Commit graph

1426 commits

Author SHA1 Message Date
Elliott Hughes
658b938700 linker: add ld.config.txt parse time to systrace.
Bug: http://b/172640358
Test: treehugger
Change-Id: I9d6b7c1e200d2effb737508d3c282063edefa888
2020-11-06 09:28:16 -08:00
Yifan Hong
02bee7182e Merge "Make vendor_ramdisk_available." 2020-10-29 17:17:29 +00:00
Yifan Hong
b04490d7e5 Make vendor_ramdisk_available.
Test: pass
Bug: 156098440
Change-Id: I8fe2deb8fa3b24c227202be02d8af648629cffeb
2020-10-27 17:06:45 -07:00
Yi Kong
a7e363f873 No global ThinLTO for linker
Previous CL aosp/1432874 missed one project to exclude.

Test: make
Change-Id: Ib39e6a86c410e35141cba17948a0f30e197ea9a3
2020-10-01 04:10:01 +08:00
Yi Kong
15a05a77b4 No global ThinLTO for bionic
There are multiple build breakages with bionic when we enable ThinLTO
globally. Opt bionic out of ThinLTO for now.

#global-thinlto-opt-out

Test: TreeHugger
Bug: 169004486
Change-Id: I546a8074f9c3e0ddbd01d3b7cd730e215e3c0c49
2020-09-29 17:24:04 +00:00
Tamas Petz
8d55d1872a Enable BTI in bionic linker
This patch adds support to load BTI-enabled objects.

According to the ABI, BTI is recorded in the .note.gnu.property section.
The new parser evaluates the property section, if exists.
It searches for .note section with NT_GNU_PROPERTY_TYPE_0.
Once found it tries to find GNU_PROPERTY_AARCH64_FEATURE_1_AND.
The results are cached.

The main change in linker is when protection of loaded ranges gets
applied. When BTI is requested and the platform also supports it
the prot flags have to be amended with PROT_BTI for executable ranges.
Failing to add PROT_BTI flag would disable BTI protection.
Moreover, adding the new PROT flag for shared objects without BTI
compatibility would break applications.

Kernel does not add PROT_BTI to a loaded ELF which has interpreter.
Linker handles this case too.

Test: 1. Flame boots
      2. Tested on FVP with BTI enabled

Change-Id: Iafdf223b74c6e75d9f17ca90500e6fe42c4c1218
2020-09-23 17:53:28 -07:00
Jiyong Park
3b47d603fa Add arm64 source to linker_wrapper
As we enable arm64-based Bionic host target (linux_bionic_arm64),
linker_wrapper is added with the corresponding source.

Bug: 159685774
Test: HOST_CROSS_OS=linux_bionic HOST_CROSS_ARCH=arm64 m
Test: copy out/soong/host/linux_bionic_arm64/ to an ARM64 emulator
running Linux and execute the binaries

Change-Id: I4f367a349f7e0015318352cb7f2870fc856eab05
2020-09-22 11:28:22 +09:00
Vy Nguyen
d500751443 Add a thread-properties API
(Based on proposal at https://sourceware.org/glibc/wiki/ThreadPropertiesAPI)

This includes API to:
 - locate static and dynamic TLS
 - register thread-exit and  dynamic TLS creation/destruction callbacks

Change-Id: Icd9d29a5b2f47495395645e19d3b2c96826f19c8
2020-08-11 16:51:43 +00:00
Ryan Prichard
aff9a34bd8 Rename linker greylist to exempt-list
Update a comment in android-changes-for-ndk-developers.md about the
removed debug.ld.greylist_disabled system property.

Update language to comply with Android's inclusive language guidance

  #inclusivefixit

See https://source.android.com/setup/contribute/respectful-code for reference

Bug: http://b/162536543
Test: bionic-unit-tests
Change-Id: I760ee14bce14d9d799926c43d2c14fd8ffbc6968
2020-08-03 16:17:00 -07:00
Treehugger Robot
0f4bdb04fb Merge "linker: Cleanup for Android's inclusive language guidance" 2020-08-02 14:48:01 +00:00
Luke Huang
30f2f053f2 linker: Cleanup for Android's inclusive language guidance
1. Cleanup for #inclusivefixit. (whitelisted -> allowed_libs)
2. Support the old term for backwards compatibility. (Also update test.)
3. Fix the formatting errors found by clang-format.

See https://source.android.com/setup/contribute/respectful-code
for reference.

Bug: 161896447
Test: atest linker-unit-tests linker-benchmarks
Change-Id: I19dbed27a6d874ac0049cb7b67d2cb0f75369c1b
2020-07-31 11:37:28 +08:00
Ryan Prichard
238609328f Remove debug.ld.greylist_disabled property
This property provided a way to disable the greylist, for testing
whether an app targeting < 24 still works. Instead of turning off the
greylist, though, an app developer should simply target a newer API.

(If app developers really need this property for testing, they can
still use it on versions of Android between N and R, inclusive.)

Update language to comply with Android's inclusive language guidance

See https://source.android.com/setup/contribute/respectful-code for reference

#inclusivefixit

Bug: http://b/162536543
Test: bionic-unit-tests
Change-Id: Id1eb2807fbb7436dc9ed7fe47e15b7d165a26789
2020-07-30 19:29:17 -07:00
Elliott Hughes
68ae6ad12e Changes for #inclusivefixit.
Test: treehugger
Change-Id: I7ff0496c5c2792a41781e74634247f55b0548213
2020-07-21 16:34:58 -07:00
Evgenii Stepanov
e0848bbf89 Pagetable-friendly shared library address randomization.
Add inaccessible gaps between shared libraries to make it harder for the
attackers to defeat ASLR by random probing.

