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too many auto-generated attributes may slow down the context_struct_compute_av() in kernel #9
Comments
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On 03/20/2017 10:56 PM, stesen wrote:
I found that if using the checkpolicy tool to generate sepolicy with cil mode, a
lot of "base_typeattr_xx" will be auto-generated. And each of them contain a lot
of types. So the "ebitmap_for_each_positive_bit" loop in
context_struct_compute_av() function will run 10x times more than policy
directly generated from policy.conf file.
if I comment the libsepol's set_to_cil_attr() function and re-generate cil.
Kernel runs fast and happy as the non-cil mode
So, why we need so many "base_typeattr_xx" ? Is it a safe way to remove those
auto-generated attributes?
CIL does not allow type set expressions in av rules (allow, neverallow, etc), so
an attribute needs to be created anywhere a type set expression occurs. Most of
the type sets occur in neverallow rules, so this often does not cause a problem.
It is true that too many attributes can slow things down. Originally, all
attributes were expanded when the policy was created, but at some point the
policy size started becoming too large and the kernel was modified to allow
attributes to be preserved.
What policy did you observe this for? Fedora's, Refpolicy, or something else?
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Thankyou for your reply :) I am working on android. the latest code shows that android will using CIL in the next version. It seems that base_typeattr_x can decrease the policy size, but use more cpu resource. So do you have some advices? Is that a good choice to set a limit number for one "base_typeattr_"? |
jwcart2
pushed a commit
to SELinuxProject/selinux
that referenced
this issue
May 9, 2017
This commit adds attribute expansion statements to the policy
language allowing compiler defaults to be overridden.
Always expands an attribute example:
expandattribute { foo } true;
CIL example:
(expandtypeattribute (foo) true)
Never expand an attribute example:
expandattribute { bar } false;
CIL example:
(expandtypeattribute (bar) false)
Adding the annotations directly to policy was chosen over other
methods as it is consistent with how targeted runtime optimizations
are specified in other languages. For example, in C the "inline"
command.
Motivation
expandattribute true:
Android has been moving away from a monolithic policy binary to
a two part split policy representing the Android platform and the
underlying vendor-provided hardware interface. The goal is a stable
API allowing these two parts to be updated independently of each
other. Attributes provide an important mechanism for compatibility.
For example, when the vendor provides a HAL for the platform,
permissions needed by clients of the HAL can be granted to an
attribute. Clients need only be assigned the attribute and do not
need to be aware of the underlying types and permissions being
granted.
Inheriting permissions via attribute creates a convenient mechanism
for independence between vendor and platform policy, but results
in the creation of many attributes, and the potential for performance
issues when processes are clients of many HALs. [1] Annotating these
attributes for expansion at compile time allows us to retain the
compatibility benefits of using attributes without the performance
costs. [2]
expandattribute false:
Commit 0be23c3 added the capability to aggresively remove unused
attributes. This is generally useful as too many attributes assigned
to a type results in lengthy policy look up times when there is a
cache miss. However, removing attributes can also result in loss of
information used in external tests. On Android, we're considering
stripping neverallow rules from on-device policy. This is consistent
with the kernel policy binary which also did not contain neverallows.
Removing neverallow rules results in a 5-10% decrease in on-device
policy build and load and a policy size decrease of ~250k. Neverallow
rules are still asserted at build time and during device
certification (CTS). If neverallow rules are absent when secilc is
run, some attributes are being stripped from policy and neverallow
tests in CTS may be violated. [3] This change retains the aggressive
attribute stripping behavior but adds an override mechanism to
preserve attributes marked as necessary.
[1] SELinuxProject/cil#9
[2] Annotating all HAL client attributes for expansion resulted in
system_server's dropping from 19 attributes to 8. Because these
attributes were not widely applied to other types, the final
policy size change was negligible.
[3] data_file_type and service_manager_type are stripped from AOSP
policy when using secilc's -G option. This impacts 11 neverallow
tests in CTS.
Test: Build and boot Marlin with all hal_*_client attributes marked
for expansion. Verify (using seinfo and sesearch) that permissions
are correctly expanded from attributes to types.
Test: Mark types being stripped by secilc with "preserve" and verify
that they are retained in policy and applied to the same types.
Signed-off-by: Jeff Vander Stoep <jeffv@google.com>
KronicBot
pushed a commit
to AOSiP/platform_external_selinux
that referenced
this issue
Nov 18, 2017
This commit adds attribute expansion statements to the policy
language allowing compiler defaults to be overridden.
