On Wed 31-07-13 15:31:24, Qiang Huang wrote: > 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 from this list: send the line "unsubscribe cgroups" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- Michal Hocko SUSE Labs -- 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>