To avoid excessive page table bloat, only do this when a library is
about to cross a huge page boundary, effectively allowing several
smaller libraries to be lumped together.

Bug: 158113540
Test: look at /proc/$$/maps
Change-Id: I39c0100b81f72447e8b3c6faafa561111492bf8c
2020-07-16 13:57:20 -07:00
Evgenii Stepanov
b5f301eaaf Merge "Revert "Add randomized padding around shared library mappings."" 2020-07-06 22:18:45 +00:00
Evgenii Stepanov
474f2f5c8b Revert "Add randomized padding around shared library mappings."
This reverts commit a8cf3fef2a.

Reason for revert: memory regression due to the fragmentation of the page tables
Bug: 159810641
Bug: 158113540

Change-Id: I6212c623ff440c7f6889f0a1e82cf7a96200a411
2020-07-06 19:27:55 +00:00
Kiyoung Kim
46e731caf5 Disable warning message for missing linker config in some cases
There are some special cases - such as init process - when linker
configuration is not expected to exist. This change disables warning
message that generated linker configuration does not exist in those
cases.

Bug: 158800902
Test: Tested from cuttlefish that warning message is not generated from
init

Change-Id: Ie2fbb5210175cf1e6f2b7e638f57c3b74d395368
2020-06-30 09:21:07 +09:00
Evgenii Stepanov
a8cf3fef2a Add randomized padding around shared library mappings.
Improve ASLR by increasing the randomly sized gaps between shared
library mappings, and keep them mapped PROT_NONE.

Bug: 158113540
Test: look at /proc/$$/maps
Change-Id: Ie72c84047fb624fe2ac8b7744b2a2d0d255ea974
2020-06-17 17:28:28 -07:00
Evgenii Stepanov
071416b700 Use PROT_NONE on the unused parts of CFI shadow.
This replaces a single 2Gb readable memory region with a bunch of tiny
regions, and leaves the bulk of 2Gb mapped but unaccessible. This makes
it harder to defeat ASLR by probing for the CFI shadow region.

Sample CFI shadow mapping with this change:
7165151000-716541f000 ---p 00000000 00:00 0                              [anon:cfi shadow]
716541f000-7165420000 r--p 00000000 00:00 0                              [anon:cfi shadow]
7165420000-71654db000 ---p 00000000 00:00 0                              [anon:cfi shadow]
71654db000-71654dc000 r--p 00000000 00:00 0                              [anon:cfi shadow]
71654dc000-71654dd000 r--p 00000000 00:00 0                              [anon:cfi shadow]
71654dd000-71654f0000 ---p 00000000 00:00 0                              [anon:cfi shadow]
71654f0000-71654f1000 r--p 00000000 00:00 0                              [anon:cfi shadow]
71654f1000-71e5151000 ---p 00000000 00:00 0                              [anon:cfi shadow]

This change degrades CFI diagnostics for wild jumps and casts (i.e. when
the target of a CFI check is outside of any known library bounds). This
is acceptable, because CFI does not have much to tell about those cases
anyway. Such bugs will show up as SEGV_ACCERR crashes inside
__cfi_slowpath in libdl.so from now on.

Bug: 158113540
Test: bionic-unit-tests/cfi_test.*
Test: adb shell cat /proc/$PID/maps | grep cfi

Change-Id: I57cbd0d3f87eb1610ad99b48d98ffd497ba214b4
Merged-In: I57cbd0d3f87eb1610ad99b48d98ffd497ba214b4
2020-06-12 12:22:32 -07:00
Elliott Hughes
3205cddff0 linker: CHECK() or async_safe_fatal() rather than abort().
In particular, add the strerror() output if mprotect() fails.

Fix the CHECK macro so that you can make assertions involving operator%
without that being confused for a printf format specifier.

Bug: https://issuetracker.google.com/158645318
Test: treehugger
Change-Id: I6817f8ca5f094c52dc2c9067bfac90385a8743f5
2020-06-10 14:49:28 -07:00
Jooyung Han
61a9a4016c Make .whitelisted property "append"-able
.whitelisted is a list of sonames seperated by ":" just like
.shared_libs and .paths properties. It makes sense to make it appendable
using += as well ass .shared_libs and .paths.

Bug: n/a
Test: atest linker-unit-tests
Change-Id: If61cc553c8080e8a58de8a3a6051c1853f7bfe5f
2020-06-02 16:05:01 +09:00
Victor Khimenko
9b3e026c8f Refactor translateSystemPathToApexPath
This is more efficient and easier to read.

Test: bionic-unit-tests --gtest_filter=*icu*

Change-Id: Iddeed7cd4a1d48d8968f97951a9af004ccce52e8
2020-05-19 02:32:07 +02:00
Victor Khimenko
01790fdc69 Allow native_bridge linker to use different APEX from native one
Bug: http://b/156397945

Test: dlfcn.dlopen_system_libicuuc_android_api_level_28 with native_bridge

Change-Id: I3ecd929a0c31dda8cd424795f21f6ef472776557
2020-05-15 20:56:22 +00:00
Victor Khimenko
d15229df76 Copy translateSystemPathToApexPath to linker_translate_path.cpp
Bug: http://b/156397945

