason <mason@kernel.org>, Alice Ryhl <aliceryhl@google.com>,
Andrew Ballance <andrewjballance@gmail.com>,
"Liam R. Howlett (Google)" <liam@infradead.org>,
stable@vger.kernel.org
Subject: [PATCH v2 3/3] maple_tree: Update internal warning and bug_on code
Date: Mon, 2 Nov 2026 21:07:24 -0500 [thread overview]
Message-ID: <20261103020724.2614498-4-liam@infradead.org> (raw)
In-Reply-To: <20261103020724.2614498-1-liam@infradead.org>
When CONFIG_DEBUG_MAPLE_TREE is set, call WARN_ON() once per site after
the custom information is dumped about the tree. Without using the
kernel's WARN_ON calls, syzbot will not catch issues detected by this
code. The BUG_ON variants now stop instead of dumping and continuing.
Update the non-debug code to call WARN_ON_ONCE() as well.
The userspace tests asserted on dump_stack() but only print on
WARN_ON(), so make WARN() fatal in maple-shared.h and have the maple
test exit with the result of maple_tree_seed().
Cc: <stable@vger.kernel.org>
Reported-by: Lorenzo Stoakes <ljs@kernel.org>
Fixes: f0a1f866aba1 ("maple_tree: add debug BUG_ON and WARN_ON variants")
Signed-off-by: Liam R. Howlett (Google) <liam@infradead.org>
---
include/linux/maple_tree.h | 48 ++++++++++++++---------------
tools/testing/radix-tree/maple.c | 13 +++++---
tools/testing/shared/maple-shared.h | 33 ++++++++++++++++++++
3 files changed, 66 insertions(+), 28 deletions(-)
diff --git a/include/linux/maple_tree.h b/include/linux/maple_tree.h
index e30e57f5f3df9..3a9751c6689fc 100644
--- a/include/linux/maple_tree.h
+++ b/include/linux/maple_tree.h
@@ -680,7 +680,7 @@ void mt_cache_shrink(void);
pr_info("Pass: %u Run:%u\n", \
atomic_read(&maple_tree_tests_passed), \
atomic_read(&maple_tree_tests_run)); \
- dump_stack(); \
+ BUG_ON(1); \
} else { \
atomic_inc(&maple_tree_tests_passed); \
} \
@@ -696,7 +696,7 @@ void mt_cache_shrink(void);
pr_info("Pass: %u Run:%u\n", \
atomic_read(&maple_tree_tests_passed), \
atomic_read(&maple_tree_tests_run)); \
- dump_stack(); \
+ BUG_ON(1); \
} else { \
atomic_inc(&maple_tree_tests_passed); \
} \
@@ -713,7 +713,7 @@ void mt_cache_shrink(void);
pr_info("Pass: %u Run:%u\n", \
atomic_read(&maple_tree_tests_passed), \
atomic_read(&maple_tree_tests_run)); \
- dump_stack(); \
+ BUG_ON(1); \
} else { \
atomic_inc(&maple_tree_tests_passed); \
} \
@@ -722,16 +722,16 @@ void mt_cache_shrink(void);
#define MT_WARN_ON(__tree, __x) ({ \
int ret = !!(__x); \
atomic_inc(&maple_tree_tests_run); \
- if (ret) { \
- pr_info("WARN at %s:%d (%u)\n", \
- __func__, __LINE__, __x); \
+ if (!ret) { \
+ atomic_inc(&maple_tree_tests_passed); \
+ } else if (__ONCE_LITE_IF(ret)) { \
+ pr_info("WARN at %s:%d\n", \
+ __func__, __LINE__); \
mt_dump(__tree, mt_dump_hex); \
pr_info("Pass: %u Run:%u\n", \
atomic_read(&maple_tree_tests_passed), \
atomic_read(&maple_tree_tests_run)); \
- dump_stack(); \
- } else { \
- atomic_inc(&maple_tree_tests_passed); \
+ WARN_ON(1); \
} \
unlikely(ret); \
})
@@ -739,17 +739,17 @@ void mt_cache_shrink(void);
#define MAS_WARN_ON(__mas, __x) ({ \
int ret = !!(__x); \
atomic_inc(&maple_tree_tests_run); \
- if (ret) { \
- pr_info("WARN at %s:%d (%u)\n", \
- __func__, __LINE__, __x); \
+ if (!ret) { \
+ atomic_inc(&maple_tree_tests_passed); \
+ } else if (__ONCE_LITE_IF(ret)) { \
+ pr_info("WARN at %s:%d\n", \
+ __func__, __LINE__); \
mas_dump(__mas); \
mt_dump((__mas)->tree, mt_dump_hex); \
pr_info("Pass: %u Run:%u\n", \
atomic_read(&maple_tree_tests_passed), \
atomic_read(&maple_tree_tests_run)); \
- dump_stack(); \
- } else { \
- atomic_inc(&maple_tree_tests_passed); \
+ WARN_ON(1); \
} \
unlikely(ret); \
})
@@ -757,18 +757,18 @@ void mt_cache_shrink(void);
#define MAS_WR_WARN_ON(__wrmas, __x) ({ \
int ret = !!(__x); \
atomic_inc(&maple_tree_tests_run); \
- if (ret) { \
