libc's stack protector initialization routine (__guard_setup)
is in bionic/ssp.c. This code deliberately modifies the stack
canary. This code should never be compiled with -fstack-protector-all
otherwise it will crash (mismatched canary value).
Force bionic/ssp.c to be compiled with -fno-stack-protector
Change-Id: Ib95a5736e4bafe1a460d6b4e522ca660b417d8d6
Add fortify_source support for openat(). This change requires that
an argument be supplied when using O_CREAT.
Fix unnecessary call to __open_2. If, at compile time, we know that
"flags" is constant and DOESN'T contain O_CREAT, the call to __open_2
is useless.
Change-Id: Ifcd29c4fb25e25656961d7552d672e161f0cfdbd
Since linker is built with -fvisibility=hidden rtld_db_dlactivity()
if hidden from gdb. Unhide it otherwise gdb may not know linker
activity and rescan solib
Change-Id: Ia8cd8d9738c6ea5696ba2ef0ebf2cf783f9ca70a
Prefix private functions with underscores, to prevent name
conflicts.
Use __error__ instead of error, since occasionally programs will
create their own "#define error ...".
Change-Id: I7bb171df58aec5627e61896032a140db547fd95d
Add a FORTIFY_SOURCE check which requires that you pass a
"mode" argument when calling open(..., O_CREAT). If a mode isn't
passed, then the file is created with "undefined" permissions.
Change-Id: I4427be4f9ce170c69da01af5b00fb05b03613a28
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
This moves the code that determines where the .dynamic and .ARM.exidx
sections are to a single place in soinfo_link_image().
Change-Id: I98adcb440577bed86442349f03f3c629c945efec
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
This patch changes the load_library() function in the
dynamic linker to avoid reserving a huge read-only
address-space range just to read the ELF header and
program header (which are typically very small and easily
fit in the first page).
Instead, we use the functions in linker_phdr.c to only
load the data that we need in a temporary mmap-allocated
page of memory, which we release when the function exits.
This avoids issues when loading very large libraries, or
simply debug versions that only need to load a tiny percentage
of their overall file content in RAM.
Change-Id: Id3a189fad2119a870a1b3d43dd81380c54ea6044
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
This patch adds a trivial implementation of snprintf() that calls
our internal vsnprintf().
Inspection of the generated machine code showed that the linker
contained a full implementation of stdio's vfprintf. It was pulled
in because the pthread implementation uses snprintf() somewhere.
ProTip: It's possible to see why specific objects files are included
in a final binary by adding the following to your Android.mk, then
looking at the content of /tmp/MAP.TXT:
LOCAL_LDFLAGS += -Wl,-Map=/tmp/MAP.TXT
Change-Id: I325e71b0cad1d01116a2e00c09e30a80cb716aa3
Add strlcpy / strlcat support to FORTIFY_SOURCE. This allows
us to do consistency checks on to ensure we don't overflow buffers
when the compiler is able to tell us the size of the buffer we're
dealing with.
Unlike previous changes, this change DOES NOT use the compiler's
builtin support. Instead, we do everything the compiler would
normally do.
Change-Id: I47c099a911382452eafd711f8e9bfe7c2d0a0d22
According to
http://gcc.gnu.org/onlinedocs/gcc/Function-Attributes.html
realloc should NOT be marked with __attribute__((malloc)). Quoting:
realloc-like functions do not have this property as the memory
pointed to does not have undefined content.
For reference, __mallocfunc is defined in sys/cdefs.h as:
#define __mallocfunc __attribute__((malloc))
Change-Id: I56083542ba92e4608dd7c55fb5596a138eb50cc9
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
sprintf FORTIFY_SOURCE protections are not available
on clang.
Also add various __attribute__s to stdio functions.
Change-Id: I936d1f9e55fe53a68885c4524b7b59e68fed218d
