From: Randy Dunlap rdunlap@infradead.org
commit 460a79e18842caca6fa0c415de4a3ac1e671ac50 upstream.
__setup() handlers should return 1 if the command line option is handled and 0 if not (or maybe never return 0; it just pollutes init's environment).
The only reason that this particular __setup handler does not pollute init's environment is that the setup string contains a '.', as in "cgroup.memory". This causes init/main.c::unknown_boottoption() to consider it to be an "Unused module parameter" and ignore it. (This is for parsing of loadable module parameters any time after kernel init.) Otherwise the string "cgroup.memory=whatever" would be added to init's environment strings.
Instead of relying on this '.' quirk, just return 1 to indicate that the boot option has been handled.
Note that there is no warning message if someone enters: cgroup.memory=anything_invalid
Link: https://lkml.kernel.org/r/20220222005811.10672-1-rdunlap@infradead.org Fixes: f7e1cb6ec51b0 ("mm: memcontrol: account socket memory in unified hierarchy memory controller") Signed-off-by: Randy Dunlap rdunlap@infradead.org Reported-by: Igor Zhbanov i.zhbanov@omprussia.ru Link: lore.kernel.org/r/64644a2f-4a20-bab3-1e15-3b2cdd0defe3@omprussia.ru Reviewed-by: Michal Koutný mkoutny@suse.com Cc: Johannes Weiner hannes@cmpxchg.org Cc: Michal Hocko mhocko@kernel.org Cc: Vladimir Davydov vdavydov.dev@gmail.com Cc: Roman Gushchin roman.gushchin@linux.dev Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- mm/memcontrol.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -6973,7 +6973,7 @@ static int __init cgroup_memory(char *s) if (!strcmp(token, "nokmem")) cgroup_memory_nokmem = true; } - return 0; + return 1; } __setup("cgroup.memory=", cgroup_memory);