Commit Graph

71 Commits

Author SHA1 Message Date
Brigid Smith
c5a13efa9b Added test for ifunc support in dynamic linker.
ifuncs now work in i386 and x86_64 when called in the same library as
well as in a different library.

Bug:6657325
Change-Id: Ic0c48b1b0a76cb90f36c20c79f68294cc3fd44a1
2014-08-08 11:29:35 -07:00
Dmitriy Ivanov
aa0f2bdbc2 Fix dlsym(3) to do breadth first search.
dlsym(3) with handle != RTLD_DEFAULT|RTLD_NEXT performs
  breadth first search through the dependency tree.

Bug: 16653281
Change-Id: I017a6975d1a62abb0218a7eb59ae4deba458e324
2014-07-29 14:35:13 -07:00
Dmitriy Ivanov
d97e9f546e Add support for protected local symbol lookup.
Bug: http://code.google.com/p/android/issues/detail?id=66048
Change-Id: Ib334223df27adad9477fb241ab099c5e26df4a7d
2014-07-01 10:25:54 -07:00
Elliott Hughes
1a58629340 Remove an unused parameter from the dlopen implementation.
Change-Id: I9297913a743bb570b48ebbe594ff711a481e89e0
2014-06-03 16:23:08 -07:00
Dmitriy Ivanov
b648a8a57e Add RTLD_NOLOAD support and some related changes.
* Aligned RTLD_ values with glibc for lp64
 * dlopen supports RTLD_NOLOAD flag
 * soinfo_unload calls find_library(.., RTLD_NOLOAD)
   instead of naive find_loaded_library_by_name()
 * dlopen changed to add child to caller soinfo instead
   of somain.

Bug: https://code.google.com/p/android/issues/detail?id=64069
Change-Id: I1a65f2c34f3e0edc6d2c41a2e408b58195feb640
2014-05-20 12:02:24 -07:00
Dmitriy Ivanov
d59e50063a Improve detection of already loaded libraries
Linker is now able to resolve symlinked libraries correctly.

soinfo is extended to save the graph of dependencies during
load/unload. Dependencies are used only in CallConstructor.

Bug: 9741592
Change-Id: Id9c48a74c46aa89bcdf3d54ec2f8ba3d398130b1
2014-05-14 15:16:35 -07:00
Elliott Hughes
1728b23965 Switch to g_ for globals.
That's what the Google style guide recommends, and we're starting
to get a mix.

Change-Id: Ib0c53a890bb5deed5c679e887541a715faea91fc
2014-05-14 10:02:03 -07:00
Torne (Richard Coles)
012cb4583a Add android_dlopen_ext() interface to linker.
Add a function "android_dlopen_ext()", defined in <android/dlext.h>.
This is an extended version of dlopen() which takes a struct for passing
additional parameters for Android-specific functionality. This will be
used to support RELRO section sharing between separate processes.

Bug: 13005501
Change-Id: I9c99b2f2a02ee329dedaeba09ef3a1113b17b2d6
2014-04-17 13:50:55 +01:00
Chris Dearman
9918665a45 [MIPS64] Dynamic linker
Change-Id: I937c7c776cae3d66e214798d5217a922cd106bfc
Signed-off-by: Chris Dearman <chris.dearman@imgtec.com>
Signed-off-by: Duane Sand <duane.sand@imgtec.com>
2014-02-11 15:33:14 -08:00
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
3a9c5d66dc Fix <link.h>.
Also move some of the stuff that should be in <link.h> out of the
private "linker.h", to make it clearer that these are public API
known to gdb that we can't change.

Bug: 12554197
Change-Id: I830e1260d3d8b833ed99bc1518f1c6b6102be8af
2014-02-10 13:31:13 -08:00
Weiwu Chen
5ceb889ac9 bionic: Change the type of soinfo's size to size_t
Some system functions like munmap expect soinfo's size to be size_t, but currently
it is unsigned. Change it to size_t to fit 64bit's portability.

Change-Id: I0bf6d522b38b0cd9bf1db05b004b5326217412a2
Signed-off-by: Weiwu Chen <weiwu.chen@intel.com>
Signed-off-by: Qiming Shi <qiming.shi@intel.com>
2014-01-28 11:54:01 -08:00
Elliott Hughes
a4aafd1560 Make it possible for code to query the dynamic linker's default search path.
We're not going to have init(1) set LD_LIBRARY_PATH globally on 64-bit.
This patch makes it possible for libnativehelper to set LD_LIBRARY_PATH
in each Java VM (to support System.loadLibrary) without also hard-coding
the default search path there.

