https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=276426
--- Comment #9 from John F. Carr <j...@mit.edu> --- Here is the complete backtrace (abbreviated form in comment #2) and evaluation of the td variable in that stack. (kgdb) bt #0 __curthread () at /usr/home/jfc/freebsd/src/sys/amd64/include/pcpu_aux.h:53 #1 doadump (textdump=<optimized out>) at /usr/home/jfc/freebsd/src/sys/kern/kern_shutdown.c:394 #2 0xffffffff80bce802 in kern_reboot (howto=260) at /usr/home/jfc/freebsd/src/sys/kern/kern_shutdown.c:482 #3 0xffffffff80bcec5f in vpanic (fmt=0xffffffff812041f3 "%s", ap=ap@entry=0xfffffe03a79d7af0) at /usr/home/jfc/freebsd/src/sys/kern/kern_shutdown.c:921 #4 0xffffffff80bce9f3 in panic (fmt=<unavailable>) at /usr/home/jfc/freebsd/src/sys/kern/kern_shutdown.c:845 #5 0xffffffff8108c56c in trap_fatal (frame=0xfffffe03a79d7be0, eva=62185075507200) at /usr/home/jfc/freebsd/src/sys/amd64/amd64/trap.c:940 #6 0xffffffff8108c5d7 in trap_pfault (frame=0xfffffe03a79d7be0, usermode=false, signo=<optimized out>, ucode=<optimized out>) at /usr/home/jfc/freebsd/src/sys/amd64/amd64/trap.c:759 #7 <signal handler called> #8 copyout_smap_std () at /usr/home/jfc/freebsd/src/sys/amd64/amd64/support.S:849 #9 0xffffffff80c337d5 in uiomove_faultflag (cp=0xfffffe01bedc0000, n=n@entry=105, uio=uio@entry=0xfffffe03a79d7da0, nofault=nofault@entry=0) at /usr/home/jfc/freebsd/src/sys/kern/subr_uio.c:256 #10 0xffffffff80c33699 in uiomove (cp=0x388e97560000, n=-1092878336, n@entry=105, uio=0x636f6c2f7273752f, uio@entry=0xfffffe03a79d7da0) at /usr/home/jfc/freebsd/src/sys/kern/subr_uio.c:196 #11 0xffffffff80c3de55 in pipe_read (fp=0xfffff801441abe10, uio=0xfffffe03a79d7da0, active_cred=<optimized out>, flags=<optimized out>, td=0xfffff80103c48000) at /usr/home/jfc/freebsd/src/sys/kern/sys_pipe.c:732 #12 0xffffffff80c3a586 in fo_read (fp=0xfffff801441abe10, uio=0xfffffe03a79d7da0, active_cred=0x636f6c2f7273752f, td=0xfffff80103c48000, flags=<optimized out>) at /usr/home/jfc/freebsd/src/sys/sys/file.h:336 #13 dofileread (td=td@entry=0xfffff80103c48000, fd=fd@entry=0, fp=0xfffff801441abe10, auio=auio@entry=0xfffffe03a79d7da0, offset=offset@entry=-1, flags=flags@entry=0) at /usr/home/jfc/freebsd/src/sys/kern/sys_generic.c:367 #14 0xffffffff80c3a0d2 in kern_readv (td=0xfffff80103c48000, fd=0, auio=0xfffffe03a79d7da0) at /usr/home/jfc/freebsd/src/sys/kern/sys_generic.c:288 #15 sys_read (td=0xfffff80103c48000, uap=<optimized out>) at /usr/home/jfc/freebsd/src/sys/kern/sys_generic.c:204 #16 0xffffffff8108ced0 in syscallenter (td=<optimized out>) at /usr/home/jfc/freebsd/src/sys/amd64/amd64/../../kern/subr_syscall.c:188 #17 amd64_syscall (td=0xfffff80103c48000, traced=0) at /usr/home/jfc/freebsd/src/sys/amd64/amd64/trap.c:1181 #18 <signal handler called> #19 0x0000388e94230d9a in ?? () Backtrace stopped: Cannot access memory at address 0x388e93262428 (kgdb) up 13 #13 dofileread (td=td@entry=0xfffff80103c48000, fd=fd@entry=0, fp=0xfffff801441abe10, auio=auio@entry=0xfffffe03a79d7da0, offset=offset@entry=-1, flags=flags@entry=0) at /usr/home/jfc/freebsd/src/sys/kern/sys_generic.c:367 367 if ((error = fo_read(fp, auio, td->td_ucred, flags, td))) { (kgdb) p td->td_critnest $22 = 1 (kgdb) p/x td->td_md.md_pcb $23 = {pcb_r15 = 0xfffff80101bba000, pcb_r14 = 0xffffffff81e97788, pcb_r13 = 0xfffffe010aeec0d8, pcb_r12 = 0xfffffe010aeec0c0, pcb_rbp = 0xfffffe03a79d7bb0, pcb_rsp = 0xfffffe03a79d7b18, pcb_rbx = 0xfffff80103c48000, pcb_rip = 0xffffffff80bfe4b6, pcb_fsbase = 0x388e9378c120, pcb_gsbase = 0x0, pcb_kgsbase = 0x0, pcb_cr0 = 0x0, pcb_cr2 = 0x0, pcb_cr3 = 0x0, pcb_cr4 = 0x0, pcb_dr0 = 0x0, pcb_dr1 = 0x0, pcb_dr2 = 0x0, pcb_dr3 = 0x0, pcb_dr6 = 0x0, pcb_dr7 = 0x0, pcb_gdt = {rd_limit = 0x0, rd_base = 0x0}, pcb_idt = {rd_limit = 0x0, rd_base = 0x0}, pcb_ldt = {rd_limit = 0x0, rd_base = 0x0}, pcb_tr = 0x0, pcb_flags = 0x19, pcb_initial_fpucw = 0x37f, pcb_onfault = 0x0, pcb_saved_ucr3 = 0x0, pcb_tssp = 0x0, pcb_efer = 0x0, pcb_star = 0x0, pcb_lstar = 0x0, pcb_cstar = 0x0, pcb_sfmask = 0x0, pcb_save = 0xfffffe02699f4c00, pcb_pad = {0x0, 0x0, 0x0, 0x0, 0x0}} (kgdb) -- You are receiving this mail because: You are the assignee for the bug.