Re: Where is dumbcon_init() called?

[Zoltan B. <zb...@fr...>]

Aivils =EDrta:
>=20
> vt_console_init() is very early function and must start only
> single bootmem_alloc console. Later kernel call vty_init()
> and add additional consoles, when kmalloc()
> is ready. dummycon.c uses dumbcon_add() for this case.
>=20
> Special for You dumdum module was created. Please
> boot in to Your target kernel and try load dumdum module :)
> cd dumdum
> make
> make install
> modprobe dumdum
> I You doubt please add some printk.
>=20
> I am so sorry , but dumdum is untested.
>=20
> Aivils Stoss

# modprobe dumdum
# dmesg
...
dumdum: module license 'unspecified' taints kernel.
Unable to handle kernel NULL pointer dereference at 0000000000000073 RIP:
<ffffffff80466365>{vt_create_sysfs_dev_files+53}PML4 1afa5067 PGD
19d2d067 PMD 0
Oops: 0000 [1]
CPU 0
Modules linked in: dumdum snd_emu10k1 snd_util_mem snd_hwdep
snd_mixer_oss snd_via82xx snd_ac97_codec snd_pcm snd_timer
snd_page_alloc gameport snd_mpu401_uart snd_rawmidi snd_seq_device snd
soundcore radeon ipv6 parport_pc lp parport autofs4 rfcomm l2cap
bluetooth pcmcia_core sunrpc r8169 orinoco_pci orinoco hermes ipt_REJECT
ipt_state ip_conntrack iptable_filter ip_tables ide_cd cdrom floppy sg
scsi_mod tsdev evdev usbhid dm_mod uhci_hcd ehci_hcd usbcore thermal
processor fan button battery asus_acpi ac
Pid: 4463, comm: modprobe Tainted: P   2.6.7-rc1-mm1-ruby
RIP: 0010:[<ffffffff80466365>]
<ffffffff80466365>{vt_create_sysfs_dev_files+53}
RSP: 0018:000001001c2fdef0  EFLAGS: 00010282
RAX: ffffffff8031c8ef RBX: 000001001e5ee000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000001001e5ee000
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001
R10: 0000000000000001 R11: 0000000000000000 R12: ffffffffa02631e8
R13: 0000000000539020 R14: 0000000000538100 R15: 0000000000000000
FS:  0000002a9557b4c0(0000) GS:ffffffff80449a40(0000) knlGS:0000000000000=
000
CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: 0000000000000073 CR3: 0000000000101000 CR4: 00000000000006e0
Process modprobe (pid: 4463, threadinfo 000001001c2fc000, task
000001000261e2b0)
Stack: ffffffff8020bdd9 ffffff0000a6a670 ffffff0000a69826 000001001e5ee00=
0
         0000000000000000 ffffffff8031f360 ffffffffa02630c6 0000000000001=
7d5
         ffffffff8031f390 ffffffffa0263ac0
Call Trace:<ffffffff8020bdd9>{vt_map_display+489}
<ffffffffa02630c6>{:dumdum:dumbcon_add+86}
         <ffffffffa0267099>{:dumdum:init_module+9}
<ffffffff80148ff5>{sys_init_module+245}
         <ffffffff801115ea>{system_call+126}

Code: 69 6e 73 74 61 6c 6c 2f 64 65 76 2f 74 74 79 56 31 33 27 20
RIP <ffffffff80466365>{vt_create_sysfs_dev_files+53} RSP <000001001c2fdef=
0>
CR2: 0000000000000073

There is still only /proc/bus/console/00.

Find attached my printk changes in dumbcon_add(),
with it I got these messages, there may be problems
with the linker itself:

$ make
make[1]: `arch/x86_64/kernel/asm-offsets.s' is up to date.
    CHK     include/asm-x86_64/offset.h
    CHK     include/linux/compile.h
    CC      drivers/video/console/dummycon.o
    LD      drivers/video/console/built-in.o
    LD      drivers/video/built-in.o
    LD      drivers/built-in.o
    GEN     .version
    CHK     include/linux/compile.h
    UPD     include/linux/compile.h
    CC      init/version.o
    LD      init/built-in.o
    LD      .tmp_vmlinux1
ld: BFD 2.15.90.0.3 20040415 assertion fail ../../bfd/linker.c:619
    KSYM    .tmp_kallsyms1.S
    AS      .tmp_kallsyms1.o
    LD      .tmp_vmlinux2
ld: BFD 2.15.90.0.3 20040415 assertion fail ../../bfd/linker.c:619
    KSYM    .tmp_kallsyms2.S
    AS      .tmp_kallsyms2.o
    LD      vmlinux
ld: BFD 2.15.90.0.3 20040415 assertion fail ../../bfd/linker.c:619
    AS      arch/x86_64/boot/setup.o
    LD      arch/x86_64/boot/setup
    OBJCOPY arch/x86_64/boot/compressed/vmlinux.bin
    GZIP    arch/x86_64/boot/compressed/vmlinux.bin.gz
    LD      arch/x86_64/boot/compressed/piggy.o
    LD      arch/x86_64/boot/compressed/vmlinux
    OBJCOPY arch/x86_64/boot/vmlinux.bin
    BUILD   arch/x86_64/boot/bzImage
Root device is (3, 6)
Boot sector 512 bytes.
Setup is 4773 bytes.
System is 1338 kB
Kernel: arch/x86_64/boot/bzImage is ready
    Building modules, stage 2.
    MODPOST
*** Warning: "acpi_register_gsi" [drivers/serial/8250_acpi.ko] undefined!

Anyway, booting the new kernel I didn't get any messages
telling me that dumbcon_add() was at least called (and failed)...

Best regards,
Zolt=E1n B=F6sz=F6rm=E9nyi