- pr_info("WARN at %s:%d (%u)\n", \
- __func__, __LINE__, __x); \
+ if (!ret) { \
+ atomic_inc(&maple_tree_tests_passed); \
+ } else if (__ONCE_LITE_IF(ret)) { \
+ pr_info("WARN at %s:%d\n", \
+ __func__, __LINE__); \
mas_wr_dump(__wrmas); \
mas_dump((__wrmas)->mas); \
mt_dump((__wrmas)->mas->tree, mt_dump_hex); \
pr_info("Pass: %u Run:%u\n", \
atomic_read(&maple_tree_tests_passed), \
atomic_read(&maple_tree_tests_run)); \
- dump_stack(); \
- } else { \
- atomic_inc(&maple_tree_tests_passed); \
+ WARN_ON(1); \
} \
unlikely(ret); \
})
@@ -776,9 +776,9 @@ void mt_cache_shrink(void);
#define MT_BUG_ON(__tree, __x) BUG_ON(__x)
#define MAS_BUG_ON(__mas, __x) BUG_ON(__x)
#define MAS_WR_BUG_ON(__mas, __x) BUG_ON(__x)
-#define MT_WARN_ON(__tree, __x) WARN_ON(__x)
-#define MAS_WARN_ON(__mas, __x) WARN_ON(__x)
-#define MAS_WR_WARN_ON(__mas, __x) WARN_ON(__x)
+#define MT_WARN_ON(__tree, __x) WARN_ON_ONCE(__x)
+#define MAS_WARN_ON(__mas, __x) WARN_ON_ONCE(__x)
+#define MAS_WR_WARN_ON(__mas, __x) WARN_ON_ONCE(__x)
#endif /* CONFIG_DEBUG_MAPLE_TREE */
/**
diff --git a/tools/testing/radix-tree/maple.c b/tools/testing/radix-tree/maple.c
index bfe4b8626c429..846c67e20e82a 100644
--- a/tools/testing/radix-tree/maple.c
+++ b/tools/testing/radix-tree/maple.c
@@ -36502,22 +36502,27 @@ static void regression_tests(void)
test_spanning_store_regression();
}
-void maple_tree_tests(void)
+int maple_tree_tests(void)
{
+ int ret;
+
#if !defined(BENCH)
regression_tests();
farmer_tests();
#endif
- maple_tree_seed();
+ ret = maple_tree_seed();
maple_tree_harvest();
+ return ret;
}
int __weak main(void)
{
+ int ret;
+
maple_tree_init();
- maple_tree_tests();
+ ret = maple_tree_tests();
rcu_barrier();
if (nr_allocated)
printf("nr_allocated = %d\n", nr_allocated);
- return 0;
+ return ret ? EXIT_FAILURE : EXIT_SUCCESS;
}
diff --git a/tools/testing/shared/maple-shared.h b/tools/testing/shared/maple-shared.h
index 2a1e9a8594a28..5f827709773a0 100644
--- a/tools/testing/shared/maple-shared.h
+++ b/tools/testing/shared/maple-shared.h
@@ -8,6 +8,7 @@
#include "shared.h"
#include <stdlib.h>
#include <time.h>
+#include <assert.h>
#include "linux/init.h"
void maple_rcu_cb(struct rcu_head *head);
@@ -20,5 +21,37 @@ do { \
call_rcu(&((_p_struct)->_memb), rcu_cb); \
} while(0);
+/* Make WARN() fatal */
+#undef WARN
+#undef WARN_ON
+#undef WARN_ONCE
+#undef WARN_ON_ONCE
+#define WARN(condition, format...) ({ \
+ int __ret_warn_on = !!(condition); \
+ if (unlikely(__ret_warn_on)) { \
+ __WARN_printf(format); \
+ assert(0); \
+ } \
+ unlikely(__ret_warn_on); \
+})
+#define WARN_ON(condition) \
+ WARN(condition, "assertion failed at %s:%d\n", __FILE__, __LINE__)
+#define WARN_ONCE(condition, format...) WARN(condition, format)
+#define WARN_ON_ONCE(condition) WARN_ON(condition)
+
+/* Once state for the debug macros */
+#ifndef __ONCE_LITE_IF
+#define __ONCE_LITE_IF(condition) \
+ ({ \
+ static bool __already_done; \
+ bool __ret_once = false; \
+ \
+ if ((condition) && !__already_done) { \
+ __already_done = true; \
+ __ret_once = true; \
+ } \
+ __ret_once; \
+ })
+#endif
#endif /* __MAPLE_SHARED_H__ */
--
2.47.3
next prev parent reply other threads:[~2026-11-03 2:07 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-11-03 2:07 [PATCH v2 0/3] maple_tree fixes for 7.3 Liam R. Howlett (Google)
2026-11-03 2:07 ` [PATCH v2 1/3] maple_tree: Fix rcu reader NULL dereference after the tree is emptied Liam R. Howlett (Google)
2026-11-03 2:07 ` [PATCH v2 2/3] maple_tree: Test emptying tree while RCU reading Liam R. Howlett (Google)
2026-11-03 2:07 ` Liam R. Howlett (Google) [this message]
2026-11-03 11:52 ` [PATCH v2 3/3] maple_tree: Update internal warning and bug_on code Lorenzo Stoakes (ARM)
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