Change-Id: If13961fae976e06dd80d5ef522f31e8b7eb01154
2014-01-13 16:37:47 -08:00
Elliott Hughes
1272dbd1d7 Add NT_PRSTATUS to <elf.h>.
Needed by aarch64.

Bug: 12476126
Change-Id: I7764664459a06cf4f2a60e707bd968d321a78430
2014-01-09 15:45:07 -08:00
Elliott Hughes
74ce45972d Update <sys/exec_elf.h> to get the DF_* flags.
Change-Id: Ia9e785f6b95122f94ee3b01a312db1d5bb91a72e
2013-10-28 14:59:41 -07:00
Elliott Hughes
e4d792adb8 Don't allow text relocations on 64-bit.
I've also updated our <sys/exec_elf.h> to match upstream.

Change-Id: I52f9fce3167541811208d273ff23ceaa112f7135
2013-10-28 14:34:56 -07:00
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
Elliott Hughes
7e5a8cc523 Make LD_PRELOAD failures just warnings.
This matches glibc and makes life easier for developers who want to
sometimes preload a library from init (which has no conditionals); they
can simply move/remove the library to disable.

Change-Id: I579b8633f958235af6e46bb53b378b9e363afb1f
2013-06-18 13:15:00 -07:00
Elliott Hughes
0d787c1fa1 Make abort messages available to debuggerd.
This adds __libc_fatal, cleans up the internal logging code a bit more,
and switches suitable callers over to __libc_fatal. In addition to logging,
__libc_fatal stashes the message somewhere that the debuggerd signal handler
can find it before calling abort.

In the debuggerd signal handler, we pass this address to debuggerd so that
it can come back with ptrace to read the message and present it to the user.

Bug: 8531731
Change-Id: I416ec1da38a8a1b0d0a582ccd7c8aaa681ed4a29
2013-04-05 11:24:19 -07:00
Elliott Hughes
8f2a5a0b40 Clean up internal libc logging.
We only need one logging API, and I prefer the one that does no
allocation and is thus safe to use in any context.

Also use O_CLOEXEC when opening the /dev/log files.

Move everything logging-related into one header file.

Change-Id: Ic1e3ea8e9b910dc29df351bff6c0aa4db26fbb58
2013-03-15 16:12:58 -07:00
Elliott Hughes
ca0c11bd82 Use more types than just 'unsigned' in the linker.
Still chipping away at the situation where every variable in the
linker was of type 'unsigned'. This patch switches counts over to
being size_t and adds an explicit type for init/fini function pointers
and arrays of function pointers.

Also improve logging from CallArray.

Also remove trailing "\n"s from log messages.

Change-Id: Ie036d2622caac50f4d29f0570888bb527661d77e
2013-03-12 11:26:56 -07:00
Kito Cheng
fa8c05dc00 Use Elf32_Addr instead of unsigned in linker
Change-Id: I52dcbb4b0ff0a4052e0ad7a9bbeb2df65c9d2f66
2013-03-12 10:19:14 -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
Elliott Hughes
d2b1a7311f Remove partial implementation of MIPS non-PIC support.
Change-Id: I3c287e52aae10559508174e73113367aea40e5c2
2013-02-06 11:02:28 -08:00
Elliott Hughes
a6a3ac5924 Use the NetBSD <sys/exec_elf.h>.
Replace a kernel header file dependency with files from NetBSD.
They're more complete, and ELF is ELF, whether you're on Linux or a BSD.

Bug: 7973611
Change-Id: I83ee719e7efdf432ec2ddbe8be271d05b2f558d7
2013-01-29 15:02:50 -08:00
Elliott Hughes
cade4c36e7 Support System.loadLibrary for libraries with transitive dependencies.
Also fix the FLAG_ERROR annoyance --- it's not helpful to cache failures.

