hash elements, and a helper matched_symbol() which match the given hash
entry and request, performing needed type and version checks.
Based on dragonflybsd support for GNU hash by John Marino <draco marino st>
Reviewed by: kan
Tested by: bapt
MFC after: 2 weeks
through the filter loading call chain. This fixes attempts to
write-lock the already locked rtld_bind_lock when filter loading is
initiated by relocation of dlopening dso.
Reported and tested by: Taku YAMAMOTO <taku tackymt homeip net>
MFC after: 1 week
for the same object. This can happen when object is a dependency of the
dlopen()ed dso. When called several times, we waste time due to unneeded
processing, and memory, because obj->vertab is allocated anew on each
iteration.
Reviewed by: kan
MFC after: 2 weeks
are assumed to not fail.
Make the xcalloc() calling conventions follow the calloc(3) calling
conventions and replace unchecked calls to calloc() with calls to
xcalloc().
Remove redundand declarations from xmalloc.c, which are already
present in rtld.h.
Reviewed by: kan
Discussed with: bde
MFC after: 2 weeks
Do not relocate twice an object which happens to be needed by loaded
binary (or dso) and some filtee opened due to symbol resolution when
relocating need objects. Record the state of the relocation
processing in Obj_Entry and short-circuit relocate_objects() if
current object already processed.
Do not call constructors for filtees loaded during the early
relocation processing before image is initialized enough to run
user-provided code. Filtees are loaded using dlopen_object(), which
normally performs relocation and initialization. If filtee is
lazy-loaded during the relocation of dso needed by the main object,
dlopen_object() runs too earlier, when most runtime services are not
yet ready.
Postpone the constructors call to the time when main binary and
depended libraries constructors are run, passing the new flag
RTLD_LO_EARLY to dlopen_object(). Symbol lookups callers inform
symlook_* functions about early stage of initialization with
SYMLOOK_EARLY. Pass flags through all functions participating in
object relocation.
Use the opportunity and fix flags argument to find_symdef() in
arch-specific reloc.c to use proper name SYMLOOK_IN_PLT instead of
true, which happen to have the same numeric value.
Reported and tested by: theraven
Reviewed by: kan
MFC after: 2 weeks
Stop using strerror(3) in rtld, which brings in msgcat and stdio.
Directly access sys_errlist array of errno messages with private
rtld_strerror() function.
Now,
$ size /libexec/ld-elf.so.1
text data bss dec hex filename
96983 2480 8744 108207 1a6af /libexec/ld-elf.so.1
Reviewed by: dim, kan
MFC after: 2 weeks
Provide rtld-private implementations of __stack_chk_guard,
__stack_chk_fail() and __chk_fail() symbols, to be used by functions
linked from libc_pic.a. This avoids use of libc stack_protector.c,
which pulls in syslog(3) and stdio as dependency.
Also, do initialize rtld-private copy __stack_chk_guard, previously
libc-provided one was not initialized, since we do not call rtld
object _init() methods.
Reviewed by: kan
MFC after: 3 weeks
yet, and object segments are not yet mapped. Only parse the notes that
appear in the first page of the dso (as it should be anyway), and use
the preloaded page content.
Reported and tested by: stass
MFC after: 20 days
particular on ARM, do require working init arrays.
Traditional FreeBSD crt1 calls _init and _fini of the binary, instead
of allowing runtime linker to arrange the calls. This was probably
done to have the same crt code serve both statically and dynamically
linked binaries. Since ABI mandates that first is called preinit
array functions, then init, and then init array functions, the init
have to be called from rtld now.
To provide binary compatibility to old FreeBSD crt1, which calls _init
itself, rtld only calls intializers and finalizers for main binary if
binary has a note indicating that new crt was used for linking. Add
parsing of ELF notes to rtld, and cache p_osrel value since we parsed
it anyway.
The patch is inspired by init_array support for DragonflyBSD, written
by John Marino.
Reviewed by: kan
Tested by: andrew (arm, previous version), flo (sparc64, previous version)
MFC after: 3 weeks
for TLS microbenchmark using global-dynamic TLS model on amd64 (which is
default for PIC dso objects).
Split the slow path into tls_get_addr_slow(), for which inlining is
disabled. This prevents the registers spill on tls_get_addr_common()
entry.
Provide static branch hint to the compiler, indicating that slow path
is not likely to be taken.
While there, do some minimal style adjustments.
Reported and tested by: davidxu
MFC after: 1 week
Since after r232498 the ctype macros require working access to
thread-local variables, rtld crashes when libmap.conf is present.
Use hand-made isspace1() macro which is enough to detect spaces in
libmap.conf.
Reported by: alc, lme, many on current@
Tested by: lme
Reviewed by: dim, kan
MFC after: 1 week
relocations until tls is initialized and stacks permissions correctly
set. This allows the ifunc to call malloc(3) and some other heavy
services.
Add debug banner.
MFC after: 3 days
from the dispatcher would also acquire bind lock in read mode, which
is the supported operation. plt is explicitely designed to allow safe
multithreaded updates, so the shared lock do not cause problems.
The error in r228435 is that it allows read lock acquisition after the
write lock for the bind block. If we dlopened the shared object that
contains IRELATIVE or jump slot which target is STT_GNU_IFUNC, then
possible recursive plt resolve from the dispatcher would cause it.
Postpone the resolution for irelative/ifunc right before initializers
are called, and drop bind lock around calls to dispatcher. Use
initlist to iterate over the objects instead of the ->next, due to
drop of the bind lock in iteration.
For i386/reloc.c:reloc_iresolve(), fix calculation of the dispatch
function address for dso, by taking into account possible non-zero
relocbase.
MFC after: 3 weeks
rtld on 386 and amd64. This adds runtime bits neccessary for the use
of the dispatch functions from the dynamically-linked executables and
shared libraries.
To allow use of external references from the dispatch function, resolution
of the R_MACHINE_IRESOLVE relocations in PLT is postponed until GOT entries
for PLT are prepared, and normal resolution of the GOT entries is finished.
Similar to how it is done by GNU, IRELATIVE relocations are resolved in
advance, instead of normal lazy handling for PLT.
Move the init_pltgot() call before the relocations for the object are
processed.
MFC after: 3 weeks
