lld on RISC-V is not yet able to handle undefined weak symbols for
non-PIC code in the code model (medany/medium) used by the RISC-V
kernel.
Both GCC and clang emit an auipc / addi pair of instructions to
generate an address relative to the current PC with a 31-bit offset.
Undefined weak symbols need to have an address of 0, but the kernel
runs with PC values much greater than 2^31, so there is no way to
construct a NULL pointer as a PC-relative value. The bfd linker
rewrites the instruction pair to use lui / addi with values of 0 to
force a NULL pointer address. (There are similar cases for 'ld'
becoming auipc / ld that bfd rewrites to lui / ld with an address of
0.)
To work around this, compile the kernel with -fPIE when using lld.
This does not make the kernel position-independent, but it does
force the compiler to indirect address lookups through GOT entries
(so auipc / ld against a GOT entry to fetch the address). This
adds extra memory indirections for global symbols, so should be
disabled once lld is finally fixed.
A few 'la' instructions in locore that depend on PC-relative
addressing to load physical addresses before paging is enabled have to
use auipc / addi and not indirect via GOT entries, so change those to
use 'lla' which always uses auipc / addi for both PIC and non-PIC.
Submitted by: jrtc27
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D23064
other files.
Arm and mips systems need to replace the SYSTEM_LD variable because they
need to create intermediate files which are post-processed with objcopy to
create the final .TARGET file. Previously they did so by pasting the full
expansion of SYSTEM_LD with the output filename replaced. This means
changing SYSTEM_LD in kern.pre.mk means you need to chase down anything that
replaces it and figure out how it differs so you can paste your changes in
there too.
Now there is a SYSTEM_LD_BASECMD variable that holds the entire basic kernel
linker command without the input and output files. This will allow arm and
mips makefiles to create their custom versions by refering to
SYSTEM_LD_BASECMD, which then becomes the one place where you have to make
changes to the basic linker command args.
Differential Revision: https://reviews.freebsd.org/D22921
Update the NetBSD Kernel Concurrency Sanitizer (KCSAN) runtime to work in
the FreeBSD kernel. It is a useful tool for finding data races between
threads executing on different CPUs.
This can be enabled by enabling KCSAN in the kernel config, or by using the
GENERIC-KCSAN amd64 kernel. It works on amd64 and arm64, however the later
needs a compiler change to allow -fsanitize=thread that KCSAN uses.
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D22315
It was defined with the wrong MACHINE_ARCH previously. This permits
using an MFS image without defining MD_ROOT_SIZE which has various
benefits (one being that the build is able to treat the MFS image as
a dependency and properly re-link the kernel with the new image when
building with NO_CLEAN).
MFC after: 2 weeks
Sponsored by: DARPA
As part of marching gcc 4.2.1 out of the tree, turn off -Werror on gcc 4.2.1
compiles by default. It generates too many false positives and breaks CI
for no benefit.
Discussed on: arch@
Reviewed by: jhb@, emaste@, pfg@
Differential Revision: https://reviews.freebsd.org/D21378
with an eventual goal to convert all legacl zlib callers to the new zlib
version:
* Move generic zlib shims that are not specific to zlib 1.0.4 to
sys/dev/zlib.
* Connect new zlib (1.2.11) to the zlib kernel module, currently built
with Z_SOLO.
* Prefix the legacy zlib (1.0.4) with 'zlib104_' namespace.
* Convert sys/opencrypto/cryptodeflate.c to use new zlib.
* Remove bundled zlib 1.2.3 from ZFS and adapt it to new zlib and make
it depend on the zlib module.
* Fix Z_SOLO build of new zlib.
PR: 229763
Submitted by: Yoshihiro Ota <ota j email ne jp>
Reviewed by: markm (sys/dev/zlib/zlib_kmod.c)
Relnotes: yes
Differential Revision: https://reviews.freebsd.org/D19706
The upstream implementation of -z ifunc-noplt disallows its combination
with -z text. The option does not have much significance for kernel
builds, though.
Reviewed by: kib (previous version)
Discussed with: emaste
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D20260
add gcov support and export results as files in debugfs
Reviewed by: hps@
MFC after: 1 week
Sponsored by: iX Systems
Differential Revision: https://reviews.freebsd.org/D19260
This will allow multiple consumers of the coverage data to be compiled
into the kernel together. The only requirement is only one can be
registered at a given point in time, however it is expected they will
only register when the coverage data is needed.
A new kernel conflig option COVERAGE is added. This will allow kcov to
become a module that can be loaded as needed, or compiled into the
kernel.
While here clean up the #include style a little.
Reviewed by: kib
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D18955
When building with KCOV enabled the compiler will insert function calls
to probes allowing us to trace the execution of the kernel from userspace.
These probes are on function entry (trace-pc) and on comparison operations
(trace-cmp).
