Commit graph

30 commits

Author SHA1 Message Date
Dimitry Ivanov
f45b0e9ede Do not unmap reserved region on dlclose
dlclose used to unmap the part of the reserved region
for ANDROID_DLEXT_RESERVED_ADDRESS that was neccessary
to map PT_LOAD segments. With this change dlclose
replaces mapped PT_LOAD segments with a PROT_NONE,
MAP_ANONYMOUS | MAP_NORESERVE.

Previously caller was unmapping the reserved region after
the failed dlclose which led to race condition when someone
else reused the region freed by dlclose but before the unmap
by the chromium code.

Bug: http://code.google.com/p/chromium/issues/detail?id=568880
Change-Id: I0f5eaa2bf6641f83dde469b631c518482acc59a2
2016-01-20 20:57:47 -08:00
Dmitriy Ivanov
3c5248182e Handling invalid section headers
The linker crashes if native library has invalid section
headers. This change adds boundary checks on target offsets
and generates dlerror instead of crash.

Bug: http://b/25800330
Change-Id: Ibe282029997302b9b557637c3aad064d7d0febc5
2015-11-22 23:25:06 -08:00
Dmitriy Ivanov
4f7a7ad3fe Implement Library Load Order Randomization
Bug: http://b/24047022
Change-Id: I36e05b403bfbaae8542a95147f9114a8b9c8ac0e
2015-10-22 18:26:07 -07:00
Dmitriy Ivanov
cf1cbbe432 refactoring: introduce MappedFileFragment
Change-Id: I97b0c1131711ed0ac13ab33e3357e99e0b6b1a4e
2015-10-22 18:01:56 -07:00
Evgenii Stepanov
d640b225ec A special linker for ASan executables.
Setup a /system/bin/linker_asan as a symlink to "linker".
Read the linker name from PT_INTERP, and if it is linker_asan,
switch default library lookup paths to the ASan set, which
starts with the path to the instrumented libraries
(/data/lib), followed by /system/lib as a fallback.

This ensures that ASan binaries prefer ASan libraries, when
available. This approach is way better then RPATH/RUNPATH and even
better than LD_LIBRARY_PATH:
- RUNPATH is per-DSO, while default paths are global.
- LD_LIBRARY_PATH is overwritten by android_update_LD_LIBRARY_PATH.
- neither RUNPATH nor LD_LIBRARY_PATH appear in
  android_get_LD_LIBRARY_PATH which is used to build java.lang.path.
  Having ASan libraries in java.lang.path is a good thing.

Bug: 22355945
Change-Id: I1d2791fbf5740618f18f71a3ae3d873714669d3f
2015-07-14 16:12:27 -07:00
Dmitriy Ivanov
3f987f5b3e Fix crash when trying to load invalid ELF file.
Bug: http://b/22047255
Bug: http://b/22091640
Change-Id: I6c51cff43287a6ac4b25fa9ce6a6fc3d232fd047
(cherry picked from commit 06700b2b5e)
2015-06-25 20:05:50 -07:00
Dimitry Ivanov
56be6ed9e4 Revert "Remove text-relocation support for lp32"
This reverts commit cb00add1b3.

Bug: 20020312
Bug: 20013628
Change-Id: I8baa3d4b6c7fef50c9e2531257d5b96762099eb3
2015-04-01 21:18:48 +00:00
Dmitriy Ivanov
cb00add1b3 Remove text-relocation support for lp32
Bug: 20013628
Change-Id: Idaf8012f00ee1304d429c3b42f9ebc6b648c55b8
2015-03-31 17:42:45 -07:00
Dmitriy Ivanov
20d89cb5b0 Fix long lines and replace macros with functions.
Change-Id: I4e1cab488d5b2c8e4289da617350a86e72a4ba12
2015-03-31 11:49:25 -07:00
Dmitriy Ivanov
1649e7ee5b Enable -Wold-style-cast warnings for linker
And fix old style casts.

Change-Id: I37e7a3e3fd852528ea76f02d967c7bd8cd5b06c9
2015-01-22 16:33:30 -08:00
Dmitriy Ivanov
07e5bc152d Add file_offset parameter to android_extinfo
Bug: 17762003
Change-Id: I8fb267a3155acef3dba534038cf5d1ef00d7154b
2014-10-06 10:02:34 -07:00
Ningsheng Jian
e93be99da0 Fix gdb could not get shared library list issue
Get dynamic flags from phdr table's correct entry rather the first
entry, so that the following DT_DEBUG entry can be set.

