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2020-09-20Linux 5.9-rc6Linus Torvalds
2020-09-13Linux 5.9-rc5Linus Torvalds
2020-09-08Merge tag 'livepatching-for-5.9-rc5' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/livepatching/livepatching Pull livepatching fix from Petr Mladek: "Workaround for 'unreachable instruction' objtool warnings that happen with some compiler versions" * tag 'livepatching-for-5.9-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/livepatching/livepatching: Revert "kbuild: use -flive-patching when CONFIG_LIVEPATCH is enabled"
2020-09-06Linux 5.9-rc4Linus Torvalds
2020-09-03Revert "kbuild: use -flive-patching when CONFIG_LIVEPATCH is enabled"Josh Poimboeuf
Use of the new -flive-patching flag was introduced with the following commit: 43bd3a95c98e ("kbuild: use -flive-patching when CONFIG_LIVEPATCH is enabled") This flag has several drawbacks: - It disables some optimizations, so it can have a negative effect on performance. - According to the GCC documentation it's not compatible with LTO, which will become a compatibility issue as LTO support gets upstreamed in the kernel. - It was intended to be used for source-based patch generation tooling, as opposed to binary-based patch generation tooling (e.g., kpatch-build). It probably should have at least been behind a separate config option so as not to negatively affect other livepatch users. - Clang doesn't have the flag, so as far as I can tell, this method of generating patches is incompatible with Clang, which like LTO is becoming more mainstream. - It breaks GCC's implicit noreturn detection for local functions. This is the cause of several "unreachable instruction" objtool warnings. - The broken noreturn detection is an obvious GCC regression, but we haven't yet gotten GCC developers to acknowledge that, which doesn't inspire confidence in their willingness to keep the feature working as optimizations are added or changed going forward. - While there *is* a distro which relies on this flag for their distro livepatch module builds, there's not a publicly documented way to create safe livepatch modules with it. Its use seems to be based on tribal knowledge. It serves no benefit to those who don't know how to use it. (In fact, I believe the current livepatch documentation and samples are misleading and dangerous, and should be corrected. Or at least amended with a disclaimer. But I don't feel qualified to make such changes.) Also, we have an idea for using objtool to detect function changes, which could potentially obsolete the need for this flag anyway. At this point the flag has no benefits for upstream which would counteract the above drawbacks. Revert it until it becomes more ready. This reverts commit 43bd3a95c98e1a86b8b55d97f745c224ecff02b9. Fixes: 43bd3a95c98e ("kbuild: use -flive-patching when CONFIG_LIVEPATCH is enabled") Reported-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Acked-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/696262e997359666afa053fe7d1a9fb2bb373964.1595010490.git.jpoimboe@redhat.com
2020-08-30Linux 5.9-rc3Linus Torvalds
2020-08-23Linux 5.9-rc2Linus Torvalds
2020-08-18kbuild: remove redundant patterns in filter/filter-outMasahiro Yamada
The '%' in filter/filter-out matches to any number of any characters, including empty string. So, '%config' matches to 'config', and '%install' to 'install'. Drop the redundant patterns. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-08-16Linux 5.9-rc1Linus Torvalds
2020-08-12./Makefile: add debug option to enable function aligned on 32 bytesFeng Tang
