From: Yosry Ahmed <yosryahmed@google.com> mainline inclusion from mainline-v5.19-rc1 commit a3622a53e620700053b648478dbc638ad373be3b category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I545DF CVE: NA Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- Currently, alloc_anon_noexit() calls alloc_anon() which instantly frees the allocated memory. alloc_anon_noexit() is usually used with cg_run_nowait() to run a process in the background that allocates memory. It makes sense for the background process to keep the memory allocated and not instantly free it (otherwise there is no point of running it in the background). Link: https://lkml.kernel.org/r/20220425190040.2475377-4-yosryahmed@google.com Signed-off-by: Yosry Ahmed <yosryahmed@google.com> Acked-by: Roman Gushchin <roman.gushchin@linux.dev> Acked-by: Shakeel Butt <shakeelb@google.com> Acked-by: David Rientjes <rientjes@google.com> Cc: Chen Wandun <chenwandun@huawei.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Greg Thelen <gthelen@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Michal Hocko <mhocko@suse.com> Cc: "Michal Koutn" <mkoutny@suse.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Tejun Heo <tj@kernel.org> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Vaibhav Jain <vaibhav@linux.ibm.com> Cc: Wei Xu <weixugc@google.com> Cc: Yu Zhao <yuzhao@google.com> Cc: Zefan Li <lizefan.x@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Chen Wandun <chenwandun@huawei.com> Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> --- tools/testing/selftests/cgroup/test_memcontrol.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/cgroup/test_memcontrol.c b/tools/testing/selftests/cgroup/test_memcontrol.c index c19a97dd02d4..9f5cdcf0593f 100644 --- a/tools/testing/selftests/cgroup/test_memcontrol.c +++ b/tools/testing/selftests/cgroup/test_memcontrol.c @@ -210,13 +210,17 @@ static int alloc_pagecache_50M_noexit(const char *cgroup, void *arg) static int alloc_anon_noexit(const char *cgroup, void *arg) { int ppid = getppid(); + size_t size = (unsigned long)arg; + char *buf, *ptr; - if (alloc_anon(cgroup, arg)) - return -1; + buf = malloc(size); + for (ptr = buf; ptr < buf + size; ptr += PAGE_SIZE) + *ptr = 0; while (getppid() == ppid) sleep(1); + free(buf); return 0; } -- 2.20.1