Since commit 7ecaf069da ("kbuild: move headers_check rule to
usr/include/Makefile"), 'make headers_check' is no-op.
This stub target is remaining here in case some scripts still invoke it.
In order to prompt people to remove stale code, show a noisy warning
message if used. The stub will be really removed after the Linux 5.15
release.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Since commit f2f02ebd8f ("kbuild: improve cc-option to clean up all
temporary files"), running 'make kernelversion' in a read-only source
tree emits a bunch of warnings:
mkdir: cannot create directory '.tmp_12345': Permission denied
No-build targets such as kernelversion, clean, help, etc. do not
need to evaluate $(call cc-option,) or friends. Skip Makefile.compiler
so $(call cc-option,) becomes no-op.
This not only fixes the warnings, but also runs non-build targets much
faster.
Basically, all installation targets should also be non-build targets.
Unfortunately, vdso_install requires the compiler because it builds
vdso before installation. This is a problem that must be fixed by a
separate patch.
Reported-by: Israel Tsadok <itsadok@gmail.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
scripts/Kbuild.include is included everywhere, but macros such as
cc-option are needed by build targets only.
For example, when 'make clean' traverses the tree, it does not need
to evaluate $(call cc-option,).
Split cc-option, ld-option, etc. to scripts/Makefile.compiler, which
is only included from the top Makefile and scripts/Makefile.build.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
When the .config file is missing, 'make config', 'make menuconfig', etc.
uses a file listed in DEFCONFIG_LIST, if found, as base configuration.
Ususally, /boot/config-$(uname -r) exists, and is used as default.
However, when you are cross-compiling the kernel, it does not make
sense to use /boot/config-* on the build host. It should default to
arch/$(SRCARCH)/configs/$(KBUILD_DEFCONFIG).
UML previously did not use DEFCONFIG_LIST at all, but it should be
able to use arch/um/configs/$(KBUILD_DEFCONFIG) as a base config file.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
This is a partial revert of commit 2a86f66121 ("kbuild: use
KBUILD_DEFCONFIG as the fallback for DEFCONFIG_LIST").
Now that the reference to $(DEFCONFIG_LIST) was removed from
init/Kconfig, the default KBUILD_DEFCONFIG can go back home.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
The "mrproper" target is still looking for build time generated keys in
the kernel root directory instead of certs directory. Fix the path and
remove the names of the files which are no longer generated.
Fixes: cfc411e7ff ("Move certificate handling to its own directory")
Signed-off-by: Nayna Jain <nayna@linux.ibm.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
This change adds support for Clang’s forward-edge Control Flow
Integrity (CFI) checking. With CONFIG_CFI_CLANG, the compiler
injects a runtime check before each indirect function call to ensure
the target is a valid function with the correct static type. This
restricts possible call targets and makes it more difficult for
an attacker to exploit bugs that allow the modification of stored
function pointers. For more details, see:
https://clang.llvm.org/docs/ControlFlowIntegrity.html
Clang requires CONFIG_LTO_CLANG to be enabled with CFI to gain
visibility to possible call targets. Kernel modules are supported
with Clang’s cross-DSO CFI mode, which allows checking between
independently compiled components.
With CFI enabled, the compiler injects a __cfi_check() function into
the kernel and each module for validating local call targets. For
cross-module calls that cannot be validated locally, the compiler
calls the global __cfi_slowpath_diag() function, which determines
the target module and calls the correct __cfi_check() function. This
patch includes a slowpath implementation that uses __module_address()
to resolve call targets, and with CONFIG_CFI_CLANG_SHADOW enabled, a
shadow map that speeds up module look-ups by ~3x.
Clang implements indirect call checking using jump tables and
offers two methods of generating them. With canonical jump tables,
the compiler renames each address-taken function to <function>.cfi
and points the original symbol to a jump table entry, which passes
__cfi_check() validation. This isn’t compatible with stand-alone
assembly code, which the compiler doesn’t instrument, and would
result in indirect calls to assembly code to fail. Therefore, we
default to using non-canonical jump tables instead, where the compiler
generates a local jump table entry <function>.cfi_jt for each
address-taken function, and replaces all references to the function
with the address of the jump table entry.
Note that because non-canonical jump table addresses are local
to each component, they break cross-module function address
equality. Specifically, the address of a global function will be
different in each module, as it's replaced with the address of a local
jump table entry. If this address is passed to a different module,
it won’t match the address of the same function taken there. This
may break code that relies on comparing addresses passed from other
components.
CFI checking can be disabled in a function with the __nocfi attribute.
Additionally, CFI can be disabled for an entire compilation unit by
filtering out CC_FLAGS_CFI.
By default, CFI failures result in a kernel panic to stop a potential
exploit. CONFIG_CFI_PERMISSIVE enables a permissive mode, where the
kernel prints out a rate-limited warning instead, and allows execution
to continue. This option is helpful for locating type mismatches, but
should only be enabled during development.
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210408182843.1754385-2-samitolvanen@google.com
This provides the ability for architectures to enable kernel stack base
address offset randomization. This feature is controlled by the boot
param "randomize_kstack_offset=on/off", with its default value set by
CONFIG_RANDOMIZE_KSTACK_OFFSET_DEFAULT.
This feature is based on the original idea from the last public release
of PaX's RANDKSTACK feature: https://pax.grsecurity.net/docs/randkstack.txt
All the credit for the original idea goes to the PaX team. Note that
the design and implementation of this upstream randomize_kstack_offset
feature differs greatly from the RANDKSTACK feature (see below).
Reasoning for the feature:
This feature aims to make harder the various stack-based attacks that
rely on deterministic stack structure. We have had many such attacks in
past (just to name few):
https://jon.oberheide.org/files/infiltrate12-thestackisback.pdfhttps://jon.oberheide.org/files/stackjacking-infiltrate11.pdfhttps://googleprojectzero.blogspot.com/2016/06/exploiting-recursion-in-linux-kernel_20.html
As Linux kernel stack protections have been constantly improving
(vmap-based stack allocation with guard pages, removal of thread_info,
STACKLEAK), attackers have had to find new ways for their exploits
to work. They have done so, continuing to rely on the kernel's stack
determinism, in situations where VMAP_STACK and THREAD_INFO_IN_TASK_STRUCT
were not relevant. For example, the following recent attacks would have
been hampered if the stack offset was non-deterministic between syscalls:
https://repositorio-aberto.up.pt/bitstream/10216/125357/2/374717.pdf
(page 70: targeting the pt_regs copy with linear stack overflow)
https://a13xp0p0v.github.io/2020/02/15/CVE-2019-18683.html
(leaked stack address from one syscall as a target during next syscall)
The main idea is that since the stack offset is randomized on each system
call, it is harder for an attack to reliably land in any particular place
on the thread stack, even with address exposures, as the stack base will
change on the next syscall. Also, since randomization is performed after
placing pt_regs, the ptrace-based approach[1] to discover the randomized
offset during a long-running syscall should not be possible.
Design description:
During most of the kernel's execution, it runs on the "thread stack",
which is pretty deterministic in its structure: it is fixed in size,
and on every entry from userspace to kernel on a syscall the thread
stack starts construction from an address fetched from the per-cpu
cpu_current_top_of_stack variable. The first element to be pushed to the
thread stack is the pt_regs struct that stores all required CPU registers
and syscall parameters. Finally the specific syscall function is called,
with the stack being used as the kernel executes the resulting request.
The goal of randomize_kstack_offset feature is to add a random offset
after the pt_regs has been pushed to the stack and before the rest of the
thread stack is used during the syscall processing, and to change it every
time a process issues a syscall. The source of randomness is currently
architecture-defined (but x86 is using the low byte of rdtsc()). Future
improvements for different entropy sources is possible, but out of scope
for this patch. Further more, to add more unpredictability, new offsets
are chosen at the end of syscalls (the timing of which should be less
easy to measure from userspace than at syscall entry time), and stored
in a per-CPU variable, so that the life of the value does not stay
explicitly tied to a single task.
As suggested by Andy Lutomirski, the offset is added using alloca()
and an empty asm() statement with an output constraint, since it avoids
changes to assembly syscall entry code, to the unwinder, and provides
correct stack alignment as defined by the compiler.
In order to make this available by default with zero performance impact
for those that don't want it, it is boot-time selectable with static
branches. This way, if the overhead is not wanted, it can just be
left turned off with no performance impact.
The generated assembly for x86_64 with GCC looks like this:
...
ffffffff81003977: 65 8b 05 02 ea 00 7f mov %gs:0x7f00ea02(%rip),%eax
# 12380 <kstack_offset>
ffffffff8100397e: 25 ff 03 00 00 and $0x3ff,%eax
ffffffff81003983: 48 83 c0 0f add $0xf,%rax
ffffffff81003987: 25 f8 07 00 00 and $0x7f8,%eax
ffffffff8100398c: 48 29 c4 sub %rax,%rsp
ffffffff8100398f: 48 8d 44 24 0f lea 0xf(%rsp),%rax
ffffffff81003994: 48 83 e0 f0 and $0xfffffffffffffff0,%rax
...
As a result of the above stack alignment, this patch introduces about
5 bits of randomness after pt_regs is spilled to the thread stack on
x86_64, and 6 bits on x86_32 (since its has 1 fewer bit required for
stack alignment). The amount of entropy could be adjusted based on how
much of the stack space we wish to trade for security.
My measure of syscall performance overhead (on x86_64):
lmbench: /usr/lib/lmbench/bin/x86_64-linux-gnu/lat_syscall -N 10000 null
randomize_kstack_offset=y Simple syscall: 0.7082 microseconds
randomize_kstack_offset=n Simple syscall: 0.7016 microseconds
So, roughly 0.9% overhead growth for a no-op syscall, which is very
manageable. And for people that don't want this, it's off by default.
