From: Linus Torvalds > Sent: 08 September 2021 19:30 > > On Tue, Sep 7, 2021 at 7:58 PM Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote: > > > > When the destination buffer is before the source one, or when the buffers > > doesn't overlap, it's safe to use memcpy() instead, which is optimized to > > use a bigger data size possible. > > This one is actively buggy. > > It depends on the possibly incorrect assumption that memcpy() always > copies upwards. Even if the memcpy() 'mostly' copies upwards it may copy the last 8 bytes first and then copy the rest of the buffer in 8 byte chunks. OTOH the change to libc that made it do backwards is just stupid. David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)
