09 Aug, 2021
1 commit
08 Aug, 2021
1 commit
-
…t/masahiroy/linux-kbuild
Pull Kbuild fixes from Masahiro Yamada:
- Correct the Extended Regular Expressions in tools
- Adjust scripts/checkversion.pl for the current Kbuild
- Unset sub_make_done for 'make install' to make DKMS work again
* tag 'kbuild-fixes-v5.14-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
kbuild: cancel sub_make_done for the install target to fix DKMS
scripts: checkversion: modernize linux/version.h search strings
mips: Fix non-POSIX regexp
x86/tools/relocs: Fix non-POSIX regexp
06 Aug, 2021
1 commit
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Pull tracing fixes from Steven Rostedt:
"Various tracing fixes:- Fix NULL pointer dereference caused by an error path
- Give histogram calculation fields a size, otherwise it breaks
synthetic creation based on them.- Reject strings being used for number calculations.
- Fix recordmcount.pl warning on llvm building RISC-V allmodconfig
- Fix the draw_functrace.py script to handle the new trace output
- Fix warning of smp_processor_id() in preemptible code"
* tag 'trace-v5.14-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing: Quiet smp_processor_id() use in preemptable warning in hwlat
scripts/tracing: fix the bug that can't parse raw_trace_func
scripts/recordmcount.pl: Remove check_objcopy() and $can_use_local
tracing: Reject string operand in the histogram expression
tracing / histogram: Give calculation hist_fields a size
tracing: Fix NULL pointer dereference in start_creating
05 Aug, 2021
2 commits
-
Since commit bcf637f54f6d ("kbuild: parse C= and M= before changing the
working directory"), external module builds invoked by DKMS fail because
M= option is not parsed.I wanted to add 'unset sub_make_done' in install.sh but similar scripts,
arch/*/boot/install.sh, are duplicated, so I set sub_make_done empty in
the top Makefile.Fixes: bcf637f54f6d ("kbuild: parse C= and M= before changing the working directory")
Reported-by: John S Gruber
Signed-off-by: Masahiro Yamada
Tested-by: John S Gruber -
When building ARCH=riscv allmodconfig with llvm-objcopy, the objcopy
version warning from this script appears:WARNING: could not find objcopy version or version is less than 2.17.
Local function references are disabled.The check_objcopy() function in scripts/recordmcount.pl is set up to
parse GNU objcopy's version string, not llvm-objcopy's, which triggers
the warning.Commit 799c43415442 ("kbuild: thin archives make default for all archs")
made binutils 2.20 mandatory and commit ba64beb17493 ("kbuild: check the
minimum assembler version in Kconfig") enforces this at configuration
time so just remove check_objcopy() and $can_use_local instead, assuming
--globalize-symbol is always available.llvm-objcopy has supported --globalize-symbol since LLVM 7.0.0 in 2018
and the minimum version for building the kernel with LLVM is 10.0.1 so
there is no issue introduced:Link: https://github.com/llvm/llvm-project/commit/ee5be798dae30d5f9414b01f76ff807edbc881aa
Link: https://lkml.kernel.org/r/20210802210307.3202472-1-nathan@kernel.orgReviewed-by: Nick Desaulniers
Signed-off-by: Nathan Chancellor
Signed-off-by: Steven Rostedt (VMware)
02 Aug, 2021
1 commit
26 Jul, 2021
1 commit
19 Jul, 2021
2 commits
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…masahiroy/linux-kbuild
Pull Kbuild fixes from Masahiro Yamada:
- Restore the original behavior of scripts/setlocalversion when
LOCALVERSION is set to empty.- Show Kconfig prompts even for 'make -s'
- Fix the combination of COFNIG_LTO_CLANG=y and CONFIG_MODVERSIONS=y
for older GNU Make versions* tag 'kbuild-fixes-v5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
Documentation: Fix intiramfs script name
Kbuild: lto: fix module versionings mismatch in GNU make 3.X
kbuild: do not suppress Kconfig prompts for silent build
scripts/setlocalversion: fix a bug when LOCALVERSION is empty
18 Jul, 2021
1 commit
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When a new CONFIG option is available, Kbuild shows a prompt to get
the user input.$ make
[ snip ]
Core Scheduling for SMT (SCHED_CORE) [N/y/?] (NEW)This is the only interactive place in the build process.
