In the future, we will Default to _FORTIFY_SOURCE=2 if SSP is enabled,
otherwise default to _FORTIFY_SOURCE=0. For now we default it to 0
unconditionally to ease bisect across older versions without the new
symbols, and we'll put out a call for testing.
include/*.h include their ssp/*.h equivalents as needed based on the
knob. Programs and users are allowed to override FORTIFY_SOURCE in their
Makefiles or src.conf/make.conf to force it off.
Reviewed by: des, markj
Relnotes: yes
Sponsored by: Stormshield
Sponsored by: Klara, Inc.
Differential Revision: https://reviews.freebsd.org/D32308
To allow gcc -m32 to work, link libc and libthr with --rpath-/usr/lib32.
When called with -m32, gcc is currently unable to communicate to
the bfd linker that it should look in /usr/lib32 to resolve needed (as
opposed to explicitly linked) libraries so we need to provide a hint.
See also: https://sourceware.org/bugzilla/show_bug.cgi?id=31395
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D43910
Continue to filter the public interface (elf_aux_info()), but entierly
relocate the private interfaces (_elf_aux_info(),
__init_elf_aux_vector(), and __elf_aux_vector) to libsys.
This ensures that rtld updates the correct (only) copy of
__elf_aux_vector. After 968a18975a
updates were confused and __getosreldate was failing, causing
the system to fall back to compat compat12 syscalls in some cases.
Return to explicitly linking libc to libsys and link libthr with libc
and libsys (in that order).
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D43910
The allows gcc + GNU ld to link programs with -m32 -pthread without
erroring out due to _umtx_op_err being undefined (unless -lsys is added
to the link command.
We now always link _umtx_op_err into libthr (not just when it's static)
and filter it with libsys so we call that implementation. The dynamic
implementations (at least the assembly ones) should likely become stubs
as a further refinement.
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D43783
Declare in sys/umtx.h and implement in libsys. Explicitly link libthr
with libsys.
When building libthr static include _umtx_op_err so we don't break static
linkage with -lpthread.
Reviewed by: kib, emaste, imp
Pull Request: https://github.com/freebsd/freebsd-src/pull/908
This patch fixes a bug which prevents building libthr without
_PTHREADS_INVARIANTS defined. The default remains to build libthr
with -D_PTHREADS_INVARIANTS. However, with this patch, if one builds
libthr with WITHOUT_PTHREADS_ASSERTIONS=true then the latency to
acquire+release a default pthread mutex is reduced by roughly 5%, and a
robust mutex by roughly 18% (as measured by a simple synthetic test on a
Xeon E5-2697a based machine).
Reviewed by: jhb, kib, mjg
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D40900
When a thread exits, _Unwind_ForcedUnwind() is used to walk up stack
frames executing pending cleanups pushed by pthread_cleanup_push().
The cleanups are popped by thread_unwind_stop() which is passed as a
callback function to _Unwind_ForcedUnwind().
LLVM's libunwind uses a different function type for the callback on
32-bit ARM relative to all other platforms. The previous unwind.h
header (as well as the unwind.h from libcxxrt) use the non-ARM type on
all platforms, so this has likely been broken on 32-bit arm since it
switched to using LLVM's libunwind.
For now, just disable stack unwinding on 32-bit arm to unbreak the
build until a proper fix is tested.
Install headers from LLVM's libunwind in place of the headers from
libcxxrt and allow C applications to use the library.
As part of this, remove include/unwind.h and switch libthr over to
using the installed unwind.h.
Reviewed by: dim, emaste
MFC after: 10 days
Differential Revision: https://reviews.freebsd.org/D34065
I got the following error with an ASAN-instrument libthr:
==803==ERROR: AddressSanitizer: stack-buffer-overflow on address 0x7fffffffcdb0 at pc 0x000801863396 bp 0x7ff8
READ of size 4 at 0x7fffffffcdb0 thread T0
#0 0x801863395 in handle_signal /local/scratch/alr48/cheri/freebsd/lib/libthr/thread/thr_sig.c:262:2
#1 0x801860da2 in thr_sighandler /local/scratch/alr48/cheri/freebsd/lib/libthr/thread/thr_sig.c:246:2
Address 0x7fffffffcdb0 is located in stack of thread T0 at offset 208 in frame
#0 0x80186080f in thr_sighandler /local/scratch/alr48/cheri/freebsd/lib/libthr/thread/thr_sig.c:213
This frame has 1 object(s):
[32, 64) 'act' (line 216) <== Memory access at offset 208 overflows this variable
HINT: this may be a false positive if your program uses some custom stack
This seems like a false-positive since the line in question is
`SIGSETOR(actp->sa_mask, ucp->uc_sigmask);` and it complains about a read
operation (from the ucontext_t argument) so this indicates to me that ASAN
does not understand that thr_sighandler() is a signal handler.