Recently 0day reported many strange performance changes (regression or improvement), in which there was no obvious relation between the culprit commit and the benchmark at the first look, and it causes people to doubt the test itself is wrong. Upon further check, many of these cases are caused by the change to the alignment of kernel text or data, as whole text/data of kernel are linked together, change in one domain may affect alignments of other domains. gcc has an option '-falign-functions=n' to force text aligned, and with that option enabled, some of those performance changes will be gone, like [1][2][3]. Add this option so that developers and 0day can easily find performance bump caused by text alignment change, as tracking these strange bump is quite time consuming. Though it can't help in other cases like data alignment changes like [4]. Following is some size data for v5.7 kernel built with a RHEL config used in 0day: text data bss dec filename 19738771 13292906 5554236 38585913 vmlinux.noalign 19758591 13297002 5529660 38585253 vmlinux.align32 Raw vmlinux size in bytes: v5.7 v5.7+align32 253950832 254018000 +0.02% Some benchmark data, most of them have no big change: * hackbench: [ -1.8%, +0.5%] * fsmark: [ -3.2%, +3.4%] # ext4/xfs/btrfs * kbuild: [ -2.0%, +0.9%] * will-it-scale: [ -0.5%, +1.8%] # mmap1/pagefault3 * netperf: - TCP_CRR [+16.6%, +97.4%] - TCP_RR [-18.5%, -1.8%] - TCP_STREAM [ -1.1%, +1.9%] [1] https://lore.kernel.org/lkml/20200114085637.GA29297@shao2-debian/ [2] https://lore.kernel.org/lkml/20200330011254.GA14393@feng-iot/ [3] https://lore.kernel.org/lkml/1d98d1f0-fe84-6df7-f5bd-f4cb2cdb7f45@intel.com/ [4] https://lore.kernel.org/lkml/20200205123216.GO12867@shao2-debian/ Signed-off-by: Feng Tang <feng.tang@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Masahiro Yamada <masahiroy@kernel.org> Cc: Michal Marek <michal.lkml@markovi.net> Cc: Andi Kleen <andi.kleen@intel.com> Cc: Huang Ying <ying.huang@intel.com> Cc: Andy Shevchenko <andriy.shevchenko@intel.com> Link: http://lkml.kernel.org/r/1595475001-90945-1-git-send-email-feng.tang@intel.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-09Merge tag 'kbuild-v5.9' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild updates from Masahiro Yamada: - run the checker (e.g. sparse) after the compiler - remove unneeded cc-option tests for old compiler flags - fix tar-pkg to install dtbs - introduce ccflags-remove-y and asflags-remove-y syntax - allow to trace functions in sub-directories of lib/ - introduce hostprogs-always-y and userprogs-always-y syntax - various Makefile cleanups * tag 'kbuild-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: kbuild: stop filtering out $(GCC_PLUGINS_CFLAGS) from cc-option base kbuild: include scripts/Makefile.* only when relevant CONFIG is enabled kbuild: introduce hostprogs-always-y and userprogs-always-y kbuild: sort hostprogs before passing it to ifneq kbuild: move host .so build rules to scripts/gcc-plugins/Makefile kbuild: Replace HTTP links with HTTPS ones kbuild: trace functions in subdirectories of lib/ kbuild: introduce ccflags-remove-y and asflags-remove-y kbuild: do not export LDFLAGS_vmlinux kbuild: always create directories of targets powerpc/boot: add DTB to 'targets' kbuild: buildtar: add dtbs support kbuild: remove cc-option test of -ffreestanding kbuild: remove cc-option test of -fno-stack-protector Revert "kbuild: Create directory for target DTB" kbuild: run the checker after the compiler
2020-08-10kbuild: stop filtering out $(GCC_PLUGINS_CFLAGS) from cc-option baseMasahiro Yamada
Commit d26e94149276 ("kbuild: no gcc-plugins during cc-option tests") was neeeded because scripts/Makefile.gcc-plugins was too early. This is unneeded by including scripts/Makefile.gcc-plugins last, and being careful to not add cc-option tests after it. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-08-10kbuild: include scripts/Makefile.* only when relevant CONFIG is enabledMasahiro Yamada