There are two gotchas with using the alloca() trick. First,
compilers that have Stack Clash protection (-fstack-clash-protection)
enabled by default (e.g. Ubuntu[3]) add pagesize stack probes to
any dynamic stack allocations. While the randomization offset is
always less than a page, the resulting assembly would still contain
(unreachable!) probing routines, bloating the resulting assembly. To
avoid this, -fno-stack-clash-protection is unconditionally added to
the kernel Makefile since this is the only dynamic stack allocation in
the kernel (now that VLAs have been removed) and it is provably safe
from Stack Clash style attacks.
The second gotcha with alloca() is a negative interaction with
-fstack-protector*, in that it sees the alloca() as an array allocation,
which triggers the unconditional addition of the stack canary function
pre/post-amble which slows down syscalls regardless of the static
branch. In order to avoid adding this unneeded check and its associated
performance impact, architectures need to carefully remove uses of
-fstack-protector-strong (or -fstack-protector) in the compilation units
that use the add_random_kstack() macro and to audit the resulting stack
mitigation coverage (to make sure no desired coverage disappears). No
change is visible for this on x86 because the stack protector is already
unconditionally disabled for the compilation unit, but the change is
required on arm64. There is, unfortunately, no attribute that can be
used to disable stack protector for specific functions.
Comparison to PaX RANDKSTACK feature:
The RANDKSTACK feature randomizes the location of the stack start
(cpu_current_top_of_stack), i.e. including the location of pt_regs
structure itself on the stack. Initially this patch followed the same
approach, but during the recent discussions[2], it has been determined
to be of a little value since, if ptrace functionality is available for
an attacker, they can use PTRACE_PEEKUSR/PTRACE_POKEUSR to read/write
different offsets in the pt_regs struct, observe the cache behavior of
the pt_regs accesses, and figure out the random stack offset. Another
difference is that the random offset is stored in a per-cpu variable,
rather than having it be per-thread. As a result, these implementations
differ a fair bit in their implementation details and results, though
obviously the intent is similar.
[1] https://lore.kernel.org/kernel-hardening/2236FBA76BA1254E88B949DDB74E612BA4BC57C1@IRSMSX102.ger.corp.intel.com/
[2] https://lore.kernel.org/kernel-hardening/20190329081358.30497-1-elena.reshetova@intel.com/
[3] https://lists.ubuntu.com/archives/ubuntu-devel/2019-June/040741.html
Co-developed-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210401232347.2791257-4-keescook@chromium.org
VPATH is used in Kbuild to make pattern rules search for prerequisites
in both $(objtree) and $(srctree). Some of *.c, *.S files are not real
sources, but generated by tools such as flex, bison, perl.
In contrast, I doubt the benefit of --include-dir=$(abs_srctree) because
it is always clear which Makefiles are real sources, and which are not.
So, my hope is to add $(srctree)/ prefix to all check-in Makefiles,
then remove --include-dir=$(abs_srctree) flag in the future.
I am touching only some Kbuild core parts for now. Treewide fixes will
be needed to achieve this goal.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Linus reported a build error due to the GCC plugin incompatibility
when the compiler is upgraded. [1]
GCC plugins are tied to a particular GCC version. So, they must be
rebuilt when the compiler is upgraded.
This seems to be a long-standing flaw since the initial support of
GCC plugins.
Extend commit 8b59cd81dc ("kbuild: ensure full rebuild when the
compiler is updated"), so that GCC plugins are covered by the
compiler upgrade detection.
[1]: https://lore.kernel.org/lkml/CAHk-=wieoN5ttOy7SnsGwZv+Fni3R6m-Ut=oxih6bbZ28G+4dw@mail.gmail.com/
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
'make image_name' needs include/config/auto.conf to show the correct
output because KBUILD_IMAGE depends on CONFIG options, but should not
attempt to resync the configuration.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Commit 78d3bb4483 ("kbuild: Fix <linux/version.h> for empty SUBLEVEL
or PATCHLEVEL") fixed the build error for empty SUBLEVEL or PATCHLEVEL
by prepending a zero.
Commit 9b82f13e7e ("kbuild: clamp SUBLEVEL to 255") re-introduced
this issue.
This time, we cannot take the same approach because we have C code:
#define LINUX_VERSION_PATCHLEVEL $(PATCHLEVEL)
#define LINUX_VERSION_SUBLEVEL $(SUBLEVEL)
Replace empty SUBLEVEL/PATCHLEVEL with a zero.
Fixes: 9b82f13e7e ("kbuild: clamp SUBLEVEL to 255")
Reported-by: Christian Zigotzky <chzigotzky@xenosoft.de>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-and-tested-by: Sasha Levin <sashal@kernel.org>
'make -s' should be really silent. However, 'make -s V=1' prints noisy
log messages from some shell scripts.
Of course, such a combination is odd, but the build system needs to do
the right thing even if a user gives strange input.
If -s is given, KBUILD_VERBOSE should be forced to 0.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Instead of 'make distclean', 'make clean' should remove build artifacts
unneeded by external module builds. Obviously, you do not need to keep
this directory.
Fixes: dc5723b02e ("kbuild: add support for Clang LTO")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210225193912.3303604-1-masahiroy@kernel.org
- Fix false-positive build warnings for ARCH=ia64 builds
- Optimize dictionary size for module compression with xz
- Check the compiler and linker versions in Kconfig
- Fix misuse of extra-y
- Support DWARF v5 debug info
- Clamp SUBLEVEL to 255 because stable releases 4.4.x and 4.9.x
exceeded the limit
- Add generic syscall{tbl,hdr}.sh for cleanups across arches
- Minor cleanups of genksyms
- Minor cleanups of Kconfig
-----BEGIN PGP SIGNATURE-----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=sLxb
-----END PGP SIGNATURE-----
Merge tag 'kbuild-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild updates from Masahiro Yamada:
- Fix false-positive build warnings for ARCH=ia64 builds
- Optimize dictionary size for module compression with xz
- Check the compiler and linker versions in Kconfig
- Fix misuse of extra-y
- Support DWARF v5 debug info
- Clamp SUBLEVEL to 255 because stable releases 4.4.x and 4.9.x
exceeded the limit
- Add generic syscall{tbl,hdr}.sh for cleanups across arches
- Minor cleanups of genksyms
- Minor cleanups of Kconfig
* tag 'kbuild-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (38 commits)
initramfs: Remove redundant dependency of RD_ZSTD on BLK_DEV_INITRD
kbuild: remove deprecated 'always' and 'hostprogs-y/m'
kbuild: parse C= and M= before changing the working directory
kbuild: reuse this-makefile to define abs_srctree
kconfig: unify rule of config, menuconfig, nconfig, gconfig, xconfig
kconfig: omit --oldaskconfig option for 'make config'
kconfig: fix 'invalid option' for help option
kconfig: remove dead code in conf_askvalue()
kconfig: clean up nested if-conditionals in check_conf()
kconfig: Remove duplicate call to sym_get_string_value()
Makefile: Remove # characters from compiler string
Makefile: reuse CC_VERSION_TEXT
kbuild: check the minimum linker version in Kconfig
kbuild: remove ld-version macro
scripts: add generic syscallhdr.sh
scripts: add generic syscalltbl.sh
arch: syscalls: remove $(srctree)/ prefix from syscall tables
arch: syscalls: add missing FORCE and fix 'targets' to make if_changed work
gen_compile_commands: prune some directories
kbuild: simplify access to the kernel's version
...
If Kbuild recurses to the top Makefile (for example, 'make deb-pkg'),
C= and M= are parsed over again, needlessly.
Parse them before changing the working directory. After that,
sub_make_done is set to 1, so they are parsed just once.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
When using AMD's Optimizing C/C++ Compiler (AOCC), the build fails due
to a # character in the version string, which is interpreted as a
comment:
$ make CC=clang defconfig init/main.o
include/config/auto.conf.cmd:1374: *** invalid syntax in conditional. Stop.
$ sed -n 1374p include/config/auto.conf.cmd
ifneq "$(CC_VERSION_TEXT)" "AMD clang version 11.0.0 (CLANG: AOCC_2.3.0-Build#85 2020_11_10) (based on LLVM Mirror.Version.11.0.0)"
Remove all # characters in the version string so that the build does not
fail unexpectedly.
Link: https://github.com/ClangBuiltLinux/linux/issues/1298
Reported-by: Michael Fuckner <michael@fuckner.net>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
I noticed we're invoking $(CC) via $(shell) more than once to check the
version. Let's reuse the first string captured in $CC_VERSION_TEXT.
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
[masahiro.yamada:
CC_VERSION_TEXT is assigned by = instead of :=, so this $(shell ) is
evaluated multiple times anyway. The number of $(CC) invocations will
be still the same. Replacing 'grep' with the built-in $(findstring )
will give real performance benefit.]
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
- Generate __mcount_loc in objtool (Peter Zijlstra)
- Support running objtool against vmlinux.o (Sami Tolvanen)
- Clang LTO enablement for x86 (Sami Tolvanen)
-----BEGIN PGP SIGNATURE-----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=htKJ
-----END PGP SIGNATURE-----
Merge tag 'clang-lto-v5.12-rc1-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull more clang LTO updates from Kees Cook:
"Clang LTO x86 enablement.
Full disclosure: while this has _not_ been in linux-next (since it
initially looked like the objtool dependencies weren't going to make
v5.12), it has been under daily build and runtime testing by Sami for
quite some time. These x86 portions have been discussed on lkml, with
Peter, Josh, and others helping nail things down.
The bulk of the changes are to get objtool working happily. The rest
of the x86 enablement is very small.
