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-rw-r--r--Documentation/ABI/testing/evm23
-rw-r--r--Documentation/kernel-parameters.txt6
2 files changed, 29 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/evm b/Documentation/ABI/testing/evm
new file mode 100644
index 000000000000..8374d4557e5d
--- /dev/null
+++ b/Documentation/ABI/testing/evm
@@ -0,0 +1,23 @@
+What: security/evm
+Date: March 2011
+Contact: Mimi Zohar <zohar@us.ibm.com>
+Description:
+ EVM protects a file's security extended attributes(xattrs)
+ against integrity attacks. The initial method maintains an
+ HMAC-sha1 value across the extended attributes, storing the
+ value as the extended attribute 'security.evm'.
+
+ EVM depends on the Kernel Key Retention System to provide it
+ with a trusted/encrypted key for the HMAC-sha1 operation.
+ The key is loaded onto the root's keyring using keyctl. Until
+ EVM receives notification that the key has been successfully
+ loaded onto the keyring (echo 1 > <securityfs>/evm), EVM
+ can not create or validate the 'security.evm' xattr, but
+ returns INTEGRITY_UNKNOWN. Loading the key and signaling EVM
+ should be done as early as possible. Normally this is done
+ in the initramfs, which has already been measured as part
+ of the trusted boot. For more information on creating and
+ loading existing trusted/encrypted keys, refer to:
+ Documentation/keys-trusted-encrypted.txt. (A sample dracut
+ patch, which loads the trusted/encrypted key and enables
+ EVM, is available from http://linux-ima.sourceforge.net/#EVM.)
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index d6e6724446c8..d317f6cf0d35 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -49,6 +49,7 @@ parameter is applicable:
EDD BIOS Enhanced Disk Drive Services (EDD) is enabled
EFI EFI Partitioning (GPT) is enabled
EIDE EIDE/ATAPI support is enabled.
+ EVM Extended Verification Module
FB The frame buffer device is enabled.
FTRACE Function tracing enabled.
GCOV GCOV profiling is enabled.
@@ -760,6 +761,11 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
This option is obsoleted by the "netdev=" option, which
has equivalent usage. See its documentation for details.
+ evm= [EVM]
+ Format: { "fix" }
+ Permit 'security.evm' to be updated regardless of
+ current integrity status.
+
failslab=
fail_page_alloc=
fail_make_request=[KNL]