The clang-r370808 upgrade contains a change to LLD allow PT_LOAD
segments to reside at non-multiples of the page size in the resulting
object file. https://reviews.llvm.org/rL369344
While this helps reduce the alignment waste and resulting image size, it
has interesting implications for execute only memory (XOM): The runtime
loader will now load code or data from other segments into pages with
different protections than intended.
This would partially defeat execute only (XOM) text sections as the
segment could now overlap with previous and following sections. This
might allow for code or data from the preceding and following sections
(like .eh_frame, and .data.rel.ro) to be executable, and either ends of
.text to be readable.
When the runtime loader (linker[64]) `mmap`s segments from *.so files,
the file offset parameter (see `man 2 mmap`) MUST be a multiple of the
page size. Since the updated LLD can now pack segments in a file (which
helps minimize resulting object file size) (previously, the segment
offsets were page aligned), this has interesting implications.
To appreciate the current bug, consider the following output from
`readelf` before this patch is applied, but after the toolchain upgrade:
```
$ readelf -lSW $OUT/symbols/apex/com.android.runtime/lib64/bionic/libc.so
...
[Nr] Name Type Address Off Size ES Flg Lk Inf Al
...
[13] .eh_frame PROGBITS 000000000002e7c0 02e7c0 013374 00 A 0 0 8
[14] .text PROGBITS 0000000000042b40 041b40 09ecb4 00 AX 0 0 64
[15] .plt PROGBITS 00000000000e1800 0e0800 001f30 00 AX 0 0 16
[16] .data.rel.ro PROGBITS 00000000000e4740 0e2740 005208 00 WA 0 0 32
...
Type Offset VirtAddr PhysAddr FileSiz MemSiz Flg Align
PHDR 0x000040 0x0000000000000040 0x0000000000000040 0x000230 0x000230 R 0x8
LOAD 0x000000 0x0000000000000000 0x0000000000000000 0x041b34 0x041b34 R 0x1000
LOAD 0x041b40 0x0000000000042b40 0x0000000000042b40 0x0a0bf0 0x0a0bf0 E 0x1000
LOAD 0x0e2740 0x00000000000e4740 0x00000000000e4740 0x006720 0x006720 RW 0x1000
...
01 .note.android.ident .note.gnu.build-id .dynsym .gnu.version .gnu.version_d .gnu.version_r .gnu.hash .dynstr .rela.dyn .rela.plt .rodata .eh_frame_hdr .eh_frame
02 .text .plt
03 .data.rel.ro .fini_array .init_array .dynamic .got .got.plt
...
The above output tells us:
1. .text will wind up in the third (02) segment.
2. The third segment will be (LOAD)'ed as (E)xecutable.
3. Because the file (Offset) of the first segment (0x41b40) is NOT a
multiple of the page size, it cannot be passed as the `offset` to
`mmap`. As such it will be rounded down to the first multiple of the
page size, 0x41000.
4. The preceding section (.eh_frame) will be loaded in the preceding
segment (01). It occupies file (Off)set range [(0x2e7c0):0x41b34].
0x41b34 is not explicit in the output, instead you must use the
formula:
Off + Size == End
ie.
0x2e7c0 + 0x13374 == 0x41b34
(This happens to match (FileSiz) of the second segment, which makes
sense as .eh_frame is the final section in the second segment.)
5. mmap'ing file offset 0x41000 when loading the second segment will
include 0x4c0 bytes (0x42000 - 0x41b40) from .text, now mapped as
readable (oops). Suddenly code from .text is now readable (and thus
scannable for gadgets for ROP chains).
6. mmap'ing file offset 0x41000 when loading the third segment will
include 0xb34 bytes (0x41b34 - 0x41000) from .eh_frame, now mapped as
executable (oops). Suddenly data from .eh_frame is now executable
(and thus a potential gadget for ROP chains).
7. mmap'ing file offset 0xe2000 when loading the third segment will
include 0x8CO bytes (0xe3000 - 0xe2740) from .data.rel.ro, now mapped
as executable (oops). Suddenly data from .data.rel.ro is now
executable (and thus a potential gadget for ROP chains).
8. mmap'ing file offset 0xe2000 when loading the fourth segment will
include 0x730 bytes (0xe0800 + 0x1f30 - 0xe2000) from .plt, now
mapped as readable (oops). Suddenly data from .plt is now readable
(and thus scannable for gadgets for ROP chains).
All these oops' could be avoided if the linker placed .text+.plt at page
size aligned file offsets, which is what `-Wl,-z,separate-code` code
does. After this patch, we have:
```
$ readelf -lSW $OUT/symbols/apex/com.android.runtime/lib64/bionic/libc.so
...
