but still for tightly coupled things like ldd(1)
Rename paths.h to rtld_paths.h.
Add guard for rtld-specific externs declarations.
Add _COMPAT32_BASENAME_RTLD and _COMPAT32_PATH_RTLD.
Reviewed by: arichardson, jhb
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D32464
Reset both pagepool_start and pagepool_end after a mmap(2) failure,
to avoid using invalid pagepool either for allocation or munmap(2).
PR: 259076
Noted by: Denis Koreshkov <dynamic-wind@mail.ru>
Reviewed by: arichardson
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D32514
PIE and shared objects usually have many relative relocations. In
2017/2018, a compact relative relocation format RELR was proposed on
https://groups.google.com/g/generic-abi/c/bX460iggiKg/m/GxjM0L-PBAAJ
("Proposal for a new section type SHT_RELR") and is a pre-standard.
RELR usually takes 3% or smaller space than R_*_RELATIVE relocations.
The virtual memory size of a mostly statically linked PIE is typically
5~10% smaller.
ld.lld --pack-dyn-relocs=relr emits RELR relocations. DT_RELR has been
adopted by Android bionic, Linux kernel's arm64 port, Chrome OS (patched
glibc).
This patch adds DT_RELR support to FreeBSD rtld-elf.
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D32524
This has the effect of installing the same file twice at the same location
and confuse pkgbase as we add this file twice in the package config part.
MFC after: 1 week
Sponsored by: Beckhoff Automation GmbH & Co. KG
to ignore lack of execute permission on the binary. The check is a
bad security theatre anyway.
Reviewed by: arichardson, imp
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D32464
In the situation with limited address space, together with
fragmentation, it is possible for mmap() request in morecore() to fail
when asking for required size + NPOOLPAGES, but succeed without the
addend. Retry allocation there.
PR: 259076
Reported by: Denis Koreshkov <dynamic-wind@mail.ru>
Reviewed by: arichardson
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D32474
Scan through the set of environment variables during initialization and
store values in the corresponding ld_env_var_desc structure, in the
single pass at init time. This does not eliminate use of getenv(3) and
unsetenv(3) completely, but provides a foundation to do that as the next
step.
Also organize the scan in a way that makes it easier to support aliases
like LD_DEBUG vs. LD_64_DEBUG.
Suggested by: arichardson
Reviewed by: arichardson, markj
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D31545
Instead of specifying the main name part of the environment variable as the
string literal, create array of the var names and access them by symbolic
index. Convert main name parts into complete names by prefixing with
ABI-specific ld_env_vars.
This way the name is not repeated, and also it can carry additional
proporties explicitly. For instance, cleanup of the environment for
the setuid image does not require retyping all names.
Reviewed by: arichardson, markj
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential revision: https://reviews.freebsd.org/D31545
The current lookup prefers a strong definition to a STB_WEAK definition
(similar to glibc pre-2.2 behavior) which does not conform to the ELF
specification.
The non-compliant behavior provoked https://reviews.llvm.org/D4418
which was intended to fix -shared-libasan but introduced
new problems (and caused some sanitizer tests (e.g.
test/asan/TestCases/interception_failure_test.cpp) to fail): sanitizer
interceptors are STB_GLOBAL instead of STB_WEAK, so defining a second
STB_GLOBAL interceptor can lead to a multiple definition linker error.
For example, in a -fsanitize={address,memory,...} build, libc functions
like malloc/free/strtol/... cannot be provided by user object files.
See
https://docs.freebsd.org/cgi/getmsg.cgi?fetch=16483939+0+archive/2014/freebsd-current/20140716.freebsd-current
for discussions.
This patch implements the ELF-compliant behavior when LD_DYNAMIC_WEAK is
set. STB_WEAK wrestling in symbol lookups in `Search the dynamic linker
itself` are untouched.
Reviewed by: kib
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D26352
Variant I architectures use off and Variant II ones use size + off.
Define TLS_VARIANT_I/TLS_VARIANT_II symbols similarly to how libc
handles it.
Reviewed by: kib
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D31539
Differential revision: https://reviews.freebsd.org/D31541
For a Variant II architecture, the TP offset of a TLS symbol is st_value -
tlsoffset + r_addend. tlsoffset is computed by either calculate_tls_offset
or calculate_first_tls_offset.
The return value of calculate_first_tls_offset is the smallest integer
satisfying res >= size and (-res) % p_align = p_vaddr % p_align
(= p_offset % p_align). (The formula is a bit contrived. The basic idea
is to subtract the minimum integer from size + align - 1 so that the result
ihas the expected remainder.)
Reviewed by: kib
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D31538
Differential revision: https://reviews.freebsd.org/D31541
lld rounds up p_memsz(PT_GNU_RELRO) to satisfy common-page-size. If the
page size is smaller than common-page-size, rounding up relro_size may
incorrectly make some RW pages read-only.
GNU ld, gold, and ld.lld ensures p_vaddr+p_memsz is a multiple of
common-page-size. While max-page-size >= system the page size,
common-page-size can be smaller than the system page size.
Submitted by: MaskRay
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D31498
This adds two new options WITH_ASAN/WITH_UBSAN that can be set to
enable instrumentation of all binaries with AddressSanitizer and/or
UndefinedBehaviourSanitizer. This current patch is almost sufficient
to get a complete buildworld with sanitizer instrumentation but in
order to actually build and boot a system it depends on a few more
follow-up commits.
Reviewed By: brooks, kib, markj
Differential Revision: https://reviews.freebsd.org/D31043
lld emits several GOT relocations referencing the null sumbol in libc.so
when compiled with -ftls-model=initial-exec. This symbol is specified
to be undefined.