Commit 174a1dcc9642 ("kbuild: sink stdout from cmd for silent build")
suppressed Kconfig prompts as well because syncconfig is invoked by
the 'cmd' macro. You cannot notice the fact that Kconfig is waiting
for the user input.Use 'kecho' to show the equivalent short log without suppressing stdout
from sub-make.Fixes: 174a1dcc9642 ("kbuild: sink stdout from cmd for silent build")
Reported-by: Tetsuo Handa
Signed-off-by: Masahiro Yamada
Tested-by: Tetsuo Handa
16 Jul, 2021
1 commit
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This reverts commit b7eb335e26a9c7f258c96b3962c283c379d3ede0.
It turns out that the problem with the clang -Wimplicit-fallthrough
warning is not about the kernel source code, but about clang itself, and
that the warning is unusable until clang fixes its broken ways.In particular, when you enable this warning for clang, you not only get
warnings about implicit fallthroughs. You also get this:warning: fallthrough annotation in unreachable code [-Wimplicit-fallthrough]
which is completely broken becasue it
(a) doesn't even tell you where the problem is (seriously: no line
numbers, no filename, no nothing).(b) is fundamentally broken anyway, because there are perfectly valid
reasons to have a fallthrough statement even if it turns out that
it can perhaps not be reached.In the kernel, an example of that second case is code in the scheduler:
switch (state) {
case cpuset:
if (IS_ENABLED(CONFIG_CPUSETS)) {
cpuset_cpus_allowed_fallback(p);
state = possible;
break;
}
fallthrough;
case possible:where if CONFIG_CPUSETS is enabled you actually never hit the
fallthrough case at all. But that in no way makes the fallthrough
wrong.So the warning is completely broken, and enabling it for clang is a very
bad idea.In the meantime, we can keep the gcc option enabled, and make the gcc
build use-Wimplicit-fallthrough=5
which means that we will at least continue to require a proper
fallthrough statement, and that gcc won't silently accept the magic
comment versions. Because gcc does this all correctly, and while the odd
"=5" part is kind of obscure, it's documented in [1]:"-Wimplicit-fallthrough=5 doesn’t recognize any comments as
fallthrough comments, only attributes disable the warning"so if clang ever fixes its bad behavior we can try enabling it there again.
Link: https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html [1]
Cc: Kees Cook
Cc: Gustavo A. R. Silva
Cc: Nathan Chancellor
Cc: Nick Desaulniers
Signed-off-by: Linus Torvalds
15 Jul, 2021
1 commit
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With the recent fixes for fallthrough warnings, it is now possible to
enable -Wimplicit-fallthrough for Clang.It's important to mention that since we have adopted the use of the
pseudo-keyword macro fallthrough; we also want to avoid having more
/* fall through */ comments being introduced. Notice that contrary
to GCC, Clang doesn't recognize any comments as implicit fall-through
markings when the -Wimplicit-fallthrough option is enabled. So, in
order to avoid having more comments being introduced, we have to use
the option -Wimplicit-fallthrough=5 for GCC, which similar to Clang,
will cause a warning in case a code comment is intended to be used
as a fall-through marking.Co-developed-by: Kees Cook
Signed-off-by: Kees Cook
Signed-off-by: Gustavo A. R. Silva
12 Jul, 2021
1 commit
11 Jul, 2021
1 commit
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Pull Kbuild updates from Masahiro Yamada:
- Increase the -falign-functions alignment for the debug option.
- Remove ugly libelf checks from the top Makefile.
- Make the silent build (-s) more silent.
- Re-compile the kernel if KBUILD_BUILD_TIMESTAMP is specified.