Userspace can enable the use of these probes on a single kernel thread with
an ioctl interface. It can allocate space for the probe with KIOSETBUFSIZE,
then mmap the allocated buffer and enable tracing with KIOENABLE, with the
trace mode being passed in as the int argument. When complete KIODISABLE
is used to disable tracing.
The first item in the buffer is the number of trace event that have
happened. Userspace can write 0 to this to reset the tracing, and is
expected to do so on first use.
The format of the buffer depends on the trace mode. When in PC tracing just
the return address of the probe is stored. Under comparison tracing the
comparison type, the two arguments, and the return address are traced. The
former method uses on entry per trace event, while the later uses 4. As
such they are incompatible so only a single mode may be enabled.
KCOV is expected to help fuzzing the kernel, and while in development has
already found a number of issues. It is required for the syzkaller system
call fuzzer [1]. Other kernel fuzzers could also make use of it, either
with the current interface, or by extending it with new modes.
A man page is currently being worked on and is expected to be committed
soon, however having the code in the kernel now is useful for other
developers to use.
[1] https://github.com/google/syzkaller
Submitted by: Mitchell Horne <mhorne063@gmail.com> (Earlier version)
Reviewed by: kib
Testing by: tuexen
Sponsored by: DARPA, AFRL
Sponsored by: The FreeBSD Foundation (Mitchell Horne)
Differential Revision: https://reviews.freebsd.org/D14599
This allows us to build the ubsan code added in r340189 into the kernel
with the KUBSAN option. This will report when undefined behaviour is
detected in the currently running kernel.
As it can be large, the kernel is 65MB on arm64, loader may not be able to
load the kernel on all architectures so is disabled by default for now.
Sponsored by: DARPA, AFRL
Tested with ifunc resolvers in the kernel and module with calls from
kernel to kernel, module to kernel, and module to module.
Reviewed by: kib (previous version)
Approved by: re (gjb)
Differential Revision: https://reviews.freebsd.org/D17370
The amd64 kernel started using ifunc for a variety of functions with
arch-specific implementations, and we would like to make use of the
same functionality on i386 and as much as possible avoid divergence
between i386 and amd64. In particular, future changes for security
improvements and mitigations may rely on ifunc support.
Approved by: re (kib)
Sponsored by: The FreeBSD Foundation
Per r338251, this ensures that ifunc calls have the same ordinary
function calls.
Reviewed by: emaste (previous version)
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D16750
Avoid pulling in all of the <sys/proc.h> dependencies by
automatically generating a stripped down thread_lite exporting
only the fields of interest. The field declarations are type checked
against the original and the offsets of the generated result is
automatically checked.
kib has expressed disagreement and would have preferred to simply
use genassym style offsets (which loses type check enforcement).
jhb has expressed dislike of it due to header pollution and a
duplicate structure. He would have preferred to just have defined
thread in _thread.h. Nonetheless, he admits that this is the only
viable solution at the moment.
The impetus for this came from mjg's D15331:
"Inline critical_enter/exit for amd64"
Reviewed by: jeff
Differential Revision: https://reviews.freebsd.org/D16078
As of r333461 we require ifunc support to link a working amd64 kernel.
The default in-tree bootstrap linker is lld and it has the required
support, as does any modern out-of-tree binutils linker. The in-tree
GNU ld is from binutils 2.17.50 and it does not have ifunc support,
so produce an error rather than a broken kernel.
Reviewed by: kib
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D15378
Read locking is over used in the kernel to guarantee liveness. This API makes
it easy to provide livenes guarantees without atomics.
Includes epoch_test kernel module to stress test the API.
Documentation will follow initial use case.
Test case and improvements to preemption handling in response to discussion
with mjg@
Reviewed by: imp@, shurd@
Approved by: sbruno@
separate 2M pages. The binutils default for max-page-size and
common-page-size used to produce this result. By setting these
values, we can nudge lld to also separate these sections into separate
2M pages.
Reviewed by: jhb, kib
Discussed with: emaste
Sponsored by: Netflix
Differential Revision: D14282
Disable Zstd experimental support for __BMI__ intrinsics, when built with
-march=foo supporting such intrinsics, to avoid attempting to include
immintrin.h. If a later Zstd marks the support non-experimental, we may want
to revisit this approach.
Submitted by: jkim
Reported by: jkim, "Oliver Hartmann" <ohartmann AT walstatt.org>
By disabling the -Winline warning. Fixes the powerpc and sparc64 build
after r327706.
Note: MIPS and RISCV builds still broken due to absense of __ctzdi2 (aka
__builtin_ctzll) in their libgcc or libcompiler-rt libraries.
Reported by: markj
Sponsored by: Dell EMC Isilon
Mock userspace headers and include mocked headers first in compilation
command to inject kernel headers and override e.g., malloc(3) with
malloc(9).
