From: Sha Zhengju <handai.szj@xxxxxxxxxx> Since PAGE_ALIGN is aligning up(the next page boundary), so after PAGE_ALIGN, the value might be overflow, such as write the MAX value to *.limit_in_bytes. $ cat /cgroup/memory/memory.limit_in_bytes 18446744073709551615 # echo 18446744073709551615 > /cgroup/memory/memory.limit_in_bytes bash: echo: write error: Invalid argument Some user programs might depend on such behaviours(like libcg, we read the value in snapshot, then use the value to reset cgroup later), and that will cause confusion. So we need to fix it. Signed-off-by: Sha Zhengju <handai.szj@xxxxxxxxxx> Signed-off-by: Qiang Huang <h.huangqiang@xxxxxxxxxx> Reviewed-by: Michal Hocko <mhocko@xxxxxxx> --- kernel/res_counter.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/kernel/res_counter.c b/kernel/res_counter.c index 3f0417f..085d3ae 100644 --- a/kernel/res_counter.c +++ b/kernel/res_counter.c @@ -195,6 +195,10 @@ int res_counter_memparse_write_strategy(const char *buf, if (*end != '\0') return -EINVAL; - *res = PAGE_ALIGN(*res); + if (PAGE_ALIGN(*res) >= *res) + *res = PAGE_ALIGN(*res); + else + *res = RES_COUNTER_MAX; + return 0; } -- 1.8.3 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>