Test: m

Change-Id: I33f11b8a6a41475b6cdd65e1ff49b2084c33b197
2020-05-14 22:17:45 +02:00
vichang
10bad3e882 Merge "Move libicuuc.so into com.android.i18n module." 2020-05-11 11:37:06 +00:00
Victor Chang
f248d2de84 Move libicuuc.so into com.android.i18n module.
Change the location set in the linker

Bug: 130219528
Bug: 138994281
Test: atest CtsBionicTestCases
Test: atest CtsJniTestCases
Change-Id: I215a8e023ccc4d5ffdd7df884c809f8d12050c8f
2020-05-07 23:15:01 +00:00
Peter Collingbourne
144a6ab341 Merge "Introduce a new heap tagging level, M_HEAP_TAGGING_LEVEL_SYNC." 2020-05-07 17:51:51 +00:00
Peter Collingbourne
d3060019de Introduce a new heap tagging level, M_HEAP_TAGGING_LEVEL_SYNC.
The SYNC tagging level enables stack trace collection for allocations and
deallocations, which allows allocation and deallocation stack traces to
appear in tombstones when encountering a tag check fault in synchronous tag
checking mode.

Bug: 135772972
Change-Id: Ibda9f51b29d2c8e2c993fc74425dea7bfa23ab1e
2020-05-05 13:28:16 -07:00
Martin Stjernholm
82d84bcd7e Make Bionic and kernel system includes explicit in the blueprints.
Before this Soong added hardcoded system include paths to
bionic/libc/{include,kernel}, which won't work when Bionic libs are
packaged up as prebuilts in an SDK module snapshot.

Test: Build and boot
Test: Check in out/verbose.log.gz that a C file doesn't get any bionic
  include path for linux_glibc.
Bug: 153590472
Change-Id: I13c8eb3dd7150d6e0fee001b290b53fcebebcfea
2020-05-05 13:34:14 +01:00
Ryan Prichard
172611f5ce __loader_cfi_fail: acquire g_dl_mutex
CfiFail calls find_containing_library, which searches the linker's
internal soinfo list, which could be modified by another thread.

Bug: http://b/150372650
Test: bionic-unit-tests
Change-Id: I59024a0a47913caa75702f15ec058b0a360727b5
2020-04-20 18:14:51 -07:00
Ryan Prichard
c2a93792fc android_get_exported_namespace: acquire g_dl_mutex
android_get_exported_namespace searches g_exported_namespaces, which
isn't modified after process initialization, but it does the search
using a new std::string object, and the linker's malloc/free functions
aren't thread-safe. (They're protected by the same lock (g_dl_mutex) as
the rest of the linker's state.)

Bug: http://b/150372650
Test: bionic-unit-tests
Change-Id: Iafd12e5ab36ae61f0642aad59939f528d31bda16
2020-04-20 17:59:43 -07:00
Ryan Prichard
df3dc8039d Merge changes Ia359d9f2,Ibabbf559,I1b542e47,I4b6f48af,I82e442f0
* changes:
  Fix bootstrap linker library searching
  Remove dangling soinfo* from elf_readers_map_
  Fix DL_WARN_documented_change URL
  remove search_linked_namespaces param
  Refactor linker lookup code a bit
2020-03-31 21:02:18 +00:00
Peter Collingbourne
aed48830ac Merge "Switch to debugger_process_info in bionic." 2020-03-30 21:36:41 +00:00
Ryan Prichard
40494406b8 Fix bootstrap linker library searching
For the bootstrap linker, insert /system/${LIB}/bootstrap in front of
/system/${LIB} in any namespace search path.

Bug: http://b/152572170
Test: bionic unit tests
Change-Id: Ia359d9f2063f4b6fff3f79b51b500ba968a18247
2020-03-27 18:46:28 -07:00
Ryan Prichard
4fa6d9978a Remove dangling soinfo* from elf_readers_map_
If ElfReader::Read fails, then it is hazardous to leave the invalid
ElfReader in the soinfo*->ElfReader table, because a future soinfo
object could happen to have the same address, then reuse the invalid
ElfReader. I'm not sure whether this can break anything, because the
linker would call ElfReader::Read on the invalid object and overwrite
its previous value.

Test: bionic unit tests
Bug: none
Change-Id: Ibabbf559443441b9caeacc34ca165feaafe5e3a7
2020-03-27 18:46:28 -07:00
Ryan Prichard
146620b644 Fix DL_WARN_documented_change URL
The doc_link argument is really a URL fragment within the
android-changes-for-ndk-developers.md document, not a filename at the
root of the bionic repository.

Test: manual
Bug: none
Change-Id: I1b542e47aca132ce43ba1d50d83db1bf3c7b10c6
2020-03-27 18:46:28 -07:00
Ryan Prichard
323d7dfe90 remove search_linked_namespaces param
The search_linked_namespaces parameter to find_library_internal is
always true.

Bug: none
Test: bionic tests
Change-Id: I4b6f48afefca4f52b34ca2c9e0f4335fa895ff34
2020-03-27 18:46:28 -07:00
Ryan Prichard
aa2db969dc Refactor linker lookup code a bit
Add a few _Nonnull / _Nullable annotations. Clang may use them to issue
warnings but violating the annotation isn't undefined behavior.

Bug: none
Test: bionic tests
Change-Id: I82e442f06a2c59c69bc0008f0f686785695cdd02
2020-03-27 18:46:28 -07:00
Treehugger Robot
2a069b24df Merge "Revert "Statically link libdl.a to linker"" 2020-03-18 16:05:54 +00:00
Jooyung Han
274e21fdb6 Revert "Statically link libdl.a to linker"
This reverts commit 8dba7fefb0.

