TOMOYO uses LSM hooks for pathname based access control and securityfs support.
Signed-off-by: NKentaro Takeda <takedakn@nttdata.co.jp>
Signed-off-by: NTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: NJames Morris <jmorris@namei.org>

DAC's permissions and TOMOYO's permissions are not one-to-one mapping.

Regarding DAC, there are "read", "write", "execute" permissions.
Regarding TOMOYO, there are "allow_read", "allow_write", "allow_read/write",
"allow_execute", "allow_create", "allow_unlink", "allow_mkdir", "allow_rmdir",
"allow_mkfifo", "allow_mksock", "allow_mkblock", "allow_mkchar",
"allow_truncate", "allow_symlink", "allow_rewrite", "allow_link",
"allow_rename" permissions.

+----------------------------------+----------------------------------+
| requested operation              | required TOMOYO's permission     |
+----------------------------------+----------------------------------+
| sys_open(O_RDONLY)               | allow_read                       |
+----------------------------------+----------------------------------+
| sys_open(O_WRONLY)               | allow_write                      |
+----------------------------------+----------------------------------+
| sys_open(O_RDWR)                 | allow_read/write                 |
+----------------------------------+----------------------------------+
| open_exec() from do_execve()     | allow_execute                    |
+----------------------------------+----------------------------------+
| open_exec() from !do_execve()    | allow_read                       |
+----------------------------------+----------------------------------+
| sys_read()                       | (none)                           |
+----------------------------------+----------------------------------+
| sys_write()                      | (none)                           |
+----------------------------------+----------------------------------+
| sys_mmap()                       | (none)                           |
+----------------------------------+----------------------------------+
| sys_uselib()                     | allow_read                       |
+----------------------------------+----------------------------------+
| sys_open(O_CREAT)                | allow_create                     |
+----------------------------------+----------------------------------+
| sys_open(O_TRUNC)                | allow_truncate                   |
+----------------------------------+----------------------------------+
| sys_truncate()                   | allow_truncate                   |
+----------------------------------+----------------------------------+
| sys_ftruncate()                  | allow_truncate                   |
+----------------------------------+----------------------------------+
| sys_open() without O_APPEND      | allow_rewrite                    |
+----------------------------------+----------------------------------+
| setfl() without O_APPEND         | allow_rewrite                    |
+----------------------------------+----------------------------------+
| sys_sysctl() for writing         | allow_write                      |
+----------------------------------+----------------------------------+
| sys_sysctl() for reading         | allow_read                       |
+----------------------------------+----------------------------------+
| sys_unlink()                     | allow_unlink                     |
+----------------------------------+----------------------------------+
| sys_mknod(S_IFREG)               | allow_create                     |
+----------------------------------+----------------------------------+
| sys_mknod(0)                     | allow_create                     |
+----------------------------------+----------------------------------+
| sys_mknod(S_IFIFO)               | allow_mkfifo                     |
+----------------------------------+----------------------------------+
| sys_mknod(S_IFSOCK)              | allow_mksock                     |
+----------------------------------+----------------------------------+
| sys_bind(AF_UNIX)                | allow_mksock                     |
+----------------------------------+----------------------------------+
| sys_mknod(S_IFBLK)               | allow_mkblock                    |
+----------------------------------+----------------------------------+
| sys_mknod(S_IFCHR)               | allow_mkchar                     |
+----------------------------------+----------------------------------+
| sys_symlink()                    | allow_symlink                    |
+----------------------------------+----------------------------------+
| sys_mkdir()                      | allow_mkdir                      |
+----------------------------------+----------------------------------+
| sys_rmdir()                      | allow_rmdir                      |
+----------------------------------+----------------------------------+
| sys_link()                       | allow_link                       |
+----------------------------------+----------------------------------+
| sys_rename()                     | allow_rename                     |
+----------------------------------+----------------------------------+

TOMOYO requires "allow_execute" permission of a pathname passed to do_execve()
but does not require "allow_read" permission of that pathname.
Let's consider 3 patterns (statically linked, dynamically linked,
shell script). This description is to some degree simplified.

  $ cat hello.c
  #include <stdio.h>
  int main() {
          printf("Hello\n");
          return 0;
  }
  $ cat hello.sh
  #! /bin/sh
  echo "Hello"
  $ gcc -static -o hello-static hello.c
  $ gcc -o hello-dynamic hello.c
  $ chmod 755 hello.sh

Case 1 -- Executing hello-static from bash.

  (1) The bash process calls fork() and the child process requests
      do_execve("hello-static").

  (2) The kernel checks "allow_execute hello-static" from "bash" domain.

  (3) The kernel calculates "bash hello-static" as the domain to transit to.

  (4) The kernel overwrites the child process by "hello-static".

  (5) The child process transits to "bash hello-static" domain.

  (6) The "hello-static" starts and finishes.

Case 2 -- Executing hello-dynamic from bash.

  (1) The bash process calls fork() and the child process requests
      do_execve("hello-dynamic").

  (2) The kernel checks "allow_execute hello-dynamic" from "bash" domain.

  (3) The kernel calculates "bash hello-dynamic" as the domain to transit to.

  (4) The kernel checks "allow_read ld-linux.so" from "bash hello-dynamic"
      domain. I think permission to access ld-linux.so should be charged
      hello-dynamic program, for "hello-dynamic needs ld-linux.so" is not
      a fault of bash program.

  (5) The kernel overwrites the child process by "hello-dynamic".

  (6) The child process transits to "bash hello-dynamic" domain.

  (7) The "hello-dynamic" starts and finishes.

Case 3 -- Executing hello.sh from bash.

  (1) The bash process calls fork() and the child process requests
      do_execve("hello.sh").

  (2) The kernel checks "allow_execute hello.sh" from "bash" domain.

  (3) The kernel calculates "bash hello.sh" as the domain to transit to.

  (4) The kernel checks "allow_read /bin/sh" from "bash hello.sh" domain.
      I think permission to access /bin/sh should be charged hello.sh program,
      for "hello.sh needs /bin/sh" is not a fault of bash program.

