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.
Bug: 145210207
Change-Id: Icd8fd0c760891eff7a0ed12ce48b4db2a85fc2ad
Link: https://lore.kernel.org/lkml/20201211184633.3213045-1-samitolvanen@google.com/
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
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.
Bug: 145210207
Change-Id: I85eb4523ea787e4f9884e12ed6301f876d0d888e
Link: https://lore.kernel.org/lkml/20201211184633.3213045-1-samitolvanen@google.com/
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
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.
Bug: 145210207
Change-Id: I6fc38abde50b602788148cb236aba1261affa896
Link: https://lore.kernel.org/lkml/20201211184633.3213045-1-samitolvanen@google.com/
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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
"xargs echo" is not a safe way to remove line breaks because the input
may exceed the command line limit and xargs may break it up into
multiple invocations of echo. This should never happen because
scripts/gen_autoksyms.sh expects all undefined symbols are placed in
the second line of .mod files.
One possible way is to replace "xargs echo" with
"sed ':x;N;$!bx;s/\n/ /g'" or something, but I rewrote the code by
using awk because it is more readable.
This issue was reported by Sami Tolvanen; in his Clang LTO patch set,
$(multi-used-m) is no longer an ELF object, but a thin archive that
contains LLVM bitcode files. llvm-nm prints out symbols for each
archive member separately, which results a lot of dupications, in some
places, beyond the system-defined limit.
This problem must be fixed irrespective of LTO, and we must ensure
zero possibility of having this issue.
Link: https://lkml.org/lkml/2020/12/1/1658
Reported-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
When merging configuration fragments, it might be of interest to
identify mismatches (redefinitions) programmatically. Hence add the
option -s (strict mode) to instruct merge_config.sh to bail out in
case any redefinition has been detected.
With strict mode, warnings are emitted as before, but the script
terminates with rc=1. If -y is set to define "builtin having
precedence over modules", fragments are still allowed to set =m (while
the base config has =y). Strict mode will tolerate that as demotions
from =y to =m are ignored when setting -y.
Bug: 174454795
Link: https://lore.kernel.org/linux-kbuild/20201202151238.3776616-1-maennich@google.com/
Cc: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Matthias Maennich <maennich@google.com>
Change-Id: Ib982a87811956e48b718a15680f06474a39dc19d
In the context of GKI we are exporting quite a few internal kernel
symbols, some of which may be static functions (yes this is bad, but
technically it works). As such, we need to be careful about conflicts
and we really should not allow a symbol to be exported more than once.
To ensure this is the case, turn the modpost check 'fatal' to bail out
immediately when such a situation is detected.
Bug: 174214891
Signed-off-by: Quentin Perret <qperret@google.com>
Change-Id: I674c9c9c327849503e94d79654e6288411a830af
Using EXPORT_SYMBOL*() on static functions is fundamentally wrong.
Modpost currently reports that as a warning, but clearly this is not a
pattern we should allow, and all in-tree occurences should have been
fixed by now. So, promote the warn() message to fatal() to make sure
this never happens again.
Bug: 174214891
Link: https://lore.kernel.org/lkml/20201124182420.2202514-1-qperret@google.com/
Signed-off-by: Quentin Perret <qperret@google.com>
Change-Id: Ic1382bfa24db556161cf1a184a4d44724d7849a1
BoringSSL does not implement the ENGINE API. In Android we do not seem
to rely on the PKCS#11 -> DER extraction. Hence, make this conditional
on the SSL library used.
Bug: 135570712
Signed-off-by: Matthias Maennich <maennich@google.com>
Change-Id: I84af6633dd470083497087c7dd1a2734480e2b0e
This warning behaves differently depending on the architecture
and compiler. Using x86 gcc, we get no output at all because
gcc knows the architecture can handle unaligned accesses.
Using x86 clang, or gcc on an architecture that needs to
manually deal with unaligned accesses, the build log is
completely flooded with these warnings, as they are commonly
invoked by inline functions of networking headers, e.g.
