sosend() and mbuf

[Maslan]

I'm running out 7.2-RELEASE-p2

Here is my bt

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Unread portion of the kernel message buffer:
loaded.


Fatal trap 12: page fault while in kernel mode
cpuid = 1; apic id = 01
fault virtual address	= 0x10
fault code		= supervisor read, page not present
instruction pointer	= 0x20:0xc085935b
stack pointer	        = 0x28:0xe6cd3a28
frame pointer	        = 0x28:0xe6cd3aa4
code segment		= base 0x0, limit 0xfffff, type 0x1b
			= DPL 0, pres 1, def32 1, gran 1
processor eflags	= interrupt enabled, resume, IOPL = 0
current process		= 1354 (test)
trap number		= 12
panic: page fault
cpuid = 1
Uptime: 4m45s
Physical memory: 1001 MB
Dumping 119 MB: 104 88 72 56 40 24 8

Reading symbols from /boot/kernel/snd_hda.ko...Reading symbols from
/boot/kernel/snd_hda.ko.symbols...done.
done.
Loaded symbols for /boot/kernel/snd_hda.ko
Reading symbols from /boot/kernel/sound.ko...Reading symbols from
/boot/kernel/sound.ko.symbols...done.
done.
Loaded symbols for /boot/kernel/sound.ko
Reading symbols from /boot/kernel/if_wpi.ko...Reading symbols from
/boot/kernel/if_wpi.ko.symbols...done.
done.
Loaded symbols for /boot/kernel/if_wpi.ko
Reading symbols from /boot/kernel/wpifw.ko...Reading symbols from
/boot/kernel/wpifw.ko.symbols...done.
done.
Loaded symbols for /boot/kernel/wpifw.ko
Reading symbols from /boot/kernel/acpi.ko...Reading symbols from
/boot/kernel/acpi.ko.symbols...done.
done.
Loaded symbols for /boot/kernel/acpi.ko
Reading symbols from /boot/kernel/i915.ko...Reading symbols from
/boot/kernel/i915.ko.symbols...done.
done.
Loaded symbols for /boot/kernel/i915.ko
Reading symbols from /boot/kernel/drm.ko...Reading symbols from
/boot/kernel/drm.ko.symbols...done.
done.
Loaded symbols for /boot/kernel/drm.ko
Reading symbols from ./test.ko...done.
Loaded symbols for ./test.ko
#0  doadump () at pcpu.h:196
196	pcpu.h: No such file or directory.
	in pcpu.h
(kgdb) bt
#0  doadump () at pcpu.h:196
#1  0xc07e25c7 in boot (howto=260) at /usr/src/sys/kern/kern_shutdown.c:418
#2  0xc07e2899 in panic (fmt=Variable "fmt" is not available.
) at /usr/src/sys/kern/kern_shutdown.c:574
#3  0xc0ae3efc in trap_fatal (frame=0xe6cd39e8, eva=16)
    at /usr/src/sys/i386/i386/trap.c:939
#4  0xc0ae4180 in trap_pfault (frame=0xe6cd39e8, usermode=0, eva=16)
    at /usr/src/sys/i386/i386/trap.c:852
#5  0xc0ae4b2c in trap (frame=0xe6cd39e8) at /usr/src/sys/i386/i386/trap.c:530
#6  0xc0ac923b in calltrap () at /usr/src/sys/i386/i386/exception.s:159
#7  0xc085935b in namei (ndp=0xe6cd3bc8) at /usr/src/sys/kern/vfs_lookup.c:191
#8  0xc08706d7 in vn_open_cred (ndp=0xe6cd3bc8, flagp=0xe6cd3cc4, cmode=1,
    cred=0xc408fc00, fp=0xc4b5b344) at /usr/src/sys/kern/vfs_vnops.c:188
#9  0xc08709a3 in vn_open (ndp=0xe6cd3bc8, flagp=0xe6cd3cc4, cmode=1,
    fp=0xc4b5b344) at /usr/src/sys/kern/vfs_vnops.c:94
#10 0xc086e0d3 in kern_open (td=0xc499dd20, path=0xc4c7a978 "/root/test.txt",
    pathseg=UIO_SYSSPACE, flags=1, mode=1)
    at /usr/src/sys/kern/vfs_syscalls.c:1042
#11 0xc4c7a805 in f_open () from ./test.ko
#12 0xc4c7a8a1 in thread_main () from ./test.ko
#13 0xc07bd079 in fork_exit (callout=0xc4c7a880 <thread_main>, arg=0x0,
    frame=0xe6cd3d38) at /usr/src/sys/kern/kern_fork.c:810
#14 0xc0ac92b0 in fork_trampoline () at /usr/src/sys/i386/i386/exception.s:264


On Mon, Aug 3, 2009 at 10:03 PM, Dag-Erling Smørgrav<des at des.no> wrote:
> Dag-Erling Smørgrav <des at des.no> writes:
>> One thing that springs to mind is that kern_open() will dereference
>> td->td_proc, and AFAIK kthread_create() does not associate the thread
>> with a process.
>
> This is wrong, and contradicts what I wrote further down.  Just ignore
> it.
>
> DES
> --
> Dag-Erling Smørgrav - des at des.no
>