  (5) The kernel overwrites the child process by "/bin/sh".

  (6) The child process transits to "bash hello.sh" domain.

  (7) The "/bin/sh" requests open("hello.sh").

  (8) The kernel checks "allow_read hello.sh" from  "bash hello.sh" domain.

  (9) The "/bin/sh" starts and finishes.

Whether a file is interpreted as a program or not depends on an application.
The kernel cannot know whether the file is interpreted as a program or not.
Thus, TOMOYO treats "hello-static" "hello-dynamic" "ld-linux.so" "hello.sh"
"/bin/sh" equally as merely files; no distinction between executable and
non-executable. Therefore, TOMOYO doesn't check DAC's execute permission.
TOMOYO checks "allow_read" permission instead.

Calling do_execve() is a bold gesture that an old program's instance (i.e.
current process) is ready to be overwritten by a new program and is ready to
transfer control to the new program. To split purview of programs, TOMOYO
requires "allow_execute" permission of the new program against the old
program's instance and performs domain transition. If do_execve() succeeds,
the old program is no longer responsible against the consequence of the new
program's behavior. Only the new program is responsible for all consequences.

But TOMOYO doesn't require "allow_read" permission of the new program.
If TOMOYO requires "allow_read" permission of the new program, TOMOYO will
allow an attacker (who hijacked the old program's instance) to open the new
program and steal data from the new program. Requiring "allow_read" permission
will widen purview of the old program.

Not requiring "allow_read" permission of the new program against the old
program's instance is my design for reducing purview of the old program.
To be able to know whether the current process is in do_execve() or not,
I want to add in_execve flag to "task_struct".
Signed-off-by: NKentaro Takeda <takedakn@nttdata.co.jp>
Signed-off-by: NTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: NToshiharu Harada <haradats@nttdata.co.jp>
Signed-off-by: NJames Morris <jmorris@namei.org>

This file controls domain creation/deletion/transition.

Every process belongs to a domain in TOMOYO Linux.
Domain transition occurs when execve(2) is called
and the domain is expressed as 'process invocation history',
such as '<kernel> /sbin/init /etc/init.d/rc'.
Domain information is stored in current->cred->security field.
Signed-off-by: NKentaro Takeda <takedakn@nttdata.co.jp>
Signed-off-by: NTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: NToshiharu Harada <haradats@nttdata.co.jp>
Signed-off-by: NJames Morris <jmorris@namei.org>

This file controls file related operations of TOMOYO Linux.

tomoyo/tomoyo.c calls the following six functions in this file.
Each function handles the following access types.

 * tomoyo_check_file_perm
sysctl()'s "read" and "write".

 * tomoyo_check_exec_perm
"execute".

 * tomoyo_check_open_permission
open(2) for "read" and "write".

 * tomoyo_check_1path_perm
"create", "unlink", "mkdir", "rmdir", "mkfifo",
"mksock", "mkblock", "mkchar", "truncate" and "symlink".

 * tomoyo_check_2path_perm
"rename" and "unlink".

 * tomoyo_check_rewrite_permission
"rewrite".
("rewrite" are operations which may lose already recorded data of a file,
i.e. open(!O_APPEND) || open(O_TRUNC) || truncate() || ftruncate())

The functions which actually checks ACLs are the following three functions.
Each function handles the following access types.
ACL directive is expressed by "allow_<access type>".

 * tomoyo_check_file_acl
Open() operation and execve() operation.
("read", "write", "read/write" and "execute")

 * tomoyo_check_single_write_acl
Directory modification operations with 1 pathname.
("create", "unlink", "mkdir", "rmdir", "mkfifo", "mksock",
 "mkblock", "mkchar", "truncate", "symlink" and "rewrite")

 * tomoyo_check_double_write_acl
Directory modification operations with 2 pathname.
("link" and "rename")

Also, this file contains handlers of some utility directives
for file related operations.

 * "allow_read":   specifies globally (for all domains) readable files.
 * "path_group":   specifies pathname macro.
 * "deny_rewrite": restricts rewrite operation.
Signed-off-by: NKentaro Takeda <takedakn@nttdata.co.jp>
Signed-off-by: NTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: NToshiharu Harada <haradats@nttdata.co.jp>
Signed-off-by: NJames Morris <jmorris@namei.org>

This file contains common functions (e.g. policy I/O, pattern matching).

-------------------- About pattern matching --------------------

Since TOMOYO Linux is a name based access control, TOMOYO Linux seriously
considers "safe" string representation.

TOMOYO Linux's string manipulation functions make reviewers feel crazy,
but there are reasons why TOMOYO Linux needs its own string manipulation
functions.

----- Part 1 : preconditions -----

People definitely want to use wild card.

  To support pattern matching, we have to support wild card characters.

  In a typical Linux system, filenames are likely consists of only alphabets,
  numbers, and some characters (e.g. + - ~ . / ).
  But theoretically, the Linux kernel accepts all characters but NUL character
  (which is used as a terminator of a string).

    Some Linux systems can have filenames which contain * ? ** etc.

Therefore, we have to somehow modify string so that we can distinguish
wild card characters and normal characters.

  It might be possible for some application's configuration files to restrict
  acceptable characters.
  It is impossible for kernel to restrict acceptable characters.

    We can't accept approaches which will cause troubles for applications.

----- Part 2 : commonly used approaches -----

Text formatted strings separated by space character (0x20) and new line
character (0x0A) is more preferable for users over array of NUL-terminated
string.

  Thus, people use text formatted configuration files separated by space
  character and new line.

We sometimes need to handle non-printable characters.

  Thus, people use \ character (0x5C) as escape character and represent
  non-printable characters using octal or hexadecimal format.

At this point, we remind (at least) 3 approaches.