Always expands an attribute example:
expandattribute { foo } true;
CIL example:
(expandtypeattribute (foo) true)
Never expand an attribute example:
expandattribute { bar } false;
CIL example:
(expandtypeattribute (bar) false)
Adding the annotations directly to policy was chosen over other
methods as it is consistent with how targeted runtime optimizations
are specified in other languages. For example, in C the "inline"
command.
Motivation
expandattribute true:
Android has been moving away from a monolithic policy binary to
a two part split policy representing the Android platform and the
underlying vendor-provided hardware interface. The goal is a stable
API allowing these two parts to be updated independently of each
other. Attributes provide an important mechanism for compatibility.
For example, when the vendor provides a HAL for the platform,
permissions needed by clients of the HAL can be granted to an
attribute. Clients need only be assigned the attribute and do not
need to be aware of the underlying types and permissions being
granted.
Inheriting permissions via attribute creates a convenient mechanism
for independence between vendor and platform policy, but results
in the creation of many attributes, and the potential for performance
issues when processes are clients of many HALs. [1] Annotating these
attributes for expansion at compile time allows us to retain the
compatibility benefits of using attributes without the performance
costs. [2]
expandattribute false:
Commit 0be23c3 added the capability to aggresively remove unused
attributes. This is generally useful as too many attributes assigned
to a type results in lengthy policy look up times when there is a
cache miss. However, removing attributes can also result in loss of
information used in external tests. On Android, we're considering
stripping neverallow rules from on-device policy. This is consistent
with the kernel policy binary which also did not contain neverallows.
Removing neverallow rules results in a 5-10% decrease in on-device
policy build and load and a policy size decrease of ~250k. Neverallow
rules are still asserted at build time and during device
certification (CTS). If neverallow rules are absent when secilc is
run, some attributes are being stripped from policy and neverallow
tests in CTS may be violated. [3] This change retains the aggressive
attribute stripping behavior but adds an override mechanism to
preserve attributes marked as necessary.
[1] SELinuxProject/cil#9
[2] Annotating all HAL client attributes for expansion resulted in
system_server's dropping from 19 attributes to 8. Because these
attributes were not widely applied to other types, the final
policy size change was negligible.
[3] data_file_type and service_manager_type are stripped from AOSP
policy when using secilc's -G option. This impacts 11 neverallow
tests in CTS.
Test: Build and boot Marlin with all hal_*_client attributes marked
for expansion. Verify (using seinfo and sesearch) that permissions
are correctly expanded from attributes to types.
Test: Mark types being stripped by secilc with "preserve" and verify
that they are retained in policy and applied to the same types.
Change-Id: I516cd6920fa34411a64cb321ed7fade8bb591a91
Signed-off-by: Jeff Vander Stoep <jeffv@google.com>
lineageos-gerrit
pushed a commit
to LineageOS/android_external_selinux
that referenced
this issue
Nov 19, 2017
This commit adds attribute expansion statements to the policy
language allowing compiler defaults to be overridden.
Always expands an attribute example:
expandattribute { foo } true;
CIL example:
(expandtypeattribute (foo) true)
Never expand an attribute example:
expandattribute { bar } false;
CIL example:
(expandtypeattribute (bar) false)
Adding the annotations directly to policy was chosen over other
methods as it is consistent with how targeted runtime optimizations
are specified in other languages. For example, in C the "inline"
command.
Motivation
expandattribute true:
Android has been moving away from a monolithic policy binary to
a two part split policy representing the Android platform and the
underlying vendor-provided hardware interface. The goal is a stable
API allowing these two parts to be updated independently of each
other. Attributes provide an important mechanism for compatibility.
For example, when the vendor provides a HAL for the platform,
permissions needed by clients of the HAL can be granted to an
attribute. Clients need only be assigned the attribute and do not
need to be aware of the underlying types and permissions being
granted.
Inheriting permissions via attribute creates a convenient mechanism
for independence between vendor and platform policy, but results
in the creation of many attributes, and the potential for performance
issues when processes are clients of many HALs. [1] Annotating these
attributes for expansion at compile time allows us to retain the
compatibility benefits of using attributes without the performance
costs. [2]
expandattribute false:
Commit 0be23c3 added the capability to aggresively remove unused
attributes. This is generally useful as too many attributes assigned
to a type results in lengthy policy look up times when there is a
cache miss. However, removing attributes can also result in loss of
information used in external tests. On Android, we're considering
stripping neverallow rules from on-device policy. This is consistent
with the kernel policy binary which also did not contain neverallows.