Type Offset VirtAddr PhysAddr FileSiz MemSiz Flg Align
PHDR 0x000040 0x0000000000000040 0x0000000000000040 0x000230 0x000230 R 0x8
LOAD 0x000000 0x0000000000000000 0x0000000000000000 0x041b34 0x041b34 R 0x1000
LOAD 0x042000 0x0000000000042000 0x0000000000042000 0x0a0be0 0x0a0be0 E 0x1000
LOAD 0x0e3000 0x00000000000e3000 0x00000000000e3000 0x006720 0x006720 RW 0x1000
```
In the future, we could go back to tightly packing segments in the
binary if the runtime loader was improved to detect the previously
stated problem, and `memset` over the problematic ranges of the freshly
`mmap`ed pages (implying additional startup cost for reduced binary
size). This might save ~6 KB from each native binary, which adds up to
~17 MB for an AOSP image.
Also, prefer
-Wl,--execute-only
rather than
-Wl,-execute-only
Bug: 139945549
Bug: 146144180
Test: readelf -lSW $OUT/symbols/apex/com.android.runtime/lib64/bionic/libc.so
Change-Id: I64527e034ca3c71565ea52ed06f81f75d5216627
Reported-by: Ryan Prichard <rprichard@google.com>
Suggested-by: Fangrui Song <maskray@google.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
This reverts commit 862eb4648a.
Re-upgrades the compiler to clang-r370808, after first dealing with
regressions in ndk_translate and execute only pages.
Bug: 139945549
Bug: 145807809
Bug: 145827049
Bug: 145825270
Test: atest \
CtsSelinuxTargetSdk27TestCases:android.security.SELinuxTargetSdkTest#testNoExecuteOnly
Test: m ndk_translation_host_unit_tests && \
./out/host/linux-x86/nativetest/ndk_translation_host_unit_tests/ndk_translation_host_unit_tests
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Change-Id: I714b582faffa8c92384818a7b12338d621968548
The exported include dirs includes both source and generated
directories (e.g. containing aidl generated headers). The latter are
always arch specific so if they are present they make all the include
directories arch specific.
This change separates the source and generated include dirs so that
the source include dirs (which are probably not arch specific) can be
optimized separately from the arch specific generated include dirs.
The FilterPathList() func was refactored to extract the more general
FilterPathListPredicate() func.
A number of tests needed to be updated to reflect the more optimal
snapshot creation.
Bug: 142918168
Test: m checkbuild
Change-Id: Id1a23d35a45b250ae2168834f9c2a65c86a5fd77
Previously, code that attempted to optimize the generated .bp rules
treated the properties structure as a single entity. So, a single arch
specific value would cause all properties to be treated as arch
specific. Also, that code was specific to one structure type.
This generalizes the optimization to work with any properties structure
which will be helpful for other multi-variant module types. It also
treats each property separately.
The hasArchSpecificFlags field has been removed from nativeLibInfo and
a commonProperties field has been added instead into which the common
values will be found. File path creation that conditionally prefixed a
path with archType has been replaced with general code that relies on
archType being "" for common properties and filepath.Join(..) ignoring
empty string components.
The common and arch variant properties are always processed. The first
within the context of the .bp module's property set and the latter
within an arch specific property set. There are always some properties
that are arch specific, e.g. outputFile, so there is no need to worry
about an empty arch property set being created.
The archSpecificNativeLibInfo type was renamed nativeLibInfoProperties
as it may not be arch specific.
The printExportedDirCopyCommandsForNativeLibs variable was renamed to
addExportedDirCopyCommandsForNativeLibs as it no longer does any
printing.
Bug: 142918168
Test: m checkbuild
Change-Id: Iad45913299c37fd76fe03ed0ca68bdc68ed76431
Parameterized the cc.librarySdkMemberType to allow it to support
both static and shared libraries. Created two instances, one for shared
and one for static libraries. A follow up change will add support for
libraries that can be both.
Added *librarySdkMemberType to nativeMemberInfo as information from
there is needed when generating the snapshot.
Made organizeVariants() func a method of *librarySdkMemberType so that
it can initialize the new field. Moved it to be with all the other
methods of that type.
Added host and device tests for the new module type.
Bug: 142918168
Test: m nothing
Change-Id: I00b1e8424b9d81f7d15edc4883971d10668ec2cc
Header include directories are copied into the snapshot separately for
each cc library that exports them. However, the same include
directories can be exported by multiple libraries which caused ninja
error because two separate rules (albeit identical) were defined to
create the same files.
This avoids the duplicate ninja rules by detecting and discarding
duplicate copies, i.e. where the source and destination are the same.
It will also report an error if two or more different source files are
copied to the same destination.
Bug: 142918168
Test: m nothing
added test and verified it produced two identical copy rules
fixed code and verified duplicate copy rules had been eliminated
Change-Id: I39e37405035bee5093f96e03248e9e29ed30962c
This reverts commit 4d2eeed0da.