  (1) Shell glob style expression
  (2) POSIX regular expression (UNIX style regular expression)
  (3) Maverick wild card expression

On the surface, (1) and (2) sound good choices. But they have a big pitfall.
All meta-characters in (1) and (2) are legal characters for representing
a pathname, and users easily write incorrect expression. What is worse, users
unlikely notice incorrect expressions because characters used for regular
pathnames unlikely contain meta-characters. This incorrect use of
meta-characters in pathname representation reveals vulnerability
(e.g. unexpected results) only when irregular pathname is specified.

The authors of TOMOYO Linux think that approaches which adds some character
for interpreting meta-characters as normal characters (i.e. (1) and (2)) are
not suitable for security use.

Therefore, the authors of TOMOYO Linux propose (3).

----- Part 3: consideration points -----

We need to solve encoding problem.

  A single character can be represented in several ways using encodings.

    For Japanese language, there are "ShiftJIS", "ISO-2022-JP", "EUC-JP",
    "UTF-8" and more.

  Some languages (e.g. Japanese language) supports multi-byte characters
  (where a single character is represented using several bytes).

    Some multi-byte characters may match the escape character.

    For Japanese language, some characters in "ShiftJIS" encoding match
    \ character, and bothering Web's CGI developers.

  It is important that the kernel string is not bothered by encoding problem.

    Linus said, "I really would expect that kernel strings don't have
    an encoding. They're just C strings: a NUL-terminated stream of bytes."
    http://lkml.org/lkml/2007/11/6/142

    Yes. The kernel strings are just C strings.
    We are talking about how to store and carry "kernel strings" safely.

  If we store "kernel string" into policy file as-is, the "kernel string" will
  be interpreted differently depending on application's encoding settings.
  One application may interpret "kernel string" as "UTF-8",
  another application may interpret "kernel string" as "ShiftJIS".

    Therefore, we propose to represent strings using ASCII encoding.
    In this way, we are no longer bothered by encoding problems.

We need to avoid information loss caused by display.

  It is difficult to input and display non-printable characters, but we have to
  be able to handle such characters because the kernel string is a C string.

  If we use only ASCII printable characters (from 0x21 to 0x7E) and space
  character (0x20) and new line character (0x0A), it is easy to input from
  keyboard and display on all terminals which is running Linux.

  Therefore, we propose to represent strings using only characters which value
  is one of "from 0x21 to 0x7E", "0x20", "0x0A".

We need to consider ease of splitting strings from a line.

  If we use an approach which uses "\ " for representing a space character
  within a string, we have to count the string from the beginning to check
  whether this space character is accompanied with \ character or not.
  As a result, we cannot monotonically split a line using space character.

  If we use an approach which uses "\040" for representing a space character
  within a string, we can monotonically split a line using space character.

  If we use an approach which uses NUL character as a delimiter, we cannot
  use string manipulation functions for splitting strings from a line.

  Therefore, we propose that we represent space character as "\040".

We need to avoid wrong designations (incorrect use of special characters).

  Not all users can understand and utilize POSIX's regular expressions
  correctly and perfectly.

  If a character acts as a wild card by default, the user will get unexpected
  result if that user didn't know the meaning of that character.

    Therefore, we propose that all characters but \ character act as
    a normal character and let the user add \ character to make a character
    act as a wild card.

    In this way, users needn't to know all wild card characters beforehand.
    They can learn when they encountered an unseen wild card character
    for their first time.

----- Part 4: supported wild card expressions -----

At this point, we have wild card expressions listed below.

  +-----------+--------------------------------------------------------------+
  | Wild card | Meaning and example                                          |
  +-----------+--------------------------------------------------------------+
  |   \*      | More than or equals to 0 character other than '/'.           |
  |           |           /var/log/samba/\*                                  |
  +-----------+--------------------------------------------------------------+
  |   \@      | More than or equals to 0 character other than '/' or '.'.    |
  |           |           /var/www/html/\@.html                              |
  +-----------+--------------------------------------------------------------+
  |   \?      | 1 byte character other than '/'.                             |
  |           |           /tmp/mail.\?\?\?\?\?\?                             |
  +-----------+--------------------------------------------------------------+
  |   \$      | More than or equals to 1 decimal digit.                      |
  |           |           /proc/\$/cmdline                                   |
  +-----------+--------------------------------------------------------------+
  |   \+      | 1 decimal digit.                                             |
  |           |           /var/tmp/my_work.\+                                |
  +-----------+--------------------------------------------------------------+
  |   \X      | More than or equals to 1 hexadecimal digit.                  |
  |           |           /var/tmp/my-work.\X                                |
  +-----------+--------------------------------------------------------------+
  |   \x      | 1 hexadecimal digit.                                         |
  |           |           /tmp/my-work.\x                                    |
  +-----------+--------------------------------------------------------------+
  |   \A      | More than or equals to 1 alphabet character.                 |
  |           |           /var/log/my-work/\$-\A-\$.log                      |
  +-----------+--------------------------------------------------------------+
  |   \a      | 1 alphabet character.                                        |
  |           |           /home/users/\a/\*/public_html/\*.html              |
  +-----------+--------------------------------------------------------------+
  |   \-      | Pathname subtraction operator.                               |
  |           | +---------------------+------------------------------------+ |
  |           | | Example             | Meaning                            | |
  |           | +---------------------+------------------------------------+ |
  |           | | /etc/\*             | All files in /etc/ directory.      | |
  |           | +---------------------+------------------------------------+ |
  |           | | /etc/\*\-\*shadow\* | /etc/\* other than /etc/\*shadow\* | |
  |           | +---------------------+------------------------------------+ |
  |           | | /\*\-proc\-sys/     | /\*/ other than /proc/ /sys/       | |
  |           | +---------------------+------------------------------------+ |
  +-----------+--------------------------------------------------------------+

  +----------------+---------------------------------------------------------+
  | Representation | Meaning and example                                     |
  +----------------+---------------------------------------------------------+
  |   \\           | backslash character itself.                             |
  +----------------+---------------------------------------------------------+
  |   \ooo         | 1 byte character.                                       |
  |                | ooo is 001 <= ooo <= 040 || 177 <= ooo <= 377.          |
  |                |                                                         |
  |                |           \040 for space character.                     |
  |                |           \177 for del character.                       |
  |                |                                                         |
  +----------------+---------------------------------------------------------+

----- Part 5: Advantages -----

We can obtain extensibility.

