kernel February 2022

kernel@lists.fedoraproject.org

12 participants
79 discussions

[OS-BUILD PATCHv3 0/0] random: Override random with FIPS RNG in FIPS mode
by Herbert Xu (via Email Bridge) 30 Jan '25

30 Jan '25

From: Herbert Xu on gitlab.com Merge Request: https://gitlab.com/cki-project/kernel-ark/-/merge_requests/1304 NOTE: Truncated patchset since committer email 'herbert(a)gondor.apana.org.au' does not match the submitter's GitLab public email address 'herbert.xu(a)redhat.com'. Upstream: RHEL only Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1984784 The RHEL FIPS certification effort ran into an show-stopper with /dev/urandom and getrandom(2) not being FIPS-compliant. At this point there is no realistic chance of making them FIPS-compliant upstream. It has also been deemed unrealistic to change user-space to use the FIPS-compliant RNG through the Crypto API. Therefore this patch series overrides /dev/*random as well as getrandom(2) with the Crypto API RNG so that FIPS certification can proceed. Signed-off-by: Herbert Xu <herbert.xu(a)redhat.com> --- crypto/rng.c | 73 ++++++++++++++++++++++++++++++- drivers/char/random.c | 115 +++++++++++++++++++++++++++++++++++++++++++++++++ include/linux/random.h | 7 ++ 3 files changed, 194 insertions(+), 1 deletions(-)

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[OS-BUILD PATCH] Add wildcard macros -baseonly -gcov
by Don Zickus (via Email Bridge) 18 Sep '24