Summary:
- Generate __mcount_loc in objtool (Peter Zijlstra)
- Support running objtool against vmlinux.o (Sami Tolvanen)
- Clang LTO enablement for x86 (Sami Tolvanen)"
Link: https://lore.kernel.org/lkml/20201013003203.4168817-26-samitolvanen@google.com/
Link: https://lore.kernel.org/lkml/cover.1611263461.git.jpoimboe@redhat.com/
* tag 'clang-lto-v5.12-rc1-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
kbuild: lto: force rebuilds when switching CONFIG_LTO
x86, build: allow LTO to be selected
x86, cpu: disable LTO for cpu.c
x86, vdso: disable LTO only for vDSO
kbuild: lto: postpone objtool
objtool: Split noinstr validation from --vmlinux
x86, build: use objtool mcount
tracing: add support for objtool mcount
objtool: Don't autodetect vmlinux.o
objtool: Fix __mcount_loc generation with Clang's assembler
objtool: Add a pass for generating __mcount_loc
When doing non-clean builds and switching between CONFIG_LTO=n and
CONFIG_LTO=y, the build system (correctly) didn't notice that assembly
and LTO-excluded C object files were rewritten in place by objtool (to
add the .orc_unwind* sections), since their build command lines were the
same between CONFIG_LTO=y and CONFIG_LTO=n. The objtool step would fail:
vmlinux.o: warning: objtool: file already has .orc_unwind section, skipping
make: *** [Makefile:1194: vmlinux] Error 255
Avoid this by making sure the build will see a difference between an LTO
and non-LTO build (by including "-fno-lto" in KBUILD_*FLAGS). This will
get ignored when CC_FLAGS_LTO is present, and will not be included at
all when CONFIG_LTO=n.
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
- Clang LTO build infrastructure and arm64-specific enablement (Sami Tolvanen)
- Recursive build CC_FLAGS_LTO fix (Alexander Lobakin)
-----BEGIN PGP SIGNATURE-----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=6peY
-----END PGP SIGNATURE-----
Merge tag 'clang-lto-v5.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull clang LTO updates from Kees Cook:
"Clang Link Time Optimization.
This is built on the work done preparing for LTO by arm64 folks,
tracing folks, etc. This includes the core changes as well as the
remaining pieces for arm64 (LTO has been the default build method on
Android for about 3 years now, as it is the prerequisite for the
Control Flow Integrity protections).
While x86 LTO enablement is done, it depends on some pending objtool
clean-ups. It's possible that I'll send a "part 2" pull request for
LTO that includes x86 support.
For merge log posterity, and as detailed in commit dc5723b02e
("kbuild: add support for Clang LTO"), here is the lt;dr to do an LTO
build:
make LLVM=1 LLVM_IAS=1 defconfig
scripts/config -e LTO_CLANG_THIN
make LLVM=1 LLVM_IAS=1
(To do a cross-compile of arm64, add "CROSS_COMPILE=aarch64-linux-gnu-"
and "ARCH=arm64" to the "make" command lines.)
Summary:
- Clang LTO build infrastructure and arm64-specific enablement (Sami
Tolvanen)
- Recursive build CC_FLAGS_LTO fix (Alexander Lobakin)"
* tag 'clang-lto-v5.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
kbuild: prevent CC_FLAGS_LTO self-bloating on recursive rebuilds
arm64: allow LTO to be selected
arm64: disable recordmcount with DYNAMIC_FTRACE_WITH_REGS
arm64: vdso: disable LTO
drivers/misc/lkdtm: disable LTO for rodata.o
efi/libstub: disable LTO
scripts/mod: disable LTO for empty.c
modpost: lto: strip .lto from module names
PCI: Fix PREL32 relocations for LTO
init: lto: fix PREL32 relocations
init: lto: ensure initcall ordering
kbuild: lto: add a default list of used symbols
kbuild: lto: merge module sections
kbuild: lto: limit inlining
kbuild: lto: fix module versioning
kbuild: add support for Clang LTO
tracing: move function tracer options to Kconfig
- Sync dtc to upstream version v1.6.0-51-g183df9e9c2b9 and build
host fdtoverlay
- Add kbuild support to build DT overlays (%.dtbo)
- Drop NULLifying match table in of_match_device(). In preparation for
this, there are several driver cleanups to use
(of_)?device_get_match_data().
- Drop pointless wrappers from DT struct device API
- Convert USB binding schemas to use graph schema and remove old plain
text graph binding doc
- Convert spi-nor and v3d GPU bindings to DT schema
- Tree wide schema fixes for if/then schemas, array size constraints,
and undocumented compatible strings in examples
- Handle 'no-map' correctly for already reserved memblock regions
-----BEGIN PGP SIGNATURE-----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=9V4A
-----END PGP SIGNATURE-----
Merge tag 'devicetree-for-5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux
Pull devicetree updates from Rob Herring:
- Sync dtc to upstream version v1.6.0-51-g183df9e9c2b9 and build host
fdtoverlay
- Add kbuild support to build DT overlays (%.dtbo)
- Drop NULLifying match table in of_match_device().
In preparation for this, there are several driver cleanups to use
(of_)?device_get_match_data().
- Drop pointless wrappers from DT struct device API
- Convert USB binding schemas to use graph schema and remove old plain
text graph binding doc
- Convert spi-nor and v3d GPU bindings to DT schema
- Tree wide schema fixes for if/then schemas, array size constraints,
and undocumented compatible strings in examples
- Handle 'no-map' correctly for already reserved memblock regions
* tag 'devicetree-for-5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux: (35 commits)
driver core: platform: Drop of_device_node_put() wrapper
of: Remove of_dev_{get,put}()
dt-bindings: usb: Change descibe to describe in usbmisc-imx.txt
dt-bindings: can: rcar_canfd: Group tuples in pin control properties
dt-bindings: power: renesas,apmu: Group tuples in cpus properties
dt-bindings: mtd: spi-nor: Convert to DT schema format
dt-bindings: Use portable sort for version cmp
dt-bindings: ethernet-controller: fix fixed-link specification
dt-bindings: irqchip: Add node name to PRUSS INTC
dt-bindings: interconnect: Fix the expected number of cells
dt-bindings: Fix errors in 'if' schemas
dt-bindings: iommu: renesas,ipmmu-vmsa: Make 'power-domains' conditionally required
dt-bindings: Fix undocumented compatible strings in examples
kbuild: Add support to build overlays (%.dtbo)
scripts: dtc: Remove the unused fdtdump.c file
scripts: dtc: Build fdtoverlay tool
scripts/dtc: Update to upstream version v1.6.0-51-g183df9e9c2b9
scripts: dtc: Fetch fdtoverlay.c from external DTC project
dt-bindings: thermal: sun8i: Fix misplaced schema keyword in compatible strings
dt-bindings: iio: dac: Fix AD5686 references
...
Pull networking updates from David Miller:
"Here is what we have this merge window:
1) Support SW steering for mlx5 Connect-X6Dx, from Yevgeny Kliteynik.
2) Add RSS multi group support to octeontx2-pf driver, from Geetha
Sowjanya.
3) Add support for KS8851 PHY. From Marek Vasut.
4) Add support for GarfieldPeak bluetooth controller from Kiran K.
5) Add support for half-duplex tcan4x5x can controllers.
6) Add batch skb rx processing to bcrm63xx_enet, from Sieng Piaw
Liew.
7) Rework RX port offload infrastructure, particularly wrt, UDP
tunneling, from Jakub Kicinski.
8) Add BCM72116 PHY support, from Florian Fainelli.
9) Remove Dsa specific notifiers, they are unnecessary. From Vladimir
Oltean.
10) Add support for picosecond rx delay in dwmac-meson8b chips. From
Martin Blumenstingl.
11) Support TSO on xfrm interfaces from Eyal Birger.
12) Add support for MP_PRIO to mptcp stack, from Geliang Tang.
13) Support BCM4908 integrated switch, from Rafał Miłecki.
14) Support for directly accessing kernel module variables via module
BTF info, from Andrii Naryiko.
15) Add DASH (esktop and mobile Architecture for System Hardware)
support to r8169 driver, from Heiner Kallweit.
16) Add rx vlan filtering to dpaa2-eth, from Ionut-robert Aron.
17) Add support for 100 base0x SFP devices, from Bjarni Jonasson.
18) Support link aggregation in DSA, from Tobias Waldekranz.
19) Support for bitwidse atomics in bpf, from Brendan Jackman.
20) SmartEEE support in at803x driver, from Russell King.
21) Add support for flow based tunneling to GTP, from Pravin B Shelar.
22) Allow arbitrary number of interconnrcts in ipa, from Alex Elder.
23) TLS RX offload for bonding, from Tariq Toukan.
24) RX decap offklload support in mac80211, from Felix Fietkou.
25) devlink health saupport in octeontx2-af, from George Cherian.
26) Add TTL attr to SCM_TIMESTAMP_OPT_STATS, from Yousuk Seung
27) Delegated actionss support in mptcp, from Paolo Abeni.
28) Support receive timestamping when doin zerocopy tcp receive. From
Arjun Ray.
29) HTB offload support for mlx5, from Maxim Mikityanskiy.
30) UDP GRO forwarding, from Maxim Mikityanskiy.
31) TAPRIO offloading in dsa hellcreek driver, from Kurt Kanzenbach.
32) Weighted random twos choice algorithm for ipvs, from Darby Payne.
33) Fix netdev registration deadlock, from Johannes Berg.
34) Various conversions to new tasklet api, from EmilRenner Berthing.
35) Bulk skb allocations in veth, from Lorenzo Bianconi.
36) New ethtool interface for lane setting, from Danielle Ratson.
37) Offload failiure notifications for routes, from Amit Cohen.
38) BCM4908 support, from Rafał Miłecki.
39) Support several new iwlwifi chips, from Ihab Zhaika.
40) Flow drector support for ipv6 in i40e, from Przemyslaw Patynowski.
41) Support for mhi prrotocols, from Loic Poulain.
42) Optimize bpf program stats.
43) Implement RFC6056, for better port randomization, from Eric
Dumazet.
44) hsr tag offloading support from George McCollister.