Currently, the top Makefile includes all of scripts/Makefile.<feature> even if the associated CONFIG option is disabled. Do not include unneeded Makefiles in order to slightly optimize the parse stage. Include $(include-y), and ignore $(include-). Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-08-10kbuild: do not export LDFLAGS_vmlinuxMasahiro Yamada
When you clean the build tree for ARCH=arm, you may see the following error message from 'nm' command: $ make -j24 ARCH=arm clean CLEAN arch/arm/crypto CLEAN arch/arm/kernel CLEAN arch/arm/mach-at91 CLEAN arch/arm/mach-omap2 CLEAN arch/arm/vdso CLEAN certs CLEAN lib CLEAN usr CLEAN net/wireless CLEAN drivers/firmware/efi/libstub nm: 'arch/arm/boot/compressed/../../../../vmlinux': No such file /bin/sh: 1: arithmetic expression: expecting primary: " " CLEAN arch/arm/boot/compressed CLEAN drivers/scsi CLEAN drivers/tty/vt CLEAN arch/arm/boot CLEAN vmlinux.symvers modules.builtin modules.builtin.modinfo Even if you rerun the same command, the error message will not be shown despite vmlinux is already gone. To reproduce it, the parallel option -j is needed. Single thread cleaning always executes 'archclean', 'vmlinuxclean' in this order, so vmlinux still exists when arch/arm/boot/compressed/ is cleaned. Looking at arch/arm/boot/compressed/Makefile does not help understand the reason of the error message. Both KBSS_SZ and LDFLAGS_vmlinux are assigned with '=' operator, hence, they are not expanded unless used. Obviously, 'make clean' does not use them. In fact, the root cause exists in the top Makefile: export LDFLAGS_vmlinux Since LDFLAGS_vmlinux is an exported variable, LDFLAGS_vmlinux in arch/arm/boot/compressed/Makefile is expanded when scripts/Makefile.clean has a command to execute. This is why the error message shows up only when there exist build artifacts in arch/arm/boot/compressed/. Adding 'unexport LDFLAGS_vmlinux' to arch/arm/boot/compressed/Makefile will fix it as far as ARCH=arm is concerned, but I think the proper fix is to get rid of 'export LDFLAGS_vmlinux' from the top Makefile. LDFLAGS_vmlinux in the top Makefile contains linker flags for the top vmlinux. LDFLAGS_vmlinux in arch/arm/boot/compressed/Makefile is for arch/arm/boot/compressed/vmlinux. They just happen to have the same variable name, but are used for different purposes. Stop shadowing LDFLAGS_vmlinux. This commit passes LDFLAGS_vmlinux to scripts/link-vmlinux.sh via a command line parameter instead of via an environment variable. LD and KBUILD_LDFLAGS are exported, but I did the same for consistency. Anyway, they must be included in cmd_link-vmlinux to allow if_changed to detect the changes in LD or KBUILD_LDFLAGS. The following Makefiles are not affected: arch/arm/boot/compressed/Makefile arch/h8300/boot/compressed/Makefile arch/nios2/boot/compressed/Makefile arch/parisc/boot/compressed/Makefile arch/s390/boot/compressed/Makefile arch/sh/boot/compressed/Makefile arch/sh/boot/romimage/Makefile arch/x86/boot/compressed/Makefile They use ':=' or '=' to clear the LDFLAGS_vmlinux inherited from the top Makefile. We need to take a closer look at the impact to unicore32 and xtensa. arch/unicore32/boot/compressed/Makefile only uses '+=' operator for LDFLAGS_vmlinux. So, the decompressor previously inherited the linker flags from the top Makefile. However, commit 70fac51feaf2 ("unicore32 additional architecture files: boot process") was merged before commit 1f2bfbd00e46 ("kbuild: link of vmlinux moved to a script"). So, I rather consider this is a bug fix of 1f2bfbd00e46. arch/xtensa/boot/boot-elf/Makefile is also affected, but this is also considered a fix for the same reason. It did not inherit LDFLAGS_vmlinux when commit 4bedea945451 ("[PATCH] xtensa: Architecture support for Tensilica Xtensa Part 2") was merged. I deleted $(LDFLAGS_vmlinux), which is now empty. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Tested-by: Nick Desaulniers <ndesaulniers@google.com>