18 Sep '24

From: Don Zickus <dzickus(a)redhat.com> Add wildcard macros -baseonly -gcov There are multiple usecases for -baseonly and -gcov on various targets in the Makefile. Instead of calling those targets out repeatedly, lets generalize them a bit. Allow adding -baseonly and -gcov to: dist-rpm dist-srpm dist-brew dist-koji distg-brew distg-koji Gcov is useful for adding code coverage. Baseonly is useful to only build the kernel for debugging purposes without userspace tools. Signed-off-by: Don Zickus <dzickus(a)redhat.com> diff --git a/redhat/Makefile b/redhat/Makefile index blahblah..blahblah 100644 --- a/redhat/Makefile +++ b/redhat/Makefile @@ -297,6 +297,12 @@ dist-sources: dist-kabi dist-kabi-dup sources-rh dist-test-patch: generate-testpatch-tmp @mv $(TESTPATCH).tmp $(TESTPATCH); +%-baseonly: RPMBUILDOPTS=--target $(MACH) --without debug --without debuginfo --without vdso_install --without bpftool --without perf --without tools --without selftests -bb +%-baseonly: BUILDOPTS+=-debug -debuginfo -vdso_install -bpftool -perf -tools -selftests + +%-gcov: BUILDID=".gcov" +%-gcov: BUILDOPTS+="+gcov" + do-rpmbuild: dist-sources $(RPMBUILD) --define "_sourcedir $(SOURCES)" --define "_builddir $(RPM)/BUILD" --define "_srcrpmdir $(RPM)/SRPMS" --define "_rpmdir $(RPM)/RPMS" --define "_specdir $(RPM)/SPECS" --define "dist $(DIST)" $(RPMBUILDOPTS) $(RPM)/SOURCES/$(PACKAGE_NAME).spec @@ -306,9 +312,9 @@ dist-all-rpms: dist-sources do-rpmbuild dist-srpm: RPMBUILDOPTS=--nodeps -bs dist-srpm: dist-sources do-rpmbuild -dist-srpm-gcov: BUILDID=".gcov" -dist-srpm-gcov: BUILDOPTS+="+gcov" -dist-srpm-gcov: dist-srpm +dist-srpm-%: dist-srpm + @# phony command to force this to be a target and not variable + @FOO=BAR dist-rpms: RPMBUILDOPTS=--target $(MACH) -bb dist-rpms: dist-sources do-rpmbuild @@ -322,8 +328,7 @@ dist-prep: dist-sources do-rpmbuild dist-perf: RPMBUILDOPTS=--without up --without smp --without zfcpdump --without debug --without doc --without headers --without --without doc --without debuginfo --target $(MACH) -bb dist-perf: dist-sources do-rpmbuild -dist-rpm-baseonly: RPMBUILDOPTS=--target $(MACH) --without debug --without debuginfo --without vdso_install --without bpftool --without perf --without tools -bb -dist-rpm-baseonly: dist-sources do-rpmbuild +dist-rpm-%: dist-sources do-rpmbuild # unless you know what you're doing, you don't want to use the next four ones dist-release-finish: setup-source @@ -388,9 +393,25 @@ distg-koji: BUILD_FLAGS ?= $(KOJI_FLAGS) $(TEST_FLAGS) dist-brew dist-koji: dist-%: dist-srpm $* $(BUILD_PROFILE) build $(BUILD_FLAGS) $(BUILD_TARGET) $(SRPMS)/$(PACKAGE_NAME)-$(KVERSION)-$(PKGRELEASE)$(DIST).src.rpm $(OUTPUT_FILE) +dist-brew-%: dist-brew + @# phony command to force this to be a target and not variable + @FOO=BAR + +dist-koji-%: dist-koji + @# phony command to force this to be a target and not variable + @FOO=BAR + distg-brew distg-koji: distg-%: $* $(BUILD_PROFILE) build $(BUILD_FLAGS) $(BUILD_TARGET) "$(RHGITURL)?redhat/koji#$(RHGITCOMMIT)" +distg-brew-%: dist-brew + @# phony command to force this to be a target and not variable + @FOO=BAR + +distg-koji-%: dist-koji + @# phony command to force this to be a target and not variable + @FOO=BAR + .PHONY: $(REDHAT)/rpm/SOURCES/$(PACKAGE_NAME).spec $(REDHAT)/rpm/SOURCES/$(PACKAGE_NAME).spec: @echo "dist-sources" @@ -469,34 +490,30 @@ dist-full-help: @echo 'Building targets:' @echo ' All RPM/SRPM files will be put under the redhat/rpm/ directory.' @echo '' - @echo ' dist-srpm - Create a source RPM and put it into the redhat/rpm/SRPMS/' + @echo ' dist-srpm@ - Create a source RPM and put it into the redhat/rpm/SRPMS/' @echo ' directory. See the dist-brew target for available options.' - @echo ' dist-srpm-gcov - Create a source RPM with gcov enabled and put it into the' - @echo ' redhat/rpm/SRPMS/ directory.' - @echo ' dist-brew - Create a kernel SRPM and then call brew to build the' + @echo ' dist-brew@ - Create a kernel SRPM and then call brew to build the' @echo ' created SRPM. Add BUILDOPTS="+<opt> -<opt> [...]" to' @echo ' enable/disable build options.' @echo ' Available <opt>s and their default values:' \ $$(sed -n -e 's/^%define with_$[^ \t]*$.*\?_without_.*/+\1/p' \ -e 's/^%define with_$[^ \t]*$.*\?_with_.*/-\1/p' kernel.spec.template | \ grep -v 'only$$') | fmt -80 - @echo ' dist-koji - Create a kernel SRPM and then call koji to build the' + @echo ' dist-koji@ - Create a kernel SRPM and then call koji to build the' @echo ' created SRPM. See the dist-brew target for available' @echo ' options.' - @echo ' distg-brew - Pass HEAD of the current git branch to brew to build an' + @echo ' distg-brew@ - Pass HEAD of the current git branch to brew to build an' @echo ' RPM set. Do not forget to push to the remote repository' @echo ' first. Preceed make command by RHGITCOMMIT=<commitID>' @echo ' specify commit ID to use.' @echo ' To set the remote repo, invoke:' @echo ' git config rhg.url git://<repo_path>' - @echo ' distg-koji - Pass HEAD of the current git branch to koji to build an' + @echo ' distg-koji@ - Pass HEAD of the current git branch to koji to build an' @echo ' RPM set. Do not forget to push to the remote repository' @echo ' first. See the distg-brew target for options and' @echo ' configuration.' - @echo ' dist-rpms - Create the binary RPMS for the kernel.' + @echo ' dist-rpms@ - Create the binary RPMS for the kernel.' @echo ' See the dist-brew target for available options.' - @echo ' dist-rpm-baseonly - Create the binary RPMS for the kernel and modules' - @echo ' (no userspace tools or debuginfo).' @echo ' dist-kernel-<type> - Create binary RPMS for a particular kernel type.' @echo ' Available <type>s:'\ $$(sed -n 's/^%define with_$[^ ]*only$.*/\1/p' kernel.spec.template) @@ -524,6 +541,12 @@ dist-full-help: @echo ' dist-rhel-configs - build ELN configs' @echo ' dist-fedora-configs - build Fedora configs' + @echo '' + @echo 'Wildcard targets: [indicated by '@' above]' + @echo ' *-baseonly - builds only the kernel (disables userspace and debuginfo)' + @echo ' - Examples: dist-srpm-baseonly, dist-brew-baseonly' + @echo ' *-gcov - builds a kernel with gcov enabled' + @echo ' - Examples: dist-srpm-gcov, dist-brew-gcov' @echo '' @echo 'kABI targets:' @echo ' dist-kabi - Create kABI stablelist files in redhat/kabi/kabi-rhel*/' -- https://gitlab.com/cki-project/kernel-ark/-/merge_requests/1444