Removing neverallow rules results in a 5-10% decrease in on-device
policy build and load and a policy size decrease of ~250k. Neverallow
rules are still asserted at build time and during device
certification (CTS). If neverallow rules are absent when secilc is
run, some attributes are being stripped from policy and neverallow
tests in CTS may be violated. [3] This change retains the aggressive
attribute stripping behavior but adds an override mechanism to
preserve attributes marked as necessary.
[1] SELinuxProject/cil#9
[2] Annotating all HAL client attributes for expansion resulted in
system_server's dropping from 19 attributes to 8. Because these
attributes were not widely applied to other types, the final
policy size change was negligible.
[3] data_file_type and service_manager_type are stripped from AOSP
policy when using secilc's -G option. This impacts 11 neverallow
tests in CTS.
Test: Build and boot Marlin with all hal_*_client attributes marked
for expansion. Verify (using seinfo and sesearch) that permissions
are correctly expanded from attributes to types.
Test: Mark types being stripped by secilc with "preserve" and verify
that they are retained in policy and applied to the same types.
Change-Id: I516cd6920fa34411a64cb321ed7fade8bb591a91
Signed-off-by: Jeff Vander Stoep <jeffv@google.com>
Sirhc95
pushed a commit
to CypherOS/external_selinux
that referenced
this issue
Nov 20, 2017
This commit adds attribute expansion statements to the policy
language allowing compiler defaults to be overridden.
Always expands an attribute example:
expandattribute { foo } true;
CIL example:
(expandtypeattribute (foo) true)
Never expand an attribute example:
expandattribute { bar } false;
CIL example:
(expandtypeattribute (bar) false)
Adding the annotations directly to policy was chosen over other
methods as it is consistent with how targeted runtime optimizations
are specified in other languages. For example, in C the "inline"
command.
Motivation
expandattribute true:
Android has been moving away from a monolithic policy binary to
a two part split policy representing the Android platform and the
underlying vendor-provided hardware interface. The goal is a stable
API allowing these two parts to be updated independently of each
other. Attributes provide an important mechanism for compatibility.
For example, when the vendor provides a HAL for the platform,
permissions needed by clients of the HAL can be granted to an
attribute. Clients need only be assigned the attribute and do not
need to be aware of the underlying types and permissions being
granted.
Inheriting permissions via attribute creates a convenient mechanism
for independence between vendor and platform policy, but results
in the creation of many attributes, and the potential for performance
issues when processes are clients of many HALs. [1] Annotating these
attributes for expansion at compile time allows us to retain the
compatibility benefits of using attributes without the performance
costs. [2]
expandattribute false:
Commit 0be23c3 added the capability to aggresively remove unused
attributes. This is generally useful as too many attributes assigned
to a type results in lengthy policy look up times when there is a
cache miss. However, removing attributes can also result in loss of
information used in external tests. On Android, we're considering
stripping neverallow rules from on-device policy. This is consistent
with the kernel policy binary which also did not contain neverallows.
Removing neverallow rules results in a 5-10% decrease in on-device
policy build and load and a policy size decrease of ~250k. Neverallow
rules are still asserted at build time and during device
certification (CTS). If neverallow rules are absent when secilc is
run, some attributes are being stripped from policy and neverallow
tests in CTS may be violated. [3] This change retains the aggressive
attribute stripping behavior but adds an override mechanism to
preserve attributes marked as necessary.
[1] SELinuxProject/cil#9
[2] Annotating all HAL client attributes for expansion resulted in
system_server's dropping from 19 attributes to 8. Because these
attributes were not widely applied to other types, the final
policy size change was negligible.
[3] data_file_type and service_manager_type are stripped from AOSP
policy when using secilc's -G option. This impacts 11 neverallow
tests in CTS.
Test: Build and boot Marlin with all hal_*_client attributes marked
for expansion. Verify (using seinfo and sesearch) that permissions
are correctly expanded from attributes to types.
Test: Mark types being stripped by secilc with "preserve" and verify
that they are retained in policy and applied to the same types.
Change-Id: I516cd6920fa34411a64cb321ed7fade8bb591a91
Signed-off-by: Jeff Vander Stoep <jeffv@google.com>
B--B
pushed a commit
to AOSP-JF-MM/platform_external_selinux
that referenced
this issue
Nov 29, 2017
This commit adds attribute expansion statements to the policy
language allowing compiler defaults to be overridden.
Always expands an attribute example:
expandattribute { foo } true;
CIL example:
(expandtypeattribute (foo) true)
Never expand an attribute example:
expandattribute { bar } false;
CIL example:
(expandtypeattribute (bar) false)
Adding the annotations directly to policy was chosen over other
methods as it is consistent with how targeted runtime optimizations
are specified in other languages. For example, in C the "inline"
command.
