We had two copies of the backtrace code, and two copies of the
libcorkscrew /proc/pid/maps code. This patch gets us down to one.
We also had hacks so we could log in the malloc debugging code.
This patch pulls the non-allocating "printf" code out of the
dynamic linker so everyone can share.
This patch also makes the leak diagnostics easier to read, and
makes it possible to paste them directly into the 'stack' tool (by
using relative PCs).
This patch also fixes the stdio standard stream leak that was
causing a leak warning every time tf_daemon ran.
Bug: 7291287
Change-Id: I66e4083ac2c5606c8d2737cb45c8ac8a32c7cfe8
The linker is essentially a shared library, and incorporates
it's own copy of libc. Even though it's unnecessary, currently
/system/bin/linker is exporting various libc symbols (only to
apps which explicitly dlopen /system/bin/linker)
Add --exclude-libs,ALL, which tells the static linker to mark
all of the imported libc symbols as hidden. This reduces the
size of /system/bin/linker from 92K to 67K with no obvious
loss in functionality.
$ adb shell ls -l /system/bin/linker
-rwxrwxrwx root root 92260 2013-01-16 16:52 linker
$ adb shell ls -l /system/bin/linker
-rwxrwxrwx root root 67660 2013-01-16 16:49 linker
Documentation on exclude-libs can be found at
http://sourceware.org/binutils/docs-2.21/ld/Options.html
Change-Id: I4508287770e4b7a845def2e6b4af969f9c866c6a
This patch replaces .S versions of x86 crtfiles with .c which are much
easier to support. Some of the files are matching .c version of Arm
crtfiles. x86 files required some cleanup anyway and this cleanup actually
led to matching Arm files.
I didn't change anything to share the same crt*.c between x86 and Arm. I
prefer to keep them separate for a while in case any change is required
for one of the arch, but it's good thing to do in the following patches.
Change-Id: Ibcf033f8d15aa5b10c05c879fd4b79a64dfc70f3
Signed-off-by: Pavel Chupin <pavel.v.chupin@intel.com>
If you need to build your own linker to get debugging, the debugging
is never available when you need it.
Change-Id: I5ff7e55753459d49a2990f25d9aa155e0b8602e0
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
Add unit tests for dlerror(3) in various situations. I think We're at least
as good as glibc now.
Also factor out the ScopedPthreadMutexLock and use it here too.
Bug: http://code.google.com/p/android/issues/detail?id=38398
Change-Id: I040938b4366ab836e3df46d1d8055b92f4ea6ed8
Now we use private variables in transform-o-to-executable to support
build executables against the NDK.
Bug: 7170098
Change-Id: I6e505b33001b76f4b11fcbbb1d35392c4ddf4c70
Now we use private variables in transform-o-to-executable to support
build executables against the NDK.
Bug: 7170098
Change-Id: I6e505b33001b76f4b11fcbbb1d35392c4ddf4c70
This should help prevent broken builds next time I'm messing with
assembler/compiler/linker flags...
Change-Id: I30f15a3ce3c3f3c60cad7bc59aaba9f42d792224
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
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
With -fstack-protector, x86 -m32 needs __stack_chk_fail_local
defined in crtbegin_*.o.
Include __stack_chk_fail_local.S in begin.S otherwise linker
(which is built w/o crt*) may not link.
Change-Id: Id242fcf3eff157264afe3b04f27288ab7991220a
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
Use LOCAL_NO_CRT to prevent linking against crtbegin.o, rather than
messing with build rules. This also prevents linking against crtend.o,
which isn't needed for the linker.
Change-Id: I0c5b9999be7e8676560fe145c1c033ffce8db4d1
Compile the linker with -fvisibility=hidden. This reduces the number
of symbols that show up in the .dynsym section of the linker.
These symbols are never exported to other applications.
In particular, this fixes a problem with setting -DLINKER_DEBUG=1
introduced in 468319ce4f.
Because the symbols "debug_verbosity" and "format_log" have not been
resolved before the linker links itself, any attempt to call
PRINT / INFO / TRACE / WARN / ERROR will result in a segfault.
This change allows the static linker to produce a relative reference
to these symbols rather than relying on relocation.
This also has a nice side effect of making the linker slightly smaller
and slightly more optimized.
The following symbols no longer in the .dynsym section of the linker
after this change:
-addr_to_name
-call_constructors_recursi
-calloc
-debugger_init
-debugger_signal_handler
-debug_verbosity
-dladdr
-dlclose
-dlerror
-dl_lock
-dlopen
-dlsym
-dl_unwind_find_exidx
-find_containing_library
-find_containing_symbol
-find_library
-format_buffer
-free
-libdl_info
-linker_env_get
-linker_env_init
-linker_env_secure
-linker_env_unset
-linker_get_error
-__linker_init
-lookup
-lookup_in_library
-malloc
-notify_gdb_of_libraries
-notify_gdb_of_load
-notify_gdb_of_unload
-realloc
-rtld_db_dlactivity
-unload_library
-vsnprintf
Bug: 5827809
Change-Id: I5e8cd7dcf48c1d6831a970a67f63f24916c5e437
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
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>
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
Use LOCAL_NO_CRT to prevent linking against crtbegin.o, rather than
messing with build rules. This also prevents linking against crtend.o,
which isn't needed for the linker.
Change-Id: I0c5b9999be7e8676560fe145c1c033ffce8db4d1
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: I90d064743abdd29450ac0482ed28752b2196286c
Currently, the Android linker is placing shared libraries into
a well-known spot in memory. This is interfering with the kernel's
ASLR support.
This change stops forcing non-prelinked libraries into a particular
address space.
Also, get rid of FLAG_PRELINKED. As best I can tell, this flag
is never used.
Change-Id: I527af12fb54f821c2b5ca7693dbf63d022f8f4ae
This removes several unsecure environment variables from the
environment block when the program being loaded is setuid. The
list of env. variables is the same than what GLibc uses at this
point.
Change-Id: I456d3ea0880fe0d4de0d3c5dd51871dd36e87fd6
This provides a mini-printf implementation that reduces the
size of the dynamic linker by 25 KB, by preventing the drag of
formatting-related routines from the C library.
Also allow traces to be sent to the log, instead of stdout.
NOTE: You now need to modify Android.mk to enable/disable debug
output.
