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
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
Also, fixes SIGSEV during calculation of si->phdr in load_library(),
which is caused by accessing PHDR area, which is not guaranteed to be
loaded.
Note that this usually does not happen because program header area is
covered by immediately following PT_LOAD entry. But it does not hold
always.
Bug: 6561258
Change-Id: Ie376253c773b5420279ca89044e81b1aad5a5736
The ARM static linker wasn't properly handling __exidx_start
and __exidx_end symbols. Now that the static linker has been fixed,
we don't need the dynamic linker to work around this problem.
Change-Id: I041b94903609fafab33663a7d441a5e70b7ffcdd
Since e19d702b8e, dlsym and friends use recursive mutexes that
require the current thread id, which is not available before the libc
constructor. This prevents us from using dlsym() in .preinit_array.
This change moves TLS initialization from libc constructor to the earliest
possible point - immediately after linker itself is relocated. As a result,
pthread_internal_t for the initial thread is available from the start.
As a bonus, values stored in TLS in .preinit_array are not lost when libc is
initialized.
Change-Id: Iee5a710ee000173bff63e924adeb4a4c600c1e2d
This reverts commit 61ff83475c.
This code is harmless, and only applies to the linker, so
there's no harm in keeping it in the tree a little bit longer.
Let's roll this back while we try to figure out the root cause
of bug 6314858.
Bug: 6314858
Change-Id: I9f5ed81d23a7abe273baf792aa8a0a2839ef094c
The ARM static linker wasn't properly handling __exidx_start
and __exidx_end symbols. Now that the static linker has been fixed,
we don't need the dynamic linker to work around this problem.
Change-Id: Ic567122b6c7746cc016795e2befba2c6bd7c0478
When the dynamic linker loads a shared library into memory, it
initially allocates a chunk of memory. The memory is then carved
into smaller chunks for each LOAD region, and appropriate memory
protections applied.
Modify the initial memory allocation so that the pages are mapped
as PROT_NONE, rather than PROT_READ / PROT_EXEC. This ensures that
gaps between LOAD regions are not inadvertantly readable / executable.
(Long term, we should munmap() these gaps entirely)
Change-Id: If128a203ccc6fe12dcbbd2bfe0cf13a2045675af
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