Motivation
expandattribute true:
Android has been moving away from a monolithic policy binary to
a two part split policy representing the Android platform and the
underlying vendor-provided hardware interface. The goal is a stable
API allowing these two parts to be updated independently of each
other. Attributes provide an important mechanism for compatibility.
For example, when the vendor provides a HAL for the platform,
permissions needed by clients of the HAL can be granted to an
attribute. Clients need only be assigned the attribute and do not
need to be aware of the underlying types and permissions being
granted.
Inheriting permissions via attribute creates a convenient mechanism
for independence between vendor and platform policy, but results
in the creation of many attributes, and the potential for performance
issues when processes are clients of many HALs. [1] Annotating these
attributes for expansion at compile time allows us to retain the
compatibility benefits of using attributes without the performance
costs. [2]
expandattribute false:
Commit 0be23c3 added the capability to aggresively remove unused
attributes. This is generally useful as too many attributes assigned
to a type results in lengthy policy look up times when there is a
cache miss. However, removing attributes can also result in loss of
information used in external tests. On Android, we're considering
stripping neverallow rules from on-device policy. This is consistent
with the kernel policy binary which also did not contain neverallows.
Removing neverallow rules results in a 5-10% decrease in on-device
policy build and load and a policy size decrease of ~250k. Neverallow
rules are still asserted at build time and during device
certification (CTS). If neverallow rules are absent when secilc is
run, some attributes are being stripped from policy and neverallow
tests in CTS may be violated. [3] This change retains the aggressive
attribute stripping behavior but adds an override mechanism to
preserve attributes marked as necessary.
[1] SELinuxProject/cil#9
[2] Annotating all HAL client attributes for expansion resulted in
system_server's dropping from 19 attributes to 8. Because these
attributes were not widely applied to other types, the final
policy size change was negligible.
[3] data_file_type and service_manager_type are stripped from AOSP
policy when using secilc's -G option. This impacts 11 neverallow
tests in CTS.
Test: Build and boot Marlin with all hal_*_client attributes marked
for expansion. Verify (using seinfo and sesearch) that permissions
are correctly expanded from attributes to types.
Test: Mark types being stripped by secilc with "preserve" and verify
that they are retained in policy and applied to the same types.
Change-Id: I516cd6920fa34411a64cb321ed7fade8bb591a91
Signed-off-by: Jeff Vander Stoep <jeffv@google.com>
Signed-off-by: Marco Zanin (B--B) <mrczn.bb@gmail.com>
OmniBot
pushed a commit
to omnirom/android_external_selinux
that referenced
this issue
Dec 4, 2017
This commit adds attribute expansion statements to the policy
language allowing compiler defaults to be overridden.
Always expands an attribute example:
expandattribute { foo } true;
CIL example:
(expandtypeattribute (foo) true)
Never expand an attribute example:
expandattribute { bar } false;
CIL example:
(expandtypeattribute (bar) false)
Adding the annotations directly to policy was chosen over other
methods as it is consistent with how targeted runtime optimizations
are specified in other languages. For example, in C the "inline"
command.
Motivation
expandattribute true:
Android has been moving away from a monolithic policy binary to
a two part split policy representing the Android platform and the
underlying vendor-provided hardware interface. The goal is a stable
API allowing these two parts to be updated independently of each
other. Attributes provide an important mechanism for compatibility.
For example, when the vendor provides a HAL for the platform,
permissions needed by clients of the HAL can be granted to an
attribute. Clients need only be assigned the attribute and do not
need to be aware of the underlying types and permissions being
granted.
Inheriting permissions via attribute creates a convenient mechanism
for independence between vendor and platform policy, but results
in the creation of many attributes, and the potential for performance
issues when processes are clients of many HALs. [1] Annotating these
attributes for expansion at compile time allows us to retain the
compatibility benefits of using attributes without the performance
costs. [2]
expandattribute false:
Commit 0be23c3 added the capability to aggresively remove unused
attributes. This is generally useful as too many attributes assigned
to a type results in lengthy policy look up times when there is a
cache miss. However, removing attributes can also result in loss of
information used in external tests. On Android, we're considering
stripping neverallow rules from on-device policy. This is consistent
with the kernel policy binary which also did not contain neverallows.
