kern/73719: Page fault in bpf_mtap ()

[Vladimir Ivanov]

The following reply was made to PR kern/73719; it has been noted by GNATS.

From: Vladimir Ivanov <wawa at yandex-team.ru>
To: Maxim Konovalov <maxim at macomnet.ru>
Cc: bug-followup at freebsd.org
Subject: Re: kern/73719: Page fault in bpf_mtap ()
Date: Tue, 09 Nov 2004 23:12:48 +0300

 >> I don't think so. I can't say that GIANT affects system stability
 >> significantly.
 >> Anyway, we've found a bug and this bug may be fixed (e.g. with above
 >> patch).  Why not ?
 >> :-)
 >>    
 >>
 >
 >Because I do not understand what is the root of the bug and what your
 >diff fixes, do you?
 >
 >  
 >
 Hura!
 I've found my kernel debug info.
 So, we can see full picture ( bp == NULL !).
 
 
 [GDB will not be able to debug user-mode threads: 
 /usr/lib/libthread_db.so: Undefined symbol "ps_pglobal_lookup"]
 GNU gdb 6.1.1 [FreeBSD]
 Copyright 2004 Free Software Foundation, Inc.
 GDB is free software, covered by the GNU General Public License, and you are
 welcome to change it and/or distribute copies of it under certain 
 conditions.
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 There is absolutely no warranty for GDB. Type "show warranty" for details.
 This GDB was configured as "i386-marcel-freebsd".
 doadump () at pcpu.h:159
 (kgdb) bt full
 #0 doadump () at pcpu.h:159
 No locals.
 #1 0xc04f44a6 in boot (howto=260) at /usr/src/sys/kern/kern_shutdown.c:397
 first_buf_printf = 1
 #2 0xc04f4854 in panic (fmt=0xc0648063 "%s") at 
 /usr/src/sys/kern/kern_shutdown.c:553
 td = (struct thread *) 0xc1ef0190
 bootopt = 260
 newpanic = 0
 ap = 0xc1ef0190 " ЧНа╟\034Ха"
 buf = "page fault", '\0' <repeats 245 times>
 #3 0xc062a951 in trap_fatal (frame=0xe4a98be4, eva=0) at 
 /usr/src/sys/i386/i386/trap.c:809
 code = 16
 type = 12
 ss = 16
 esp = 0
 softseg = {ssd_base = 0, ssd_limit = 1048575, ssd_type = 27, ssd_dpl = 
 0, ssd_p = 1, ssd_xx = 8, ssd_xx1 = 0, ssd_def32 = 1,
 ssd_gran = 1}
 #4 0xc062a648 in trap_pfault (frame=0xe4a98be4, usermode=0, eva=8) at 
 /usr/src/sys/i386/i386/trap.c:727
 va = 0
 vm = (struct vmspace *) 0x0
 map = 0xc0699540
 rv = 1
 ftype = 1 '\001'
 td = (struct thread *) 0xc1ef0190
 p = (struct proc *) 0xc1eefe20
 #5 0xc062a22d in trap (frame=
 {tf_fs = -983629800, tf_es = -1037172720, tf_ds = -458686448, tf_edi = 
 -1032472574, tf_esi = -1040689152, tf_ebp = -458650556, tf_isp = 
 -458650608, tf_ebx = 2048, tf_edx = 64, tf_ecx = 1514, tf_eax = 0, 
 tf_trapno = 12, tf_err = 0, tf_eip = -1068069940, tf_cs = 8, tf_eflags = 
 66182, tf_esp = -1003791136, tf_ss = 32}) at 
 /usr/src/sys/i386/i386/trap.c:417
 td = (struct thread *) 0xc1ef0190
 p = (struct proc *) 0xc1eefe20
 sticks = 0
 i = 0
 ucode = 0
 type = 12
 code = 0
 eva = 8
 #6 0xc0616c2a in calltrap () at /usr/src/sys/i386/i386/exception.s:140
 No locals.
 #7 0xc55f0018 in ?? ()
 No symbol table info available.
 #8 0xc22e0010 in ?? ()
 No symbol table info available.
 #9 0xe4a90010 in ?? ()
 No symbol table info available.
 #10 0xc275b802 in ?? ()
 No symbol table info available.
 #11 0xc1f85800 in ?? ()
 No symbol table info available.
 #12 0xe4a98c44 in ?? ()
 No symbol table info available.
 #13 0xe4a98c10 in ?? ()
 No symbol table info available.
 #14 0x00000800 in ?? ()
 No symbol table info available.
 #15 0x00000040 in ?? ()
 No symbol table info available.
 #16 0x000005ea in ?? ()
 ---Type <return> to continue, or q <return> to quit---
 No symbol table info available.
 #17 0x00000000 in ?? ()
 No symbol table info available.
 #18 0x0000000c in ?? ()
 No symbol table info available.
 #19 0x00000000 in ?? ()
 No symbol table info available.
 #20 0xc0568bcc in bpf_mtap (bp=0x0, m=0xc2740c00) at 
 /usr/src/sys/net/bpf.c:1214
 d = (struct bpf_d *) 0x800
 pktlen = 3262494722
 slen = 0
 #21 0xc056fafd in ether_input (ifp=0xc1f85800, m=0xc2740c00) at 
 /usr/src/sys/net/if_ethersubr.c:543
 eh = (struct ether_header *) 0xc275b802
 etype = 2048
 #22 0xc0480cd1 in em_process_receive_interrupts (adapter=0xc1f85800, 
 count=-5) at /usr/src/sys/dev/em/if_em.c:2867
 ifp = (struct ifnet *) 0xc1f85800
 mp = (struct mbuf *) 0xc42b5ce0
 accept_frame = 1 '\001'
 eop = 1 '\001'
 len = 64
 desc_len = 0
 prev_len_adj = 0
 i = 3251
 current_desc = (struct em_rx_desc *) 0xe4c2cb30
 #23 0xc047d9ff in em_intr (arg=0xc1f85800) at 
 /usr/src/sys/dev/em/if_em.c:1016
 loop_cnt = 3
 reg_icr = 0
 ifp = (struct ifnet *) 0xc1f85800
 adapter = (struct adapter *) 0xc1f85800
 #24 0xc04dc01f in ithread_loop (arg=0xc1e78a00) at 
 /usr/src/sys/kern/kern_intr.c:547
 ithd = (struct ithd *) 0xc1e78a00
 ih = (struct intrhand *) 0xc1fad940
 td = (struct thread *) 0xc1ef0190
 p = (struct proc *) 0xc1eefe20
 count = 0
 warming = 0
 warned = 0
 #25 0xc04dadb3 in fork_exit (callout=0xc04dbe7b <ithread_loop>, arg=0x0, 
 frame=0x0) at /usr/src/sys/kern/kern_fork.c:811
 p = (struct proc *) 0xc1eefe20
 td = (struct thread *) 0x0
 #26 0xc0616c8c in fork_trampoline () at 
 /usr/src/sys/i386/i386/exception.s:209
 No locals.