Reason for revert: This workaround is not necessary with ag/10700799

Merged-In: I2bf469bfe00f3a70e67085abfb3822db6908d522
Change-Id: If351aedfce23d60582f0c5ff965f94356d1900d9
Bug: 150860940
2020-03-18 08:45:25 +00:00
Peter Collingbourne
de9c34601a Switch to debugger_process_info in bionic.
Bug: 135772972
Change-Id: I2b4eae107fc7f62a5ad7ead3a8cfa26e444532d4
2020-03-17 14:35:09 -07:00
Kiyoung Kim
8bc0353dbc Update linkerconfig missing message to warning
Update message that generated linker configuration is missing to from
into to warning again. Also do not raise this message from host
environment which is expected.

Bug: 146386369
Test: m -j passed
Change-Id: Ia5c2969d77fbc70e0406fbb449920080989a1ea8
2020-03-17 09:52:55 +09:00
Jiyong Park
8dba7fefb0 Statically link libdl.a to linker
When libbase is built for an APEX, it uses dlsym to reflectively access
liblog symbols that are added in R. This is because the APEX where
libbasse is packaged into might be running in pre-R devices where the
symbols don't exist in liblog.so.

This however causes a problem for a static executable in an APEX. Since
it is in an APEX, the dlsym is used. But libdl.so which provides dlsym
is not available to static executable. Currently, the dynamic linker is
the only executable in an APEX that all of its dependencies are
statically linked. Fixing the issue by providing fake dlsym by
statically linking to libdl.a.

Exempt-From-Owner-Approval: cherry-pick rvc-dev

Bug: 149569129
Test: m

Merged-In: I2e9e45d9876c2d6c878e541715389e6d1ef56996
(cherry picked from commit ec829ed4ea)
Change-Id: I2e9e45d9876c2d6c878e541715389e6d1ef56996
2020-03-11 07:53:47 +00:00
Treehugger Robot
ae35f675bb Merge "Delete definitions of __aeabi_unwind_cpp_pr0." 2020-03-10 18:30:30 +00:00
Chih-Hung Hsieh
fa658eb094 Fix bugprone-macro-parentheses warnings
Bug: 150783705
Test: WITH_TIDY=1 make
Change-Id: If47b7adaa5f3ba3c518fb0be48f0ffdc81d204b2
2020-03-04 13:22:05 -08:00
Mitch Phillips
4c9293f29a [GWP-ASan] Export GWP-ASan regions to libdebuggerd.
Exports GWP-ASan allocator information callbacks to libdebuggerd so that
tombstoned can get information from the GWP-ASan allocator in the case
of a crash.

Bug: 135634846
Test: atest bionic-unit-tests

Change-Id: Ie16426af55602fb2a76c4e69217773354c365843
2020-02-19 09:01:27 -08:00
Kiyoung Kim
47ddeb1ae4 Merge "Deprecate sys.linker.use_generated_config property" 2020-02-18 00:52:59 +00:00
Kiyoung Kim
1878690fdd Deprecate sys.linker.use_generated_config property
sys.linker.use_generated_config property was introduced at the beginning
of linkerconfig development to skip this generated configuration if it
does not work properly during dev. However, linkerconfig development is
now completed and is working properly from most of devices, so this
property is no longer in use. Therefore deprecating this property as
this would not be used.

Bug: 149335054
Test: m -j passed
Test: No linking error from Cuttlefish and Crosshatch
Change-Id: I0a1b3f36b69872862196b1613718a75d482e0a92
2020-02-15 04:35:37 +09:00
Ivan Lozano
c65b55cded Merge "Remove XOM properties." 2020-02-14 14:42:49 +00:00
Elliott Hughes
14798930ec Remove unused mips/mips64 code from the linker.
Test: treehugger
Change-Id: I42f1e4c492ac644cf78e7c1196ba9b3518f9c8f8
2020-02-13 15:58:48 -08:00
Ivan Lozano
3e928edc77 Remove XOM properties.
XOM is no longer supported by the build system, so remove these
properties.

Bug: 123034666
Bug: 147300048
Test: Build succeeds.
Change-Id: I77efc98241f45b1a78b1cca5560f64eef5ef22f4
2020-02-13 14:20:44 -05:00
Roland Levillain
57e6b8612a Adjust the documentation of get_ld_config_file_apex_path.
Test: n/a
Bug: 147987608
Change-Id: I479a63a2fa7e0975db80fcfdda78d2ee154c53cb
2020-02-12 17:34:20 +00:00
Kiyoung Kim
a399ede44e Merge "Use generated linker config for APEX binaries" 2020-02-07 03:25:42 +00:00
Ryan Prichard
22fa3dde07 Ignore symbols of imported libs' dependencies
When a library is present in a namespace via the secondary_namespaces
list (i.e. the executable, LD_PRELOAD, DF_1_GLOBAL, or
android_create_namespace inheritance), then we want to search that
library's symbols, but not the symbols of its dependencies. Otherwise,
we want to search the dependencies to handle cross-NS dependency.

Bug: http://b/148569846
Test: bionic unit tests
Change-Id: If798d69de28ed5c0f1a155e4ff85c7e08934e531
2020-02-03 14:20:40 -08:00
Kiyoung Kim
fb58744f6b Use generated linker config for APEX binaries
LinkerConfig will start to generate linker configuration for APEX
binaries. Linker should check if this generated file exists first, and
use it if exists and otherwise use ld.config.txt under APEX etc.