Bug: 7896159
Bug: http://code.google.com/p/android/issues/detail?id=34416
Bug: http://code.google.com/p/android/issues/detail?id=22143
Change-Id: I60f235edb4ea4756e1f7ce56f7739f18e8a50789
2012-12-20 14:42:14 -08:00
Elliott Hughes
e66190d2a9 Check for unknown flags passed to dlopen(3).
Change-Id: I56f4aab0e5a1487bc32d2c4d231e8bd15c4ac8da
2012-12-18 15:57:55 -08:00
Elliott Hughes
d23736e4f2 Keep the dynamic linker's soinfo pools mostly read-only.
We'll need a lot more refactoring of this code before we can reduce
the granularity, but this is a step forward.

Change-Id: I07061720e734b571a8399c1d5b4f2f35cd681307
2012-11-01 16:48:14 -07:00
Elliott Hughes
1a6961650c Stop defining our own PAGE_SIZE and PAGE_MASK, and test dlclose(3) too.
Also remove an unnecessary #include and a now-obsolete TODO.

Change-Id: I36d923721e349a286934b9534090a67ce0786e7b
2012-11-01 13:53:26 -07:00
Magnus Malmborn
ba98d9237b Dynamically allocate soinfo-structs in linker
Request memory from the system when needed instead of having a fixed
array for soinfo structs. Note that malloc() et al can't be used in
linker, so use mmap() instead.

Change-Id: I4b495995931d7752b0e8c944e64d1fe41b9f7144
2012-11-01 11:31:39 -07:00
Ard Biesheuvel
5ae44f302b linker: handle R_ARM_COPY relocations in a proper way
If an executable contain copy relocations, other references
to the symbol it points to should be preempted and made to
point to the copy instead.

Also, the linker should make sure the target area has
sufficient space to contain the copy. It also checks
whether the library that supplies the symbol is built
with -Bsymbolic, and errors out if this is the case.

Change-Id: If135c83590092741cfd8f82f54816f363a4a4a3b
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@gmail.com>
2012-10-30 17:09:21 -07:00
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
Pavel Chupin
b7beb69075 Add link.h for all platforms with dl_phdr_info
This header is used on bionic build and should be propagated into
sysroot on toolchain rebuild. Discussion re. this header is here:
http://gcc.gnu.org/ml/gcc-patches/2012-08/msg00936.html

It is available already in mips NDK platforms:
development/ndk/platforms/android-9/arch-mips/include/link.h

Change-Id: I39ff467cdac9f448e31c11ee3e14a6200e82ab57
Signed-off-by: Pavel Chupin <pavel.v.chupin@intel.com>
2012-08-17 12:44:23 -07:00
Elliott Hughes
bedfe38b8b More cleanup.
Make more stuff static, remove some dead code, and fix a few typos.

Change-Id: I010b0eadeaf61e2899c37014ad1e7082c70bd510
2012-08-14 14:07:59 -07:00
Nick Kralevich
5135b3ae6e linker: don't perform unnecessary mprotects
The linker only needs to mark the text segment as
writable iff the file has text relocations. Unnecessarily
calling mprotect when it isn't necessary is slow, and some
security enhanced kernels don't like it. Pages which are
simultaneously writable and executable are considered a no-no.

The vast majority of executables / shared libraries on Android
do NOT have text relocations.

Change-Id: Ic38ce30a99b7e33ecf21efd9c108547a58eafa35
2012-08-13 08:50:11 -07:00
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
Raghu Gandham
d7daacb463 MIPS support to the linker
Change-Id: I37ec2d6c51d82bb9e9dbfef4b38c85366bead255
Signed-off-by: Chris Dearman <chris@mips.com>
Signed-off-by: Raghu Gandham <raghu@mips.com>
Signed-off-by: Bhanu Chetlapalli <bhanu@mips.com>
2012-08-02 14:39:50 -07:00
David 'Digit' Turner
b52e4385c4 linker: improve loadable segment protection.
Use the functions in linker_phdr.c to load the PT_LOAD segments
in memory, and toggle their mapping's writable protection bit
as needed. In particular:

  - when loading a library, load the segments then unprotected
    them to allow relocations to work.

  - when relocating the linker of the executable, unprotect
    the segments loaded by the kernel to make relocations work
    too.

  - after all relocations are done, re-protect the segments,
    and apply GNU RELRO protection if needed.

  - just before calling the destructors, undo the GNU RELRO
    protection.