45) Netpoll support in qede, from Bhaskar Upadhaya.
46) 2005/400g speed support in bonding 3ad mode, from Nikolay
Aleksandrov.
47) Netlink event support in mptcp, from Florian Westphal.
48) Better skbuff caching, from Alexander Lobakin.
49) MRP (Media Redundancy Protocol) offloading in DSA and a few
drivers, from Horatiu Vultur.
50) mqprio saupport in mvneta, from Maxime Chevallier.
51) Remove of_phy_attach, no longer needed, from Florian Fainelli"
* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1766 commits)
octeontx2-pf: Fix otx2_get_fecparam()
cteontx2-pf: cn10k: Prevent harmless double shift bugs
net: stmmac: Add PCI bus info to ethtool driver query output
ptp: ptp_clockmatrix: clean-up - parenthesis around a == b are unnecessary
ptp: ptp_clockmatrix: Simplify code - remove unnecessary `err` variable.
ptp: ptp_clockmatrix: Coding style - tighten vertical spacing.
ptp: ptp_clockmatrix: Clean-up dev_*() messages.
ptp: ptp_clockmatrix: Remove unused header declarations.
ptp: ptp_clockmatrix: Add alignment of 1 PPS to idtcm_perout_enable.
ptp: ptp_clockmatrix: Add wait_for_sys_apll_dpll_lock.
net: stmmac: dwmac-sun8i: Add a shutdown callback
net: stmmac: dwmac-sun8i: Minor probe function cleanup
net: stmmac: dwmac-sun8i: Use reset_control_reset
net: stmmac: dwmac-sun8i: Remove unnecessary PHY power check
net: stmmac: dwmac-sun8i: Return void from PHY unpower
r8169: use macro pm_ptr
net: mdio: Remove of_phy_attach()
net: mscc: ocelot: select PACKING in the Kconfig
net: re-solve some conflicts after net -> net-next merge
net: dsa: tag_rtl4_a: Support also egress tags
...
CC_FLAGS_LTO gets initialized only via +=, never with := or =.
When building with CONFIG_TRIM_UNUSED_KSYMS, Kbuild may perform
several kernel rebuilds to satisfy symbol dependencies. In this
case, value of CC_FLAGS_LTO is concatenated each time, which
triggers a full rebuild.
Initialize it with := to fix this.
Fixes: dc5723b02e ("kbuild: add support for Clang LTO")
Signed-off-by: Alexander Lobakin <alobakin@pm.me>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210121184544.659998-1-alobakin@pm.me
Daniel Borkmann says:
====================
pull-request: bpf-next 2021-02-16
The following pull-request contains BPF updates for your *net-next* tree.
There's a small merge conflict between 7eeba1706e ("tcp: Add receive timestamp
support for receive zerocopy.") from net-next tree and 9cacf81f81 ("bpf: Remove
extra lock_sock for TCP_ZEROCOPY_RECEIVE") from bpf-next tree. Resolve as follows:
[...]
lock_sock(sk);
err = tcp_zerocopy_receive(sk, &zc, &tss);
err = BPF_CGROUP_RUN_PROG_GETSOCKOPT_KERN(sk, level, optname,
&zc, &len, err);
release_sock(sk);
[...]
We've added 116 non-merge commits during the last 27 day(s) which contain
a total of 156 files changed, 5662 insertions(+), 1489 deletions(-).
The main changes are:
1) Adds support of pointers to types with known size among global function
args to overcome the limit on max # of allowed args, from Dmitrii Banshchikov.
2) Add bpf_iter for task_vma which can be used to generate information similar
to /proc/pid/maps, from Song Liu.
3) Enable bpf_{g,s}etsockopt() from all sock_addr related program hooks. Allow
rewriting bind user ports from BPF side below the ip_unprivileged_port_start
range, both from Stanislav Fomichev.
4) Prevent recursion on fentry/fexit & sleepable programs and allow map-in-map
as well as per-cpu maps for the latter, from Alexei Starovoitov.
5) Add selftest script to run BPF CI locally. Also enable BPF ringbuffer
for sleepable programs, both from KP Singh.
6) Extend verifier to enable variable offset read/write access to the BPF
program stack, from Andrei Matei.
7) Improve tc & XDP MTU handling and add a new bpf_check_mtu() helper to
query device MTU from programs, from Jesper Dangaard Brouer.
8) Allow bpf_get_socket_cookie() helper also be called from [sleepable] BPF
tracing programs, from Florent Revest.
9) Extend x86 JIT to pad JMPs with NOPs for helping image to converge when
otherwise too many passes are required, from Gary Lin.
10) Verifier fixes on atomics with BPF_FETCH as well as function-by-function
verification both related to zero-extension handling, from Ilya Leoshkevich.
11) Better kernel build integration of resolve_btfids tool, from Jiri Olsa.
12) Batch of AF_XDP selftest cleanups and small performance improvement
for libbpf's xsk map redirect for newer kernels, from Björn Töpel.
13) Follow-up BPF doc and verifier improvements around atomics with
BPF_FETCH, from Brendan Jackman.
14) Permit zero-sized data sections e.g. if ELF .rodata section contains
read-only data from local variables, from Yonghong Song.
15) veth driver skb bulk-allocation for ndo_xdp_xmit, from Lorenzo Bianconi.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Instead of storing the version in a single integer and having various
kernel (and userspace) code how it's constructed, export individual
(major, patchlevel, sublevel) components and simplify kernel code that
uses it.
This should also make it easier on userspace.
Signed-off-by: Sasha Levin <sashal@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Right now if SUBLEVEL becomes larger than 255 it will overflow into the
territory of PATCHLEVEL, causing havoc in userspace that tests for
specific kernel version.
While userspace code tests for MAJOR and PATCHLEVEL, it doesn't test
SUBLEVEL at any point as ABI changes don't happen in the context of
stable tree.
Thus, to avoid overflows, simply clamp SUBLEVEL to it's maximum value in
the context of LINUX_VERSION_CODE. This does not affect "make
kernelversion" and such.
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
DWARF v5 is the latest standard of the DWARF debug info format. GCC 11
will change the implicit default DWARF version, if left unspecified, to
DWARF v5.
Allow users of Clang and older versions of GCC that have not changed the
implicit default DWARF version to DWARF v5 to opt in. This can help
testing consumers of DWARF debug info in preparation of v5 becoming more
widespread, as well as result in significant binary size savings of the
pre-stripped vmlinux image.
DWARF5 wins significantly in terms of size when mixed with compression
(CONFIG_DEBUG_INFO_COMPRESSED).
363M vmlinux.clang12.dwarf5.compressed
434M vmlinux.clang12.dwarf4.compressed
439M vmlinux.clang12.dwarf2.compressed
457M vmlinux.clang12.dwarf5
536M vmlinux.clang12.dwarf4
548M vmlinux.clang12.dwarf2
515M vmlinux.gcc10.2.dwarf5.compressed
599M vmlinux.gcc10.2.dwarf4.compressed
624M vmlinux.gcc10.2.dwarf2.compressed
630M vmlinux.gcc10.2.dwarf5
765M vmlinux.gcc10.2.dwarf4
809M vmlinux.gcc10.2.dwarf2
Though the quality of debug info is harder to quantify; size is not a
proxy for quality.
Jakub notes:
One thing is GCC DWARF-5 support, that is whether the compiler will
support -gdwarf-5 flag, and that support should be there from GCC 7
onwards.
All [GCC] 5.1 - 6.x did was start accepting -gdwarf-5 as experimental
option that enabled some small DWARF subset (initially only a few
DW_LANG_* codes newly added to DWARF5 drafts). Only GCC 7 (released
after DWARF 5 has been finalized) started emitting DWARF5 section
headers and got most of the DWARF5 changes in...
Another separate thing is whether the assembler does support
the -gdwarf-5 option (i.e. if you can compile assembler files
with -Wa,-gdwarf-5) ... That option is about whether the assembler
will emit DWARF5 or DWARF2 .debug_line. It is fine to compile C sources
with -gdwarf-5 and use DWARF2 .debug_line for assembler files if as
doesn't support it.
Version check GCC so that we don't need to worry about the difference in
command line args between GNU readelf and llvm-readelf/llvm-dwarfdump to
validate the DWARF Version in the assembler feature detection script.
Most issues with clang produced assembler were fixed in binutils 2.35.1,
but 2.35.2 fixed issues related to requiring the flag -Wa,-gdwarf-5
explicitly. The added shell script test checks for the latter, and is
only required when using clang without its integrated assembler, though
we use for clang regardless as we do not yet have a way to query the
assembler from Kconfig.
Disabled for now if CONFIG_DEBUG_INFO_BTF is set; pahole doesn't yet
recognize the new additions to the DWARF debug info.
This only modifies the DWARF version emitted by the compiler, not the
assembler.
The DWARF version of a binary can be validated with:
$ llvm-dwarfdump <object file> | head -n 4 | grep version
or
$ readelf --debug-dump=info <object file> 2>/dev/null | grep Version
Parts of the tree don't reuse DEBUG_CFLAGS as they should; such cleanup
is left as a follow up.
Link: http://www.dwarfstd.org/doc/DWARF5.pdf
Link: https://bugzilla.redhat.com/show_bug.cgi?id=1922707
Reported-by: Sedat Dilek <sedat.dilek@gmail.com>
Suggested-by: Arvind Sankar <nivedita@alum.mit.edu>
Suggested-by: Caroline Tice <cmtice@google.com>
Suggested-by: Fangrui Song <maskray@google.com>
Suggested-by: Jakub Jelinek <jakub@redhat.com>
Suggested-by: Masahiro Yamada <masahiroy@kernel.org>
Suggested-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com> # LLVM/Clang v12.0.0-rc1 x86-64
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Adds a default CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT which allows
the implicit default version of DWARF emitted by the toolchain to
progress over time.
