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>
The flag to avoid calling ELF constructors recursively (in the case
of recursive .so dependencies) was being set after the dangerous
recursive constructor call had already been made.
This fixes the libc's debug malloc implementation.
Change-Id: I5e601f0ea19ab1df81b8b1ad4df25c3eab0ccda4
The Linux kernel provides an AT_SECURE auxv flag to inform userspace
whether or not a security transition has occurred. This is more reliable
than directly checking the uid/gid against the euid/egid, because it covers
not only setuid/setgid but also file capabilities, SELinux, and AppArmor
security transitions. It is also a more efficient test since it does
not require any additional system calls.
Change-Id: I9752a4f6da452273258d2876d13b05e402fb0409
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
android linker doesn't check machine type, it may load some
libraries which it doesn't support sometimes.
Author: Zhenghua Wang <zhenghua.wang@intel.com>
Signed-off-by: Bruce Beare <bruce.j.beare@intel.com>
The computation of si->base assumed that the first entry in the
program header table is a PT_PHDR. This results in the dynamic
linker crashing with a SIGSEGV/MAPERR when trying to load some
of the NDK unit test programs, which happen to have an EXIDX
header first, followed byu a PHDR one.
This patch fixes the computation by parsing the program header
table, looking explicitely for the PHDR entry. This fixes the
load of the NDK unit test programs, and doesn't affect system
libraries.
Change-Id: Id18ea6037dbe950b5abbbce816c2960321f0b81d
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
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
Modify the dynamic linker so that executables can be loaded
at locations other than 0x00000000.
Modify crtbegin* so that non-PIC compilant "thumb interwork
veneers" are not created by the linker.
Bug: 5323301
Change-Id: Iece0272e2b708c79034f302c20160e1fe9029588
This patch allows the debugging of constructors in shared
libraries and executables. It does so by ensuring that the
corresponding binary is visible to gdb before running the
constructors.
Change-Id: I0a3df726a04ad109944c834dcbba672b85d3991e
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
Prelinked libraries must be mapped to a fixed address. MAP_FIXED is ignored
for non-prelinked libraries (si->base==0)
Signed-off-by: Raghu Gandham <raghu@mips.com>
system_server loads up 87 shared libraries upon start. Running under
valgrind pushes this just over the edge of 96. Increase SO_MAX to 128 to
give us some more headroom.
Change-Id: Iadceb14ab6d9621bdccd292570d50867828057d9
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
The LD_PRELOAD environment variable allows the user to specify a list of
libraries which should be unconditionally loaded before any others. This
makes possible some useful tricks, such as library interposers.
Change-Id: I433d775ab08ef63a5fbe7b21f87a5642954fc32f
The previous implementation of this flag was broken--it behaved identically
to RTLD_DEFAULT. This adds a proper implementation, which examines the address
of the calling function, and uses it to determine which library to use to begin
the symbol search process.
Change-Id: I2ad2b46363f68932af63a3828a22f9c7987eea67
dladdr() is a GNU extension function, which allows the caller to retrieve
symbol information for a specified memory address. It is useful for things
like generating backtrace information at runtime.
Change-Id: I3a1def1a6c9c666d93e1e97b7d260dfa5b9b79a9
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.
-- fixes b/2432550
-- ba_prelink is used to manage non-prelinked libraries, hence ba_nonprelink is
a more appropriate name for it
Signed-off-by: Iliyan Malchev <malchev@google.com>
Merge commit 'fe62de1ad036a1417df44b7b1a7c65cc79dc7091' into eclair-plus-aosp
* commit 'fe62de1ad036a1417df44b7b1a7c65cc79dc7091':
Add support for R_ARM_REL32 to the dynamic linker.
Merge commit 'ebf3ea006e5367fff93d2491eec24c4b1a633805'
* commit 'ebf3ea006e5367fff93d2491eec24c4b1a633805':
Add support for R_ARM_REL32 to the dynamic linker.
Merge commit '34ea5117dbeba41ae5dfdfb2c2ec8cae23388b66' into eclair-mr2-plus-aosp
* commit '34ea5117dbeba41ae5dfdfb2c2ec8cae23388b66':
Add support for R_ARM_REL32 to the dynamic linker.
Merge commit '83362689f5b1f6393d376d242fe29541b63ead2d'
* commit '83362689f5b1f6393d376d242fe29541b63ead2d':
added and modified linker to support SuperH architecture
Add the BSD sys_signame array.
added and modified bionic code to support SuperH architecture