Change-Id: I50e709f03958204b8d6140c0f51ebe24fe089a1b
2012-06-26 10:39:55 +02:00
David 'Digit' Turner
bea23e59f7 linker: rename load_offset to load_bias.
This patch changes the definition of the 'load_offset' field
in struct soinfo. The field is renamed because it is not the
basic load bias to add to every p_vaddr value read from the ELF
file to get the corresponding memory address.

This also slightly simplifies the relocation code.

+ Fix for proper load_bias computation for relocatable executables.

Change-Id: I72502c75a70751cba324deee7d313ae61f96609e
2012-06-25 11:52:40 +02:00
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
David 'Digit' Turner
1608416811 linker: small code-cleanup
This patch adds to make the linker a little bit easier to understand
by making all functions that acts on a sofino object with a soinfo_
prefix.

This is to more easily distinguish functions that operate on global
state, and those that operate on individual libraries.

This should be purely stylistic, i.e. no feature/behaviour change.

Change-Id: Ie510d13d743aa4317644caefa9910b8af7e84f44
2012-06-13 22:47:20 +02:00
Ji-Hwan Lee
f186a1819a Support non-zero p_vaddr in first PT_LOAD segment
Before changing mmap() permission to PROT_NONE in alloc_mem_region(),
such libraries once worked with a bug that uses mmap'ed region outside of
memory region allocated by alloc_mem_region().  This possibly incurs
SIGSEGV because it can overwrite memory region of previously loaded
library, but it sometimes worked, depending on loading order.

After PROT_NONE, this caused SIGSEGV earlier during calculation of
si->phdr in load_library(), but this was fixed by:

    75917c84d1  Use mmap to read an ...

Now the behaviour is the same as before applying PROT_NONE in
alloc_mem_region().

This CL fixed the original issue, supporting shared libraries that have
non-zero p_vaddr in first (= with lowest p_vaddr) PT_LOAD segment.

Bug: 6561258
Change-Id: Ib6176dd3e44c4d99a340eb1cbd16fb037586b0bc
2012-06-04 07:44:10 -07:00
Nick Kralevich
9ec0f03a0d Add relro support
Add support for PT_GNU_RELRO. This allows the static linker to
indicate that certain regions of memory should be marked as
"read-only" after dynamic linking is complete.

See:
  * http://www.akkadia.org/drepper/nonselsec.pdf (section 6)
  * http://tk-blog.blogspot.com/2009/02/relro-not-so-well-known-memory.html

Note that this change has no effect on Android right now, because
we don't compile our code with relro enabled.

Change-Id: I6541f8775367e8558b4388f7d105b1ae6e8f046b
2012-03-05 16:44:42 -08:00
Jean-Baptiste Queru
25b7a16a6e Merge c4cb87f3
Change-Id: I4cc14eba43fde75a7702fdc7ad07d3d949e9c092
2012-02-01 09:46:08 -08:00
David 'Digit' Turner
70b1668a76 remove obsolete SuperH support
We don't have a toolchain anymore, we don't have working original
kernel headers, and nobody is maintaining this so there is really
no point in keeping this here. Details of the patch:

- removed code paths from Android.mk files related to the SuperH
  architecture ("sh")

- removed libc/arch-sh, linker/arch-sh, libc/kernel/arch-sh

- simplified libc/SYSCALLS.TXT

- simplified the scripts in libc/tools/ and libc/kernel/tools

Change-Id: I26b0e1422bdc347489e4573e2fbec0e402f75560

Signed-off-by: David 'Digit' Turner <digit@android.com>
2012-01-31 20:28:23 +01:00
Evgeniy Stepanov
e83c56dfbb Execute .preinit_array before any shared object initialization functions.
This change makes linker handling of .preinit_array compliant with the
System V ABI:

"These [pre-initialization] functions are executed after the dynamic linker has
built the process image and performed relocations but before any shared object
initialization functions."
http://www.sco.com/developers/gabi/latest/ch5.dynamic.html#init_fini

Change-Id: Iebfee22bb1ebe1d7c7e69cb4686e4ebae0dfc4bb
2012-01-10 13:30:41 +04:00
Nick Kralevich
468319ce4f Make the linker relocatable.
Previously, the linker always loaded itself into the same
location in memory, which inhibited the effectiveness of Android's
ASLR implementation. Modify the linker code so it can be relocatable
and link itself at runtime.

Change-Id: Ia80273d7a00ff648b4da545f4b69debee6343968
2011-11-11 18:01:53 -08:00