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| author | Dmitry Shmidt <dimitrysh@google.com> | 2016-08-22 14:09:08 -0700 |
|---|---|---|
| committer | Dmitry Shmidt <dimitrysh@google.com> | 2016-08-22 14:09:08 -0700 |
| commit | aa349c0a96998f651f246581c395069343e3e008 (patch) | |
| tree | 8f04ac2049a7629100745c331dc569c1f067b062 /Documentation | |
| parent | 8e4f993802d3d853d5377b9aaa8df28926140077 (diff) | |
| parent | 85184740541c2b80b72ebfa46cfe065ec1d1058f (diff) | |
Merge tag 'v4.4.19' into android-4.4.y
This is the 4.4.19 stable release
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/module-signing.txt | 6 | ||||
| -rw-r--r-- | Documentation/x86/pat.txt | 32 |
2 files changed, 38 insertions, 0 deletions
diff --git a/Documentation/module-signing.txt b/Documentation/module-signing.txt index a78bf1ffa68c..39b7f612c418 100644 --- a/Documentation/module-signing.txt +++ b/Documentation/module-signing.txt @@ -271,3 +271,9 @@ Since the private key is used to sign modules, viruses and malware could use the private key to sign modules and compromise the operating system. The private key must be either destroyed or moved to a secure location and not kept in the root node of the kernel source tree. + +If you use the same private key to sign modules for multiple kernel +configurations, you must ensure that the module version information is +sufficient to prevent loading a module into a different kernel. Either +set CONFIG_MODVERSIONS=y or ensure that each configuration has a different +kernel release string by changing EXTRAVERSION or CONFIG_LOCALVERSION. diff --git a/Documentation/x86/pat.txt b/Documentation/x86/pat.txt index 54944c71b819..2a4ee6302122 100644 --- a/Documentation/x86/pat.txt +++ b/Documentation/x86/pat.txt @@ -196,3 +196,35 @@ Another, more verbose way of getting PAT related debug messages is with "debugpat" boot parameter. With this parameter, various debug messages are printed to dmesg log. +PAT Initialization +------------------ + +The following table describes how PAT is initialized under various +configurations. The PAT MSR must be updated by Linux in order to support WC +and WT attributes. Otherwise, the PAT MSR has the value programmed in it +by the firmware. Note, Xen enables WC attribute in the PAT MSR for guests. + + MTRR PAT Call Sequence PAT State PAT MSR + ========================================================= + E E MTRR -> PAT init Enabled OS + E D MTRR -> PAT init Disabled - + D E MTRR -> PAT disable Disabled BIOS + D D MTRR -> PAT disable Disabled - + - np/E PAT -> PAT disable Disabled BIOS + - np/D PAT -> PAT disable Disabled - + E !P/E MTRR -> PAT init Disabled BIOS + D !P/E MTRR -> PAT disable Disabled BIOS + !M !P/E MTRR stub -> PAT disable Disabled BIOS + + Legend + ------------------------------------------------ + E Feature enabled in CPU + D Feature disabled/unsupported in CPU + np "nopat" boot option specified + !P CONFIG_X86_PAT option unset + !M CONFIG_MTRR option unset + Enabled PAT state set to enabled + Disabled PAT state set to disabled + OS PAT initializes PAT MSR with OS setting + BIOS PAT keeps PAT MSR with BIOS setting + |