From: David Laight > Sent: 14 February 2022 09:12 > > From: Helge Deller > > Sent: 13 February 2022 22:10 > > > > The put_user(val,ptr) macro wants a pointer in the second parameter, but in > > fat_ioctl_filldir() the d_name field references a whole "array of chars". > > Usually the compiler automatically converts it and uses a pointer to that > > array, but it's more clean to explicitly give the real pointer to where someting > > is put, which is in this case the first character of the d_name[] array. > > That just isn't true. > > In C both x->char_array and &x->char_array[0] have the same type > 'char *'. > > The 'bug' is caused by put_user() trying to do: > __typeof__(ptr) __ptr = ptr; > where __typeof__ is returning char[n] not char *. > > I've tried a few things but can't get __typeof__ to > generate a suitable type for both a simple type and array. Actually the issue is that put_user() writes a single variable and needs a pointer to one. So changing to: put_user(0, &array[0]); is probably fine. But the description is all wrong. David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)