- Various script cleanups
* tag 'kbuild-v5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (27 commits)
scripts: add generic syscallnr.sh
scripts: check duplicated syscall number in syscall table
sparc: syscalls: use pattern rules to generate syscall headers
parisc: syscalls: use pattern rules to generate syscall headers
nds32: add arch/nds32/boot/.gitignore
kbuild: mkcompile_h: consider timestamp if KBUILD_BUILD_TIMESTAMP is set
kbuild: modpost: Explicitly warn about unprototyped symbols
kbuild: remove trailing slashes from $(KBUILD_EXTMOD)
kconfig.h: explain IS_MODULE(), IS_ENABLED()
kconfig: constify long_opts
scripts/setlocalversion: simplify the short version part
scripts/setlocalversion: factor out 12-chars hash construction
scripts/setlocalversion: add more comments to -dirty flag detection
scripts/setlocalversion: remove workaround for old make-kpkg
scripts/setlocalversion: remove mercurial, svn and git-svn supports
kbuild: clean up ${quiet} checks in shell scripts
kbuild: sink stdout from cmd for silent build
init: use $(call cmd,) for generating include/generated/compile.h
kbuild: merge scripts/mkmakefile to top Makefile
sh: move core-y in arch/sh/Makefile to arch/sh/Kbuild
...
29 Jun, 2021
1 commit
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Pull arm64 updates from Will Deacon:
"There's a reasonable amount here and the juicy details are all below.It's worth noting that the MTE/KASAN changes strayed outside of our
usual directories due to core mm changes and some associated changes
to some other architectures; Andrew asked for us to carry these [1]
rather that take them via the -mm tree.Summary:
- Optimise SVE switching for CPUs with 128-bit implementations.
- Fix output format from SVE selftest.
- Add support for versions v1.2 and 1.3 of the SMC calling
convention.- Allow Pointer Authentication to be configured independently for
kernel and userspace.- PMU driver cleanups for managing IRQ affinity and exposing event
attributes via sysfs.- KASAN optimisations for both hardware tagging (MTE) and out-of-line
software tagging implementations.- Relax frame record alignment requirements to facilitate 8-byte
alignment with KASAN and Clang.- Cleanup of page-table definitions and removal of unused memory
types.- Reduction of ARCH_DMA_MINALIGN back to 64 bytes.
- Refactoring of our instruction decoding routines and addition of
some missing encodings.- Move entry code moved into C and hardened against harmful compiler
instrumentation.- Update booting requirements for the FEAT_HCX feature, added to v8.7
of the architecture.- Fix resume from idle when pNMI is being used.
- Additional CPU sanity checks for MTE and preparatory changes for
systems where not all of the CPUs support 32-bit EL0.- Update our kernel string routines to the latest Cortex Strings
implementation.- Big cleanup of our cache maintenance routines, which were
confusingly named and inconsistent in their implementations.- Tweak linker flags so that GDB can understand vmlinux when using
RELR relocations.- Boot path cleanups to enable early initialisation of per-cpu
operations needed by KCSAN.- Non-critical fixes and miscellaneous cleanup"
* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (150 commits)
arm64: tlb: fix the TTL value of tlb_get_level
arm64: Restrict undef hook for cpufeature registers
arm64/mm: Rename ARM64_SWAPPER_USES_SECTION_MAPS
arm64: insn: avoid circular include dependency
arm64: smp: Bump debugging information print down to KERN_DEBUG
drivers/perf: fix the missed ida_simple_remove() in ddr_perf_probe()
perf/arm-cmn: Fix invalid pointer when access dtc object sharing the same IRQ number
arm64: suspend: Use cpuidle context helpers in cpu_suspend()
PSCI: Use cpuidle context helpers in psci_cpu_suspend_enter()
arm64: Convert cpu_do_idle() to using cpuidle context helpers
arm64: Add cpuidle context save/restore helpers
arm64: head: fix code comments in set_cpu_boot_mode_flag
arm64: mm: drop unused __pa(__idmap_text_start)
arm64: mm: fix the count comments in compute_indices
arm64/mm: Fix ttbr0 values stored in struct thread_info for software-pan
arm64: mm: Pass original fault address to handle_mm_fault()
arm64/mm: Drop SECTION_[SHIFT|SIZE|MASK]
arm64/mm: Use CONT_PMD_SHIFT for ARM64_MEMSTART_SHIFT
arm64/mm: Drop SWAPPER_INIT_MAP_SIZE
arm64: Conditionally configure PTR_AUTH key of the kernel.