Modifies CONFIG_DEBUG_INFO_DWARF4 to be a member of a choice, making it
mutually exclusive with CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT. Users
may want to select this if they are using a newer toolchain, but have
consumers of the DWARF debug info that aren't yet ready for newer DWARF
versions' debug info.
Does so in a way that's forward compatible with existing
configs, and makes adding future versions more straightforward. This
patch does not change the current behavior or selection of DWARF
version for users upgrading to kernels with this patch.
GCC since ~4.8 has defaulted to DWARF v4 implicitly, and GCC 11 has
bumped this to v5.
Remove the Kconfig help text about DWARF v4 being larger. It's
empirically false for the latest toolchains for x86_64 defconfig, has no
point of reference (I suspect it was DWARF v2 but that's stil
empirically false), and debug info size is not a qualatative measure.
Suggested-by: Arvind Sankar <nivedita@alum.mit.edu>
Suggested-by: Fangrui Song <maskray@google.com>
Suggested-by: Jakub Jelinek <jakub@redhat.com>
Suggested-by: Mark Wielaard <mark@klomp.org>
Suggested-by: Masahiro Yamada <masahiroy@kernel.org>
Suggested-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Revert commit 223c24a7db ("kbuild: Automatically remove stale
<linux/version.h> file").
It was more than 6 years ago. I do not expect anybody to start
git-bisect for such a big window.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
By default, xz without parameters uses a dictionary size of 8 MB.
However, most modules are much smaller than that.
The xz manpage states that 'increasing dictionary size usually improves
compression ratio, but a dictionary bigger than the uncompressed file
is waste of memory'.
Use a dictionary size of 2 MB for module compression, resulting in
slightly higher compression speed while still maintaining a good
compression ratio.
Signed-off-by: Tor Vic <torvic9@mailbox.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Nathan reported issue with cleaning empty build directory:
$ make -s O=build distclean
../../scripts/Makefile.include:4: *** \
O=/ho...build/tools/bpf/resolve_btfids does not exist. Stop.
The problem that tools scripts require existing output
directory, otherwise it fails.
Adding check around the resolve_btfids clean target to
ensure the output directory is in place.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/bpf/20210211124004.1144344-1-jolsa@kernel.org
The resolve_btfids tool is used during the kernel build,
so we should clean it on kernel's make clean.
Invoking the the resolve_btfids clean as part of root
'make clean'.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20210205124020.683286-5-jolsa@kernel.org
with certain kernel configs and LLVM.
- Disable setting breakpoints on facilities involved in #DB exception handling
to avoid infinite loops.
- Add extra serialization to non-serializing MSRs (IA32_TSC_DEADLINE and
x2 APIC MSRs) to adhere to SDM's recommendation and avoid any theoretical
issues.
- Re-add the EPB MSR reading on turbostat so that it works on older
kernels which don't have the corresponding EPB sysfs file.
- Add Alder Lake to the list of CPUs which support split lock.
- Fix %dr6 register handling in order to be able to set watchpoints with gdb
again.
- Disable CET instrumentation in the kernel so that gcc doesn't add
ENDBR64 to kernel code and thus confuse tracing.
-----BEGIN PGP SIGNATURE-----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=XwH4
-----END PGP SIGNATURE-----
Merge tag 'x86_urgent_for_v5.11_rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Borislav Petkov:
"I hope this is the last batch of x86/urgent updates for this round:
- Remove superfluous EFI PGD range checks which lead to those
assertions failing with certain kernel configs and LLVM.
- Disable setting breakpoints on facilities involved in #DB exception
handling to avoid infinite loops.
- Add extra serialization to non-serializing MSRs (IA32_TSC_DEADLINE
and x2 APIC MSRs) to adhere to SDM's recommendation and avoid any
theoretical issues.
- Re-add the EPB MSR reading on turbostat so that it works on older
kernels which don't have the corresponding EPB sysfs file.
- Add Alder Lake to the list of CPUs which support split lock.
- Fix %dr6 register handling in order to be able to set watchpoints
with gdb again.
- Disable CET instrumentation in the kernel so that gcc doesn't add
ENDBR64 to kernel code and thus confuse tracing"
* tag 'x86_urgent_for_v5.11_rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/efi: Remove EFI PGD build time checks
x86/debug: Prevent data breakpoints on cpu_dr7
x86/debug: Prevent data breakpoints on __per_cpu_offset
x86/apic: Add extra serialization for non-serializing MSRs
tools/power/turbostat: Fallback to an MSR read for EPB
x86/split_lock: Enable the split lock feature on another Alder Lake CPU
x86/debug: Fix DR6 handling
x86/build: Disable CET instrumentation in the kernel
- Use the 'python3' command to invoke python scripts because some
distributions do not provide the 'python' command any more.
- Clean-up and update documents
- Use pkg-config to search libcrypto
- Fix duplicated debug flags
- Ignore some more stubs in scripts/kallsyms.c
-----BEGIN PGP SIGNATURE-----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=DI2e
-----END PGP SIGNATURE-----
Merge tag 'kbuild-fixes-v5.11-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild fixes from Masahiro Yamada:
- Use the 'python3' command to invoke python scripts because some
distributions do not provide the 'python' command any more.
- Clean-up and update documents
- Use pkg-config to search libcrypto
- Fix duplicated debug flags
- Ignore some more stubs in scripts/kallsyms.c
* tag 'kbuild-fixes-v5.11-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
kallsyms: fix nonconverging kallsyms table with lld
kbuild: fix duplicated flags in DEBUG_CFLAGS
scripts/clang-tools: switch explicitly to Python 3
kbuild: remove PYTHON variable
Documentation/llvm: Add a section about supported architectures
Revert "checkpatch: add check for keyword 'boolean' in Kconfig definitions"
scripts: use pkg-config to locate libcrypto
kconfig: mconf: fix HOSTCC call
doc: gcc-plugins: update gcc-plugins.rst
kbuild: simplify GCC_PLUGINS enablement in dummy-tools/gcc
Documentation/Kbuild: Remove references to gcc-plugin.sh
scripts: switch explicitly to Python 3
Sedat Dilek noticed duplicated flags in DEBUG_CFLAGS when building
deb-pkg with CONFIG_DEBUG_INFO. For example, 'make CC=clang bindeb-pkg'
reproduces the issue.
Kbuild recurses to the top Makefile for some targets such as package
builds.
With commit 121c5d08d5 ("kbuild: Only add -fno-var-tracking-assignments
for old GCC versions") applied, DEBUG_CFLAGS is now reset only when
CONFIG_CC_IS_GCC=y.
Fix it to reset DEBUG_CFLAGS all the time.
Fixes: 121c5d08d5 ("kbuild: Only add -fno-var-tracking-assignments for old GCC versions")
Reported-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Reviewed-by: Mark Wielaard <mark@klomp.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Add support for building DT overlays (%.dtbo). The overlay's source file
will have the usual extension, i.e. .dts, though the blob will have
.dtbo extension to distinguish it from normal blobs.
Acked-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/434ba2467dd0cd011565625aeb3450650afe0aae.1611904394.git.viresh.kumar@linaro.org
Python retired in 2020, and some distributions do not provide the
'python' command any more.
As in commit 51839e29cb ("scripts: switch explicitly to Python 3"),
we need to use more specific 'python3' to invoke scripts even if they
are written in a way compatible with both Python 2 and 3.
This commit removes the variable 'PYTHON', and switches the existing
users to 'PYTHON3'.
BTW, PEP 394 (https://www.python.org/dev/peps/pep-0394/) is a helpful
material.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
With retpolines disabled, some configurations of GCC, and specifically
the GCC versions 9 and 10 in Ubuntu will add Intel CET instrumentation
to the kernel by default. That breaks certain tracing scenarios by
adding a superfluous ENDBR64 instruction before the fentry call, for
functions which can be called indirectly.
CET instrumentation isn't currently necessary in the kernel, as CET is
only supported in user space. Disable it unconditionally and move it
into the x86's Makefile as CET/CFI... enablement should be a per-arch
decision anyway.
[ bp: Massage and extend commit message. ]
Fixes: 29be86d7f9 ("kbuild: add -fcf-protection=none when using retpoline flags")
Reported-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Tested-by: Nikolay Borisov <nborisov@suse.com>
Cc: <stable@vger.kernel.org>
Cc: Seth Forshee <seth.forshee@canonical.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Link: https://lkml.kernel.org/r/20210128215219.6kct3h2eiustncws@treble
drivers/net/can/dev.c
b552766c87 ("can: dev: prevent potential information leak in can_fill_info()")
3e77f70e73 ("can: dev: move driver related infrastructure into separate subdir")
0a042c6ec9 ("can: dev: move netlink related code into seperate file")
Code move.
drivers/net/ethernet/mellanox/mlx5/core/en_ethtool.c
57ac4a31c4 ("net/mlx5e: Correctly handle changing the number of queues when the interface is down")
214baf2287 ("net/mlx5e: Support HTB offload")
Adjacent code changes
net/switchdev/switchdev.c
20776b465c ("net: switchdev: don't set port_obj_info->handled true when -EOPNOTSUPP")
ffb68fc58e ("net: switchdev: remove the transaction structure from port object notifiers")
bae33f2b5a ("net: switchdev: remove the transaction structure from port attributes")
Transaction parameter gets dropped otherwise keep the fix.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When CONFIG_NET is disabled, nothing under the net/ directory is
compiled. Move the CONFIG_NET guard to the top Makefile so the net/
directory is entirely skipped.
When Kbuild visits net/Makefile, CONFIG_NET is obvioulsy 'y' because
CONFIG_NET is a bool option. Clean up net/Makefile.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Link: https://lore.kernel.org/r/20210125231659.106201-1-masahiroy@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This change limits function inlining across translation unit boundaries
in order to reduce the binary size with LTO. The -import-instr-limit
flag defines a size limit, as the number of LLVM IR instructions, for
importing functions from other TUs, defaulting to 100.
