The patch titled Subject: mm/damon/core-test: fix memory leak in damon_new_ctx() has been added to the -mm mm-unstable branch. Its filename is mm-damon-core-test-fix-memory-leak-in-damon_new_ctx.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-damon-core-test-fix-memory-leak-in-damon_new_ctx.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Jinjie Ruan <ruanjinjie@xxxxxxxxxx> Subject: mm/damon/core-test: fix memory leak in damon_new_ctx() Date: Mon, 18 Sep 2023 20:09:51 +0800 When CONFIG_DAMON_KUNIT_TEST=y and making CONFIG_DEBUG_KMEMLEAK=y and CONFIG_DEBUG_KMEMLEAK_AUTO_SCAN=y, the below memory leak is detected. The damon_ctx which is allocated by kzalloc() in damon_new_ctx() in damon_test_ops_registration() and damon_test_set_attrs() are not freed. So use damon_destroy_ctx() to free it. After applying this patch, the following memory leak is never detected unreferenced object 0xffff2b49c6968800 (size 512): comm "kunit_try_catch", pid 350, jiffies 4294895294 (age 557.028s) hex dump (first 32 bytes): 88 13 00 00 00 00 00 00 a0 86 01 00 00 00 00 00 ................ 00 87 93 03 00 00 00 00 0a 00 00 00 00 00 00 00 ................ backtrace: [<0000000088e71769>] slab_post_alloc_hook+0xb8/0x368 [<0000000073acab3b>] __kmem_cache_alloc_node+0x174/0x290 [<00000000b5f89cef>] kmalloc_trace+0x40/0x164 [<00000000eb19e83f>] damon_new_ctx+0x28/0xb4 [<00000000daf6227b>] damon_test_ops_registration+0x34/0x328 [<00000000559c4801>] kunit_try_run_case+0x50/0xac [<000000003932ed49>] kunit_generic_run_threadfn_adapter+0x20/0x2c [<000000003c3e9211>] kthread+0x124/0x130 [<0000000028f85bdd>] ret_from_fork+0x10/0x20 unreferenced object 0xffff2b49c1a9cc00 (size 512): comm "kunit_try_catch", pid 356, jiffies 4294895306 (age 557.000s) hex dump (first 32 bytes): 88 13 00 00 00 00 00 00 a0 86 01 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 0a 00 00 00 00 00 00 00 ................ backtrace: [<0000000088e71769>] slab_post_alloc_hook+0xb8/0x368 [<0000000073acab3b>] __kmem_cache_alloc_node+0x174/0x290 [<00000000b5f89cef>] kmalloc_trace+0x40/0x164 [<00000000eb19e83f>] damon_new_ctx+0x28/0xb4 [<00000000058495c4>] damon_test_set_attrs+0x30/0x1a8 [<00000000559c4801>] kunit_try_run_case+0x50/0xac [<000000003932ed49>] kunit_generic_run_threadfn_adapter+0x20/0x2c [<000000003c3e9211>] kthread+0x124/0x130 [<0000000028f85bdd>] ret_from_fork+0x10/0x20 Link: https://lkml.kernel.org/r/20230918120951.2230468-3-ruanjinjie@xxxxxxxxxx Fixes: d1836a3b2a9a ("mm/damon/core-test: initialise context before test in damon_test_set_attrs()") Fixes: 4f540f5ab4f2 ("mm/damon/core-test: add a kunit test case for ops registration") Signed-off-by: Jinjie Ruan <ruanjinjie@xxxxxxxxxx> Reviewed-by: Feng Tang <feng.tang@xxxxxxxxx> Reviewed-by: SeongJae Park <sj@xxxxxxxxxx> Cc: Brendan Higgins <brendan.higgins@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/damon/core-test.h | 4 ++++ 1 file changed, 4 insertions(+) --- a/mm/damon/core-test.h~mm-damon-core-test-fix-memory-leak-in-damon_new_ctx +++ a/mm/damon/core-test.h @@ -269,6 +269,8 @@ static void damon_test_ops_registration( /* Check double-registration failure again */ KUNIT_EXPECT_EQ(test, damon_register_ops(&ops), -EINVAL); + + damon_destroy_ctx(c); } static void damon_test_set_regions(struct kunit *test) @@ -346,6 +348,8 @@ static void damon_test_set_attrs(struct invalid_attrs = valid_attrs; invalid_attrs.aggr_interval = 4999; KUNIT_EXPECT_EQ(test, damon_set_attrs(c, &invalid_attrs), -EINVAL); + + damon_destroy_ctx(c); } static void damon_test_moving_sum(struct kunit *test) _ Patches currently in -mm which might be from ruanjinjie@xxxxxxxxxx are mm-damon-core-test-fix-memory-leak-in-damon_new_region.patch mm-damon-core-test-fix-memory-leak-in-damon_new_ctx.patch