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[OS-BUILD PATCHv3 0/2] redhat: introduce RH_KABI_EXCLUDE_WITH_SIZE and enable size checks
by Sabrina Dubroca (via Email Bridge) 16 Nov '23

16 Nov '23

From: Sabrina Dubroca on gitlab.com Merge Request: https://gitlab.com/cki-project/kernel-ark/-/merge_requests/1619 This MR introduces a new kABI macro, RH_KABI_EXCLUDE_WITH_SIZE. The implementation is identical to RH_KABI_EXTEND_WITH_SIZE, but the meaning is more in line with RH_KABI_EXCLUDE. The size check and reserved space allows us to exclude an element embedded inside a kABI-protected structure while reserving space for it to grow in the future. The size checks that are part of multiple kABI macros are currently not enabled because the config option to turn them on is missing. Those size checks only make sense on regular builds, so they're disabled on debug kernels. Signed-off-by: Sabrina Dubroca <sdubroca(a)redhat.com> --- include/linux/rh_kabi.h | 26 ++++++++++ redhat/configs/ark/debug/CONFIG_RH_KABI_SIZE_ALIGN_CHECKS | 1 + redhat/configs/ark/generic/CONFIG_RH_KABI_SIZE_ALIGN_CHECKS | 1 + redhat/configs/ark/kgcov/CONFIG_RH_KABI_SIZE_ALIGN_CHECKS | 1 + redhat/configs/common/generic/CONFIG_RH_KABI_SIZE_ALIGN_CHECKS | 1 + Kconfig.redhat | 9 +++ 6 files changed, 39 insertions(+), 0 deletions(-)

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[OS-BUILD PATCHv3 0/0] scriptlets: clean up declared installation dependencies, stop calling kernel-install in chroot or container
by Zbigniew Jędrzejewski-Szmek (via Email Bridge) 06 Feb '23

06 Feb '23

From: Zbigniew Jędrzejewski-Szmek on gitlab.com Merge Request: https://gitlab.com/cki-project/kernel-ark/-/merge_requests/1617 NOTE: Truncated patchset due to missing public @redhat.com email address on your GitLab profile at https://gitlab.com/-/profile. Once that is fixed, close and reopen the merge request to retrigger sending the emails. --- redhat/kernel.spec.template | 30 ++++++++++++++---------------- 1 files changed, 14 insertions(+), 16 deletions(-)

