Linus Torvalds <[email protected]> writes: > On Fri, Apr 7, 2017 at 8:51 AM, Liping Zhang <[email protected]> wrote: >> From: Liping Zhang <[email protected]> >> >> Currently, inputting the following command will succeed but actually the >> value will be truncated: >> # echo 0x12ffffffff > /proc/sys/net/ipv4/tcp_notsent_lowat >> >> This is not friendly to the user, so instead, we should report error >> when the value is larger than UINT_MAX. > > I applied the two other patches, but I didn't apply this one. > > It's entirely possible that people end up doing something like > > echo -1 > /proc/sys/some_random_uint > > because that's a fairly normal thing to do to set all bits. Making > that an error seems wrong.
Except that doesn't help in this case. The function do_uintvec_conv rules already rejects all negative values on write. So -1 is already rejected. In fact the function proc_douintvec_conv has always rejected negative values so this change won't even create a regression. So it looks perfectly reasonable to reject values that are simply too large to be written to the uint. So even today to write all bits set you do have to do: echo 0xffffffff > /proc/sys/some_random_uint Eric
