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What's new in Linux 3.2

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Re: What's new in Linux 3.2

#2

Post by keeperofdakeys »

Making the RC6 engine for Intel graphics the default was reverted at the last minute due to instability, http://www.phoronix.com/scan.php?page=news_item&px=MTAzN.... It can still be enabled manually by adding i915.i916_enable_rc6=1 to the kernel boot parameters, just like 3.1.

Another interesting change concerning Logitech Unifying devices is that multiple devices are now given separate /dev entries, instead of being multiplexed into one device.

Re: What's new in Linux 3.2

#3

Post by nodata »

The EVM part interests me. It provides a way of guaranteeing that a file has not been changed by using a combination of a passphrase and a key stored in the TPM, along with hashes of files stored as xattrs on disk.

More info here: http://lwn.net/Articles/394170/

One question I have though is how to guarantee that the kernel hasn't been modified to misread the xattrs or log the passphrase. Anyone know?

Re: What's new in Linux 3.2

#5

Post by sciurus »

jsvaughan wrote: post #4

The algorithm for determining when writeback from memory to persistent storage is interesting: https://lwn.net/Articles/456904/ (Linked from http://kernelnewbies.org/Linux_3.2 , which has more detail than the HN posted article)

I'm curious what is viewed as a backing device. Lets say I have a SAN exporting three volumes via iSCSI to a single server. Does this patch think those volumes share a single BDI, or does it treat them separately?

Re: What's new in Linux 3.2

#6

Post by obtu »

sciurus wrote: post #5
jsvaughan wrote: post #4

The algorithm for determining when writeback from memory to persistent storage is interesting: https://lwn.net/Articles/456904/ (Linked from http://kernelnewbies.org/Linux_3.2 , which has more detail than the HN posted article)

I'm curious what is viewed as a backing device. Lets say I have a SAN exporting three volumes via iSCSI to a single server. Does this patch think those volumes share a single BDI, or does it treat them separately?

I think the three volumes will be seen as independent BDIs, because that's the simplest implementation (look at the block device the pages are for, don't attempt to count things at multiple levels). Being too granular isn't a problem, because a process will be slowed down if it writes to any of the three iSCSI volumes that are throttled by the network.

Re: What's new in Linux 3.2

#7

Post by sp332 »

nodata wrote: post #3

The EVM part interests me. It provides a way of guaranteeing that a file has not been changed by using a combination of a passphrase and a key stored in the TPM, along with hashes of files stored as xattrs on disk. More info here: http://lwn.net/Articles/394170/ One question I have though is how to guarantee that the kernel hasn't been modified to misread the xattrs or log the passphrase. Anyone know?

TCCBOOT? You could verify the source code of the kernel on a thumb drive, then boot the computer with TCCBOOT and compile the kernel from source every time you boot the computer. http://bellard.org/tcc/tccboot.html

Re: What's new in Linux 3.2

#8

Post by nodata »

jsvaughan wrote: post #4

The algorithm for determining when writeback from memory to persistent storage is interesting: https://lwn.net/Articles/456904/ (Linked from http://kernelnewbies.org/Linux_3.2 , which has more detail than the HN posted article)

As long as there's a "dirtytop" to watch what's going on this will make a lot of people happy.

Re: What's new in Linux 3.2

#10

Post by wmf »

nodata wrote: post #3

The EVM part interests me. It provides a way of guaranteeing that a file has not been changed by using a combination of a passphrase and a key stored in the TPM, along with hashes of files stored as xattrs on disk. More info here: http://lwn.net/Articles/394170/ One question I have though is how to guarantee that the kernel hasn't been modified to misread the xattrs or log the passphrase. Anyone know?

GRUB-IMA (based on TCPA) and TBOOT (based on TXT) have been around for a while: http://linux-ima.sourceforge.net/

Google invented their own verified boot system for ChromeOS: http://www.chromium.org/chromium-os/chromiumos-design-docs/v...

Or you could use upcoming UEFI secure boot: http://mjg59.dreamwidth.org/6054.html

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