...
28 Jun, 2021
1 commit
21 Jun, 2021
1 commit
17 Jun, 2021
1 commit
-
M= (or KBUILD_EXTMOD) generally expects a directory path without any
trailing slashes, like M=a/b/c.If you add a trailing slash, like M=a/b/c/, you will get ugly build
logs (two slashes in a series), but it still works fine as long as it
is consistent between 'make modules' and 'make modules_install'.The following commands correctly build and install the modules.
$ make M=a/b/c/ modules
$ sudo make M=a/b/c/ modules_installSince commit ccae4cfa7bfb ("kbuild: refactor scripts/Makefile.modinst"),
a problem happens if you add a trailing slash only for modules_install.$ make M=a/b/c modules
$ sudo make M=a/b/c/ modules_installNo module is installed in this case, Johannes Berg reported. [1]
Trim any trailing slashes from $(KBUILD_EXTMOD).
I used the 'dirname' command to remove all the trailing slashes in
case someone adds more slashes like M=a/b/c/////. The Make's built-in
function, $(dir ...) cannot take care of such a case.[1]: https://lore.kernel.org/lkml/10cc8522b27a051e6a9c3e158a4c4b6414fd04a0.camel@sipsolutions.net/
Fixes: ccae4cfa7bfb ("kbuild: refactor scripts/Makefile.modinst")
Reported-by: Johannes Berg
Signed-off-by: Masahiro Yamada
16 Jun, 2021
1 commit
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Pull clang LTO fix from Kees Cook:
"It seems Clang has been scrubbing through the missing LTO IR flags for
Clang 13, and the last of these 'only with LTO' flags is fixed now.I've asked that they please consider making these changes in a less
'break all the Clang kernel builds' kind of way in the future. :PSummary:
- The '-warn-stack-size' option under LTO has moved in Clang 13 (Tor
Vic)"* tag 'clang-features-v5.13-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
Makefile: lto: Pass -warn-stack-size only on LLD < 13.0.0
15 Jun, 2021
1 commit
-
Since LLVM commit fc018eb, the '-warn-stack-size' flag has been dropped
[1], leading to the following error message when building with Clang-13
and LLD-13:ld.lld: error: -plugin-opt=-: ld.lld: Unknown command line argument
'-warn-stack-size=2048'. Try: 'ld.lld --help'
ld.lld: Did you mean '--asan-stack=2048'?In the same way as with commit 2398ce80152a ("x86, lto: Pass
-stack-alignment only on LLD < 13.0.0") , make '-warn-stack-size'
conditional on LLD < 13.0.0.[1] https://reviews.llvm.org/D103928
Fixes: 24845dcb170e ("Makefile: LTO: have linker check -Wframe-larger-than")
Cc: stable@vger.kernel.org
Link: https://github.com/ClangBuiltLinux/linux/issues/1377
Signed-off-by: Tor Vic
Reviewed-by: Nathan Chancellor
Reviewed-by: Nick Desaulniers
Signed-off-by: Kees Cook
Link: https://lore.kernel.org/r/7631bab7-a8ab-f884-ab54-f4198976125c@mailbox.org
14 Jun, 2021
1 commit
08 Jun, 2021
1 commit
-
GDB produces the following warning when debugging kernels built with
CONFIG_RELR:BFD: /android0/linux-next/vmlinux: unknown type [0x13] section `.relr.dyn'
when loading a kernel built with CONFIG_RELR into GDB. It can also
prevent debugging symbols using such relocations.Peter sugguests:
[That flag] means that lld will use dynamic tags and section type
numbers in the OS-specific range rather than the generic range. The
kernel itself doesn't care about these numbers; it determines the
location of the RELR section using symbols defined by a linker script.Link: https://github.com/ClangBuiltLinux/linux/issues/1057
Suggested-by: Peter Collingbourne
Reviewed-by: Nathan Chancellor
Signed-off-by: Nick Desaulniers
Link: https://lore.kernel.org/r/20210522012626.2811297-1-ndesaulniers@google.com
Signed-off-by: Will Deacon
07 Jun, 2021
1 commit
31 May, 2021
1 commit
29 May, 2021
1 commit
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Pull clang feature fixes from Kees Cook:
- Correctly pass stack frame size checking under LTO (Nick Desaulniers)
- Avoid CFI mismatches by checking initcall_t types (Marco Elver)
* tag 'clang-features-v5.13-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
Makefile: LTO: have linker check -Wframe-larger-than
init: verify that function is initcall_t at compile-time
27 May, 2021
1 commit
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scripts/mkmakefile is simple enough to be merged in the Makefile.