Differential Revision: https://reviews.freebsd.org/D31074
This warning is very rarely useful (inline is a hint and not mandatory).
This flag results in many warnings being printed when compiling C++
code that uses the standard library with GCC.
This flag was originally added in back in r94332 but the flag is a no-op
in Clang ("This diagnostic flag exists for GCC compatibility, and has no
effect in Clang"). Removing it should make the GCC build output slightly
more readable.
Reviewed By: jrtc27, imp
Differential Revision: https://reviews.freebsd.org/D29235
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
If dso uses initial exec TLS mode, rtld tries to allocate TLS in
static space. If there is no space left, the dlopen(3) fails. If space
if allocated, initial content from PT_TLS segment is distributed to
all threads' pcbs, which was missed and caused un-initialized TLS
segment for such dso after dlopen(3).
The mode is auto-detected either due to the relocation used, or if the
DF_STATIC_TLS dynamic flag is set. In the later case, the TLS segment
is tried to allocate earlier, which increases chance of the dlopen(3)
to succeed. LLD was recently fixed to properly emit the flag, ld.bdf
did it always.
Initial test by: dumbbell
Tested by: emaste (amd64), ian (arm)
Tested by: Gerald Aryeetey <aryeeteygerald_rogers.com> (arm64)
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Differential revision: https://reviews.freebsd.org/D19072
r345620 by kib@ fixed the rtld issue that caused a crash at startup
during resolution of libc's ifuncs with BIND_NOW.
PR: 233333
Sponsored by: The FreeBSD Foundation
The need to use libc malloc(3) from some places in libthr always
caused issues. For instance, per-thread key allocation was switched to
use plain mmap(2) to get storage, because some third party mallocs
used keys for implementation of calloc(3).
Even more important, libthr calls calloc(3) during initialization of
pthread mutexes, and jemalloc uses pthread mutexes. Jemalloc provides
some way to both postpone the initialization, and to make
initialization to use specialized allocator, but this is very fragile
and often breaks. See the referenced PR for another example.
Add the small malloc implementation used by rtld, to libthr. Use it in
thr_spec.c and for mutexes initialization. This avoids the issues with
mutual dependencies between malloc and libthr in principle. The
drawback is that some more allocations are not interceptable for
alternate malloc implementations. There should be not too much memory
use from this allocator, and the alternative, direct use of mmap(2) is
obviously worse.
PR: 235211
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential revision: https://reviews.freebsd.org/D18988
An issue remains with BIND_NOW and processes using threads. For now,
restore libc's BIND_NOW disable, and also disable BIND_NOW in rtld and
libthr.
A patch is in review (D18400) that likely fixes this issue, but just
disable BIND_NOW pending further testing after it is committed.
PR: 233333
Sponsored by: The FreeBSD Foundation
directories to SUBDIR.${MK_TESTS} idiom
This is being done to pave the way for future work (and homogenity) in
^/projects/make-check-sandbox .
No functional change intended.
MFC after: 1 weeks
People tweaking the build system or compilers tend to look into
the Makefile and not into the source. Having some warning controls
in the Makefile and some in the source code is surprising.
Pragmas have the advantage that they leave the warnings enabled
for more code, but that advantage isn't very relevant in these cases.
Requested by: kib
Reviewed by: kib
MFC after: 3 days
Sponsored by: Dell EMC
Differential Revision: https://reviews.freebsd.org/D10832
These warnings don't make sense for code that implements
the locking primitives.
Reviewed by: kib
MFC after: 3 days
Sponsored by: Dell EMC
Differential Revision: https://reviews.freebsd.org/D10832
the constraints on what needs to be installed in a specific to
maintain consistency during upgrades.