  Since our proposed approach adds \ to a character to interpret as a wild
  card, we can introduce new wild card in future while maintaining backward
  compatibility.

We can process monotonically.

  Since our proposed approach separates strings using a space character,
  we can split strings using existing string manipulation functions.

We can reliably analyze access logs.

  It is guaranteed that a string doesn't contain space character (0x20) and
  new line character (0x0A).

  It is guaranteed that a string won't be converted by FTP and won't be damaged
  by a terminal's settings.

  It is guaranteed that a string won't be affected by encoding converters
  (except encodings which insert NUL character (e.g. UTF-16)).

----- Part 6: conclusion -----

TOMOYO Linux is using its own encoding with reasons described above.
There is a disadvantage that we need to introduce a series of new string
manipulation functions. But TOMOYO Linux's encoding is useful for all users
(including audit and AppArmor) who want to perform pattern matching and
safely exchange string information between the kernel and the userspace.

-------------------- About policy interface --------------------

TOMOYO Linux creates the following files on securityfs (normally
mounted on /sys/kernel/security) as interfaces between kernel and
userspace. These files are for TOMOYO Linux management tools *only*,
not for general programs.

  * profile
  * exception_policy
  * domain_policy
  * manager
  * meminfo
  * self_domain
  * version
  * .domain_status
  * .process_status

** /sys/kernel/security/tomoyo/profile **

This file is used to read or write profiles.

"profile" means a running mode of process. A profile lists up
functions and their modes in "$number-$variable=$value" format. The
$number is profile number between 0 and 255. Each domain is assigned
one profile. To assign profile to domains, use "ccs-setprofile" or
"ccs-editpolicy" or "ccs-loadpolicy" commands.

(Example)
[root@tomoyo]# cat /sys/kernel/security/tomoyo/profile
0-COMMENT=-----Disabled Mode-----
0-MAC_FOR_FILE=disabled
0-MAX_ACCEPT_ENTRY=2048
0-TOMOYO_VERBOSE=disabled
1-COMMENT=-----Learning Mode-----
1-MAC_FOR_FILE=learning
1-MAX_ACCEPT_ENTRY=2048
1-TOMOYO_VERBOSE=disabled
2-COMMENT=-----Permissive Mode-----
2-MAC_FOR_FILE=permissive
2-MAX_ACCEPT_ENTRY=2048
2-TOMOYO_VERBOSE=enabled
3-COMMENT=-----Enforcing Mode-----
3-MAC_FOR_FILE=enforcing
3-MAX_ACCEPT_ENTRY=2048
3-TOMOYO_VERBOSE=enabled

- MAC_FOR_FILE:
Specifies access control level regarding file access requests.
- MAX_ACCEPT_ENTRY:
Limits the max number of ACL entries that are automatically appended
during learning mode. Default is 2048.
- TOMOYO_VERBOSE:
Specifies whether to print domain policy violation messages or not.

** /sys/kernel/security/tomoyo/manager **

This file is used to read or append the list of programs or domains
that can write to /sys/kernel/security/tomoyo interface. By default,
only processes with both UID = 0 and EUID = 0 can modify policy via
/sys/kernel/security/tomoyo interface. You can use keyword
"manage_by_non_root" to allow policy modification by non root user.

(Example)
[root@tomoyo]# cat /sys/kernel/security/tomoyo/manager
/usr/lib/ccs/loadpolicy
/usr/lib/ccs/editpolicy
/usr/lib/ccs/setlevel
/usr/lib/ccs/setprofile
/usr/lib/ccs/ld-watch
/usr/lib/ccs/ccs-queryd

** /sys/kernel/security/tomoyo/exception_policy **

This file is used to read and write system global settings. Each line
has a directive and operand pair. Directives are listed below.

- initialize_domain:
To initialize domain transition when specific program is executed,
use initialize_domain directive.
  * initialize_domain "program" from "domain"
  * initialize_domain "program" from "the last program part of domain"
  * initialize_domain "program"
If the part "from" and after is not given, the entry is applied to
all domain. If the "domain" doesn't start with "<kernel>", the entry
is applied to all domain whose domainname ends with "the last program
part of domain".
This directive is intended to aggregate domain transitions for daemon
program and program that are invoked by the kernel on demand, by
transiting to different domain.

- keep_domain
To prevent domain transition when program is executed from specific
domain, use keep_domain directive.
  * keep_domain "program" from "domain"
  * keep_domain "program" from "the last program part of domain"
  * keep_domain "domain"
  * keep_domain "the last program part of domain"
If the part "from" and before is not given, this entry is applied to
all program. If the "domain" doesn't start with "<kernel>", the entry
is applied to all domain whose domainname ends with "the last program
part of domain".
This directive is intended to reduce total number of domains and
memory usage by suppressing unneeded domain transitions.
To declare domain keepers, use keep_domain directive followed by
domain definition.
Any process that belongs to any domain declared with this directive,
the process stays at the same domain unless any program registered
with initialize_domain directive is executed.

In order to control domain transition in detail, you can use
no_keep_domain/no_initialize_domain keywrods.

