Pram Fs - Revision history

Tim Bird: /* Patch */ fix link to recent patch submission

2009-06-15T17:05:08Z

‎Patch: fix link to recent patch submission

Greywolf82: /* Sample Results */

2008-11-24T08:59:34Z

‎Sample Results

Greywolf82: /* Sample Results */

2008-11-24T08:58:41Z

‎Sample Results

Greywolf82: /* Sample Results */

2008-11-24T08:50:48Z

‎Sample Results

FransMeulenbroeks:

2008-11-15T11:01:57Z

RBot: Bot (Edward's framework)

2007-03-06T03:35:56Z

Bot (Edward's framework)

New page

== Introduction ==
This page describes the Protectec RAM File System (PRAM FS) feature.

PRAM FS is a file system that enhances the security of system data in the
presence of kernel bugs or rogue programs.

The protected RAM file system will ordinarily remain consistent even if kernel data pointers
are corrupted, or if the kernel starts executing unexpectedly in the wrong location.
This is accomplished by making the RAM pages used by PRAM FS non-writable except during
the actual file operations themselves.

=== Rationale ===
A single bug in the Linux kernel may cause catastrophic damage to a system.
If a product holds irreproducible security keys, financial data, or account
information, then loss of such data could render the product unusable, or worse.
The customer could suffer financial or legal harm (from account theft or
identity theft).

It is not possible to guarantee with certainty that there are no bugs in the
Linux kernel. However, it is possible to decrease the probability that a bug
in the kernel will cause damage to a particular area of memory or storage. This
protected area can then be used, with greater confidence, to hold sensitive user
or product data.

== References ==
The home page for the PRAMFS project is at:
http://pramfs.sourceforge.net/

That site contains a LOT of detailed technical information and more explanation of
the rationale for this feature.

== Downloads ==

=== Patch ===
- [Patch for CELF version XXXXXX is *here*]
- [Patch for 2.4.xx is *here*]
- Patch for 2.6.7 is pending... (see [http://tree.celinuxforum.org/pipermail/celinux-dev/2004-September/000197.html celinux-dev archive message 197] for a recent submission to forum)

=== Utility programs ===
Pram fs can be created and populated using normal Linux filesystem utilities.

== How To Use ==
See the file <code>Documentation/filesystems/pramfs.txt</code> for instructions on its use (once the patch is applied).

== Status ==
Pramfs was submitted for consideration for inclusion in the 2.6.4 kernel, in March 2004.
There was a thread of discussion [http://groups.google.com/groups?hl=en&lr=&threadm=1vJLx-4GI-57%40gated-at.bofh.it&rnum=1&prev=/groups%3Fhl%3Den%26lr%3D%26selm%3D1vJLx-4GI-57%2540gated-at.bofh.it here]

There were a few, easily answered, concerns raised. But the patch was not accepted into mainstream.

I talked to Andrew Morton about this in April, 2004, and he said the threshold is high for getting a new filesystem into the
mainline kernel, because each filesystem adds incremental, ongoing, source maintenance overhead.

== Sample Results ==
[Examples of use with measurement of the effects.]

== Future Work ==
Here is a list of things that could be worked on for this feature:
-

@@ Line 53: / Line 53: @@
 == Sample Results ==
-Here there are some benchmark results made with bonnie++. The board used was an Atmel ngw100 (avr32 architecture) with ap7000 processor.
+Here there are some benchmark results made with bonnie++. The board used was an Atmel ngw100 (avr32 architecture) with ap7000 processor and 32MB of SDRAM.
 *(2.1 KB) [[Media:benchmark_bonnie--_pramfs_noxip.txt|Without XIP]]

@@ Line 55: / Line 55: @@
 Here there are some benchmark results made with bonnie++. The board used was an Atmel ngw100 (avr32 architecture) with ap7000 processor.
-*(2.1 KB) [[Media:benchmark_bonnie++_pramfs_noxip.txt|Without XIP]]
+*(2.1 KB) [[Media:benchmark_bonnie--_pramfs_noxip.txt|Without XIP]]
-*(2.1 KB) [[Media:benchmark_bonnie++_pramfs_xip.txt|With XIP]]
+*(2.1 KB) [[Media:benchmark_bonnie--_pramfs_xip.txt|With XIP]]
 == Future Work ==

@@ Line 33: / Line 33: @@
 === Patch ===
- - [Patch for CELF version XXXXXX is *here*]
+* See [http://tree.celinuxforum.org/pipermail/celinux-dev/2004-September/000197.html celinux-dev archive message 197] for a submission to CELF in 2004)
- - [Patch for 2.4.xx is *here*]
+* Patches for 2.6.30 were posted to lkml in June 2009 - see http://lkml.org/lkml/2009/6/13/86
- - Patch for 2.6.7 is pending... (see [http://tree.celinuxforum.org/pipermail/celinux-dev/2004-September/000197.html celinux-dev archive message 197] for a recent submission to forum)
 === Utility programs ===

@@ Line 1: / Line 1: @@
 == Introduction ==
 This page describes the Protectec RAM File System (PRAM FS) feature.
@@ Line 60: / Line 58: @@
 Here is a list of things that could be worked on for this feature:
+  -