From: Al Viro > Sent: 10 May 2020 00:41 > > One of the uaccess-related branches; this one is just the > cases when access_ok() calls are trivially pointless - the address > in question gets fed only to primitives that do access_ok() checks > themselves. There is also the check in rw_copy_check_uvector() that should always be replicated by the copy_to/from_user() in _copy_to/from_iter(). And the strange call to rw_copy_check_uvector() in mm/process_vm_access.c which carefully avoids the access_ok() check for the target process. I did a quick look, but failed to see an obvious check further down the call path. The code is doing a read/write from another process, not sure when it is used - not by gdb. David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)