Use $(call cmd,...) to show the log instead of doing it in the
shell script.Signed-off-by: Masahiro Yamada
26 May, 2021
1 commit
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arch/$(SRCARCH)/Kbuild is useful for Makefile cleanups because you can
use the obj-y syntax.Add an empty file if it is missing in arch/$(SRCARCH)/.
Signed-off-by: Masahiro Yamada
25 May, 2021
1 commit
-
-Wframe-larger-than= requires stack frame information, which the
frontend cannot provide. This diagnostic is emitted late during
compilation once stack frame size is available.When building with LTO, the frontend simply lowers C to LLVM IR and does
not have stack frame information, so it cannot emit this diagnostic.
When the linker drives LTO, it restarts optimizations and lowers LLVM IR
to object code. At that point, it has stack frame information but
doesn't know to check for a specific max stack frame size.I consider this a bug in LLVM that we need to fix. There are some
details we're working out related to LTO such as which value to use when
there are multiple different values specified per TU, or how to
propagate these to compiler synthesized routines properly, if at all.Until it's fixed, ensure we don't miss these. At that point we can wrap
this in a compiler version guard or revert this based on the minimum
support version of Clang.The error message is not generated during link:
LTO vmlinux.o
ld.lld: warning: stack size limit exceeded (8224) in foobarbazCc: Sami Tolvanen
Reported-by: Candle Sun
Suggested-by: Fangrui Song
Signed-off-by: Nick Desaulniers
Signed-off-by: Kees Cook
Link: https://lore.kernel.org/r/20210312010942.1546679-1-ndesaulniers@google.com
24 May, 2021
4 commits
-
I do not see a good reason why only the libelf development package must
be so carefully checked.Kbuild generally does not check host tools or libraries.
For example, x86_64 defconfig fails to build with no libssl development
package installed.scripts/extract-cert.c:21:10: fatal error: openssl/bio.h: No such file or directory
21 | #include
| ^~~~~~~~~~~~~~~To solve the build error, you need to install libssl-dev or openssl-devel
package, depending on your distribution.'apt-file search', 'dnf provides', etc. is your frined to find a proper
package to install.This commit removes all the libelf checks from the top Makefile.
If libelf is missing, objtool will fail to build in a similar pattern:
.../linux/tools/objtool/include/objtool/elf.h:10:10: fatal error: gelf.h: No such file or directory
10 | #includeYou need to install libelf-dev, libelf-devel, or elfutils-libelf-devel
to proceed.Another remarkable change is, CONFIG_STACK_VALIDATION (without
CONFIG_UNWINDER_ORC) previously continued to build with a warning,
but now it will treat missing libelf as an error.This is just a one-time installation, so it should not hurt to break
a build and make a user install the package.BTW, the traditional way to handle such checks is autotool, but according
to [1], I do not expect the kernel build would have similar scripting
like './configure' does.[1]: https://lore.kernel.org/lkml/CA+55aFzr2HTZVOuzpHYDwmtRJLsVzE-yqg2DHpHi_9ePsYp5ug@mail.gmail.com/
Signed-off-by: Masahiro Yamada
Acked-by: Andrii Nakryiko -
The tools/ directory only exists in the kernel source tree, not in
external modules.Do not expose the meaningless targets to external modules.