Reason for revert: breaks avd/avd_boot_health_check test
on cf_x86_phone-userdebug_coverage on branch rvc-release
(the device fails to boot).
Test: m
Test: aosp_walleye-userdebug boots
Bug: 145749668
Exempt-From-Owner-Approval: revert
Change-Id: Ie1d93a200222e26461c1bcd384fdb69b7351e259
Previously, the -hostdex library was emitted using the ExtraFooters.
Now, it has its own AndroidMkEntries, which can be returned together
with the AndroidMkEntries for the main library.
Bug: 128708192
Test: m
Change-Id: Ic9eb0d3839572ed340ccbc5fc6c4b54241e1cb24
AndroidMkEntries now returns multiple AndroidMkEntires so that a module
can emit multiple Make modules if needed.
Bug: 128708192
Test: m
Change-Id: I56b6f76d22943b80329951c5acb80a1b932441ad
Prevents the META-INF/MANIFEST.MF file from the source jar from being
copied to the snapshot zip file.
Bug: 143678475
Test: m conscrypt-module-sdk
manually check contents of generated zip
Change-Id: I6eca1435dfc25b562e49de46b049fa81cf8daf90
Exports visibility and package mutator registration functions so they
can be used in sdk testing. Updates sdk test to support visibility and
package modules.
Adds EffectiveVisibility(...)[]string function to make the effective
visibility rules available to sdk snapshot creation.
Extracts compositeRule.Strings() []string from compositeRule.String()
method so that it can be used by above func.
Adds visibility property to sdk snapshot and prebuilt modules along
with a test to ensure it works properly.
Adds dir parameter to CheckSnapshot so that it can check the snapshot
generated for a non-root package. That is required in order to ensure
that visibility of :__subpackages__ on a source module in package
<pkg> is resolved to an effective visibility of
//<pkg>:__subpackages__ on its corresponding prebuilt.
Test: m conscrypt-module-sdk
Bug: 143678475
Change-Id: Icaacac5b9c04726d28e6fec93e49715ac45df7f4
This is needed for a follow up change that makes sure that the
prebuilt modules have the same visibility as the source modules.
Bug: 143678475
Test: m conscrypt-module-sdk
Change-Id: I9461c8c094ab19ee9ececb5e5fd50565789f2fa2
Because aidl_interface depends on some ndk modules, their factories are
exposed so that aidl_test.go can use them.
Bug: n/a
Test: m
Change-Id: I98d282cc77310d5896a7abaf3936456a14d56ccf
For VNDK snapshot and SDK snapshot, deps files have been used to capture
generated headers. But exported deps might contain intermediate phony
files instead of actual header files, which are for optimization of
ninja. To correctly capture all headers, exported generated header files
are gathered separately.
Bug: 65377115
Test: m nothing
Change-Id: Ia03fa69186490a818578190e3c0bfb0261d1fd6e
The two were missing.
Bug: 145678884
Test: m out/dist/mainline_modules_arm64/com.android.tzdata-base.zip and
inspect the content
Change-Id: I7e244561f59e5adce56b6a64f363a413faa106f2
Move the ImageMutator to be registered just after the archMutator
in preparation for moving it between osMutator and archMutator.
Requries updating variants in a few tests that now run the
ImageMutator.
Bug: 142286466
Test: no change to build.ninja
Test: all soong tests
Change-Id: Ia9d2a7bc0e225bedec3c9a83ea04f471a931bf47
This function took a props varargs parameter but it was only ever
called with no parameters. The props parameter meant it could not be
used directly with RegisterModuleType() so the defaultsFactory() func
was added which simply called through to DefaultsFactory().
Removing the props varargs parameter allowed it to be used directly
with RegisterModuleType() and so the defaultsFactory() could be
removed.
This was needed because a follow up change adds a test in another
package that uses java_defaults and so it needs the factory method
(defaultsFactory()) to be exported.
Test: m nothing
Change-Id: I33d5c4d4ce8f349b1e6fc706d5e9656faf303b4f
Add a new java_header_libs property that exports header jars (as
java_libs currently does) and switch java_libs to export implementation
jars instead.
Refactors implementation of the existing library sdk member type so
both properties can be supported from common code as they differ only
on the jar being exported.
Bug: 143678475
Test: m nothing
Change-Id: I04642122f72d083bbdfd3290624f957b71ee8875
* changes:
Organize sdk member properties
Extract the cc and java sdk related tests out into their own file
Improve testing of sdk snapshot generation
Separate sdk testing infrastructure from sdk tests
Parameterize the sdk member processing
Link type checking for java_library has not been working unintentionally.
So turn on link type checking for these types.
And also add tests for link type checking.
Bug: 145799020
Test: cherry-pick aosp/1182522 and check if build fails
Test: m nothing and there is no error(soong unittest)
Change-Id: Ifc347f657885de1028ac0076ddd103c0387b597a