- alias:
To allow executing programs using the name of symbolic links, use
alias keyword followed by dereferenced pathname and reference
pathname. For example, /sbin/pidof is a symbolic link to
/sbin/killall5 . In normal case, if /sbin/pidof is executed, the
domain is defined as if /sbin/killall5 is executed. By specifying
"alias /sbin/killall5 /sbin/pidof", you can run /sbin/pidof in the
domain for /sbin/pidof .
(Example)
alias /sbin/killall5 /sbin/pidof

- allow_read:
To grant unconditionally readable permissions, use allow_read keyword
followed by canonicalized file. This keyword is intended to reduce
size of domain policy by granting read access to library files such
as GLIBC and locale files. Exception is, if ignore_global_allow_read
keyword is given to a domain, entries specified by this keyword are
ignored.
(Example)
allow_read /lib/libc-2.5.so

- file_pattern:
To declare pathname pattern, use file_pattern keyword followed by
pathname pattern. The pathname pattern must be a canonicalized
Pathname. This keyword is not applicable to neither granting execute
permissions nor domain definitions.
For example, canonicalized pathname that contains a process ID
(i.e. /proc/PID/ files) needs to be grouped in order to make access
control work well.
(Example)
file_pattern /proc/\$/cmdline

- path_group
To declare pathname group, use path_group keyword followed by name of
the group and pathname pattern. For example, if you want to group all
files under home directory, you can define
   path_group HOME-DIR-FILE /home/\*/\*
   path_group HOME-DIR-FILE /home/\*/\*/\*
   path_group HOME-DIR-FILE /home/\*/\*/\*/\*
in the exception policy and use like
   allow_read @HOME-DIR-FILE
to grant file access permission.

- deny_rewrite:
To deny overwriting already written contents of file (such as log
files) by default, use deny_rewrite keyword followed by pathname
pattern. Files whose pathname match the patterns are not permitted to
open for writing without append mode or truncate unless the pathnames
are explicitly granted using allow_rewrite keyword in domain policy.
(Example)
deny_rewrite /var/log/\*

- aggregator
To deal multiple programs as a single program, use aggregator keyword
followed by name of original program and aggregated program. This
keyword is intended to aggregate similar programs.
For example, /usr/bin/tac and /bin/cat are similar. By specifying
"aggregator /usr/bin/tac /bin/cat", you can run /usr/bin/tac in the
domain for /bin/cat .
For example, /usr/sbin/logrotate for Fedora Core 3 generates programs
like /tmp/logrotate.\?\?\?\?\?\? and run them, but TOMOYO Linux
doesn't allow using patterns for granting execute permission and
defining domains. By specifying
"aggregator /tmp/logrotate.\?\?\?\?\?\? /tmp/logrotate.tmp", you can
run /tmp/logrotate.\?\?\?\?\?\? as if /tmp/logrotate.tmp is running.

** /sys/kernel/security/tomoyo/domain_policy **

This file contains definition of all domains and permissions that are
granted to each domain.

Lines from the next line to a domain definition ( any lines starting
with "<kernel>") to the previous line to the next domain definitions
are interpreted as access permissions for that domain.

** /sys/kernel/security/tomoyo/meminfo **

This file is to show the total RAM used to keep policy in the kernel
by TOMOYO Linux in bytes.
(Example)
[root@tomoyo]# cat /sys/kernel/security/tomoyo/meminfo
Shared:       61440
Private:      69632
Dynamic:        768
Total:       131840

You can set memory quota by writing to this file.
(Example)
[root@tomoyo]# echo Shared: 2097152 > /sys/kernel/security/tomoyo/meminfo
[root@tomoyo]# echo Private: 2097152 > /sys/kernel/security/tomoyo/meminfo

** /sys/kernel/security/tomoyo/self_domain **

This file is to show the name of domain the caller process belongs to.
(Example)
[root@etch]# cat /sys/kernel/security/tomoyo/self_domain
<kernel> /usr/sbin/sshd /bin/zsh /bin/cat

** /sys/kernel/security/tomoyo/version **

This file is used for getting TOMOYO Linux's version.
(Example)
[root@etch]# cat /sys/kernel/security/tomoyo/version
2.2.0-pre

** /sys/kernel/security/tomoyo/.domain_status **

This is a view (of a DBMS) that contains only profile number and
domainnames of domain so that "ccs-setprofile" command can do
line-oriented processing easily.

** /sys/kernel/security/tomoyo/.process_status **

This file is used by "ccs-ccstree" command to show "list of processes
currently running" and "domains which each process belongs to" and
"profile number which the domain is currently assigned" like "pstree"
command. This file is writable by programs that aren't registered as
policy manager.
Signed-off-by: NKentaro Takeda <takedakn@nttdata.co.jp>
Signed-off-by: NTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: NToshiharu Harada <haradats@nttdata.co.jp>
Signed-off-by: NJames Morris <jmorris@namei.org>

TOMOYO Linux performs pathname based access control.
To remove factors that make pathname based access control difficult
(e.g. symbolic links, "..", "//" etc.), TOMOYO Linux derives realpath
of requested pathname from "struct dentry" and "struct vfsmount".

The maximum length of string data is limited to 4000 including trailing '\0'.
Since TOMOYO Linux uses '\ooo' style representation for non ASCII printable
characters, maybe TOMOYO Linux should be able to support 16336 (which means
(NAME_MAX * (PATH_MAX / (NAME_MAX + 1)) * 4 + (PATH_MAX / (NAME_MAX + 1)))
including trailing '\0'), but I think 4000 is enough for practical use.

TOMOYO uses only 0x21 - 0x7E (as printable characters) and 0x20 (as word
delimiter) and 0x0A (as line delimiter).
0x01 - 0x20 and 0x80 - 0xFF is handled in \ooo style representation.
The reason to use \ooo is to guarantee that "%s" won't damage logs.
Userland program can request

 open("/tmp/file granted.\nAccess /tmp/file ", O_WRONLY | O_CREAT, 0600)

and logging such crazy pathname using "Access %s denied.\n" format will cause
"fabrication of logs" like

 Access /tmp/file granted.
 Access /tmp/file denied.

TOMOYO converts such characters to \ooo so that the logs will become

 Access /tmp/file\040granted.\012Access\040/tmp/file denied.

and the administrator can read the logs safely using /bin/cat .
Likewise, a crazy request like

 open("/tmp/\x01\x02\x03\x04\x05\x06\x07\x08\x09", O_WRONLY | O_CREAT, 0600)

will be processed safely by converting to

 Access /tmp/\001\002\003\004\005\006\007\010\011 denied.
Signed-off-by: NKentaro Takeda <takedakn@nttdata.co.jp>
Signed-off-by: NTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: NToshiharu Harada <haradats@nttdata.co.jp>
Signed-off-by: NJames Morris <jmorris@namei.org>

This patch allows LSM modules to determine whether current process is in an
execve operation or not so that they can behave differently while an execve
operation is in progress.