Bug: 147987608
Test: m -j passed
Test: Tested with adbd and SWCodec from Cuttlefish and Crosshatch
Change-Id: I5a0c28ee1a427adface3e67c8af062e1b2ef6197
2020-02-03 10:27:56 +09:00
Ryan Prichard
e503383c92 Comment two linker namespace functions
Test: it builds
Change-Id: I4dee0d4da230bd559319317b504e2c597f814f50
2020-01-31 14:48:35 -08:00
Ryan Prichard
272458ee9f Rename dlsym_handle_lookup:6 to dlsym_handle_lookup_impl
Rearrange a function to remove a forward declaration.

Test: m linker
Change-Id: I014eac3319bd6f4c10f8bba50f8006f96bb33dce
2020-01-31 14:48:19 -08:00
Elliott Hughes
1d8f6f2f5d Merge "Modernize SHT_RELR support." 2020-01-27 18:10:13 +00:00
Elliott Hughes
6663f5525d Modernize SHT_RELR support.
Until now we've only supported RELR with our own OS-private-use
constants. Add support for the official numbers (while maintaining
support for the historical numbers).

Add tests to ensure we continue to support both indefinitely.

We can't yet flip the build system over to using the official constants
because the old GNU binutils objcopy we still use in most cases (for the
mini-debug section) only supports the historical constants.

Bug: http://b/147452927
Test: treehugger
Change-Id: If214fce7fade4316115947e90b78ab40864b61f2
2020-01-24 15:39:01 -08:00
Yifan Hong
29546b9133 Merge "Make ramdisk_available." 2020-01-24 22:39:41 +00:00
Ryan Prichard
928c2492a3 Remove an unused code path
A static analyzer is complaining that num_valid_bits could be 64, and if
it were 64, then two later accesses would be out-of-bounds. is_nul_u64
can't be zero, though, because we only exit the loop when part of is_nul
is non-zero.

Bug: none
Test: manual
Change-Id: I75c3f70b600aa5478cb32fdf4ca0ae1173b69524
2020-01-22 13:59:15 -08:00
Yifan Hong
5a39cee1ce Make ramdisk_available.
Test: pass
Bug: 147347110
Change-Id: I142311a7558a19d209bcd63207a88e12cf6f130e
2020-01-22 12:09:33 -08:00
Peter Collingbourne
39d9156bdc Merge "Export the unwinder implementation from libc." 2020-01-21 21:28:44 +00:00
Ryan Prichard
0bf9aed92e Merge "Neon-optimized version of the GNU symbol calculation" 2020-01-17 20:48:14 +00:00
Ryan Prichard
4f140695d9 Restore handling of R_GENERIC_NONE relocations
Previously, the linker was ignoring the symbol of the R_GENERIC_NONE
relocation, so continue ignoring it. This is a little unfortunate because
it requires adding an extra condition on the fast path for relocation
handling.

I tried benchmarking this change, and I can't tell whether it has no
effect or is a regression of up to 1%. It might be possible to refactor
this code (e.g. do the lookup anyway, but avoid reporting an error), or by
changing the linker behavior, but this simple change gets the linker
working again.

Bug: http://b/147719203
Test: verify that the broken app works again
Change-Id: I7589b65705fec522d5fbadc05136dd5489833aea
2020-01-15 15:19:17 -08:00
Ryan Prichard
129f7a1d8e Neon-optimized version of the GNU symbol calculation
On 64-bit walleye, improves the linker relocation benchmark from 71.9ms to
70.7ms (1.7% of the run-time).

On a 32-bit device, it improves the linker relocation benchmark from
205.5ms to 201.2ms (2.1% of the run-time).

$ adb shell taskset 10 /data/benchmarktest64/linker-benchmarks/linker-benchmarks --benchmark_repetitions=100 --benchmark_display_aggregates_only
--------------------------------------------------------------------
Benchmark                          Time             CPU   Iterations
--------------------------------------------------------------------
BM_gnu_hash_simple_mean        15232 ns        15212 ns          100
BM_gnu_hash_simple_median      15176 ns        15159 ns          100
BM_gnu_hash_simple_stddev        111 ns          110 ns          100
BM_gnu_hash_neon_mean          10265 ns        10252 ns          100
BM_gnu_hash_neon_median        10261 ns        10249 ns          100
BM_gnu_hash_neon_stddev         28.1 ns         23.9 ns          100

Bug: none
Test: linker-unit-tests
Test: linker-benchmarks
Change-Id: I3983bca1dddc9241bb70290ad3651d895f046660
2020-01-13 13:29:25 -08:00
Ryan Prichard
339ecef22d Optimize GNU hash linking for large inputs
Symbol lookup is O(L) where L is the number of libraries to search (e.g.
in the global and local lookup groups). Factor out the per-DSO work into
soinfo_do_lookup_impl, and optimize for the situation where all the DSOs
are using DT_GNU_HASH (rather than SysV hashes).

To load a set of libraries, the loader first constructs an auxiliary list
of libraries (SymbolLookupList, containing SymbolLookupLib objects). The
SymbolLookupList is reused for each DSO in a load group. (-Bsymbolic is
accommodated by modifying the SymbolLookupLib at the front of the list.)
To search for a symbol, soinfo_do_lookup_impl has a small loop that first
scans a vector of GNU bloom filters looking for a possible match.

There was a slight improvement from templatizing soinfo_do_lookup_impl
and skipping the does-this-DSO-lack-GNU-hash check.

Rewrite the relocation processing loop to be faster. There are specialized
functions that handle the expected relocation types in normal relocation
sections and in PLT relocation sections.

