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
Follow-up to r353959 and r368070: do the same for other architectures.
arm32 already seems to use its own .fnstart/.fnend directives, which
appear to be ARM-specific variants of the same thing. Likewise, MIPS
uses .frame directives.
Reviewed by: arichardson
Differential Revision: https://reviews.freebsd.org/D27387
- whitespace at end of input line
- skipping paragraph macro: Pp at the end of Sh
- new sentence, new line
- consider using OS macro: Fx
- AUTHORS section without An macro
- skipping paragraph macro: Pp before Ss
Repeating the default WARNS here makes it slightly more difficult to
experiment with default WARNS changes, e.g. if we did something absolutely
bananas and introduced a WARNS=7 and wanted to try lifting the default to
that.
Drop most of them; there is one in the blake2 kernel module, but I suspect
it should be dropped -- the default WARNS in the rest of the build doesn't
currently apply to kernel modules, and I haven't put too much thought into
whether it makes sense to make it so.
Given that we have converted to ELFv2 for BE already, endianness is the only
difference between the two ARCHs.
As such, there is no need to differentiate LIBC_ARCH between the two.
Combining them like this lets us avoid needing to have two copies of several
bits for no good reason.
Sponsored by: Tag1 Consulting, Inc.
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