Create a new clibs package containing libraries that are needed
as a bare minimum for consistency.
With much help and input from: kib
Sponsored by: The FreeBSD Foundation
Since METAMODE has been added, sys.mk loads bsd.mkopt.mk which ends load loading
bsd.own.mk which then defines SHLIBDIR before all the Makefile.inc everywhere.
This makes /lib being populated again.
Reported by: many
pwrite(2) syscalls are wrapped to provide compatibility with pre-7.x
kernels which required padding before the off_t parameter. The
fcntl(2) contains compatibility code to handle kernels before the
struct flock was changed during the 8.x CURRENT development. The
shims were reasonable to allow easier revert to the older kernel at
that time.
Now, two or three major releases later, shims do not serve any
purpose. Such old kernels cannot handle current libc, so revert the
compatibility code.
Make padded syscalls support conditional under the COMPAT6 config
option. For COMPAT32, the syscalls were under COMPAT6 already.
Remove WITHOUT_SYSCALL_COMPAT build option, which only purpose was to
(partially) disable the removed shims.
Reviewed by: jhb, imp (previous versions)
Discussed with: peter
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
The amd64, i386, and sparc64 versions were identical, with the one
difference where the former two used inline asm instead of _tcb_get. I
have compared the function before and after replacing the asm with _tcb_get
and found the object files to be identical.
The arm, mips, and powerpc versions were almost identical. The only
difference was the powerpc version used an alignment of 1 where arm and
mips used 16. As this is an increase in alignment is will be safe.
Along with this arm, mips, and powerpc all passed, when initial was true,
the value returned from _tcb_get as the first argument to
_rtld_allocate_tls. This would then return this pointer back to the caller.
We can remove these extra calls by checking if initial is set and setting
the thread control block directly. As this is what the sparc64 code does
we can use it directly.
As after these observations all the architectures can now have identical
code we can merge them into a common file.
Differential Revision: https://reviews.freebsd.org/D1556
Reviewed by: kib
Sponsored by: The FreeBSD Foundation
(or loading a dso linked to libthr.so into process which was not
linked against threading library).
- Remove libthr interposers of the libc functions, including
__error(). Instead, functions calls are indirected through the
interposing table, similar to how pthread stubs in libc are already
done. Libc by default points either to syscall trampolines or to
existing libc implementations. On libthr load, libthr rewrites the
pointers to the cancellable implementations already in libthr. The
interposition table is separate from pthreads stubs indirection
table to not pull pthreads stubs into static binaries.
- Postpone the malloc(3) internal mutexes initialization until libthr
is loaded. This avoids recursion between calloc(3) and static
pthread_mutex_t initialization.
- Reinstall signal handlers with wrapper on libthr load. The
_rtld_is_dlopened(3) is used to avoid useless calls to sigaction(2)
when libthr is statically referenced from the main binary.
In the process, fix openat(2), swapcontext(2) and setcontext(2)
interposing. The libc symbols were exported at different versions
than libthr interposers. Export both libc and libthr versions from
libc now, with default set to the higher version from libthr.
Remove unused and disconnected swapcontext(3) userspace implementation
from libc/gen.
No objections from: deischen
Tested by: pho, antoine (exp-run) (previous versions)
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
lib/libthr/tests
A variant of this code has been tested on amd64/i386 for some time by
EMC/Isilon on 10-STABLE/11-CURRENT. It builds on other architectures, but the
code will remain off until it's proven it works on virtual hardware or real
hardware on other architectures
Original work by: pho
Sponsored by: EMC / Isilon Storage Division
for them, two functions _pthread_cancel_enter and _pthread_cancel_leave
are added to let thread enter and leave a cancellation point, it also
makes it possible that other functions can be cancellation points in
libraries without having to be rewritten in libthr.
defer-mode cancellation works, asynchrnous mode does not work because
it lacks of libuwind's support. stack unwinding is not enabled unless
LIBTHR_UNWIND_STACK is defined in Makefile.
For all libthr contexts, use ${MACHINE_CPUARCH}
for all libc contexts, use ${MACHINE_ARCH} if it exists, otherwise use
${MACHINE_CPUARCH}
Move some common code up a layer (the .PATH statement was the same in
all the arch submakefiles).
# Hope she hasn't busted powerpc64 with this...