This CL can reduce the initial link time of large programs by around
40-50% (e.g. audioserver, cameraserver, etc). On the linker relocation
benchmark (64-bit walleye), it reduces the time from 131.6ms to 71.9ms.

Bug: http://b/143577578 (incidentally fixed by this CL)
Test: bionic-unit-tests
Change-Id: If40a42fb6ff566570f7280b71d58f7fa290b9343
2020-01-13 13:29:25 -08:00
Peter Collingbourne
f2b1e03606 Export the unwinder implementation from libc.
This supports the soong commit which causes most platform binaries to stop
statically linking against the unwinder implementation. The soong commit
message has more motivation for this change.

ARM32 uses LLVM libunwind, while all other platforms use libgcc as the
unwinder implementation. This matches the current choices of unwinders on
the various architectures, but means that apps which were directly linking
against the libc.so unwinder symbols on ARM32 are now using LLVM libunwind
instead of libgcc.

Set libc_headers sdk_version to 1 so that libunwind_llvm can depend on it,
and stop statically linking libunwind into libc_malloc_debug.

Bug: 144430859
Change-Id: I52c7f7893d93f500383aeb0b76086c3b6f1935a5
2020-01-10 19:07:59 -08:00
Ryan Prichard
a04764bd28 Merge changes I578d36a1,Id17508ab,I385f312b
* changes:
  Create linker_log[_va_list] functions
  Validate defined versions in prelink_image
  Prelink each library only once
2020-01-10 22:21:15 +00:00
Peter Collingbourne
27c1e22036 Delete definitions of __aeabi_unwind_cpp_pr0.
These are no longer necessary now that LLVM no longer emits references to
this symbol on Android.

Bug: 144430859
Change-Id: I6c43338f755ce5a79e2df36bd3f2006a748fab27
2020-01-10 10:40:43 -08:00
Ryan Prichard
cec75e3303 Merge "Do not add duplicate soinfos to g_default_namespace" 2020-01-07 20:18:14 +00:00
Ryan Prichard
551565e87c Create linker_log[_va_list] functions
A later linker CL defines a function that needs to forward a printf format
and argument list to TRACE(), but there is no version of the TRACE macro
that works with a va_list. The CL also needs to check the verbosity level,
using a slow path if tracing is enabled, so define LINKER_VERBOSITY_xxx
macros.

Bug: none
Test: bionic unit tests
Change-Id: I578d36a12dc40f9a651956b4b09adc1a7c644e24
2020-01-06 16:06:37 -08:00
Ryan Prichard
0e12ccedd4 Validate defined versions in prelink_image
Validate the list of defined versions explicitly, during library
prelinking, rather than implicitly as part of constructing the
VersionTracker in soinfo::link_image.

Doing the validation upfront allows removing the symbol lookup failure
code paths, which only happen on a library with invalid version
information.

Helps on the walleye 64-bit linker relocation benchmark (146.2ms ->
131.6ms)

Bug: none
Test: bionic unit tests
Change-Id: Id17508aba3af2863909f0526897c4277419322b7
2020-01-06 16:06:37 -08:00
Ryan Prichard
ae320cde07 Prelink each library only once
Previously, during a find_libraries call that loaded a library, a
library was prelinked once for each DT_NEEDED reference to the library.

This CL has a negligible effect on the linker relocation benchmark
(146.9ms -> 146.2ms).

Bug: none
Test: bionic unit tests
Change-Id: I385f312b8acf8d35aa0af9722131fe367b5edd9b
2020-01-02 17:40:32 -08:00
NIEJuhu
e2871bd0d8 Do not add duplicate soinfos to g_default_namespace
The soinfo instances of linker and vdso have been added to g_default_namespace
before init_default_namespace() is called. So init_default_namespace() don't
have to add them a second time.

Test: manual
Change-Id: I29b3da782b1e9445509f45a7698561fc3e19e9a1
2019-12-27 11:32:29 +08:00
Elliott Hughes
5e2ac29165 Merge "Stop using the __ANDROID_API_x__ constants." 2019-12-23 03:26:37 +00:00
Elliott Hughes
95c6cd753f Stop using the __ANDROID_API_x__ constants.
Historically we've made a few mistakes where they haven't matched the
right number. And most non-Googlers are much more familiar with the
numbers, so it seems to make sense to rely more on them. Especially in
header files, which we actually expect real people to have to read from
time to time.

Test: treehugger
Change-Id: I0d4a97454ee108de1d32f21df285315c5488d886
2019-12-20 13:26:14 -08:00
Elliott Hughes
fa8774462f Make the linker NOTICE file match the linker source.
Test: eyeball
Change-Id: I3e10bd813eff5cc05fc9c4f50a75777b82df9a5c
2019-12-20 12:29:39 -08:00
Kiyoung Kim
19f95dd872 Do not DL_WARN when failed to find generated linker config
DL_WARN message when failed to find generated linker config makes some
of the ART tests fail. Lowering log level as ART test does not have
linkerconfig generated for the test.

Bug: 146386369
Test: Cuttlefish boot succeeded without any error
Test: run_build_test_target.py art-linux-bionic-x64-zipapex passed
Change-Id: I4f876c3ac5c30d32d51346d4cd16b5205da8f1bf
2019-12-17 13:59:57 +09:00
Evgeny Eltsin
ff43ec0147 Prefer arch-specific linker config when available
New linker configuration from /linkerconfig is not suitbale for emulated
architectures. But as of now, native_bridge linkers pick it up as well
and thus fail to find the libraries for emulated architectures.