Based on testing with arm64 defconfig, we found that a limit of 5 is a
reasonable compromise between performance and binary size, reducing the
size of a stripped vmlinux by 11%.
Suggested-by: George Burgess IV <gbiv@google.com>
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20201211184633.3213045-5-samitolvanen@google.com
With CONFIG_MODVERSIONS, version information is linked into each
compilation unit that exports symbols. With LTO, we cannot use this
method as all C code is compiled into LLVM bitcode instead. This
change collects symbol versions into .symversions files and merges
them in link-vmlinux.sh where they are all linked into vmlinux.o at
the same time.
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20201211184633.3213045-4-samitolvanen@google.com
This change adds build system support for Clang's Link Time
Optimization (LTO). With -flto, instead of ELF object files, Clang
produces LLVM bitcode, which is compiled into native code at link
time, allowing the final binary to be optimized globally. For more
details, see:
https://llvm.org/docs/LinkTimeOptimization.html
The Kconfig option CONFIG_LTO_CLANG is implemented as a choice,
which defaults to LTO being disabled. To use LTO, the architecture
must select ARCH_SUPPORTS_LTO_CLANG and support:
- compiling with Clang,
- compiling all assembly code with Clang's integrated assembler,
- and linking with LLD.
While using CONFIG_LTO_CLANG_FULL results in the best runtime
performance, the compilation is not scalable in time or
memory. CONFIG_LTO_CLANG_THIN enables ThinLTO, which allows
parallel optimization and faster incremental builds. ThinLTO is
used by default if the architecture also selects
ARCH_SUPPORTS_LTO_CLANG_THIN:
https://clang.llvm.org/docs/ThinLTO.html
To enable LTO, LLVM tools must be used to handle bitcode files, by
passing LLVM=1 and LLVM_IAS=1 options to make:
$ make LLVM=1 LLVM_IAS=1 defconfig
$ scripts/config -e LTO_CLANG_THIN
$ make LLVM=1 LLVM_IAS=1
To prepare for LTO support with other compilers, common parts are
gated behind the CONFIG_LTO option, and LTO can be disabled for
specific files by filtering out CC_FLAGS_LTO.
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20201211184633.3213045-3-samitolvanen@google.com
Move function tracer options to Kconfig to make it easier to add
new methods for generating __mcount_loc, and to make the options
available also when building kernel modules.
Note that FTRACE_MCOUNT_USE_* options are updated on rebuild and
therefore, work even if the .config was generated in a different
environment.
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20201211184633.3213045-2-samitolvanen@google.com
- Use /usr/bin/env for shebang lines in scripts
- Remove useless -Wnested-externs warning flag
- Update documents
- Refactor log handling in modpost
- Stop building modules without MODULE_LICENSE() tag
- Make the insane combination of 'static' and EXPORT_SYMBOL an error
- Improve genksyms to handle _Static_assert()
-----BEGIN PGP SIGNATURE-----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=+27V
-----END PGP SIGNATURE-----
Merge tag 'kbuild-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild updates from Masahiro Yamada:
- Use /usr/bin/env for shebang lines in scripts
- Remove useless -Wnested-externs warning flag
- Update documents
- Refactor log handling in modpost
- Stop building modules without MODULE_LICENSE() tag
- Make the insane combination of 'static' and EXPORT_SYMBOL an error
- Improve genksyms to handle _Static_assert()
* tag 'kbuild-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
Documentation/kbuild: Document platform dependency practises
Documentation/kbuild: Document COMPILE_TEST dependencies
genksyms: Ignore module scoped _Static_assert()
modpost: turn static exports into error
modpost: turn section mismatches to error from fatal()
modpost: change license incompatibility to error() from fatal()
modpost: turn missing MODULE_LICENSE() into error
modpost: refactor error handling and clarify error/fatal difference
modpost: rename merror() to error()
kbuild: don't hardcode depmod path
kbuild: doc: document subdir-y syntax
kbuild: doc: clarify the difference between extra-y and always-y
kbuild: doc: split if_changed explanation to a separate section
kbuild: doc: merge 'Special Rules' and 'Custom kbuild commands' sections
kbuild: doc: fix 'List directories to visit when descending' section
kbuild: doc: replace arch/$(ARCH)/ with arch/$(SRCARCH)/
kbuild: doc: update the description about kbuild Makefiles
Makefile.extrawarn: remove -Wnested-externs warning
tweewide: Fix most Shebang lines
depmod is not guaranteed to be in /sbin, just let make look for
it in the path like all the other invoked programs
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
- Move -Wcast-align to W=3, which tends to be false-positive and there
is no tree-wide solution.
- Pass -fmacro-prefix-map to KBUILD_CPPFLAGS because it is a preprocessor
option and makes sense for .S files as well.
- Disable -gdwarf-2 for Clang's integrated assembler to avoid warnings.
- Disable --orphan-handling=warn for LLD 10.0.1 to avoid warnings.
- Fix undesirable line breaks in *.mod files.
-----BEGIN PGP SIGNATURE-----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=/ysh
-----END PGP SIGNATURE-----
Merge tag 'kbuild-fixes-v5.10-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild fixes from Masahiro Yamada:
- Move -Wcast-align to W=3, which tends to be false-positive and there
is no tree-wide solution.
- Pass -fmacro-prefix-map to KBUILD_CPPFLAGS because it is a
preprocessor option and makes sense for .S files as well.
- Disable -gdwarf-2 for Clang's integrated assembler to avoid warnings.
- Disable --orphan-handling=warn for LLD 10.0.1 to avoid warnings.
- Fix undesirable line breaks in *.mod files.
* tag 'kbuild-fixes-v5.10-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
kbuild: avoid split lines in .mod files
kbuild: Disable CONFIG_LD_ORPHAN_WARN for ld.lld 10.0.1
kbuild: Hoist '--orphan-handling' into Kconfig
Kbuild: do not emit debug info for assembly with LLVM_IAS=1
kbuild: use -fmacro-prefix-map for .S sources
Makefile.extrawarn: move -Wcast-align to W=3
Currently, '--orphan-handling=warn' is spread out across four different
architectures in their respective Makefiles, which makes it a little
unruly to deal with in case it needs to be disabled for a specific
linker version (in this case, ld.lld 10.0.1).
To make it easier to control this, hoist this warning into Kconfig and
the main Makefile so that disabling it is simpler, as the warning will
only be enabled in a couple places (main Makefile and a couple of
compressed boot folders that blow away LDFLAGS_vmlinx) and making it
conditional is easier due to Kconfig syntax. One small additional
benefit of this is saving a call to ld-option on incremental builds
because we will have already evaluated it for CONFIG_LD_ORPHAN_WARN.
To keep the list of supported architectures the same, introduce
CONFIG_ARCH_WANT_LD_ORPHAN_WARN, which an architecture can select to
gain this automatically after all of the sections are specified and size
asserted. A special thanks to Kees Cook for the help text on this
config.
Link: https://github.com/ClangBuiltLinux/linux/issues/1187
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Clang's integrated assembler produces the warning for assembly files:
warning: DWARF2 only supports one section per compilation unit
If -Wa,-gdwarf-* is unspecified, then debug info is not emitted for
assembly sources (it is still emitted for C sources). This will be
re-enabled for newer DWARF versions in a follow up patch.
Enables defconfig+CONFIG_DEBUG_INFO to build cleanly with
LLVM=1 LLVM_IAS=1 for x86_64 and arm64.
Cc: <stable@vger.kernel.org>
Link: https://github.com/ClangBuiltLinux/linux/issues/716
Reported-by: Dmitry Golovin <dima@golovin.in>
Reported-by: Nathan Chancellor <natechancellor@gmail.com>
Suggested-by: Dmitry Golovin <dima@golovin.in>
Suggested-by: Nathan Chancellor <natechancellor@gmail.com>
Suggested-by: Sedat Dilek <sedat.dilek@gmail.com>
Reviewed-by: Fangrui Song <maskray@google.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Follow-up to commit a73619a845 ("kbuild: use -fmacro-prefix-map to
make __FILE__ a relative path"). Assembler sources also use __FILE__
macro so this flag should be also applied to those sources.
Signed-off-by: Denys Zagorui <dzagorui@cisco.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
The "size" tool has been solely used by s390 to enforce .bss section usage
restrictions in early startup code. Since commit 980d5f9ab3 ("s390/boot:
enable .bss section for compressed kernel") and commit 2e83e0eb85
("s390: clean .bss before running uncompressed kernel") these restrictions
have been lifted for the decompressor and uncompressed kernel and the
size tool is now unused.