Removing neverallow rules results in a 5-10% decrease in on-device
policy build and load and a policy size decrease of ~250k. Neverallow
rules are still asserted at build time and during device
certification (CTS). If neverallow rules are absent when secilc is
run, some attributes are being stripped from policy and neverallow
tests in CTS may be violated. [3] This change retains the aggressive
attribute stripping behavior but adds an override mechanism to
preserve attributes marked as necessary.
[1] SELinuxProject/cil#9
[2] Annotating all HAL client attributes for expansion resulted in
system_server's dropping from 19 attributes to 8. Because these
attributes were not widely applied to other types, the final
policy size change was negligible.
[3] data_file_type and service_manager_type are stripped from AOSP
policy when using secilc's -G option. This impacts 11 neverallow
tests in CTS.
Test: Build and boot Marlin with all hal_*_client attributes marked
for expansion. Verify (using seinfo and sesearch) that permissions
are correctly expanded from attributes to types.
Test: Mark types being stripped by secilc with "preserve" and verify
that they are retained in policy and applied to the same types.
Change-Id: I516cd6920fa34411a64cb321ed7fade8bb591a91
Signed-off-by: Jeff Vander Stoep <jeffv@google.com>
chenyt9
pushed a commit
to MotorolaMobilityLLC/external-selinux
that referenced
this issue
Jul 6, 2018
This commit adds attribute expansion statements to the policy
language allowing compiler defaults to be overridden.
Always expands an attribute example:
expandattribute { foo } true;
CIL example:
(expandtypeattribute (foo) true)
Never expand an attribute example:
expandattribute { bar } false;
CIL example:
(expandtypeattribute (bar) false)
Adding the annotations directly to policy was chosen over other
methods as it is consistent with how targeted runtime optimizations
are specified in other languages. For example, in C the "inline"
command.
Motivation
expandattribute true:
Android has been moving away from a monolithic policy binary to
a two part split policy representing the Android platform and the
underlying vendor-provided hardware interface. The goal is a stable
API allowing these two parts to be updated independently of each
other. Attributes provide an important mechanism for compatibility.
For example, when the vendor provides a HAL for the platform,
permissions needed by clients of the HAL can be granted to an
attribute. Clients need only be assigned the attribute and do not
need to be aware of the underlying types and permissions being
granted.
Inheriting permissions via attribute creates a convenient mechanism
for independence between vendor and platform policy, but results
in the creation of many attributes, and the potential for performance
issues when processes are clients of many HALs. [1] Annotating these
attributes for expansion at compile time allows us to retain the
compatibility benefits of using attributes without the performance
costs. [2]
expandattribute false:
Commit 0be23c3 added the capability to aggresively remove unused
attributes. This is generally useful as too many attributes assigned
to a type results in lengthy policy look up times when there is a
cache miss. However, removing attributes can also result in loss of
information used in external tests. On Android, we're considering
stripping neverallow rules from on-device policy. This is consistent
with the kernel policy binary which also did not contain neverallows.
Removing neverallow rules results in a 5-10% decrease in on-device
policy build and load and a policy size decrease of ~250k. Neverallow
rules are still asserted at build time and during device
certification (CTS). If neverallow rules are absent when secilc is
run, some attributes are being stripped from policy and neverallow
tests in CTS may be violated. [3] This change retains the aggressive
attribute stripping behavior but adds an override mechanism to
preserve attributes marked as necessary.
[1] SELinuxProject/cil#9
[2] Annotating all HAL client attributes for expansion resulted in
system_server's dropping from 19 attributes to 8. Because these
attributes were not widely applied to other types, the final
policy size change was negligible.
[3] data_file_type and service_manager_type are stripped from AOSP
policy when using secilc's -G option. This impacts 11 neverallow
tests in CTS.
Test: Build and boot Marlin with all hal_*_client attributes marked
for expansion. Verify (using seinfo and sesearch) that permissions
are correctly expanded from attributes to types.
Test: Mark types being stripped by secilc with "preserve" and verify
that they are retained in policy and applied to the same types.
Signed-off-by: Jeff Vander Stoep <jeffv@google.com>
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I found that if using the checkpolicy tool to generate sepolicy with cil mode, a lot of "base_typeattr_xx" will be auto-generated. And each of them contain a lot of types. So the "ebitmap_for_each_positive_bit" loop in context_struct_compute_av() function will run 10x times more than policy directly generated from policy.conf file.
if I comment the libsepol's set_to_cil_attr() function and re-generate cil. Kernel runs fast and happy as the non-cil mode
So, why we need so many "base_typeattr_xx" ? Is it a safe way to remove those auto-generated attributes?
The text was updated successfully, but these errors were encountered: