(kgdb) whe
#0  doadump (textdump=-2127436624) at pcpu.h:219
#1  0xffffffff80342e05 in db_fncall (dummy1=<value optimized out>, dummy2=<value optimized out>, dummy3=<value optimized out>, dummy4=<value optimized out>)
    at /usr/src/sys/ddb/db_command.c:578
#2  0xffffffff80342aed in db_command (cmd_table=<value optimized out>) at /usr/src/sys/ddb/db_command.c:449
#3  0xffffffff80342864 in db_command_loop () at /usr/src/sys/ddb/db_command.c:502
#4  0xffffffff803451d0 in db_trap (type=<value optimized out>, code=0) at /usr/src/sys/ddb/db_main.c:231
#5  0xffffffff808fab13 in kdb_trap (type=3, code=0, tf=<value optimized out>) at /usr/src/sys/kern/subr_kdb.c:656
#6  0xffffffff80cb0037 in trap (frame=0xfffffe1839e40150) at /usr/src/sys/amd64/amd64/trap.c:579
#7  0xffffffff80c96ce2 in calltrap () at /usr/src/sys/amd64/amd64/exception.S:232
#8  0xffffffff808fa2ce in kdb_enter (why=0xffffffff80f07a72 "panic", msg=<value optimized out>) at cpufunc.h:63
#9  0xffffffff808c1c95 in panic (fmt=<value optimized out>) at /usr/src/sys/kern/kern_shutdown.c:747
#10 0xffffffff80b297dd in vm_fault_hold (map=0xfffff80002000000, vaddr=<value optimized out>, fault_type=1 '\001', fault_flags=0, m_hold=0x0) at /usr/src/sys/vm/vm_fault.c:279
#11 0xffffffff80b282a7 in vm_fault (map=0xfffff80002000000, vaddr=<value optimized out>, fault_type=1 '\001', fault_flags=0) at /usr/src/sys/vm/vm_fault.c:224
#12 0xffffffff80cb068b in trap_pfault (frame=0xfffffe1839e40820, usermode=0) at /usr/src/sys/amd64/amd64/trap.c:775
#13 0xffffffff80caff46 in trap (frame=0xfffffe1839e40820) at /usr/src/sys/amd64/amd64/trap.c:463
#14 0xffffffff80c96ce2 in calltrap () at /usr/src/sys/amd64/amd64/exception.S:232
#15 0xffffffff80cae23b in copyout () at /usr/src/sys/amd64/amd64/support.S:246
#16 0xffffffff8090cb55 in uiomove_faultflag (cp=<value optimized out>, n=<value optimized out>, uio=0xfffffe1839e40ab0, nofault=<value optimized out>) at /usr/src/sys/kern/subr_uio.c:192
#17 0xffffffff80c9e515 in memrw (dev=0xfffff80011302e00, uio=0xfffffe1839e40ab0, flags=113246208) at /usr/src/sys/amd64/amd64/mem.c:101
#18 0xffffffff8087305a in giant_read (dev=0xfffff80011302e00, uio=0xfffffe1839e40ab0, ioflag=0) at /usr/src/sys/kern/kern_conf.c:444
#19 0xffffffff807b652a in devfs_read_f (fp=0xfffff801d5298410, uio=0xfffffe1839e40ab0, cred=<value optimized out>, flags=0, td=0xfffff8031e0d3920)
    at /usr/src/sys/fs/devfs/devfs_vnops.c:1193
#20 0xffffffff809115cb in dofileread (td=0xfffff8031e0d3920, fd=4, fp=0xfffff801d5298410, auio=0xfffffe1839e40ab0, offset=<value optimized out>, flags=0) at file.h:295
#21 0xffffffff80911305 in kern_readv (td=0xfffff8031e0d3920, fd=4, auio=0xfffffe1839e40ab0) at /usr/src/sys/kern/sys_generic.c:256
#22 0xffffffff80911293 in sys_read (td=<value optimized out>, uap=<value optimized out>) at /usr/src/sys/kern/sys_generic.c:171
#23 0xffffffff80cb0dd7 in amd64_syscall (td=0xfffff8031e0d3920, traced=0) at subr_syscall.c:134
#24 0xffffffff80c96fcb in Xfast_syscall () at /usr/src/sys/amd64/amd64/exception.S:391
#25 0x0000000800b74c7a in ?? ()
Previous frame inner to this frame (corrupt stack?)
(kgdb) f 17
#17 0xffffffff80c9e515 in memrw (dev=0xfffff80011302e00, uio=0xfffffe1839e40ab0, flags=113246208) at /usr/src/sys/amd64/amd64/mem.c:101
101				error = uiomove((void *)PHYS_TO_DMAP(v), (int)c, uio);
(kgdb) list
96			if (dev2unit(dev) == CDEV_MINOR_MEM) {
97				v = uio->uio_offset;
98	kmemphys:
99				o = v & PAGE_MASK;
100				c = min(uio->uio_resid, (u_int)(PAGE_SIZE - o));
101				error = uiomove((void *)PHYS_TO_DMAP(v), (int)c, uio);
102				continue;
103			}
104			else if (dev2unit(dev) == CDEV_MINOR_KMEM) {
105				v = uio->uio_offset;
(kgdb) p memrw+0x195
$2 = (int (*)(struct cdev *, struct uio *, int)) 0xffffffff80c9e515 <memrw+405>