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[OS-BUILD PATCH] Add gcc-c++ to BuildRequires
by GitLab Bridge on behalf of jmflinuxtx 20 Dec '22

20 Dec '22

From: "Justin M. Forbes" <jforbes(a)fedoraproject.org> This is required for some of the gcc plugins. Signed-off-by: Justin M. Forbes <jforbes(a)fedoraproject.org> --- redhat/kernel.spec.template | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/redhat/kernel.spec.template b/redhat/kernel.spec.template index 5941924711d4..c8ee1f82c494 100755 --- a/redhat/kernel.spec.template +++ b/redhat/kernel.spec.template @@ -501,7 +501,7 @@ Requires: kernel-modules-uname-r = %{KVERREL}%{?variant} # BuildRequires: kmod, patch, bash, tar, git-core BuildRequires: bzip2, xz, findutils, gzip, m4, perl-interpreter, perl-Carp, perl-devel, perl-generators, make, diffutils, gawk -BuildRequires: gcc, binutils, redhat-rpm-config, hmaccalc, bison, flex +BuildRequires: gcc, binutils, redhat-rpm-config, hmaccalc, bison, flex, gcc-c++ BuildRequires: net-tools, hostname, bc, elfutils-devel BuildRequires: dwarves BuildRequires: python3-devel -- GitLab

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[OS-BUILD PATCHv3] Enable KUNIT tests for redhat kernel-modules-internal
by Nico Pache (via Email Bridge) 05 Aug '22