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
- Support 'make compile_commands.json' to generate the compilation
database more easily, avoiding stale entries
- Support 'make clang-analyzer' and 'make clang-tidy' for static checks
using clang-tidy
- Preprocess scripts/modules.lds.S to allow CONFIG options in the module
linker script
- Drop cc-option tests from compiler flags supported by our minimal
GCC/Clang versions
- Use always 12-digits commit hash for CONFIG_LOCALVERSION_AUTO=y
- Use sha1 build id for both BFD linker and LLD
- Improve deb-pkg for reproducible builds and rootless builds
- Remove stale, useless scripts/namespace.pl
- Turn -Wreturn-type warning into error
- Fix build error of deb-pkg when CONFIG_MODULES=n
- Replace 'hostname' command with more portable 'uname -n'
- Various Makefile cleanups
-----BEGIN PGP SIGNATURE-----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=tZRN
-----END PGP SIGNATURE-----
Merge tag 'kbuild-v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild updates from Masahiro Yamada:
- Support 'make compile_commands.json' to generate the compilation
database more easily, avoiding stale entries
- Support 'make clang-analyzer' and 'make clang-tidy' for static checks
using clang-tidy
- Preprocess scripts/modules.lds.S to allow CONFIG options in the
module linker script
- Drop cc-option tests from compiler flags supported by our minimal
GCC/Clang versions
- Use always 12-digits commit hash for CONFIG_LOCALVERSION_AUTO=y
- Use sha1 build id for both BFD linker and LLD
- Improve deb-pkg for reproducible builds and rootless builds
- Remove stale, useless scripts/namespace.pl
- Turn -Wreturn-type warning into error
- Fix build error of deb-pkg when CONFIG_MODULES=n
- Replace 'hostname' command with more portable 'uname -n'
- Various Makefile cleanups
* tag 'kbuild-v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (34 commits)
kbuild: Use uname for LINUX_COMPILE_HOST detection
kbuild: Only add -fno-var-tracking-assignments for old GCC versions
kbuild: remove leftover comment for filechk utility
treewide: remove DISABLE_LTO
kbuild: deb-pkg: clean up package name variables
kbuild: deb-pkg: do not build linux-headers package if CONFIG_MODULES=n
kbuild: enforce -Werror=return-type
scripts: remove namespace.pl
builddeb: Add support for all required debian/rules targets
builddeb: Enable rootless builds
builddeb: Pass -n to gzip for reproducible packages
kbuild: split the build log of kallsyms
kbuild: explicitly specify the build id style
scripts/setlocalversion: make git describe output more reliable
kbuild: remove cc-option test of -Werror=date-time
kbuild: remove cc-option test of -fno-stack-check
kbuild: remove cc-option test of -fno-strict-overflow
kbuild: move CFLAGS_{KASAN,UBSAN,KCSAN} exports to relevant Makefiles
kbuild: remove redundant CONFIG_KASAN check from scripts/Makefile.kasan
kbuild: do not create built-in objects for external module builds
...
Some old GCC versions between 4.5.0 and 4.9.1 might miscompile code
with -fvar-tracking-assingments (which is enabled by default with -g -O2).
Commit 2062afb4f8 ("Fix gcc-4.9.0 miscompilation of load_balance()
in scheduler") added -fno-var-tracking-assignments unconditionally to
work around this. But newer versions of GCC no longer have this bug, so
only add it for versions of GCC before 5.0. This allows various tools
such as a perf probe or gdb debuggers or systemtap to resolve variable
locations using dwarf locations in more code.
Signed-off-by: Mark Wielaard <mark@klomp.org>
Acked-by: Ian Rogers <irogers@google.com>
Reviewed-by: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Add redirect_neigh() BPF packet redirect helper, allowing to limit stack
traversal in common container configs and improving TCP back-pressure.
Daniel reports ~10Gbps => ~15Gbps single stream TCP performance gain.
Expand netlink policy support and improve policy export to user space.
(Ge)netlink core performs request validation according to declared
policies. Expand the expressiveness of those policies (min/max length
and bitmasks). Allow dumping policies for particular commands.
This is used for feature discovery by user space (instead of kernel
version parsing or trial and error).
Support IGMPv3/MLDv2 multicast listener discovery protocols in bridge.
Allow more than 255 IPv4 multicast interfaces.
Add support for Type of Service (ToS) reflection in SYN/SYN-ACK
packets of TCPv6.
In Multi-patch TCP (MPTCP) support concurrent transmission of data
on multiple subflows in a load balancing scenario. Enhance advertising
addresses via the RM_ADDR/ADD_ADDR options.
Support SMC-Dv2 version of SMC, which enables multi-subnet deployments.
Allow more calls to same peer in RxRPC.
Support two new Controller Area Network (CAN) protocols -
CAN-FD and ISO 15765-2:2016.
Add xfrm/IPsec compat layer, solving the 32bit user space on 64bit
kernel problem.
Add TC actions for implementing MPLS L2 VPNs.
Improve nexthop code - e.g. handle various corner cases when nexthop
objects are removed from groups better, skip unnecessary notifications
and make it easier to offload nexthops into HW by converting
to a blocking notifier.
Support adding and consuming TCP header options by BPF programs,
opening the doors for easy experimental and deployment-specific
TCP option use.
Reorganize TCP congestion control (CC) initialization to simplify life
of TCP CC implemented in BPF.
Add support for shipping BPF programs with the kernel and loading them
early on boot via the User Mode Driver mechanism, hence reusing all the
user space infra we have.
Support sleepable BPF programs, initially targeting LSM and tracing.
Add bpf_d_path() helper for returning full path for given 'struct path'.
Make bpf_tail_call compatible with bpf-to-bpf calls.
Allow BPF programs to call map_update_elem on sockmaps.
Add BPF Type Format (BTF) support for type and enum discovery, as
well as support for using BTF within the kernel itself (current use
is for pretty printing structures).
Support listing and getting information about bpf_links via the bpf
syscall.
Enhance kernel interfaces around NIC firmware update. Allow specifying
overwrite mask to control if settings etc. are reset during update;
report expected max time operation may take to users; support firmware
activation without machine reboot incl. limits of how much impact
reset may have (e.g. dropping link or not).
Extend ethtool configuration interface to report IEEE-standard
counters, to limit the need for per-vendor logic in user space.
Adopt or extend devlink use for debug, monitoring, fw update
in many drivers (dsa loop, ice, ionic, sja1105, qed, mlxsw,
mv88e6xxx, dpaa2-eth).
In mlxsw expose critical and emergency SFP module temperature alarms.
Refactor port buffer handling to make the defaults more suitable and
support setting these values explicitly via the DCBNL interface.
Add XDP support for Intel's igb driver.
Support offloading TC flower classification and filtering rules to
mscc_ocelot switches.
Add PTP support for Marvell Octeontx2 and PP2.2 hardware, as well as
fixed interval period pulse generator and one-step timestamping in
dpaa-eth.
Add support for various auth offloads in WiFi APs, e.g. SAE (WPA3)
offload.
Add Lynx PHY/PCS MDIO module, and convert various drivers which have
this HW to use it. Convert mvpp2 to split PCS.
Support Marvell Prestera 98DX3255 24-port switch ASICs, as well as
7-port Mediatek MT7531 IP.
Add initial support for QCA6390 and IPQ6018 in ath11k WiFi driver,
and wcn3680 support in wcn36xx.
Improve performance for packets which don't require much offloads
on recent Mellanox NICs by 20% by making multiple packets share
a descriptor entry.
Move chelsio inline crypto drivers (for TLS and IPsec) from the crypto
subtree to drivers/net. Move MDIO drivers out of the phy directory.
Clean up a lot of W=1 warnings, reportedly the actively developed
subsections of networking drivers should now build W=1 warning free.
Make sure drivers don't use in_interrupt() to dynamically adapt their
code. Convert tasklets to use new tasklet_setup API (sadly this
conversion is not yet complete).
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
-----BEGIN PGP SIGNATURE-----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=bc1U
-----END PGP SIGNATURE-----
Merge tag 'net-next-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next
Pull networking updates from Jakub Kicinski:
- Add redirect_neigh() BPF packet redirect helper, allowing to limit
stack traversal in common container configs and improving TCP
back-pressure.
Daniel reports ~10Gbps => ~15Gbps single stream TCP performance gain.
- Expand netlink policy support and improve policy export to user
space. (Ge)netlink core performs request validation according to
declared policies. Expand the expressiveness of those policies
(min/max length and bitmasks). Allow dumping policies for particular
commands. This is used for feature discovery by user space (instead
of kernel version parsing or trial and error).
- Support IGMPv3/MLDv2 multicast listener discovery protocols in
bridge.
- Allow more than 255 IPv4 multicast interfaces.
- Add support for Type of Service (ToS) reflection in SYN/SYN-ACK
packets of TCPv6.
- In Multi-patch TCP (MPTCP) support concurrent transmission of data on
multiple subflows in a load balancing scenario. Enhance advertising
addresses via the RM_ADDR/ADD_ADDR options.
- Support SMC-Dv2 version of SMC, which enables multi-subnet
deployments.
- Allow more calls to same peer in RxRPC.
- Support two new Controller Area Network (CAN) protocols - CAN-FD and
ISO 15765-2:2016.
- Add xfrm/IPsec compat layer, solving the 32bit user space on 64bit
kernel problem.
- Add TC actions for implementing MPLS L2 VPNs.
- Improve nexthop code - e.g. handle various corner cases when nexthop
objects are removed from groups better, skip unnecessary
notifications and make it easier to offload nexthops into HW by
converting to a blocking notifier.
- Support adding and consuming TCP header options by BPF programs,
opening the doors for easy experimental and deployment-specific TCP
option use.
- Reorganize TCP congestion control (CC) initialization to simplify
life of TCP CC implemented in BPF.
- Add support for shipping BPF programs with the kernel and loading
them early on boot via the User Mode Driver mechanism, hence reusing
all the user space infra we have.
- Support sleepable BPF programs, initially targeting LSM and tracing.
- Add bpf_d_path() helper for returning full path for given 'struct
path'.
- Make bpf_tail_call compatible with bpf-to-bpf calls.
- Allow BPF programs to call map_update_elem on sockmaps.
- Add BPF Type Format (BTF) support for type and enum discovery, as
well as support for using BTF within the kernel itself (current use
is for pretty printing structures).
- Support listing and getting information about bpf_links via the bpf
syscall.
- Enhance kernel interfaces around NIC firmware update. Allow
specifying overwrite mask to control if settings etc. are reset
during update; report expected max time operation may take to users;
support firmware activation without machine reboot incl. limits of
how much impact reset may have (e.g. dropping link or not).
- Extend ethtool configuration interface to report IEEE-standard
counters, to limit the need for per-vendor logic in user space.
- Adopt or extend devlink use for debug, monitoring, fw update in many
drivers (dsa loop, ice, ionic, sja1105, qed, mlxsw, mv88e6xxx,
dpaa2-eth).
