Encrypted HD won't open in recompiled kernel

lucmove · 10-26-2008, 03:51 AM

I am running Slackware 12.1 with an encrypted home partition. I am using the stock vmlinuz-huge-smp-2.6.24.5 kernel and everything works except part of my sound system. I think I had to recompile my kernel in Slackware 12 to fix just that, so I am going to try that again.

The kernel boots, but then I am prompted to enter the encrypted partition's password and I get an error message about the key slot not being found.

When I ran 'make xconfig', I removed a lot of stuff. But I thought I had removed only things that I didn't have and/or need. I never touched the cryptography section, I left everything enabled.

So I ran 'make xconfig' again and enabled a couple of things pretty much at random, to say the truth. This second kernel doesn't work either. I still get the same error.

Compiling is boring, takes forever, I don't want to go on with this trial and error forever. I also don't want to enable a lot of junk that I don't need. Does anyone here have a clue what I could have disabled that is causing this problem?

Here is my .config file:
http://pastebin.com/m650304e7

And here is a diff against the previous vmlinuz-huge-smp-2.6.24.5 kernel:
http://pastebin.com/m2e420e8e

Thanks in advance.

Ilgar · 10-27-2008, 03:30 AM

Maybe it's trying to unlock a non-encrypted volume. How did you create your initrd image and what is your encrypted partition? If the device name changes with the new kernel then you have you take it into account.

Alien Bob · 10-27-2008, 03:51 AM

Looks like you removed at least the Device Mapper functionality. The Device Mapper is used for mapping encrypted devices.
Look for "DM_" options, which you removed completely.

If you do not know what you are messing with, stay with the defaults set for you by Slackware, and try to make incremental changes.
With remarks like "enabled a couple of things pretty much at random, to say the truth" and "Compiling is boring, takes forever, I don't want to go on with this trial and error forever" certainly are not encouraging. Lots of the stuff you see as "junk that I don't need" turns out to be important after all - you've proved that point yourself.

Eric

lucmove · 10-27-2008, 04:20 AM

Quote:

Originally Posted by Alien Bob

If you do not know what you are messing with, stay with the defaults

Dude, ONE thing in my kernel config did not work and you think I should stay with the defaults? What's the point of an open system then?

But thanks for the clue about device mapper, it does make sense. I will try it right now.

lucmove · 10-27-2008, 05:34 AM

I don't understand. The config-huge-smp-2.6.24.5-smp file has these lines:

Code:

# CONFIG_DM_DEBUG is not set
CONFIG_DM_CRYPT=y
CONFIG_DM_SNAPSHOT=y
CONFIG_DM_MIRROR=m
CONFIG_DM_ZERO=m
CONFIG_DM_MULTIPATH=m
CONFIG_DM_MULTIPATH_EMC=m
CONFIG_DM_MULTIPATH_RDAC=m
CONFIG_DM_MULTIPATH_HP=m
# CONFIG_DM_DELAY is not set
# CONFIG_DM_UEVENT is not set

But they are not shown when I run 'make xconfig', only the top, generic option is available, CONFIG_DM_CRYPT=y. I've been messing with config-huge-smp-2.6.24.5-smp and other variations of .config and 'make xconfig' and can't make those lines get included in my resulting .config file.

Then I enabled the hidden options in 'make xconfig' and they are all there indeed, but all grayed out, I can't enable them. Why? How does that stuff work?

The mods should have moved this thread to the "Kernel" section, not Slackware.

bgeddy · 10-27-2008, 06:59 AM

The options work in a structured hierarchical fashion. The controlling options when disabled will disable those that rely on them so..

Disabling

Code:

Multiple devices driver support (RAID and LVM) (MD)

will disable

Code:

RAID support (BLK_DEV_MD)
Device mapper support (BLK_DEV_DM)

and all their children. Enabling the parent controlling option will bring in the dependant children. If you switch on Show All Options it will show the options disabled by this process but grey them out.

There is a good reference from O'Reilly available on line The Linux kernel in a nutshell

Alien Bob · 10-27-2008, 07:00 AM

Quote:

Originally Posted by lucmove

I don't understand. The config-huge-smp-2.6.24.5-smp file has these lines:

Code:

# CONFIG_DM_DEBUG is not set
CONFIG_DM_CRYPT=y
CONFIG_DM_SNAPSHOT=y
CONFIG_DM_MIRROR=m
CONFIG_DM_ZERO=m
CONFIG_DM_MULTIPATH=m
CONFIG_DM_MULTIPATH_EMC=m
CONFIG_DM_MULTIPATH_RDAC=m
CONFIG_DM_MULTIPATH_HP=m
# CONFIG_DM_DELAY is not set
# CONFIG_DM_UEVENT is not set

But they are not shown when I run 'make xconfig', only the top, generic option is available, CONFIG_DM_CRYPT=y. I've been messing with config-huge-smp-2.6.24.5-smp and other variations of .config and 'make xconfig' and can't make those lines get included in my resulting .config file.

Then I enabled the hidden options in 'make xconfig' and they are all there indeed, but all grayed out, I can't enable them. Why? How does that stuff work?

The mods should have moved this thread to the "Kernel" section, not Slackware.

In the kernel configuration, look under "Device drivers > Multiple devices driver support (RAID and LVM) --->".
For me running make menuconfig, I can change all these options at will.
Try to start with a Slackware .config file and use that as a working base to change gradually.

The important ones here are:

Code:

CONFIG_DM_CRYPT=y
CONFIG_BLK_DEV_DM=y

Eric

lucmove · 10-27-2008, 07:45 AM

I enabled "Device drivers > Multiple devices driver support (RAID and LVM) --->". But it isn't helping.

Screenshot 1

Screenshot 2

dugan · 10-27-2008, 08:49 AM

Quote:

Originally Posted by lucmove

I am using the stock vmlinuz-huge-smp-2.6.24.5 kernel and everything works except part of my sound system. I think I had to recompile my kernel in Slackware 12 to fix just that, so I am going to try that again.

This is interesting.

What is the sound system (lscpi output would work best), and which part does not work?

Which kernel configuration changes, specifically, got it working last time?

lucmove · 10-27-2008, 06:16 PM

My microphone isn't working so I haven't been able to use Skype. I don't remember what I did in Slackware 12, I just recompiled my kernel, and everything worked, including HD encryption. But I removed a lot of stuff in that occasion too, just like I am trying to do now.

So nobody knows why those options are disabled for me when I run make xconfig?

newtovanilla · 11-22-2008, 11:37 PM

Some kernel include options are dependent on others, as was mentioned in the above message:

Quote:

The options work in a structured hierarchical fashion. The controlling options when disabled will disable those that rely on them so..

You came across a problem that I was looking for an answer to...that there does not seem to be a way to look up options and to find out what you need to include in the kernel. There is no way to find out what to include in your kernel to enable the functions that you want. You have to use a tool like menuconfig or xconfig and try things. That was frustrating for a newbie like me.