relocations are performed before the object's initializer is called.
When dlopen()ing an object, relocate the whole DAG rooted in the
object instead of only relocating the object itself and list of newly
loaded dependencies.
Reversed sequence currently can occur if the same object is a
dependency for both filtee and filter, since filtees are loaded
typically during the relocation processing, when some filter
dependencies might be already loaded but not relocated yet.
Reported and tested by: swills
Reviewed by: kan
MFC after: 1 week
object, and eliminate the pread(2) call as well [1]. Mmap the first
page of the object temporaly, and unmap it on error or last use.
Potentially, this leaves one-page gap between succeeding dlopen(3),
but there are other mmap(2) consumers as well.
Fix several cases were the whole mapping of the object leaked on error.
Use MAP_PREFAULT_READ for mmap(2) calls which map real object pages [2].
Insipired by the patch by: Ian Lepore <freebsd damnhippie dyndns org> [1]
Suggested by: alc [2]
MFC after: 2 weeks
object for which digest_dynamic1() was not done yet. Just return
EINVAL and do not try to dereference NULL buckets hash array.
This seems to happen on ia64 for rtld object itself, where the
R_IA_64_FPTR64LSB relocations require symbol lookup. The dynamic
linker itself does not rely on identity of the C-level function
pointers (i.e. function descriptors).
Reported and reviewed by: marcel
MFC after: 8 days
include <file>:
Parse the contents of file before continuing with the current file.
includedir <dir>:
Parse the contents of every file in dir that ends in .conf before continuing
with the current file.
Any file or directory encountered while processing include or includedir
directives will be parsed exactly once, even if it is encountered multiple
times.
Reviewed by: kib, des
Approved by: des (mentor)
MFC after: 1 month
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
When multiple users share the same UID, the old code will simply pick an
arbitrary username to attach to the utmpx entries. Make the code a bit
more accurate by first checking whether getlogin() returns a username
which corresponds to the uid of the calling process. If this fails,
simply fall back to picking an arbitrary username.
Reported by: saurik on GitHub
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
get rid of testing explicitly for clang (using ${CC:T:Mclang}) in
individual Makefiles.
Instead, use the following extra macros, for use with clang:
- NO_WERROR.clang (disables -Werror)
- NO_WCAST_ALIGN.clang (disables -Wcast-align)
- NO_WFORMAT.clang (disables -Wformat and friends)
- CLANG_NO_IAS (disables integrated assembler)
- CLANG_OPT_SMALL (adds flags for extra small size optimizations)
As a side effect, this enables setting CC/CXX/CPP in src.conf instead of
make.conf! For clang, use the following:
CC=clang
CXX=clang++
CPP=clang-cpp
MFC after: 2 weeks
A number of tftp clients, including the one in Intel's pxe boot loader,
may intentionally stop a transfer using error code 0 (i.e., EUNDEF).
These are not real errors. Avoid spamming log files with these by
logging them at level LOG_DEBUG instead.
Discussed on -hackers with an initial patch proposal; this change is an
improved approach suggested by kan@.