Submitted by: allanjude
Reviewed by: imp (earlier version), bapt (earlier version)
Differential Revision: https://reviews.freebsd.org/D10407
There's no way currently to automatically prevent the bad .OBJDIR from being
created but it can at least be prevented from being used. Passing
WITHOUT_AUTO_OBJ=yes or MK_AUTO_OBJ=no or -DNO_OBJ in will prevent it.
Reported by: jeffr
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D12989
NO_OBJ has a very specific meaning in sub-directories in that no object
directory will be made. If a user wanted to skip the 'make obj' phase then
passing -DNO_OBJ would break all sub-directories from building properly. Using
NO_OBJ internally also causes issue with NO_OBJ handling being added in
share/mk/bsd.init.mk soon.
Sponsored by: Dell EMC Isilon
Make armv7 as a new MACHINE_ARCH.
Copy all the places we do armv6 and add armv7 as basically an
alias. clang appears to generate code for armv7 by default. armv7 hard
float isn't supported by the the in-tree gcc, so it hasn't been
updated to have a new default.
Support armv7 as a new valid MACHINE_ARCH (and by extension
TARGET_ARCH).
Add armv7 to the universe build.
Differential Revision: https://reviews.freebsd.org/D12010
7431 ZFS Channel Programs
illumos/illumos-gate@dfc115332cdfc115332chttps://www.illumos.org/issues/7431
ZFS channel programs (ZCP) adds support for performing compound ZFS
administrative actions via Lua scripts in a sandboxed environment (with time
and memory limits).
This initial commit includes both base support for running ZCP scripts, and a
small initial library of API calls which support getting properties and
listing, destroying, and promoting datasets.
Testing: in addition to the included unit tests, channel programs have been in
use at Delphix for several months for batch destroying filesystems. The
dsl_destroy_snaps_nvl() call has also been replaced with
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: John Kennedy <john.kennedy@delphix.com>
Reviewed by: Dan Kimmel <dan.kimmel@delphix.com>
Approved by: Garrett D'Amore <garrett@damore.org>
Author: Chris Williamson <chris.williamson@delphix.com>
8552 ZFS LUA code uses floating point math
illumos/illumos-gate@916c8d8811916c8d8811https://www.illumos.org/issues/8552
In the LUA interpreter used by "zfs program", the lua format() function
accidentally includes support for '%f' and friends, which can cause compilation
problems when building on platforms that don't support floating-point math in
the kernel (e.g. sparc). Support for '%f' friends (%f %e %E %g %G) should be
removed, since there's no way to supply a floating-point value anyway (all
numbers in ZFS LUA are int64_t's).
Reviewed by: Yuri Pankov <yuripv@gmx.com>
Reviewed by: Igor Kozhukhov <igor@dilos.org>
Approved by: Dan McDonald <danmcd@joyent.com>
Author: Matthew Ahrens <mahrens@delphix.com>
8590 memory leak in dsl_destroy_snapshots_nvl()
illumos/illumos-gate@e6ab4525d1e6ab4525d1https://www.illumos.org/issues/8590
In dsl_destroy_snapshots_nvl(), "snaps_normalized" is not freed after it is
added to "arg".
Reviewed by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed by: Steve Gonczi <steve.gonczi@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Approved by: Dan McDonald <danmcd@joyent.com>
Author: Matthew Ahrens <mahrens@delphix.com>
FreeBSD notes:
- zfs-program.8 manual page is taken almost as is from the vendor repository,
no FreeBSD-ification done
- fixed multiple instances of NULL being used where an integer is expected
- replaced ETIME and ECHRNG with ETIMEDOUT and EDOM respectively
This commit adds a modified version of Lua 5.2.4 under
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/lua, mirroring the
upstream. See README.zfs in that directory for the description of Lua
customizations.
See zfs-program.8 on how to use the new feature.
MFC after: 5 weeks
Relnotes: yes
Differential Revision: https://reviews.freebsd.org/D12528
Without this change, modules will match the default compiler
configuration which may not be the same as the kernel values.
Reviewed by: imp
Obtained from: CheriBSD
MFC after: 2 weeks
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D11633
A Build-ID is an identifier generated at link time to uniquely identify
ELF binaries. It allows efficient confirmation that an executable or
shared library and a corresponding standalone debuginfo file match.
(Otherwise, a checksum of the debuginfo file must be calculated when
opening it in a debugger.)
The FreeBSD base system includes GNU bfd ld 2.17.50 as the linker for
architectures other than arm64. Build-ID support was added to bfd ld
shortly after that version, so was not previously available to us.
We can now start making use of Build-ID as we migrate to using lld or
bfd ld from ports, conditionally enabled based on the LINKER_TYPE and
LINKER_VERSION make variables added in r320244 and subsequent commits.
Reviewed by: dim
MFC after: 3 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D11314