2020-08-05Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextLinus Torvalds
Pull networking updates from David Miller: 1) Support 6Ghz band in ath11k driver, from Rajkumar Manoharan. 2) Support UDP segmentation in code TSO code, from Eric Dumazet. 3) Allow flashing different flash images in cxgb4 driver, from Vishal Kulkarni. 4) Add drop frames counter and flow status to tc flower offloading, from Po Liu. 5) Support n-tuple filters in cxgb4, from Vishal Kulkarni. 6) Various new indirect call avoidance, from Eric Dumazet and Brian Vazquez. 7) Fix BPF verifier failures on 32-bit pointer arithmetic, from Yonghong Song. 8) Support querying and setting hardware address of a port function via devlink, use this in mlx5, from Parav Pandit. 9) Support hw ipsec offload on bonding slaves, from Jarod Wilson. 10) Switch qca8k driver over to phylink, from Jonathan McDowell. 11) In bpftool, show list of processes holding BPF FD references to maps, programs, links, and btf objects. From Andrii Nakryiko. 12) Several conversions over to generic power management, from Vaibhav Gupta. 13) Add support for SO_KEEPALIVE et al. to bpf_setsockopt(), from Dmitry Yakunin. 14) Various https url conversions, from Alexander A. Klimov. 15) Timestamping and PHC support for mscc PHY driver, from Antoine Tenart. 16) Support bpf iterating over tcp and udp sockets, from Yonghong Song. 17) Support 5GBASE-T i40e NICs, from Aleksandr Loktionov. 18) Add kTLS RX HW offload support to mlx5e, from Tariq Toukan. 19) Fix the ->ndo_start_xmit() return type to be netdev_tx_t in several drivers. From Luc Van Oostenryck. 20) XDP support for xen-netfront, from Denis Kirjanov. 21) Support receive buffer autotuning in MPTCP, from Florian Westphal. 22) Support EF100 chip in sfc driver, from Edward Cree. 23) Add XDP support to mvpp2 driver, from Matteo Croce. 24) Support MPTCP in sock_diag, from Paolo Abeni. 25) Commonize UDP tunnel offloading code by creating udp_tunnel_nic infrastructure, from Jakub Kicinski. 26) Several pci_ --> dma_ API conversions, from Christophe JAILLET. 27) Add FLOW_ACTION_POLICE support to mlxsw, from Ido Schimmel. 28) Add SK_LOOKUP bpf program type, from Jakub Sitnicki. 29) Refactor a lot of networking socket option handling code in order to avoid set_fs() calls, from Christoph Hellwig. 30) Add rfc4884 support to icmp code, from Willem de Bruijn. 31) Support TBF offload in dpaa2-eth driver, from Ioana Ciornei. 32) Support XDP_REDIRECT in qede driver, from Alexander Lobakin. 33) Support PCI relaxed ordering in mlx5 driver, from Aya Levin. 34) Support TCP syncookies in MPTCP, from Flowian Westphal. 35) Fix several tricky cases of PMTU handling wrt. briding, from Stefano Brivio. * git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2056 commits) net: thunderx: initialize VF's mailbox mutex before first usage usb: hso: remove bogus check for EINPROGRESS usb: hso: no complaint about kmalloc failure hso: fix bailout in error case of probe ip_tunnel_core: Fix build for archs without _HAVE_ARCH_IPV6_CSUM selftests/net: relax cpu affinity requirement in msg_zerocopy test mptcp: be careful on subflow creation selftests: rtnetlink: make kci_test_encap() return sub-test result selftests: rtnetlink: correct the final return value for the test net: dsa: sja1105: use detected device id instead of DT one on mismatch tipc: set ub->ifindex for local ipv6 address ipv6: add ipv6_dev_find() net: openvswitch: silence suspicious RCU usage warning Revert "vxlan: fix tos value before xmit" ptp: only allow phase values lower than 1 period farsync: switch from 'pci_' to 'dma_' API wan: wanxl: switch from 'pci_' to 'dma_' API hv_netvsc: do not use VF device if link is down dpaa2-eth: Fix passing zero to 'PTR_ERR' warning net: macb: Properly handle phylink on at91sam9x ...