This patch is needed by TOMOYO. Please see another patch titled "LSM adapter
functions." for backgrounds.
Signed-off-by: NTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NJames Morris <jmorris@namei.org>

Based on discussions on linux-audit, as per Steve Grubb's request
http://lkml.org/lkml/2009/2/6/269, the following changes were made:
- forced audit result to be either 0 or 1.
- made template names const
- Added new stand-alone message type: AUDIT_INTEGRITY_RULE
Signed-off-by: NMimi Zohar <zohar@us.ibm.com>
Acked-by: NSteve Grubb <sgrubb@redhat.com>
Signed-off-by: NJames Morris <jmorris@namei.org>

Based on comments from Mike Frysinger and Randy Dunlap:
(http://lkml.org/lkml/2009/2/9/262)
- moved ima.h include before CONFIG_SHMEM test to fix compiler error
  on Blackfin:
mm/shmem.c: In function 'shmem_zero_setup':
mm/shmem.c:2670: error: implicit declaration of function 'ima_shm_check'

- added 'struct linux_binprm' in ima.h to fix compiler warning on Blackfin:
In file included from mm/shmem.c:32:
include/linux/ima.h:25: warning: 'struct linux_binprm' declared inside
parameter list
include/linux/ima.h:25: warning: its scope is only this definition or
declaration, which is probably not what you want

- moved fs.h include within _LINUX_IMA_H definition
Signed-off-by: NMimi Zohar <zohar@us.ibm.com>
Signed-off-by: NMike Frysinger <vapier@gentoo.org>
Signed-off-by: NJames Morris <jmorris@namei.org>

Conflicts:
	fs/namei.c

Manually merged per:

diff --cc fs/namei.c
index 734f2b5,bbc15c2..0000000
--- a/fs/namei.c
+++ b/fs/namei.c
@@@ -860,9 -848,8 +849,10 @@@ static int __link_path_walk(const char
  		nd->flags |= LOOKUP_CONTINUE;
  		err = exec_permission_lite(inode);
  		if (err == -EAGAIN)
- 			err = vfs_permission(nd, MAY_EXEC);
+ 			err = inode_permission(nd->path.dentry->d_inode,
+ 					       MAY_EXEC);
 +		if (!err)
 +			err = ima_path_check(&nd->path, MAY_EXEC);
   		if (err)
  			break;

@@@ -1525,14 -1506,9 +1509,14 @@@ int may_open(struct path *path, int acc
  		flag &= ~O_TRUNC;
  	}

- 	error = vfs_permission(nd, acc_mode);
+ 	error = inode_permission(inode, acc_mode);
  	if (error)
  		return error;
 +
- 	error = ima_path_check(&nd->path,
++	error = ima_path_check(path,
 +			       acc_mode & (MAY_READ | MAY_WRITE | MAY_EXEC));
 +	if (error)
 +		return error;
  	/*
  	 * An append-only file must be opened in append mode for writing.
  	 */
Signed-off-by: NJames Morris <jmorris@namei.org>

lseek() further than length of the file will leave stale ->index
(second-to-last during iteration). Next seq_read() will not notice
that ->f_pos is big enough to return 0, but will print last item
as if ->f_pos is pointing to it.

Introduced in commit cb510b81
aka "seq_file: more atomicity in traverse()".
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix to function which is called by IMA, now tpm_chip_find_get() considers the case in which the machine doesn't have a TPM or, if it has, its TPM isn't enabled.
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: NRajiv Andrade <srajiv@linux.vnet.ibm.com>
Acked-by: NSerge Hallyn <serue@us.ibm.com>
Signed-off-by: NJames Morris <jmorris@namei.org>

Fix ima_delete_rules() definition so sparse doesn't complain.
Signed-off-by: NJames Morris <jmorris@namei.org>

Signed-off-by: NMimi Zohar <zohar@us.ibm.com>
Signed-off-by: NJames Morris <jmorris@namei.org>

The number of calls to ima_path_check()/ima_file_free()
should be balanced.  An extra call to fput(), indicates
the file could have been accessed without first being
measured.

Although f_count is incremented/decremented in places other
than fget/fput, like fget_light/fput_light and get_file, the
current task must already hold a file refcnt.  The call to
__fput() is delayed until the refcnt becomes 0, resulting
in ima_file_free() flagging any changes.

- add hook to increment opencount for IPC shared memory(SYSV),
  shmat files, and /dev/zero
- moved NULL iint test in opencount_get()
Signed-off-by: NMimi Zohar <zohar@us.ibm.com>
Acked-by: NSerge Hallyn <serue@us.ibm.com>
Signed-off-by: NJames Morris <jmorris@namei.org>

Sequentialize access to the policy file
- permit multiple attempts to replace default policy with a valid policy
Signed-off-by: NMimi Zohar <zohar@us.ibm.com>
Acked-by: NSerge Hallyn <serue@us.ibm.com>
Signed-off-by: NJames Morris <jmorris@namei.org>

Support for a user loadable policy through securityfs
with support for LSM specific policy data.
- free invalid rule in ima_parse_add_rule()
Signed-off-by: NMimi Zohar <zohar@us.ibm.com>
Acked-by: NSerge Hallyn <serue@us.ibm.com>
Signed-off-by: NJames Morris <jmorris@namei.org>

Make the measurement lists available through securityfs.
- removed test for NULL return code from securityfs_create_file/dir
Signed-off-by: NMimi Zohar <zohar@us.ibm.com>
Acked-by: NSerge Hallyn <serue@us.ibm.com>
Signed-off-by: NJames Morris <jmorris@namei.org>

IMA provides hardware (TPM) based measurement and attestation for
file measurements. As the Trusted Computing (TPM) model requires,
IMA measures all files before they are accessed in any way (on the
integrity_bprm_check, integrity_path_check and integrity_file_mmap
hooks), and commits the measurements to the TPM. Once added to the
TPM, measurements can not be removed.

