Commit graph

20 commits

Author SHA1 Message Date
Ryan Prichard
cf9ed12d10 Use PT_INTERP as the linker's l_name path
Ordinary executables have a PT_INTERP path of /system/bin/linker[64], but:
 - executables using bootstrap Bionic use /system/bin/bootstrap/linker[64]
 - ASAN executables use /system/bin/linker_asan[64]

gdb appears to use the PT_INTERP path for debugging the dynamic linker
before the linker has initialized the r_debug module list. If the linker's
l_name differs from PT_INTERP, then gdb assumes that the linker has been
unloaded and searches for a new solib using the linker's l_name path.

gdb may print a warning like:

warning: Temporarily disabling breakpoints for unloaded shared library "$OUT/symbols/system/bin/linker64"

If I'm currently debugging the linker when this happens, gdb apparently
doesn't load debug symbols for the linker. This can be worked around with
gdb's "sharedlibrary" command, but it's better to avoid it.

Previously, when PT_INTERP was the bootstrap linker, but l_name was
"/system/bin/linker[64]", gdb would find the default non-bootstrap linker
binary and (presumably) get confused about symbol addresses.

(Also, remove the "static std::string exe_path" variable because the
soinfo::realpath_ field is a std::string that already lasts until exit. We
already use it for link_map_head.l_name in notify_gdb_of_load.)

Bug: http://b/134183407
Test: manual
Change-Id: I9a95425a3a5e9fd01e9dd272273c6ed3667dbb9a
2019-06-05 18:02:40 -07:00
Elliott Hughes
90f96b9f48 linker: support ldd(1)-like behavior via --list.
Given that we have both linker and linker64, I didn't really want to have
to have ldd and ldd64, so this change just adds the --list option to the
linkers and a shell script wrapper "ldd" that calls the appropriate
linker behind the scenes.

Test: adb shell linker --list `which app_process32`
Test: adb shell linker64 --list `which date`
Test: adb shell ldd `which app_process32`
Test: adb shell ldd `which date`
Change-Id: I33494bda1cc3cafee54e091f97c0f2ae52d1f74b
2019-05-09 22:12:17 -07:00
Ryan Prichard
e4d620bc80 Fix dlsym and dladdr for TLS symbols
* dlsym: call __tls_get_addr for TLS symbols

 * dladdr: skip TLS symbols

Bug: b/123772574
Test: bionic unit tests
Change-Id: I59a8bc4a7d455e1018b0d577b027b6417c8487cd
2019-04-03 18:19:50 -07:00
Jiyong Park
57b9d1e6c0 support LIB in runpath
In addition to ORIGIN, LIB is now expanded to either lib or lib64
depending on the ABI in the DT_RUNPATH.

Test: To be added (can't be added to AOSP directly since there are
internal tests that have to be updated as well)

Change-Id: I34a8316f1765a27c731bc270ee25c0ce287d7eed
2019-01-24 17:00:37 +09:00
Ryan Prichard
e5e69e0912 Record TLS modules and layout static TLS memory
Bug: http://b/78026329
Test: bionic unit tests
Change-Id: Ibf1bf5ec864c7830e4cd1cb882842b644e6182ae
2019-01-16 16:52:47 -08:00
Tom Cherry
c7cbef4f2d Merge "linker: changes to init work arounds" 2018-11-29 16:50:37 +00:00
Elliott Hughes
ff1428a48e Move API levels from uint32_t to int.
(cherrypick of a6c71a09670ca636cca5cfea9d74b03a951e2b5e.)

Bug: N/A
Test: builds
Change-Id: I9c414e30e3c4fe2a4e16a2fe4ce18eae85fe4844
2018-11-13 21:25:07 -08:00
Tom Cherry
66bc428f93 linker: changes to init work arounds
Change three things regarding the work around to the fact that init is
special:

1) Only first stage init is special, so we change the check to include
   accessing /proc/self/exe, which if is available, means that we're
   not first stage init and do not need any work arounds.
2) Fix the fact that /init may be a symlink and may need readlink()
3) Suppress errors from realpath_fd() since these are expected to fail
   due to /proc not being mounted.

Bug: 80395578
Test: sailfish boots without the audit generated from calling stat()
      on /init and without the errors from realpath_fd()

Change-Id: I266f1486b142cb9a41ec791eba74122bdf38cf12
2018-11-08 21:50:19 +00:00
Jiyong Park
31cd08f9eb dynamic linker is running for init
init is now built as a dynamic executable, so the dynamic linker has to
be able to run in the init process. However, since init is launched so
early, even /dev/* and /proc/* file systems are not mounted and thus
some APIs that rely on the paths do not work. The dynamic linker now
goes alternative path when it is running in the init process.

For example, /proc/self/exe is not read for the init since we always now
the path of the init (/init). Also, arc4random* APIs are not used since
the APIs rely on /dev/urandom. Linker now does not randomize library
loading order and addresses when running in the init process.

Bug: 80454183
Test: `adb reboot recovery; adb devices` shows the device ID
Change-Id: I29b6d70e4df5f7f690876126d5fe81258c1d3115
2018-06-08 14:50:14 +09:00
dimitry
55547db434 Add secondary counter in place of tls_nodelete flag
The tls_nodelete state should apply to load_group not
isolated soinfo. This actually also means that multiple
soinfos may have tls_counter on their dso_handles.

This change replaces TLS_NODELETE flag with secondary counter.
Note that access to the secondary counter (located inside soinfo)
is pretty expensive because it requires soinfo lookup by dso_handle
whereas dso_handle counter is much faster. This is why it is updated
only when dso_handle counter starts or hits 0.