Also fix the undefined reference to LoadTask::deleter issue under gcc
-O0 option.

Bug: 17524778
Change-Id: I9c679af197b034761fb739d6c980e628ff2ab84c
2014-09-26 22:58:57 +00:00
Dmitriy Ivanov
14669a939d Load libraries in breadth-first order
This patch fixes the problem with symbol search order
  for dlsym(RTLD_DEFAULT/RTLD_NEXT, .) by loading libraries
  and ld_preloads in correct order.

Bug: https://code.google.com/p/android/issues/detail?id=74255
Change-Id: If1ba5c807322409faa914e27ecb675e2c4541f0d
Attempt: 2
2014-09-08 13:02:50 -07:00
Dmitriy Ivanov
498eb18b82 Revert "Load libraries in breadth-first order"
This reverts commit a3ad450a2e.

Change-Id: Ia2b838ad2159c643b80c514849582f4b4f4f40e5
2014-09-05 16:27:54 -07:00
Dmitriy Ivanov
a3ad450a2e Load libraries in breadth-first order
This patch fixes the problem with symbol search order
  for dlsym(RTLD_DEFAULT/RTLD_NEXT, .) by loading libraries
  and ld_preloads in correct order.

Bug: https://code.google.com/p/android/issues/detail?id=74255
Change-Id: I4cf84c70dbaabe99310230dfda12385ae5401859
2014-09-03 15:06:14 -07:00
Dmitriy Ivanov
851135bf99 Replace NULL with nullptr
Change-Id: Iad50be617d318ca98883b843229c960ad5b9afa9
2014-08-29 14:13:48 -07:00
Torne (Richard Coles)
183ad9df53 Allow sharing the RELRO section via a file.
Add flags and a file descriptor to android_dlopen_ext() to allow writing
the RELRO section of the loaded library to a file after relocation
processing, and to allow mapping identical pages from the file over the
top of relocated memory in another process. Explicitly comparing the
pages is required in case a page contains a reference to a symbol
defined in another library loaded at a random base address.

Bug: 13005501
Change-Id: Ibb5b2d384edfaa5acf3e97a5f8b6115c10497a1e
2014-04-17 14:30:46 +01:00
Torne (Richard Coles)
12bbb91645 Support loading libraries to a reserved address.
Add flags and parameters to android_dlopen_ext() to allow loading a
library at an already-reserved fixed address. If the library to be
loaded will not fit within the space reserved, then the linker will
either fail, or allocate its own address space as usual, according to
which flag has been specified. This behaviour only applies to the
specific library requested; any other libraries loaded as dependencies
will be loaded in the normal fashion.

There is a new gtest included to cover the functionality added.

Bug: 13005501
Change-Id: I5d1810375b20fc51ba6a9b3191a25f9792c687f1
2014-04-17 14:22:17 +01:00
Elliott Hughes
0266ae5f88 Switch <elf.h> over to linux uapi under the covers.
Remove the linker's reliance on BSD cruft and use the glibc-style
ElfW macro. (Other code too, but the linker contains the majority
of the code that needs to work for Elf32 and Elf64.)

All platforms need dl_iterate_phdr_static, so it doesn't make sense
to have that part of the per-architecture configuration.

Bug: 12476126
Change-Id: I1d7f918f1303a392794a6cd8b3512ff56bd6e487
2014-02-10 18:22:24 -08:00
Elliott Hughes
4eeb1f12a8 Clean up linker architecture macros.
We don't need our own architecture macros; the standard ones will do.

This patch also fixes some __x86_64__ tests to be USE_RELA tests instead,
because they're not actually x86_64-specific.

I've cleaned up architecture-specific code slightly so where possible
all the code corresponding to a particular architecture is together.

This patch also fixes a bug in LP64 DT_PLTGOT handling, which should be
an error rather than falling through into DT_DEBUG! There was another #ifdef
bug where we'd only report unexpected DT_ entries on MIPS.

Change-Id: Id1d04e372611f641c1aa278a18e379f28af9eaf5
2013-10-28 11:02:49 -07:00
Elliott Hughes
c00f2cb587 x86_64 linker.
Based on I8dc3e2cb596f75dc58ae82e4dc58f8c177dd3323 by
Pavel Chupin <pavel.v.chupin@intel.com>.