include/linux/skbuff.h:1426:26: warning: cast increases required alignment of target type [-Wcast-align]
The compiler is correct to point this out, as we are dealing
with undefined behavior that does cause problems in practice,
but there is also no good way to rewrite the code in commonly
included headers to a safer method.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Pull networking fixes from Jakub Kicinski:
"Current release - regressions:
- arm64: dts: fsl-ls1028a-kontron-sl28: specify in-band mode for
ENETC
Current release - bugs in new features:
- mptcp: provide rmem[0] limit offset to fix oops
Previous release - regressions:
- IPv6: Set SIT tunnel hard_header_len to zero to fix path MTU
calculations
- lan743x: correctly handle chips with internal PHY
- bpf: Don't rely on GCC __attribute__((optimize)) to disable GCSE
- mlx5e: Fix VXLAN port table synchronization after function reload
Previous release - always broken:
- bpf: Zero-fill re-used per-cpu map element
- fix out-of-order UDP packets when forwarding with UDP GSO fraglists
turned on:
- fix UDP header access on Fast/frag0 UDP GRO
- fix IP header access and skb lookup on Fast/frag0 UDP GRO
- ethtool: netlink: add missing netdev_features_change() call
- net: Update window_clamp if SOCK_RCVBUF is set
- igc: Fix returning wrong statistics
- ch_ktls: fix multiple leaks and corner cases in Chelsio TLS offload
- tunnels: Fix off-by-one in lower MTU bounds for ICMP/ICMPv6 replies
- r8169: disable hw csum for short packets on all chip versions
- vrf: Fix fast path output packet handling with async Netfilter
rules"
* tag 'net-5.10-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (65 commits)
lan743x: fix use of uninitialized variable
net: udp: fix IP header access and skb lookup on Fast/frag0 UDP GRO
net: udp: fix UDP header access on Fast/frag0 UDP GRO
devlink: Avoid overwriting port attributes of registered port
vrf: Fix fast path output packet handling with async Netfilter rules
cosa: Add missing kfree in error path of cosa_write
net: switch to the kernel.org patchwork instance
ch_ktls: stop the txq if reaches threshold
ch_ktls: tcb update fails sometimes
ch_ktls/cxgb4: handle partial tag alone SKBs
ch_ktls: don't free skb before sending FIN
ch_ktls: packet handling prior to start marker
ch_ktls: Correction in middle record handling
ch_ktls: missing handling of header alone
ch_ktls: Correction in trimmed_len calculation
cxgb4/ch_ktls: creating skbs causes panic
ch_ktls: Update cheksum information
ch_ktls: Correction in finding correct length
cxgb4/ch_ktls: decrypted bit is not enough
net/x25: Fix null-ptr-deref in x25_connect
...
This reverts commit e145f7b103.
AOSP's distribution of GNU binutils always had a curious target triple
prefix on the binaries. Now that GNU binutils is deprecated for Android
Common Kernels, we can now remove this out of tree workaround. Now
building Android kernels with LLVM matches upstream (see
Documentation/kbuild/llvm.rst).
Bug: 118439987
Bug: 120440614
Bug: 141693040
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Change-Id: Iecaa3264a440f795f2f3a44bdf74fe28ad4ed1cc
Pull driver core documentation fixes from Greg KH:
"Some small Documentation fixes that were fallout from the larger
documentation update we did in 5.10-rc2.
Nothing major here at all, but all of these have been in linux-next
and resolve build warnings when building the documentation files"
* tag 'driver-core-5.10-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
Documentation: remove mic/index from misc-devices/index.rst
scripts: get_api.pl: Add sub-titles to ABI output
scripts: get_abi.pl: Don't let ABI files to create subtitles
docs: leds: index.rst: add a missing file
docs: ABI: sysfs-class-net: fix a typo
docs: ABI: sysfs-driver-dma-ioatdma: what starts with /sys
Alexei Starovoitov says:
====================
pull-request: bpf 2020-11-06
1) Pre-allocated per-cpu hashmap needs to zero-fill reused element, from David.
2) Tighten bpf_lsm function check, from KP.
3) Fix bpftool attaching to flow dissector, from Lorenz.
4) Use -fno-gcse for the whole kernel/bpf/core.c instead of function attribute, from Ard.
* git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
bpf: Update verification logic for LSM programs
bpf: Zero-fill re-used per-cpu map element
bpf: BPF_PRELOAD depends on BPF_SYSCALL
tools/bpftool: Fix attaching flow dissector
libbpf: Fix possible use after free in xsk_socket__delete
libbpf: Fix null dereference in xsk_socket__delete
libbpf, hashmap: Fix undefined behavior in hash_bits
bpf: Don't rely on GCC __attribute__((optimize)) to disable GCSE
tools, bpftool: Remove two unused variables.
tools, bpftool: Avoid array index warnings.
xsk: Fix possible memory leak at socket close
bpf: Add struct bpf_redir_neigh forward declaration to BPF helper defs
samples/bpf: Set rlimit for memlock to infinity in all samples
bpf: Fix -Wshadow warnings
selftest/bpf: Fix profiler test using CO-RE relocation for enums
====================
Link: https://lore.kernel.org/r/20201106221759.24143-1-alexei.starovoitov@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Pull documentation build warning fixes from Jonathan Corbet:
"This contains a series of warning fixes from Mauro; once applied, the
number of warnings from the once-noisy docs build process is nearly
zero.
Getting to this point has required a lot of work; once there,
hopefully we can keep things that way.
I have packaged this as a separate pull because it does a fair amount
of reaching outside of Documentation/. The changes are all in comments
and in code placement. It's all been in linux-next since last week"
* tag 'docs-5.10-warnings' of git://git.lwn.net/linux: (24 commits)
docs: SafeSetID: fix a warning
amdgpu: fix a few kernel-doc markup issues
selftests: kselftest_harness.h: fix kernel-doc markups
drm: amdgpu_dm: fix a typo
gpu: docs: amdgpu.rst: get rid of wrong kernel-doc markups
drm: amdgpu: kernel-doc: update some adev parameters
docs: fs: api-summary.rst: get rid of kernel-doc include
IB/srpt: docs: add a description for cq_size member
locking/refcount: move kernel-doc markups to the proper place
docs: lockdep-design: fix some warning issues
MAINTAINERS: fix broken doc refs due to yaml conversion
ice: docs fix a devlink info that broke a table
crypto: sun8x-ce*: update entries to its documentation
net: phy: remove kernel-doc duplication
mm: pagemap.h: fix two kernel-doc markups
blk-mq: docs: add kernel-doc description for a new struct member
docs: userspace-api: add iommu.rst to the index file
docs: hwmon: mp2975.rst: address some html build warnings
docs: net: statistics.rst: remove a duplicated kernel-doc
docs: kasan.rst: add two missing blank lines
...