05 Aug '22

From: Nico Pache <npache(a)redhat.com> Enable KUNIT tests for redhat kernel-modules-internal This commit will enable KUNIT tests to be compiled as modules and packaged into the kernel-modules-internal package. Signed-off-by: Nico Pache <npache(a)redhat.com> diff --git a/redhat/configs/common/debug/CONFIG_KASAN_KUNIT_TEST b/redhat/configs/common/debug/CONFIG_KASAN_KUNIT_TEST new file mode 100644 index blahblah..blahblah 100644 --- /dev/null +++ b/redhat/configs/common/debug/CONFIG_KASAN_KUNIT_TEST @@ -0,0 +1 @@ +CONFIG_KASAN_KUNIT_TEST=m diff --git a/redhat/configs/common/debug/CONFIG_TEST_LIST_SORT b/redhat/configs/common/debug/CONFIG_TEST_LIST_SORT index blahblah..blahblah 100644 --- a/redhat/configs/common/debug/CONFIG_TEST_LIST_SORT +++ b/redhat/configs/common/debug/CONFIG_TEST_LIST_SORT @@ -1 +1 @@ -CONFIG_TEST_LIST_SORT=y +CONFIG_TEST_LIST_SORT=m diff --git a/redhat/configs/common/generic/CONFIG_BITFIELD_KUNIT b/redhat/configs/common/generic/CONFIG_BITFIELD_KUNIT new file mode 100644 index blahblah..blahblah 100644 --- /dev/null +++ b/redhat/configs/common/generic/CONFIG_BITFIELD_KUNIT @@ -0,0 +1 @@ +# CONFIG_BITFIELD_KUNIT is not set diff --git a/redhat/configs/common/generic/CONFIG_BITS_TEST b/redhat/configs/common/generic/CONFIG_BITS_TEST new file mode 100644 index blahblah..blahblah 100644 --- /dev/null +++ b/redhat/configs/common/generic/CONFIG_BITS_TEST @@ -0,0 +1 @@ +# CONFIG_BITS_TEST is not set diff --git a/redhat/configs/common/generic/CONFIG_CMDLINE_KUNIT_TEST b/redhat/configs/common/generic/CONFIG_CMDLINE_KUNIT_TEST new file mode 100644 index blahblah..blahblah 100644 --- /dev/null +++ b/redhat/configs/common/generic/CONFIG_CMDLINE_KUNIT_TEST @@ -0,0 +1 @@ +# CONFIG_CMDLINE_KUNIT_TEST is not set diff --git a/redhat/configs/common/generic/CONFIG_EXT4_KUNIT_TESTS b/redhat/configs/common/generic/CONFIG_EXT4_KUNIT_TESTS new file mode 100644 index blahblah..blahblah 100644 --- /dev/null +++ b/redhat/configs/common/generic/CONFIG_EXT4_KUNIT_TESTS @@ -0,0 +1 @@ +CONFIG_EXT4_KUNIT_TESTS=m diff --git a/redhat/configs/common/generic/CONFIG_FAT_KUNIT_TEST b/redhat/configs/common/generic/CONFIG_FAT_KUNIT_TEST new file mode 100644 index blahblah..blahblah 100644 --- /dev/null +++ b/redhat/configs/common/generic/CONFIG_FAT_KUNIT_TEST @@ -0,0 +1 @@ +CONFIG_FAT_KUNIT_TEST=m diff --git a/redhat/configs/common/generic/CONFIG_KFENCE_KUNIT_TEST b/redhat/configs/common/generic/CONFIG_KFENCE_KUNIT_TEST new file mode 100644 index blahblah..blahblah 100644 --- /dev/null +++ b/redhat/configs/common/generic/CONFIG_KFENCE_KUNIT_TEST @@ -0,0 +1 @@ +CONFIG_KFENCE_KUNIT_TEST=m diff --git a/redhat/configs/common/generic/CONFIG_KUNIT b/redhat/configs/common/generic/CONFIG_KUNIT index blahblah..blahblah 100644 --- a/redhat/configs/common/generic/CONFIG_KUNIT +++ b/redhat/configs/common/generic/CONFIG_KUNIT @@ -1 +1 @@ -# CONFIG_KUNIT is not set +CONFIG_KUNIT=m diff --git a/redhat/configs/common/generic/CONFIG_KUNIT_ALL_TESTS b/redhat/configs/common/generic/CONFIG_KUNIT_ALL_TESTS new file mode 100644 index blahblah..blahblah 100644 --- /dev/null +++ b/redhat/configs/common/generic/CONFIG_KUNIT_ALL_TESTS @@ -0,0 +1 @@ +CONFIG_KUNIT_ALL_TESTS=m diff --git a/redhat/configs/common/generic/CONFIG_KUNIT_DEBUGFS b/redhat/configs/common/generic/CONFIG_KUNIT_DEBUGFS new file mode 100644 index blahblah..blahblah 100644 --- /dev/null +++ b/redhat/configs/common/generic/CONFIG_KUNIT_DEBUGFS @@ -0,0 +1 @@ +CONFIG_KUNIT_DEBUGFS=y diff --git a/redhat/configs/common/generic/CONFIG_KUNIT_EXAMPLE_TEST b/redhat/configs/common/generic/CONFIG_KUNIT_EXAMPLE_TEST new file mode 100644 index blahblah..blahblah 100644 --- /dev/null +++ b/redhat/configs/common/generic/CONFIG_KUNIT_EXAMPLE_TEST @@ -0,0 +1 @@ +CONFIG_KUNIT_EXAMPLE_TEST=m diff --git a/redhat/configs/common/generic/CONFIG_KUNIT_TEST b/redhat/configs/common/generic/CONFIG_KUNIT_TEST new file mode 100644 index blahblah..blahblah 100644 --- /dev/null +++ b/redhat/configs/common/generic/CONFIG_KUNIT_TEST @@ -0,0 +1 @@ +CONFIG_KUNIT_TEST=m diff --git a/redhat/configs/common/generic/CONFIG_LINEAR_RANGES_TEST b/redhat/configs/common/generic/CONFIG_LINEAR_RANGES_TEST new file mode 100644 index blahblah..blahblah 100644 --- /dev/null +++ b/redhat/configs/common/generic/CONFIG_LINEAR_RANGES_TEST @@ -0,0 +1 @@ +# CONFIG_LINEAR_RANGES_TEST is not set diff --git a/redhat/configs/common/generic/CONFIG_LIST_KUNIT_TEST b/redhat/configs/common/generic/CONFIG_LIST_KUNIT_TEST new file mode 100644 index blahblah..blahblah 100644 --- /dev/null +++ b/redhat/configs/common/generic/CONFIG_LIST_KUNIT_TEST @@ -0,0 +1 @@ +CONFIG_LIST_KUNIT_TEST=m diff --git a/redhat/configs/common/generic/CONFIG_MPTCP_KUNIT_TEST b/redhat/configs/common/generic/CONFIG_MPTCP_KUNIT_TEST new file mode 100644 index blahblah..blahblah 100644 --- /dev/null +++ b/redhat/configs/common/generic/CONFIG_MPTCP_KUNIT_TEST @@ -0,0 +1 @@ +CONFIG_MPTCP_KUNIT_TEST=m diff --git a/redhat/configs/common/generic/CONFIG_MPTCP_KUNIT_TESTS b/redhat/configs/common/generic/CONFIG_MPTCP_KUNIT_TESTS new file mode 100644 index blahblah..blahblah 100644 --- /dev/null +++ b/redhat/configs/common/generic/CONFIG_MPTCP_KUNIT_TESTS @@ -0,0 +1 @@ +CONFIG_MPTCP_KUNIT_TESTS=m diff --git a/redhat/configs/common/generic/CONFIG_RATIONAL_KUNIT_TEST b/redhat/configs/common/generic/CONFIG_RATIONAL_KUNIT_TEST new file mode 100644 index blahblah..blahblah 100644 --- /dev/null +++ b/redhat/configs/common/generic/CONFIG_RATIONAL_KUNIT_TEST @@ -0,0 +1 @@ +CONFIG_RATIONAL_KUNIT_TEST=m diff --git a/redhat/configs/common/generic/CONFIG_RESOURCE_KUNIT_TEST b/redhat/configs/common/generic/CONFIG_RESOURCE_KUNIT_TEST new file mode 100644 index blahblah..blahblah 100644 --- /dev/null +++ b/redhat/configs/common/generic/CONFIG_RESOURCE_KUNIT_TEST @@ -0,0 +1 @@ +# CONFIG_RESOURCE_KUNIT_TEST is not set diff --git a/redhat/configs/common/generic/CONFIG_RTC_LIB_KUNIT_TEST b/redhat/configs/common/generic/CONFIG_RTC_LIB_KUNIT_TEST new file mode 100644 index blahblah..blahblah 100644 --- /dev/null +++ b/redhat/configs/common/generic/CONFIG_RTC_LIB_KUNIT_TEST @@ -0,0 +1 @@ +CONFIG_RTC_LIB_KUNIT_TEST=m -- https://gitlab.com/cki-project/kernel-ark/-/merge_requests/1422