Change-Id: Icd582d277cbe273477b450f2848343d72c86ec9f
2013-10-08 09:57:01 -07:00
Elliott Hughes
c620059479 Remove 32-bit assumptions from the ELF code.
Change-Id: I2c1f3d34c33685799aade8866eec44479ff9f963
2013-09-30 18:43:46 -07:00
Brian Carlstrom
e7dffe150b Honor p_vaddr if set
(cherry picked from commit 88ff15c2c279d2bbe3569101b36cd2aa0931a0a9)

Change-Id: I4aabbe911d30aea8ace69e29bb6e980a4e89de90
2013-06-07 12:47:58 -07:00
Elliott Hughes
650be4e584 More linker cleanup.
Change-Id: I9fb3c7c0d4b4ffef0eeaf092d4e30ffe63a08671
2013-03-05 22:24:34 -08:00
Brian Carlstrom
d4ee82dfa3 Minor linker cleanup, primarily to use Elf32_Dyn
Change-Id: Ifa9408e9859c6f79444715bed4808b7c13fdced5
2013-03-05 15:27:21 -08:00
Chris Dearman
cf23905a4b [MIPS] Set DT_DEBUG dyntab entry if it is writable
This is primarily for MIPS exutables that do not have a
DT_MIPS_RLD_MAP entry.

Change-Id: I4c221d92debcfed961eeee2515123f3fb21ec8e6
Signed-off-by: Chris Dearman <chris@mips.com>
2013-01-14 09:30:25 -08:00
Elliott Hughes
18a206c81d More dynamic linker cleanup.
I still want to break linker_format out into its own library so we can reuse
it for malloc debugging and so forth. (There are many similar pieces of code
in bionic, but the linker's one seems to be the most complete/functional.)

Change-Id: If3721853d28937c8e821ca1d23cf200e228a409a
2012-10-30 16:35:38 -07:00
Ard Biesheuvel
12c78bbded linker: avoid clobbering the .dynamic section of shared libs
This patch removes the DT_NEEDED hack which stores pointers
to soinfo structs in the .dynamic section of the library
being loaded.

Instead, it caches the soinfo struct pointers on the stack
during relocation time. After relocation time, i.e. when
calling constructors and destructors of the shared library
and its dependencies, uncached access is used instead,
doing lookups using the string table entries pointed to by
the DT_NEEDED entries.

By removing this hack, it is no longer needed to undo the
PT_GNURELRO protection, i.e., all non-writable mappings
can remain non-writable during their entire lifespan.

Even though, strictly speaking, the algorithmic complexity
has increased somewhat, the real-world adverse effect
is negligible on the systems I have tested.

Change-Id: I2361502560b96b5878f7f94a8e8a215350d70d64
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@gmail.com>
2012-08-14 19:38:28 +02:00
Elliott Hughes
4688279db5 Clean up the linker a bit, remove prelinking support.
Also make the errors more readable, since none of us seemed to know
what they actually meant. The new style is still as verbose as the
old, but that's probably necessary in the absence of chained exceptions
in C. Here's what you'd see if you try to boot after removing
libsurfaceflinger.so:

  32267 32267 E AndroidRuntime: java.lang.UnsatisfiedLinkError: Cannot load library: (linker.c:1629, pid 32259) soinfo_link_image: could not load library "libsystem_server.so" needed by "libandroid_servers.so"; caused by (linker.c:1629, pid 32259) soinfo_link_image: could not load library "libsurfaceflinger.so" needed by "libsystem_server.so"; caused by (linker.c:709, pid 32259) load_library: library "libsurfaceflinger.so" not found

This patch also fixes almost all of the compiler warnings.

Change-Id: I64bb59aed6d4e039c15ea45be2367f319ef879f8
2012-08-07 11:41:10 -07:00
David 'Digit' Turner
c1bd559d5b linker: New sources to manage the ELF program header table.
This patch introduces two new source files containing a set of functions
to manage the program header table in an ELF binary, including the ability
to load PT_LOAD segments, and apply PT_GNU_RELRO protection.

Note: the files are not used currently, this will appear in a series
      of future patches that will gradually modify linker.c to use
      the phdr_table_xxx functions properly.

Change-Id: Ia3d4c1ff5fc3e265d8258b64b492f4e643f51bdc
2012-06-25 11:52:40 +02:00