Pull documentation fixes from Jonathan Corbet:
"A small number of fixes, plus a build tweak to respect the desire for
silence in V=0 builds"
* tag 'docs-5.10-3' of git://git.lwn.net/linux:
docs: fix automarkup regression on Python 2
documentation: arm: sunxi: add Allwinner H6 documents
scripts: kernel-doc: split typedef complex regex
scripts: kernel-doc: fix typedef parsing
docs: Makefile: honor V=0 for docs building
The ReST output should only contain documentation titles
automatically created by the script.
There are two reasons for that:
1) Consistency.
just a handful ABI docs define titles
2) To avoid critical errors.
Docutils (which is the basis for Sphinx) allows a free
assign of documentation title markups. So, one document
could be doing things like:
Level 1
=======
Level 2
-------
While another one could do the reverse:
Level 1
-------
Level 2
=======
But the same document can't mix.
As the output of get_abi.pl will join contents from multiple
files, if they don't define the levels on a consistent errors,
errors like this can happen:
Sphinx parallel build error:
docutils.utils.SystemMessage: /home/rdunlap/lnx/lnx-510-rc2/Documentation/ABI/testing/sysfs-bus-rapidio:2: (SEVERE/4) Title level inconsistent:
Attributes Common for All RapidIO Devices
-----------------------------------------
Which cause some versions of Sphinx to go into an endless
loop.
It should be noticed that an alternative to that would
be to replace all title occurrences by a single markup,
but that will make the parser more complex, and, due to
(1) it would generate an inconsistent output.
So, better to just remove the titles defined at the ABI
files from the output.
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/6c62ef5c01d39dee8d891f8390c816d2a889670a.1604312590.git.mchehab+huawei@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Building 5.10-rc1 in a setgid directory failed with the following
error:
dpkg-deb: error: control directory has bad permissions 2755 (must be
>=0755 and <=0775)
When building with fakeroot, the earlier chown call would have removed
the setgid bits, but in a rootless build they remain.
Fixes: 3e85418036 ("builddeb: Enable rootless builds")
Cc: Guillem Jover <guillem@hadrons.org>
Signed-off-by: Sven Joachim <svenjoac@gmx.de>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
The files under Documentation/ABI should follow the syntax
as defined at Documentation/ABI/README.
Allow checking if they're following the syntax by running
the ABI parser script on COMPILE_TEST.
With that, when there's a problem with a file under
Documentation/ABI, it would produce a warning like:
Warning: file ./Documentation/ABI/testing/sysfs-bus-pci-devices-aer_stats#14:
What '/sys/bus/pci/devices/<dev>/aer_stats/aer_rootport_total_err_cor' doesn't have a description
Warning: file ./Documentation/ABI/testing/sysfs-bus-pci-devices-aer_stats#21:
What '/sys/bus/pci/devices/<dev>/aer_stats/aer_rootport_total_err_fatal' doesn't have a description
Acked-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/57a38de85cb4b548857207cf1fc1bf1ee08613c9.1604042072.git.mchehab+huawei@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Sphinx C domain code after 3.2.1 will start complaning if :c:struct
would be used for an union type:
.../Documentation/gpu/drm-kms-helpers:352: ../drivers/video/hdmi.c:851: WARNING: C 'identifier' cross-reference uses wrong tag: reference name is 'union hdmi_infoframe' but found name is 'struct hdmi_infoframe'. Full reference name is 'union hdmi_infoframe'. Full found name is 'struct hdmi_infoframe'.
So, let's address this issue too in advance, in order to
avoid future issues.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/6e4ec3eec914df62389a299797a3880ae4490f35.1603791716.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
The include/linux/genalloc.h file defined this typedef:
typedef unsigned long (*genpool_algo_t)(unsigned long *map,unsigned long size,unsigned long start,unsigned int nr,void *data, struct gen_pool *pool, unsigned long start_addr);
Because it has a type composite of two words (unsigned long),
the parser gets the typedef name wrong:
.. c:macro:: long
**Typedef**: Allocation callback function type definition
Fix the regex in order to accept composite types when
defining a typedef for a function pointer.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/328e8018041cc44f7a1684e57f8d111230761c4f.1603792384.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Steps on the way to 5.10-rc1
Resolves conflicts in:
arch/arm64/kernel/vdso32/Makefile
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: Ic9edce8127b3717469dc4fa96ca95166be419e9d
Steps on the way to 5.10-rc1
Resolves conflicts in:
drivers/net/virtio_net.c
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I72bb00e45bb7b6154b56f31a2e9040c4e8fe899a
