This is consistent with how array inits are called, and also makes us
more compatible with glibc environment.
Requested by: Alex S <iwtcex@gmail.com>
PR: 249162
Reviewed by: dim, emaste
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D26351
Such objects can still have valid relocations not requiring symbolic
references.
PR: 249121
Reported by: wsh@riski.sh
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
If object has no dynamic phdr, do not try to dereference NULL. This
means that we cannot process any relocation, and that there cannot be
symbols defined, but it is up to static linker to produce meaningful
objects.
PR: 249121
Reported by: wsh@riski.sh
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
This violated the RISC-V 64-bit ABI. On CheriBSD this manifested as
a trap when attempting to store 16-byte aligned types while zeroing
the stack.
Reported by: CHERI, jrtc27
Reviewed by: mhorne, br
Obtained from: CheriBSD
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D26327
In the last IFUNC related changes to rtld, the code that handled non-PLT
GNU IFUNC relocations ended up getting lost. This could leave some
relocations unhandled, causing crashes or misbehavior. This change restores
the handling of these relocations, but now together with the other IFUNC
relocations, allowing resolvers to reference external symbols.
Reviewed by: kib
MFC after: 2 weeks
Sponsored by: Eldorado Research Institute (eldorado.org.br)
Differential Revision: https://reviews.freebsd.org/D25550
This makes old ldd to still work on newer tagged PIE binaries.
Also move debug line for hashes before both decisions to not load are
done, so that the end of digest_dynamic() processing and reason to not
load or load is seen in debug trace.
Noted by: jhb
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Which makes all calls to load_object() to observe the flag, except the
calls for preloaded DSOs.
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Rtld itself is a shared object which does not have vendor note, so
after the direct exec of ld-elf.so.1 process has p_osrel set to zero.
This affects the ABI of syscalls.
Set osrel to the __FreeBSD_version value at compile time right after
rtld identified direct exec mode. Then, switch to the osrel read from
the binary note or zero if no note, right before starting calling
ifunc resolvers, which is the first byte of the user code.
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Linkers are supposed to mark PIE binaries with DF_1_PIE, such binary
cannot be correctly and usefully loaded neither by dlopen(3) nor as a
dependency of other object. For instance, we cannot do anything
useful with COPY relocations, among other things.
Glibc already added similar restriction.
Requested and reviewed by: emaste
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D25086
It is wrong to relate on __FreeBSD_version, either from
include/param.h, kernel, or libc, to check for rtld features.
Rtld might be from newer world than the running userspace.
Add special private symbols exported by rtld itself, to indicate the
changes in runtime behavior, and features that cannot be otherwise
detected or deduced at runtime.
Note that the symbols are not exported from libc, so they intentionally
cannot be linked against, and exported from the private namespace from rtld.
Consumers are required to use dlsym(3). For instance, for
_rtld_version_laddr_offset, user should do
ptr = dlsym(RTLD_DEFAULT, "_rtld_version_laddr_offset")
or even
ptr = dlvsym(RTLD_DEFAULT, "_rtld_version_laddr_offset",
"FBSDprivate_1.0");
Non-null ptr means that the change is present.
Also add _rtld_version__FreeBSD_version indicator to report the
headers version used at time of the rtld build.
Reviewed by: jhb
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D24982
Keep link_map l_addr binary layout compatible, rename l_addr to l_base
where rtld returns map base. Provide relocbase in newly added l_addr.
This effectively reverts the patch to the initial version of D24918.
Reported by: antoine (portmgr)
Reviewed by: jhb, markj
Tested by: markj
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D24946
It previously returned the object map base address, while all other
ELF operating systems return load offset, i.e. the difference between
map base and the link base.
Explain the meaning of the field in the man page.
Stop filling the mips-only l_offs member, which is apparently unused.
PR: 246561
Requested by: Damjan Jovanovic <damjan.jov@gmail.com>
Reviewed by: emaste, jhb, cem (previous version)
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D24918
Assume gcc is at least 6.4, the oldest xtoolchain in the ports tree.
Assume clang is at least 6, which was in 11.2-RELEASE. Drop conditions
for older compilers.
Reviewed by: imp (earlier version), emaste, jhb
MFC after: 2 weeks
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D24802
Clang10 may use FPU instructions for optimizing operations with
memory blocks. But we don't want to do lengthy save/restore of all
FPU registers across each rtld_start() call.
MFC after: 3 week
For PIE binaries, ldd(1) performs dlopen(RTLD_TRACE) on the binary.
It is legal for binary to use initial exec TLS mode, but when such
binary (actually dso) is dlopened, we might not have enough free space
in the finalized static TLS segment. Make ldd operational by skipping
TLS space allocation, we are not going to execute any code from the
dso anyway.
