records: base=10 live=11 dead=11
sizeof(struct tty) assumed: 376  (4136-3760 == 376)
live[0] (ucom tty, head-inserted at attach):
  +0x018: 0xffffffff80c64d8d
  +0x100: 0xffffffff82615f80
  +0x108: 0xffffffff82615400
  +0x110: 0xffffffff82616c20
  +0x120: 0xfffff80116981198
  +0x160: 0xfffff801187fa600
  +0x168: 0xffffffff810e5200
dead[0] (same tty after USB detach + softc kfree):
  +0x018: 0xffffffff80c64d8d
  +0x100: 0xffffffff82615f80
  +0x108: 0xffffffff82615400
  +0x110: 0xffffffff82616c20
  +0x120: 0xfffff80116981198
  +0x160: 0xfffff801187fe600
  +0x168: 0xffffffff810e5200
fields identical across detach: ['0x18', '0x100', '0x108', '0x110', '0x120', '0x168']
=> driver TEXT pointers retained after detach (t_oproc/t_param/t_stop): ['+0x18=0xffffffff80c64d8d', '+0x100=0xffffffff82615f80', '+0x108=0xffffffff82615400', '+0x110=0xffffffff82616c20', '+0x168=0xffffffff810e5200']
=> HEAP pointer retained after detach (t_sc -> freed ucom_softc): ['+0x120=0xfffff80116981198']