- In mlxsw expose critical and emergency SFP module temperature alarms.
Refactor port buffer handling to make the defaults more suitable and
support setting these values explicitly via the DCBNL interface.
- Add XDP support for Intel's igb driver.
- Support offloading TC flower classification and filtering rules to
mscc_ocelot switches.
- Add PTP support for Marvell Octeontx2 and PP2.2 hardware, as well as
fixed interval period pulse generator and one-step timestamping in
dpaa-eth.
- Add support for various auth offloads in WiFi APs, e.g. SAE (WPA3)
offload.
- Add Lynx PHY/PCS MDIO module, and convert various drivers which have
this HW to use it. Convert mvpp2 to split PCS.
- Support Marvell Prestera 98DX3255 24-port switch ASICs, as well as
7-port Mediatek MT7531 IP.
- Add initial support for QCA6390 and IPQ6018 in ath11k WiFi driver,
and wcn3680 support in wcn36xx.
- Improve performance for packets which don't require much offloads on
recent Mellanox NICs by 20% by making multiple packets share a
descriptor entry.
- Move chelsio inline crypto drivers (for TLS and IPsec) from the
crypto subtree to drivers/net. Move MDIO drivers out of the phy
directory.
- Clean up a lot of W=1 warnings, reportedly the actively developed
subsections of networking drivers should now build W=1 warning free.
- Make sure drivers don't use in_interrupt() to dynamically adapt their
code. Convert tasklets to use new tasklet_setup API (sadly this
conversion is not yet complete).
* tag 'net-next-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2583 commits)
Revert "bpfilter: Fix build error with CONFIG_BPFILTER_UMH"
net, sockmap: Don't call bpf_prog_put() on NULL pointer
bpf, selftest: Fix flaky tcp_hdr_options test when adding addr to lo
bpf, sockmap: Add locking annotations to iterator
netfilter: nftables: allow re-computing sctp CRC-32C in 'payload' statements
net: fix pos incrementment in ipv6_route_seq_next
net/smc: fix invalid return code in smcd_new_buf_create()
net/smc: fix valid DMBE buffer sizes
net/smc: fix use-after-free of delayed events
bpfilter: Fix build error with CONFIG_BPFILTER_UMH
cxgb4/ch_ipsec: Replace the module name to ch_ipsec from chcr
net: sched: Fix suspicious RCU usage while accessing tcf_tunnel_info
bpf: Fix register equivalence tracking.
rxrpc: Fix loss of final ack on shutdown
rxrpc: Fix bundle counting for exclusive connections
netfilter: restore NF_INET_NUMHOOKS
ibmveth: Identify ingress large send packets.
ibmveth: Switch order of ibmveth_helper calls.
cxgb4: handle 4-tuple PEDIT to NAT mode translation
selftests: Add VRF route leaking tests
...
Catch errors which at least gcc tolerates by default:
warning: 'return' with no value, in function returning non-void [-Wreturn-type]
Signed-off-by: Olaf Hering <olaf@aepfle.de>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
namespace.pl is intended to help locate symbols which are defined but
are not used externally. The goal is to avoid bloat of the namespace in
the resulting kernel image.
The script relies on object data, and only finds unused symbols for the
configuration used to generate that object data. This results in a lot
of false positive warnings such as symbols only used by a single
architecture, or symbols which are used externally only under certain
configurations.
Running namespace.pl using allyesconfig, allmodconfig, and
x86_64_defconfig yields the following results:
* allmodconfig
* 11122 unique symbol names with no external reference
* 1194 symbols listed as multiply defined
* 214 symbols it can't resolve
* allyesconfig
* 10997 unique symbol names with no external reference
* 1194 symbols listed as multiply defined
* 214 symbols it can't resolve
* x86_64_defconfig
* 5757 unique symbol names with no external reference
* 528 symbols listed as multiply defined
* 154 symbols it can't resolve
The script also has no way to easily limit the scope of the checks to
a given subset of the kernel, such as only checking for symbols defined
within a module or subsystem.
Discussion on public mailing lists seems to indicate that many view the
tool output as suspect or not very useful (see discussions at [1] and
[2] for further context).
As described by Masahiro Yamada at [2], namespace.pl provides 3 types of
checks: listing multiply defined symbols, resolving external symbols,
and warnings about symbols with no reference.
The first category of issues is easily caught by the linker as any set
of multiply defined symbols should fail to link. The second category of
issues is also caught by linking, as undefined symbols would cause
issues. Even with modules, these types of issues where a module relies
on an external symbol are caught by modpost.
The remaining category of issues reported is the list of symbols with no
external reference, and is the primary motivation of this script.
However, it ought to be clear from the above examples that the output is
difficult to sort through. Even allyesconfig has ~10000 entries.
The current submit-checklist indicates that patches ought to go through
namespacecheck and fix any new issues arising. But that itself presents
problems. As described at [1], many cases of reports are due to
configuration where a function is used externally by some configuration
settings. Prominent maintainers appear to dislike changes modify code
such that symbols become static based on CONFIG_* flags ([3], and [4])
One possible solution is to adjust the advice and indicate that we only
care about the output of namespacecheck on allyesconfig or allmodconfig
builds...
However, given the discussion at [2], I suspect that few people are
actively using this tool. It doesn't have a maintainer in the
MAINTAINERS flie, and it produces so many warnings for unused symbols
that it is difficult to use effectively. Thus, I propose we simply
remove it.
[1] https://lore.kernel.org/netdev/20200708164812.384ae8ea@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com/
[2] https://lore.kernel.org/lkml/20190129204319.15238-1-jacob.e.keller@intel.com/
[3] https://lore.kernel.org/netdev/20190828.154744.2058157956381129672.davem@davemloft.net/
[4] https://lore.kernel.org/netdev/20190827210928.576c5fef@cakuba.netronome.com/
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
ld's --build-id defaults to "sha1" style, while lld defaults to "fast".
The build IDs are very different between the two, which may confuse
programs that reference them.
Signed-off-by: Bill Wendling <morbo@google.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Rejecting non-native endian BTF overlapped with the addition
of support for it.
The rest were more simple overlapping changes, except the
renesas ravb binding update, which had to follow a file
move as well as a YAML conversion.
Signed-off-by: David S. Miller <davem@davemloft.net>
The minimal compiler versions, GCC 4.9 and Clang 10 support this flag.
Here is the godbolt:
https://godbolt.org/z/xvjcMa
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Acked-by: Will Deacon <will@kernel.org>
The minimal compiler version, GCC 4.9 supports this flag.
Nathan Chancellor pointed out:
"This flag is technically ignored by clang (see commit
05b0798916f01690b5903302e51f3136274e291f) but that obviously
does not matter for the sake of this."
Here is the godbolt:
https://godbolt.org/z/59cK6o
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
The minimal compiler versions, GCC 4.9 and Clang 10 support this flag.
Here is the godbolt:
https://godbolt.org/z/odq8h9
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Acked-by: Will Deacon <will@kernel.org>
Move CFLAGS_KASAN*, CFLAGS_UBSAN, CFLAGS_KCSAN to Makefile.kasan,
Makefile.ubsan, Makefile.kcsan, respectively.
This commit also avoids the same -fsanitize=* flags being added to
CFLAGS_UBSAN multiple times.
Prior to this commit, the ubsan flags were appended by the '+='
operator, without any initialization. Some build targets such as
'make bindeb-pkg' recurses to the top Makefile, and ended up with
adding the same flags to CFLAGS_UBSAN twice.
Clear CFLAGS_UBSAN with ':=' to make it a simply expanded variable.
This is better than a recursively expanded variable, which evaluates
$(call cc-option, ...) multiple times before Kbuild starts descending
to subdirectories.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Marco Elver <elver@google.com>
'make M=/path/to/your/external/module' creates a pointless built-in.a
in the top of the external module directory because KBUILD_BUILTIN is
set to 1.
Clear KBUILD_BUILTIN when we are building external modules so that
'make M=...' and 'make M=... modules' work equivalently.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
There was a request to preprocess the module linker script like we
do for the vmlinux one. (https://lkml.org/lkml/2020/8/21/512)
The difference between vmlinux.lds and module.lds is that the latter
is needed for external module builds, thus must be cleaned up by
'make mrproper' instead of 'make clean'. Also, it must be created
by 'make modules_prepare'.
You cannot put it in arch/$(SRCARCH)/kernel/, which is cleaned up by
'make clean'. I moved arch/$(SRCARCH)/kernel/module.lds to
arch/$(SRCARCH)/include/asm/module.lds.h, which is included from
scripts/module.lds.S.
scripts/module.lds is fine because 'make clean' keeps all the
build artifacts under scripts/.
You can add arch-specific sections in <asm/module.lds.h>.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Jessica Yu <jeyu@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Jessica Yu <jeyu@kernel.org>
Alexei Starovoitov says:
====================
pull-request: bpf-next 2020-09-23
The following pull-request contains BPF updates for your *net-next* tree.
We've added 95 non-merge commits during the last 22 day(s) which contain
a total of 124 files changed, 4211 insertions(+), 2040 deletions(-).
The main changes are:
1) Full multi function support in libbpf, from Andrii.
2) Refactoring of function argument checks, from Lorenz.
3) Make bpf_tail_call compatible with functions (subprograms), from Maciej.
4) Program metadata support, from YiFei.
5) bpf iterator optimizations, from Yonghong.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Masahiro Yamada
Linus Torvalds
Nayna Jain
Sami Tolvanen
Kees Cook
Nathan Chancellor
Nick Desaulniers
Alexander Lobakin
David S. Miller
Sasha Levin
Tor Vic
Jiri Olsa
Viresh Kumar
Jakub Kicinski
Josh Poimboeuf
Dominique Martinet
Nathan Chancellor
Denys Zagorui
Vasily Gorbik
Mark Wielaard
Olaf Hering
Jacob Keller
Bill Wendling