Signed-off-by: Masahiro Yamada
-
Commit 09c60546f04f ("./Makefile: add debug option to enable
function aligned on 32 bytes") was introduced to help debugging
strange kernel performance changes caused by code alignment
change.Recently we found 2 similar cases [1][2] caused by code-alignment
changes, which can only be identified by forcing 64 bytes aligned
for all functions.Originally, 32 bytes was used mainly for not wasting too much
text space, but this option is only for debug anyway where text
space is not a big concern. So extend the alignment to 64 bytes
to cover more similar cases.[1].https://lore.kernel.org/lkml/20210427090013.GG32408@xsang-OptiPlex-9020/
[2].https://lore.kernel.org/lkml/20210420030837.GB31773@xsang-OptiPlex-9020/
Signed-off-by: Feng Tang
Signed-off-by: Masahiro Yamada
17 May, 2021
1 commit
10 May, 2021
1 commit
09 May, 2021
1 commit
-
Pull more Kbuild updates from Masahiro Yamada:
- Convert sh and sparc to use generic shell scripts to generate the
syscall headers- refactor .gitignore files
- Update kernel/config_data.gz only when the content of the .config
is really changed, which avoids the unneeded re-link of vmlinux- move "remove stale files" workarounds to scripts/remove-stale-files
- suppress unused-but-set-variable warnings by default for Clang
as well- fix locale setting LANG=C to LC_ALL=C
- improve 'make distclean'
- always keep intermediate objects from scripts/link-vmlinux.sh
- move IF_ENABLED out of to make it self-contained
- misc cleanups
* tag 'kbuild-v5.13-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (25 commits)
linux/kconfig.h: replace IF_ENABLED() with PTR_IF() in
kbuild: Don't remove link-vmlinux temporary files on exit/signal
kbuild: remove the unneeded comments for external module builds
kbuild: make distclean remove tag files in sub-directories
kbuild: make distclean work against $(objtree) instead of $(srctree)
kbuild: refactor modname-multi by using suffix-search
kbuild: refactor fdtoverlay rule
kbuild: parameterize the .o part of suffix-search
arch: use cross_compiling to check whether it is a cross build or not
kbuild: remove ARCH=sh64 support from top Makefile
.gitignore: prefix local generated files with a slash
kbuild: replace LANG=C with LC_ALL=C
Makefile: Move -Wno-unused-but-set-variable out of GCC only block
kbuild: add a script to remove stale generated files
kbuild: update config_data.gz only when the content of .config is changed
.gitignore: ignore only top-level modules.builtin
.gitignore: move tags and TAGS close to other tag files
kernel/.gitgnore: remove stale timeconst.h and hz.bc
usr/include: refactor .gitignore
genksyms: fix stale comment
...
06 May, 2021
3 commits
-
The supported targets for external modules are listed in the help target
a few lines below. Let's not have duplicated information in two places.Signed-off-by: Masahiro Yamada
-
'make tags' and friends create tag files in the top directory, but
people may manually create tag files in sub-directories.Signed-off-by: Masahiro Yamada
-
This reverts the old commit [1], which seems questionable to me.
It claimed 'make distclean' could not remove editor backup files,
but I believe KBUILD_OUTPUT or O= was set.When O= is given, Kbuild should always work against $(objtree).
If O= is not given, $(objtree) and $(srctree) are the same, therefore
$(srctree) is cleaned up.[1]: https://git.kernel.org/pub/scm/linux/kernel/git/history/history.git/commit/?id=dd47df980c02eb33833b2690b033c34fba2fa80d
Signed-off-by: Masahiro Yamada
03 May, 2021
1 commit
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Commit 37744feebc08 ("sh: remove sh5 support") removed the SUPERH64
support entirely.Remove the left-over code from the top Makefile.
Signed-off-by: Masahiro Yamada
Acked-by: Arnd Bergmann
02 May, 2021
1 commit
-
Pull IMA updates from Mimi Zohar:
"In addition to loading the kernel module signing key onto the builtin
keyring, load it onto the IMA keyring as well.Also six trivial changes and bug fixes"
* tag 'integrity-v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity:
ima: ensure IMA_APPRAISE_MODSIG has necessary dependencies
ima: Fix fall-through warnings for Clang
integrity: Add declarations to init_once void arguments.
ima: Fix function name error in comment.
ima: enable loading of build time generated key on .ima keyring
ima: enable signing of modules with build time generated key
keys: cleanup build time module signing keys
ima: Fix the error code for restoring the PCR value
ima: without an IMA policy loaded, return quickly