In addition, IMA maintains a list of these file measurements, which
can be used to validate the aggregate value stored in the TPM.  The
TPM can sign these measurements, and thus the system can prove, to
itself and to a third party, the system's integrity in a way that
cannot be circumvented by malicious or compromised software.

- alloc ima_template_entry before calling ima_store_template()
- log ima_add_boot_aggregate() failure
- removed unused IMA_TEMPLATE_NAME_LEN
- replaced hard coded string length with #define name
Signed-off-by: NMimi Zohar <zohar@us.ibm.com>
Signed-off-by: NJames Morris <jmorris@namei.org>

This patch replaces the generic integrity hooks, for which IMA registered
itself, with IMA integrity hooks in the appropriate places directly
in the fs directory.
Signed-off-by: NMimi Zohar <zohar@us.ibm.com>
Acked-by: NSerge Hallyn <serue@us.ibm.com>
Signed-off-by: NJames Morris <jmorris@namei.org>

In 2.6.25 some /proc files were converted to use the seq_file
infrastructure.  But seq_files do not correctly support pread(), which
broke some usersapce applications.

To handle pread correctly we can't assume that f_pos is where we left it
in seq_read.  So move traverse() so that we can eventually use it in
seq_read and do thus some day support pread().
Signed-off-by: NEric Biederman <ebiederm@xmission.com>
Cc: Paul Turner <pjt@google.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

A missing type cast results in writing way beyond the end of a kzalloc()'d
memory segment resulting in slab corruption. But it seems like the better
solution is to define ->recv_msg_slots as a 'void *' rather than a
'struct xpc_notify_mq_msg_uv *' and add the type cast.
Signed-off-by: NDean Nelson <dcn@sgi.com>
Cc: <stable@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Do usual do {} while (0) dance, otherwise

fs/gfs2/util.c:99: error: expected expression before 'else'
drivers/scsi/lpfc/lpfc_sli.c:363: error: expected expression before 'else'
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Acked-by: NIvan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Richard Henderson <rth@twiddle.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

If we return directly with -EPERM then lock_kernel() is still held.

This was found with a code checker (http://repo.or.cz/w/smatch.git/).

[akpm@linux-foundation.org: fix another such path - missed func_exit()]
Signed-off-by: NDan Carpenter <error27@gmail.com>
Cc: <R.E.Wolff@BitWizard.nl>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix namespace violations by changing non-kconfig CONFIG_ names to CNFG_*.

Fixes breakage in staging/, which adds a real CONFIG_PANEL.
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

drivers/rtc/rtc-ds1390.c:125: warning: unused variable 'rtc'
Signed-off-by: NManish Katiyar <mkatiyar@gmail.com>
Signed-off-by: NAlessandro Zummo <a.zummo@towertech.it>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Currently both da903x backlight and voltage reulator drivers have the
same name. Rename the backlight driver to allow use of both drivers as
modules.
Signed-off-by: NMike Rapoport <mike@compulab.co.il>
Acked-by: NEric Miao <eric.miao@marvell.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The ssc pointer is not valid when the id is not found in the list.
Convert the message from a debug one into an error message and avoid
dereferencing the bad pointer.
Signed-off-by: NHans-Christian Egtvedt <hans-christian.egtvedt@atmel.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Huang Weiyi <weiyi.huang@gmail.com>
Acked-by: NHaavard Skinnemoen <haavard.skinnemoen@atmel.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix do_wp_page for VM_MIXEDMAP mappings.

In the case where pfn_valid returns 0 for a pfn at the beginning of
do_wp_page and the mapping is not shared writable, the code branches to
label `gotten:' with old_page == NULL.

In case the vma is locked (vma->vm_flags & VM_LOCKED), lock_page,
clear_page_mlock, and unlock_page try to access the old_page.

This patch checks whether old_page is valid before it is dereferenced.

The regression was introduced by "mlock: mlocked pages are unevictable"
(commit b291f000).
Signed-off-by: NCarsten Otte <cotte@de.ibm.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: <stable@kernel.org>		[2.6.28.x]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

With exclusive waiters, every process woken up through the wait queue must
ensure that the next waiter down the line is woken when it has finished.

Interruptible waiters don't do that when aborting due to a signal.  And if
an aborting waiter is concurrently woken up through the waitqueue, noone
will ever wake up the next waiter.

This has been observed with __wait_on_bit_lock() used by
lock_page_killable(): the first contender on the queue was aborting when
the actual lock holder woke it up concurrently.  The aborted contender
didn't acquire the lock and therefor never did an unlock followed by
waking up the next waiter.

Add abort_exclusive_wait() which removes the process' wait descriptor from
the waitqueue, iff still queued, or wakes up the next waiter otherwise.
It does so under the waitqueue lock.  Racing with a wake up means the
aborting process is either already woken (removed from the queue) and will
wake up the next waiter, or it will remove itself from the queue and the
concurrent wake up will apply to the next waiter after it.

Use abort_exclusive_wait() in __wait_event_interruptible_exclusive() and
__wait_on_bit_lock() when they were interrupted by other means than a wake
up through the queue.