We generally do not handle dynamic TLS relocations against weak,
undefined symbols, so avoid printing a warning here. This makes it
possible to compile libc.so using the initial-exec TLS model on arm64.
Reviewed by: jrtc27, kib
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D31069
This prevents these tests from being compiled with ASAN since the asan
interceptors also define opendir() but matching the libc function.
Reviewed By: oshogbo, kib, markj
Differential Revision: https://reviews.freebsd.org/D31038
The mprotect() call was failing on CheriBSD when changing rtld's relro
page permissions due to missing CHERI capability permissions on the
mprotect() argument but did not report an error since the return value
was being ignored. It should never fail on any supported FreeBSD
architecture, but checking the return value seems like a good
sanity check to me.
Reviewed By: kib, imp
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D30820
There should be no error after startup.
PR: 255698
Reported by: Eugene M. Kim <astralblue@gmail.com>
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
rtld preserves its current error message around calls to user init/fini
lists, to not override original error with potential secondary errors
caused by user code recursing into rtld. After 4d9128da54,
the preservation of the string itself is not enough, the 'seen'
indicator must be preserved as well. Otherwise, since new code does not
clear string (it cannot), call to _rtld_error() from errmsg_restore()
revived whatever message was consumed last.
Change errmsg_save() to return structure recording both 'seen' indicator
and the message, if any.
PR: 255698
Reported by: Eugene M. Kim <astralblue@gmail.com>
Sponsored by: The FreeBSD Foundation
MFC after: 3 days
Right now, libthr does not initialize RtldLockInfo.rtli_version when calling
_rtld_thread_init(), which makes versioning the interface troublesome.
Add a workaround: if the calling object of _rtld_thread_init() exports
the "_pli_rtli_version" symbol, then consider rtli_version initialized.
Otherwise, forcibly set it to RTLI_VERSION_ONE, currently defined as
RTLI_VERSION.
Export "_pli_rtli_version" from libthr and properly initialize rtli_version.
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D29633
This eliminates some non-trivial amount of code duplication, where done.
Only x86 and mips are handled right now.
Tested by: bdragon (powerpc), mhorne (riscv)
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D29623
This fixes a regression in d36d681615, where the call to
__tls_get_address() was performed under rtld_bind_lock write-locked.
Instead use tls_get_addr_slow() directly, with locked = true.
Reported by: jkim, many others
Tested by: jkim, bdragon (powerpc), mhorne (riscv)
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D29623
This was only needed on 32-bit arm prior to ARMv6. As we only support
ARMv6 or later remove it.
Reviewed by: mannu
Sponsored by: Innovate UK
Differential Revision: https://reviews.freebsd.org/D29624
dl_iterate_phdr() dlpi_tls_data should provide the TLS module segment
address, and not the TLS init segment address as it does now.
Reported by: emacsray@gmail.com
PR: 254774
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
The new PRELOAD_FDS variable accepts a list of file descriptors
that should be loaded into the process.
This may be used to optimize a loading process - in the case when
we already have a file descriptor to the library; we don't have
to look into multiple PATH to find it.
It may also be used in capability mode to load a single additional
library without the need to open a directory that contains it.
The last use of this functionality t may be a race-free method
of loading libraries.
Reviewed by: kib, markj
Differential Revision: https://reviews.freebsd.org/D29334
Parentheses added to HASZERO macro to avoid a GCC warning, and formatted
with clang-format as we have adopted these and don't consider them
'contrib' code.
Obtained from: musl (snapshot at commit 4d0a82170a25)
Reviewed by: kib (libc integration), mjg (both earlier)
MFC after: 1 month
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D17630
When a library is opened via fdlopen, it has a null pointer for its path
and so _rtld_bind can crash as a result of passing the null pointer to
basename() (which passes it to strrchr(), which doesn't do a null check).
PR: 253081
Submitted by: theraven
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D28442
This makes text segment relocation work under W^X.
Submitted by: Greg V <greg@unrelenting.technology> (original version)
Reviewed by: kib
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D27953
to prevent obliteration of error value from the original syscall.
Also improve error message for short read.
Submitted by: Konrad Sewiłło-Jopek
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D27864
Statically link rtld-elf with libcompiler_rt on all architectures so
that we don't need to try to pick and choose the bits we need from it
for each architecture (we now leave that to the linker). Compilers may
emit calls to support functions in this library, but because of the use
of the linker flag -nostdlib for rtld's special needs, the library is
not linked as normal.
Previously we had two different solutions. On some architectures, we
were able to extract reimplementations of the necessary builtin
functions from our special build of libc. On ARM, we just linked
libcompiler_rt.
This is motivated by the same issue as D26199 and D27665, but should be
a simpler solution that will apply to all architectures.
Reviewed by: arichardson, kib
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D27736
This fixes the gcc9 build of rtld-elf32 on amd64, which needed an
implementation of udivmoddi4.
rtld-elf uses certain functions normally found in libc, and so it
includes certain files from libc in its own build. It has two
mechanisms to include files from libc: one that rebuilds source files in
the rtld-elf environment, and one that extracts object files from a
purpose-built no-SSP PIC archive.
In addition to libc functions, rtld-elf may need to link functions
normally found in libcompiler_rt (formerly libgcc). Now, add an ability
to rebuild libcompiler_rt source files in the rtld-elf environment. We
don't yet have a need for an object file extraction mechanism.
libcompiler_rt could also supply udivdi3 and umoddi3, but leave them
alone for now.
Reviewed by: arichardson, kib
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D27665
ar cr is an update of an archive, not a creation of a new one. During
incremental builds (e.g. with meta mode) the archive was not getting
cleaned, and so could retain now-deleted objects from previous builds.
Now, delete the archive before creating/updating it.
Reviewed by: arichardson, bdrewery, kib
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D27663