Reported by: tobik
PR: 245677
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
This is continuation of D21163/r359634, which handled the alignment
for global mode.
Non-x86 arches are not handled, maintainers are welcomed.
Tested by: emaste
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Differential revision: https://reviews.freebsd.org/D24366
See https://sourceware.org/bugzilla/show_bug.cgi?id=24606 for the test case.
See https://reviews.llvm.org/D64930 for the background and more discussion.
Also this fixes another bug in malloc_aligned() where total size of
the allocated memory might be not enough to fit the aligned requested
block after the initial pointer is incremented by the pointer size.
Reviewed by: bdragon
Tested by: antoine (exp-run PR 244866), bdragon, emaste
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Differential revision: https://reviews.freebsd.org/D21163
realpath(3) is used a lot e.g., by clang and is a major source of getcwd
and fstatat calls. This can be done more efficiently in the kernel.
This works by performing a regular lookup while saving the name and found
parent directory. If the terminal vnode is a directory we can resolve it using
usual means. Otherwise we can use the name saved by lookup and resolve the
parent.
See the review for sample syscall counts.
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D23574
lld 10.0 seems to generate this relocation for rdtsc_mb() ifunc in our libc.
Reported, reviewed, and tested by: dim (amd64, previous version)
Discussed with: emaste
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D23652
This allows for rtld to not issue two sigprocmask(2) syscalls for each
symbol binding operation in single-threaded processes. Rtld needs to
block signals as part of locking to ensure signal safety of the bind
process, because signal handlers might need to lazily resolve symbol
references.
As result, number of syscalls issued on startup by simple programs not
using libthr, is typically reduced 2x. For instance, for hello world,
I see:
non-sigfastblock
# (truss ./hello > /dev/null) |& wc -l
63
sigfastblock
# (truss ./hello > /dev/null) |& wc -l
37
Tested by: pho
Disscussed with: cem, emaste, jilles
Sponsored by: The FreeBSD Foundation
Differential revision: https://reviews.freebsd.org/D12773
They were introduced to take care of ifunc, but right now no architecture
provides ifunc'ed variants. Since rtld uses memset extensively this results in
a pessmization. Should someone want to use ifunc here they should provide a
mandatory symbol (e.g., rtld_memset).
See the review for profiling data.
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D23176
Move all MD statements into $MACHINE_ARCH/Makefile.inc.
Unconditionally apply version script to rtld, the interpreter is not
functional without it for long time.
Reviewed by: brooks, emaste
Sponsored by: The FreeBSD Foundation
Differential revision: https://reviews.freebsd.org/D23083
The path is already absolute.
Noted and reviewed by: rstone
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D23121
instead of killing the process. The same behaviour of terminating
image activation if the $ORIGIN cannot be resolved for the main
object, is kept.
Reported by: Greg V <greg@unrelenting.technology>
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D23053
We know the binary relative name and can reliably calculate cwd path.
Because realpath(3) was already linked into ld-elf.so.1, reuse it
there to resolve dots and dotdots making the path more canonical.
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D23014
binpath local was changed from char array to a char pointer, update
strlcpy/strlcat uses.
Reported by: Coverity through vangyzen
CID: 1412239 and 1412240
Reviewed by: emaste, imp, vangyzen
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D23090
When rtld is directly executed with arguments, it has to move the
program arguments, environment and elf aux data up a few slots to
remove its own arguments before the process being executed sees
them. When copying the environment, rtld was incorrectly testing
whether the location about to be written to currently contained
NULL, when was supposed to check whether it had just copied the
NULL terminator of the environment string. This had the result
that the ELF aux data was mostly treated as environment variables,
and rtld would quickly crash when it tried to access required
ELF aux data that it didn't think was present.
Differential Revision: https://reviews.freebsd.org/D23008
Reviewed by: kib
MFC after: 1 month
When activated in direct exec mode, kernel-provided AT_EXECPATH points
to the interpreter. We need to recalculate auxv to point to the
string with the path to the executable which is actually executed.
The somewhat problematic case is when the executable path is relative
and either $PATH use is not enabled or it contains '/' so $PATH search
is not performed. In this case resulting AT_EXECPATH is relative, I
might fix this later.
Reported and reviewed by: rstone
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D22894
Summary:
As a transition aide, implement an alternative elfN_freebsd_fixup which
is called for old powerpc binaries. Similarly, add a translation to rtld to
convert old values to new ones (as expected by a new rtld).
Translation of old<->new values is incomplete, but sufficient to allow an
installworld of a new userspace from an old one when a new kernel is running.
Test Plan:
Someone needs to see how a new kernel/rtld/libc works with an old
binary. If if works we can probalby ship this. If not we probalby need
some more compat bits.
Submitted by: brooks
Reviewed by: jhibbits
Differential Revision: https://reviews.freebsd.org/D20799