[akpm@linux-foundation.org: coding-style fixes]
Reported-by: NChris Mason <chris.mason@oracle.com>
Signed-off-by: NJohannes Weiner <hannes@cmpxchg.org>
Mentored-by: NOleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: Chuck Lever <cel@citi.umich.edu>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: <stable@kernel.org>		["after some testing"]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

I got the "list is moderated message," so add it here.
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Cc: Roland Dreier <rolandd@cisco.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add support for the HP laptops of model 6710x for having correctly setup
axes.
Signed-off-by: NMartin Kebert <gkmarty@gmail.com>
Signed-off-by: NEric Piel <eric.piel@tremplin-utc.net>
Acked-by: NPavel Machek <pavel@suse.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add support for the HP laptops of model 6730x for having correctly setup
axes.
Signed-off-by: NPavel Herrmann <morpheus.ibis@gmail.com>
Signed-off-by: NEric Piel <eric.piel@tremplin-utc.net>
Acked-by: NPavel Machek <pavel@suse.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add support for the HP laptops of model 6530x for having correctly setup
axes.
Reported-by: NJerome Poulin <jeromepoulin@gmail.com>
Signed-off-by: NEric Piel <eric.piel@tremplin-utc.net>
Acked-by: NPavel Machek <pavel@suse.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

According to dmesg my laptop model HP 6510b is not being recognized by this
driver. After I have modified "lis3lv02d.c" axes in Neverball are OK.
Signed-off-by: NJiri Tersel <tersel@mail.muni.cz>
Signed-off-by: NEric Piel <eric.piel@tremplin-utc.net>
Acked-by: NPavel Machek <pavel@suse.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The error-path code can call rfkill_unregister() with a pointer which does
not contain the result of a call to rfkill_register().  It goes BUG().

Addresses http://bugzilla.kernel.org/show_bug.cgi?id=12560.

Cc: Frans Pop <elendil@planet.nl>
Cc: Larry Finger <Larry.Finger@lwfinger.net>
Cc: Len Brown <lenb@kernel.org>
Acked-by: NMatthew Garrett <mjg@redhat.com>
Reported-by: NHelge Deller <deller@gmx.de>
Testted-by: NHelge Deller <deller@gmx.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Revert commit 0c2d64fb because it causes
(arguably poorly designed) existing userspace to spend interminable
periods closing billions of not-open file descriptors.

We could bring this back, with some sort of opt-in tunable in /proc, which
defaults to "off".

Peter's alanysis follows:

: I spent several hours trying to get to the bottom of a serious
: performance issue that appeared on one of our servers after upgrading to
: 2.6.28.  In the end it's what could be considered a userspace bug that
: was triggered by a change in 2.6.28.  Since this might also affect other
: people I figured I'd at least document what I found here, and maybe we
: can even do something about it:
:
:
: So, I upgraded some of debian.org's machines to 2.6.28.1 and immediately
: the team maintaining our ftp archive complained that one of their
: scripts that previously ran in a few minutes still hadn't even come
: close to being done after an hour or so.  Downgrading to 2.6.27 fixed
: that.
:
: Turns out that script is forking a lot and something in it or python or
: whereever closes all the file descriptors it doesn't want to pass on.
: That is, it starts at zero and goes up to ulimit -n/RLIMIT_NOFILE and
: closes them all with a few exceptions.
:
: Turns out that takes a long time when your limit -n is now 2^20 (1048576).
:
: With 2.6.27.* the ulimit -n was the standard 1024, but with 2.6.28 it is
: now a thousand times that.
:
: 2.6.28 included a patch titled "rlimit: permit setting RLIMIT_NOFILE to
: RLIM_INFINITY" (0c2d64fb)[1] that
: allows, as the title implies, to set the limit for number of files to
: infinity.
:
: Closer investigation showed that the broken default ulimit did not apply
: to "system" processes (like stuff started from init).  In the end I
: could establish that all processes that passed through pam_limit at one
: point had the bad resource limit.
:
: Apparently the pam library in Debian etch (4.0) initializes the limits
: to some default values when it doesn't have any settings in limit.conf
: to override them.  Turns out that for nofiles this is RLIM_INFINITY.
: Commenting out "case RLIMIT_NOFILE" in pam_limit.c:267 of our pam
: package version 0.79-5 fixes that - tho I'm not sure what side effects
: that has.
:
: Debian lenny (the upcoming 5.0 version) doesn't have this issue as it
: uses a different pam (version).
Reported-by: NPeter Palfrader <weasel@debian.org>
Cc: Adam Tkac <vonsch@gmail.com>
Cc: Michael Kerrisk <mtk.manpages@googlemail.com>
Cc: <stable@kernel.org>		[2.6.28.x]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

shm_get_stat() assumes that the inode is a "struct shmem_inode_info",
which is incorrect for !CONFIG_SHMEM (see fs/ramfs/inode.c:
ramfs_get_inode() vs.  mm/shmem.c: shmem_get_inode()).

This bad assumption can cause shmctl(SHM_INFO) to lockup when
shm_get_stat() tries to spin_lock(&info->lock).  Users of !CONFIG_SHMEM
may encounter this lockup simply by invoking the 'ipcs' command.

Reported by Jiri Olsa back in February 2008:
http://lkml.org/lkml/2008/2/29/74Signed-off-by: NTony Battersby <tonyb@cybernetics.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Reported-by: NJiri Olsa <olsajiri@gmail.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: <stable@kernel.org>		[2.6.everything]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Avoid calling copy_from/to_user() with fb_info->lock mutex held in fbmem
ioctl().

fb_mmap() is called under mm->mmap_sem (A) held, that also acquires
fb_info->lock (B); fb_ioctl() takes fb_info->lock (B) and does
copy_from/to_user() that might acquire mm->mmap_sem (A), causing a
deadlock.

NOTE: it doesn't push down the fb_info->lock in each own driver's
fb_ioctl(), so there are still potential deadlocks elsewhere.
Signed-off-by: NAndrea Righi <righi.andrea@gmail.com>
Cc: Dave Jones <davej@redhat.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Johannes Weiner <hannes@saeurebad.de>
Cc: Krzysztof Helt <krzysztof.h1@wp.pl>
Cc: Harvey Harrison <harvey.harrison@gmail.com>
Cc: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Simple RTC driver for the MSP430 firmware on the DM355 EVM board.  Other
than not supporting atomic reads/writes of all four bytes, this is
reasonable as a basic no-alarm RTC.
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NKevin Hilman <khilman@deeprootsystems.com>
Acked-by: NAlessandro Zummo <a.zummo@towertech.it>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>