Bug: http://b/80278285
Test: bionic-unit-tests --gtest_filter=dl*
Change-Id: I535583f6714e45fa2a7eaf7bb3126da20ee7cba9
2018-05-30 10:56:59 +02:00
Elliott Hughes
9076b0c4e7 Be clearer about linker warnings.
Explicitly say "warning" for warnings, explicitly say what action
we're going to take (such as "(ignoring)"), always provide a link to
our documentation when there is one, explicitly say what API level the
behavior changes at, and explicitly say why we're allowing the misbehavior
for now.

Bug: http://b/71852862
Test: ran tests, looked at logcat
Change-Id: I1795a5af45deb904332b866d7d666690dae4340b
2018-02-28 12:37:28 -08:00
dimitry
06016f226e Fix dlclose for libraries with thread_local dtors
Introduce new flag to mark soinfo as TLS_NODELETE when
there are thread_local dtors associated with dso_handle
belonging to it.

Test: bionic-unit-tests --gtest_filter=dl*
Test: bionic-unit-tests-glibc --gtest_filter=dl*
Bug: https://github.com/android-ndk/ndk/issues/360
Change-Id: I724ef89fc899788f95c47e6372c38b3313f18fed
2018-01-10 10:24:06 +01:00
dimitry
965d06da1e Fix logic in loading dependencies crossing namespace boundaries
This change addresses multiple problems introduced by
02586a2a34

1. In the case of unsuccessful dlopen the failure guard is triggered
for two namespaces which leads to double unload.

2. In the case where load_tasks includes libraries from 3 and more
namespaces it results in incorrect linking of libraries shared between
second and third/forth and so on namespaces.

The root cause of these problems was recursive call to find_libraries.
It does not do what it is expected to do. It does not form new load_tasks
list and immediately jumps to linking local_group. Not only this skips
reference counting it also will include unlinked but accessible library
from third (and fourth and fifth) namespaces in invalid local group. The
best case scenario here is that for 3 or more namesapces this will
fail to link. The worse case scenario it will link the library
incorrectly with will lead to very hard to catch bugs.

This change removes recursive call and replaces it with explicit list of
local_groups which should be linked. It also revisits the way we do
reference counting - with this change the reference counts are updated after
after libraries are successfully loaded.

Also update soinfo_free to abort in case when linker tries to free same
soinfo for the second time - this makes linker behavior less undefined.

Test: bionic-unit-tests
Bug: http://b/69787209
Change-Id: Iea25ced181a98c6503cce6e2b832c91d697342d5
2017-12-10 22:04:55 +01:00
Christopher Ferris
7a3681e5b6 Move libc_log code into libasync_safe.
This library is used by a number of different libraries in the system.
Make it easy for platform libraries to use this library and create
an actual exported include file.

Change the names of the functions to reflect the new name of the library.

Run clang_format on the async_safe_log.cpp file since the formatting is
all over the place.

Bug: 31919199

Test: Compiled for angler/bullhead, and booted.
Test: Ran bionic unit tests.
Test: Ran the malloc debug tests.
Change-Id: I8071bf690c17b0ea3bc8dc5749cdd5b6ad58478a
2017-05-03 08:50:43 -07:00
Dimitry Ivanov
6705e8caf5 Add systrace output for dlclose/dlsym calls
Bug: http://b/27195126
Test: manual: adb shell atrace -t 5 bionic
      and run bionic-unit-tests --gtest_filter=dl*

Change-Id: I9e93a069dd440bb643890d9952913938442ac375
2017-03-21 10:38:23 -07:00
Dimitry Ivanov
5c4a58072f Add systrace output for dlopen calls
Bug: http://b/27195126
Test: manual: adb shell atrace -t 5 bionic
      and run bionic-unit-tests --gtest_filter=dl*:Dl*

Change-Id: Ib2bad794e571b89bd1f52c9e0de642c2092e5c21
2017-03-20 13:34:52 -07:00
Dimitry Ivanov
2a6d9b2543 Extract format_string function.
Extract format_string function and add a test.

Test: run linker-unit-tests
Change-Id: I794a29aaf62e184438ce1a9224b88aa0586c17b5
2017-03-13 16:25:51 -07:00
Dimitry Ivanov
7a34b9d57a Replace public library list with shared lib sonames (part 2/2)
This commit updates interface of libdl.c.

1. android_init_namespaces is replaces with android_init_anonymous_namespace
2. added 2 arguments to android_create_namespace to specify linked namespace
   and the list of shared libraries sonames.
3. symbol lookup does not get past boundary libraries (added check and test for it).

Bug: http://b/26833548
Bug: http://b/21879602
Test: bionic-unit-tests --gtest_filter=dl*:Dl*
Change-Id: I32921da487a02e5bd0d2fc528904d1228394bfb9
2017-02-09 23:26:44 -08:00
Elliott Hughes
5bc78c8bcd Add and use constants for the Android API levels.
Test: bionic tests still pass
Change-Id: If1b619cfc9db1d3f5d91f14f2ace71058dca0c4a
2016-11-16 16:55:42 -08:00
Dimitry Ivanov
48ec288d40 Extract soinfo and globals to separate files.
Move soinfo and globals out of linker.cpp to
separate files.

Breaking up huge linker.cpp into smaller peaces
in order to make it easier to extract part of the
code that belongs to libdl.so and remove parts of
the code that do not belong to linker

(refactoring part 2 of many)

Change-Id: I868417f4b8d2b84d0e8265e354bc7977161497e2
2016-08-08 16:12:53 -07:00