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[OS-BUILD PATCH] Fix gcc 12 warning address of 'mem_section' will never be NULL
by Justin M. Forbes (via Email Bridge) 30 Mar '22

30 Mar '22

From: Justin M. Forbes <jforbes(a)fedoraproject.org> Fix gcc 12 warning address of 'mem_section' will never be NULL Signed-off-by: Justin M. Forbes <jforbes(a)fedoraproject.org> diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index blahblah..blahblah 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -1390,11 +1390,9 @@ static inline unsigned long *section_to_usemap(struct mem_section *ms) static inline struct mem_section *__nr_to_section(unsigned long nr) { #ifdef CONFIG_SPARSEMEM_EXTREME - if (!mem_section) + if (!mem_section || !mem_section[SECTION_NR_TO_ROOT(nr)]) return NULL; #endif - if (!mem_section[SECTION_NR_TO_ROOT(nr)]) - return NULL; return &mem_section[SECTION_NR_TO_ROOT(nr)][nr & SECTION_ROOT_MASK]; } extern size_t mem_section_usage_size(void); -- https://gitlab.com/cki-project/kernel-ark/-/merge_requests/1598

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Fedora kernel emails: too much or just right?
by Donald Zickus 23 Mar '22

23 Mar '22

Hi, It has been awhile since we changed how this mailing list is used. As folks have noticed, we have increased traffic significantly over the past couple of years to reflect the activity Red Hat developers are performing on the Fedora kernel. My question to this list is around the thoughts of this activity: * Is there too much noise? Should we throttle back? * is the volume ok? Folks have good filters? * Other suggestions on how we use this list? Trying to continue to make this mailing list useful. Thanks for any feedback! Cheers, Don

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[OS-BUILD PATCH] Setting CONFIG_I2C_SMBUS to "m" for ark
by Gopal Tiwari (via Email Bridge) 11 Mar '22

11 Mar '22

From: Gopal Tiwari <gtiwari(a)redhat.com> Setting CONFIG_I2C_SMBUS to "m" for ark This setting is keeping CONFIG_I2C_SMBUS in align to rhel. Signed-off-by: Gopal Tiwari <gtiwari(a)redhat.com> diff --git a/redhat/configs/common/generic/CONFIG_I2C_SMBUS b/redhat/configs/common/generic/CONFIG_I2C_SMBUS new file mode 100644 index blahblah..blahblah 100644 --- /dev/null +++ b/redhat/configs/common/generic/CONFIG_I2C_SMBUS @@ -0,0 +1 @@ +CONFIG_I2C_SMBUS=m -- https://gitlab.com/cki-project/kernel-ark/-/merge_requests/1626

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[OS-BUILD PATCHv3] mm/sparsemem: Fix 'mem_section' will never be NULL gcc 12 warning
by Justin M. Forbes (via Email Bridge) 08 Mar '22

08 Mar '22

From: Waiman Long <longman(a)redhat.com> mm/sparsemem: Fix 'mem_section' will never be NULL gcc 12 warning The gcc 12 compiler reports a "'mem_section' will never be NULL" warning on the following code: static inline struct mem_section *__nr_to_section(unsigned long nr) { #ifdef CONFIG_SPARSEMEM_EXTREME if (!mem_section) return NULL; #endif if (!mem_section[SECTION_NR_TO_ROOT(nr)]) return NULL; : It happens with both CONFIG_SPARSEMEM_EXTREME on and off. The mem_section definition is #ifdef CONFIG_SPARSEMEM_EXTREME extern struct mem_section **mem_section; #else extern struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT]; #endif In the CONFIG_SPARSEMEM_EXTREME case, mem_section obviously cannot be NULL, but *mem_section can be if memory hasn't been allocated for the dynamic mem_section[] array yet. In the !CONFIG_SPARSEMEM_EXTREME case, mem_section is a static 2-dimensional array and so the check "!mem_section[SECTION_NR_TO_ROOT(nr)]" doesn't make sense. Fix this warning by checking for "!*mem_section" instead of "!mem_section" and moving the "!mem_section[SECTION_NR_TO_ROOT(nr)]" check up inside the CONFIG_SPARSEMEM_EXTREME block. Fixes: 83e3c48729d9 ("mm/sparsemem: Allocate mem_section at runtime for CONFIG_SPARSEMEM_EXTREME=y") Fixes: 3e347261a80b ("sparsemem extreme implementation") Reported-by: Justin Forbes <jforbes(a)redhat.com> Signed-off-by: Waiman Long <longman(a)redhat.com> diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index blahblah..blahblah 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -1390,11 +1390,9 @@ static inline unsigned long *section_to_usemap(struct mem_section *ms) static inline struct mem_section *__nr_to_section(unsigned long nr) { #ifdef CONFIG_SPARSEMEM_EXTREME - if (!mem_section) + if (!*mem_section || !mem_section[SECTION_NR_TO_ROOT(nr)]) return NULL; #endif - if (!mem_section[SECTION_NR_TO_ROOT(nr)]) - return NULL; return &mem_section[SECTION_NR_TO_ROOT(nr)][nr & SECTION_ROOT_MASK]; } extern size_t mem_section_usage_size(void); -- https://gitlab.com/cki-project/kernel-ark/-/merge_requests/1598

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kernel February 2022