This is a (temporary) fix so native_bridge linker still picks up
configuration from old location.

Bug: 138920271
Test: native_bridge linker works
Change-Id: I0abbd3e95f9e6830385b0f19db0688e6183030b9
2019-12-16 19:22:07 +01:00
Kiyoung Kim
838ca10715 Merge "Enable linker configuration from generator by default" 2019-12-16 01:55:44 +00:00
Kiyoung Kim
ef04c80bf6 Enable linker configuration from generator by default
Current linker configuration is only enabled from fully treblelized
devices. This change will allow linker to first check generated linker
configuration even for non-treblelized devices and recovery.

Bug: 139638519
Test: Tested from cuttlefish
Change-Id: I655b1ab807cd8db5696d07fd2bdd00ce0558901d
2019-12-13 13:59:00 +09:00
Elliott Hughes
cdb52fc147 Make private/bionic_page.h available as platform/bionic/page.h.
Bug: http://b/145825270
Test: treehugger
Change-Id: I52958f370c0df2c02cb8250e2cf0705d4e93e908
2019-12-12 15:26:14 -08:00
Kiyoung Kim
1a2460d19c Move linker config under /linkerconfig
Due to some special environment, linker config should not be located
under /dev partition. It would be better to relocate linker config under
new root dir /linkerconfig.

Bug: 144966380
Test: m -j && tested from cuttlefish
Change-Id: Icda1d2ef34b42159c6ebce58b03211cc13f08121
2019-12-05 12:49:22 +09:00
Ryan Prichard
4d4087dc95 Replace LIB_PATH macro with kLibPath
The string is still "lib" or "lib64" with native bridge. It doesn't need
to be configured in the Android.bp file anymore, so move it to a header
file. This change will ensure that ${LIB} expands to the same thing in
both ld.config.txt and DT_RUN_PATH.

Bug: http://b/145197367
Test: manual
Change-Id: Iab87f3156f2984dd3a20e4ccda423892c8b58763
Merged-In: Iab87f3156f2984dd3a20e4ccda423892c8b58763
2019-12-04 13:31:56 -08:00
Treehugger Robot
28fb781ef7 Merge "linker: add more context to link failure error." 2019-11-09 00:13:31 +00:00
Ryan Prichard
94a8e859ed linker: avoid -O0 memset while clearing temp_tcb
With -O0, on arm64, Clang uses memset for this declaration:

    bionic_tcb temp_tcb = {};

arm64 doesn't currently have an ifunc for memset, but if it did, then this
line would crash when the linker is compiled with -O0. It looks like other
architectures would only use a memset call if the bionic_tcb struct were
larger.

Avoid memset by using a custom memclr function that the compiler optimizes
into something efficient.

Also add __attribute__((uninitialized)) to ensure that
-ftrivial-auto-var-init does not generate a call to memset. See this
change[1] in build/soong.

[1] If085ec53c619e2cebc86ca23f7039298160d99ae

Test: build linker with -O0, linker[64] --help works
Bug: none
Change-Id: I0df8065a362646de4fa021cae63a7d68ca3966b6
2019-11-05 14:56:09 -08:00
Josh Gao
1626957666 linker: add more context to link failure error.
This change makes it easier to diagnose mistakes in linker
configuration that result in a library being accidentally loaded in
multiple namespaces without its dependencies available everywhere.

Test: manually tested the error message
Test: bionic-unit-tests
Change-Id: I03a20507f8fc902c2445a7fbbf59767ffffd5ebf
2019-11-05 13:45:54 -08:00
Ryan Prichard
249757bae2 Use ifuncs in the linker
Using ifuncs allows the linker to select faster versions of libc functions
like strcmp, making linking faster.

The linker continues to first initialize TLS, then call the ifunc
resolvers. There are small amounts of code in Bionic that need to avoid
calling functions selected using ifuncs (generally string.h APIs). I've
tried to compile those pieces with -ffreestanding. Maybe it's unnecessary,
but maybe it could help avoid compiler-inserted memset calls, and maybe
it will be useful later on.

The ifuncs are called in a special early pass using special
__rel[a]_iplt_start / __rel[a]_iplt_end symbols. The linker will encounter
the ifuncs again as R_*_IRELATIVE dynamic relocations, so they're skipped
on the second pass.

Break linker_main.cpp into its own liblinker_main library so it can be
compiled with -ffreestanding.

On walleye, this change fixes a recent 2.3% linker64 start-up time
regression (156.6ms -> 160.2ms), but it also helps the 32-bit time by
about 1.9% on the same benchmark. I'm measuring the run-time using a
synthetic benchmark based on loading libandroid_servers.so.

Test: bionic unit tests, manual benchmarking
Bug: none
Merged-In: Ieb9446c2df13a66fc0d377596756becad0af6995
Change-Id: Ieb9446c2df13a66fc0d377596756becad0af6995
(cherry picked from commit 772bcbb0c2)
2019-11-05 13:37:51 -08:00
Ryan Prichard
80e40f01c8 Refactor linker/Android.bp for native-bridge
Define a "linker_bin_template" cc_defaults module that a native bridge
implementation can inherit to define a guest linker.

Break the debuggerd_init call off into separate
linker_debuggerd_{android,stub}.cpp files to allow opting in/out of the
debuggerd integration without needing to change how linker_main.cpp is
compiled. (This is necessary for a later commit that moves
linker_main.cpp into a new static library.)

Test: bionic unit tests
Bug: none
Merged-In: I7c5d79281bce1e69817b266dd91d43ea40f78522
Change-Id: I7c5d79281bce1e69817b266dd91d43ea40f78522
(cherry picked from commit 5adf402ee9)
2019-11-05 13:37:29 -08:00
Jooyung Han
dd2ed97079 Merge "Add linker config variable: VNDK_APEX_VER" 2019-10-31 00:42:35 +00:00
Ryan Prichard
859202c8e5 Merge "linker: remove COUNT_PAGES" 2019-10-30 20:49:07 +00:00
Treehugger Robot
6f9a97f864 Merge "Revert "Load /dev/linker/ld.config.txt by default"" 2019-10-29 21:15:57 +00:00
Roland Levillain
09bde95f3b Revert "Load /dev/linker/ld.config.txt by default"
This reverts commit 61a97e9505.

Reason for revert: Breaks ART run-tests (b/143458513).

Test: Run ART tests on device in a chroot environment
Bug: 143458513
Bug: 139638519
Change-Id: Ib047a24d6e82e38ebdaafeab294b8be44b74bd9c
2019-10-29 19:39:49 +00:00
Peter Collingbourne
e949195f64 Adopt GNU calling convention for ifunc resolvers.
In order for an ifunc resolver to detect the presence of certain CPU features,
access to getauxval(AT_HWCAP) or getauxval(AT_HWCAP2) may be required. In order
for getauxval() to work, it needs to access the pointer to the auxiliary vector
stored by the linker in the libc shared globals data structure. Accessing the
shared globals requires libc to call the __libc_shared_globals() function
exported by the linker. However, in order to call this function, libc must
be fully relocated, which is not guaranteed to be the case at the point when
ifunc resolvers are called.

glibc solves this problem by passing the values of getauxval(AT_HWCAP)
(and getauxval(AT_HWCAP2) on aarch64) as arguments to the ifunc resolver.
Since this seems to be not only the most straightforward way to solve the
problem but also improves our compatibility with glibc, we adopt their
calling convention.

This change is ABI compatible with old resolvers because the arguments are
passed in registers, so the old resolvers will simply ignore the new arguments.

Bug: 135772972
Change-Id: Ie65bd6e7067f0c878df3d348c815fda61dc12de2
2019-10-28 20:20:29 -07:00
Jooyung Han
09283992ca Add linker config variable: VNDK_APEX_VER
With VNDK APEX, the path for VNDK libs has been changed
from /system/lib/vndk-VER to /apex/com.android.vndk.vVER/lib

In most cases, vndk version can be substituted when generating
ld.config.txt by linkerconfig.

But, ld.config.txt files in APEX packages still rely on runtime substitution.
Specifically, com.android.media.swcodec is using VNDK_VER variable.
Moreover, it cannot migrate to a new location since it should run on
older version of system due to APEX requirements.

For backward compatibility, instead of changing the value of old
variable, a new variable is added.

- VNDK_VER : "-" prefixed vndk version, used for older path
            (e.g. /system/lib/vndk-sp-29)
- VNDK_APEX_VER : "v" prefixed vndk versions.
            (e.g. /apex/com.android.vndk.v29/lib)

Test: add a vendor binary to /apex/com.android.media.swcodec/bin
      which opens /system/lib/vndk-sp{VNDK_VER}/hw/android.hidl.memory@1.0-impl.so
      via android_load_sphal_library()
Bug: 142912195

Change-Id: I3dfb3c1068cff00d5b63e92d51da6c4af00d264e
2019-10-29 05:47:03 +09:00
Ryan Prichard
78cd283480 linker: remove COUNT_PAGES
COUNT_PAGES tries to count the pages dirtied by relocations, but this
implementation is broken because it's merging rel->r_offset values from
multiple DSOs. The functionality is hard to use, because it requires
rebuilding the linker, and it's not obvious to me that it should belong
in the linker. If we do want it, we should make it work without rebuilding
the linker.

Similar information can currently be collected by parsing the result of
`readelf -r` on a binary (or a set of binaries).

Bug: none
Test: m linker libc com.android.runtime ; adb sync ; run something
Change-Id: I760fb6ea4ea3d1927eb5145cdf4ca133851d69b4
2019-10-25 17:46:43 -07:00
Kiyoung Kim
61a97e9505 Load /dev/linker/ld.config.txt by default
Linker config generator now covers ld.config.txt for Legacy and
VNDK-Lite devices, so linker can use those instead of existing ones
under /system/etc

Bug: 139638519
Test: m -j passed
Change-Id: I90f14727148cbf9629b90dc4fd78362bed8ea4e4
2019-10-24 19:23:25 +09:00
Ryan Prichard
9da992c271 Merge changes Ia0c0018c,I2f1fc8b4,Ibe964c3b,I791da8ac
* changes:
  linker: stop relocating R_ARM_REL32
  Factor out R_GENERIC_COPY
  Factor out R_GENERIC_ABSOLUTE
  Remove broken arm64 PREL/ABS relocations
2019-10-19 00:05:29 +00:00
Ryan Prichard
495863f921 linker: stop relocating R_ARM_REL32
This relocation is labeled as a static relocation in the ARM ELF ABI and
shouldn't appear in position-independent code.

It currently calculates the value to relocate incorrectly:

   "sym_addr - rel->r_offset" should be "sym_addr - reloc"

I don't know of any other dynamic linker that handles this relocation.

Test: bionic unit tests
Bug: http://b/19197129
Change-Id: Ia0c0018c82fe98d5edb54ee6f5c9f402b1fa3076
2019-10-18 12:44:01 -07:00