2020-08-04Merge tag 'var-init-v5.9-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull automatic variable initialization updates from Kees Cook: "This adds the "zero" init option from Clang, which is being used widely in production builds of Android and Chrome OS (though it also keeps the "pattern" init, which is better for debug builds). - Introduce CONFIG_INIT_STACK_ALL_ZERO (Alexander Potapenko)" * tag 'var-init-v5.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: security: allow using Clang's zero initialization for stack variables
2020-08-03Merge tag 'x86-boot-2020-08-03' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 boot updates from Ingo Molnar: "The main change in this cycle was to add support for ZSTD-compressed kernel and initrd images. ZSTD has a very fast decompressor, yet it compresses better than gzip" * tag 'x86-boot-2020-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: Documentation: dontdiff: Add zstd compressed files .gitignore: Add ZSTD-compressed files x86: Add support for ZSTD compressed kernel x86: Bump ZO_z_extra_bytes margin for zstd usr: Add support for zstd compressed initramfs init: Add support for zstd compressed kernel lib: Add zstd support to decompress lib: Prepare zstd for preboot environment, improve performance
2020-08-02Linux 5.8Linus Torvalds
2020-08-02Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netDavid S. Miller
Resolved kernel/bpf/btf.c using instructions from merge commit 69138b34a7248d2396ab85c8652e20c0c39beaba Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-31init: Add support for zstd compressed kernelNick Terrell
- Add the zstd and zstd22 cmds to scripts/Makefile.lib - Add the HAVE_KERNEL_ZSTD and KERNEL_ZSTD options Architecture specific support is still needed for decompression. Signed-off-by: Nick Terrell <terrelln@fb.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Tested-by: Sedat Dilek <sedat.dilek@gmail.com> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20200730190841.2071656-4-nickrterrell@gmail.com
2020-07-26Linux 5.8-rc7Linus Torvalds
2020-07-26Merge tag 'kbuild-fixes-v5.8-3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild into master Pull Kbuild fixes from Masahiro Yamada: - do not use non-portable strsep() in a host program - fix single target builds for external modules - change Clang's --prefix option to make it work for the latest Clang * tag 'kbuild-fixes-v5.8-3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: Makefile: Fix GCC_TOOLCHAIN_DIR prefix for Clang cross compilation kbuild: fix single target builds for external modules modpost: remove use of non-standard strsep() in HOSTCC code
2020-07-25Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netDavid S. Miller
The UDP reuseport conflict was a little bit tricky. The net-next code, via bpf-next, extracted the reuseport handling into a helper so that the BPF sk lookup code could invoke it. At the same time, the logic for reuseport handling of unconnected sockets changed via commit efc6b6f6c3113e8b203b9debfb72d81e0f3dcace which changed the logic to carry on the reuseport result into the rest of the lookup loop if we do not return immediately. This requires moving the reuseport_has_conns() logic into the callers. While we are here, get rid of inline directives as they do not belong in foo.c files. The other changes were cases of more straightforward overlapping modifications. Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-23Makefile: Fix GCC_TOOLCHAIN_DIR prefix for Clang cross compilationFangrui Song
When CROSS_COMPILE is set (e.g. aarch64-linux-gnu-), if $(CROSS_COMPILE)elfedit is found at /usr/bin/aarch64-linux-gnu-elfedit, GCC_TOOLCHAIN_DIR will be set to /usr/bin/. --prefix= will be set to /usr/bin/ and Clang as of 11 will search for both $(prefix)aarch64-linux-gnu-$needle and $(prefix)$needle. GCC searchs for $(prefix)aarch64-linux-gnu/$version/$needle, $(prefix)aarch64-linux-gnu/$needle and $(prefix)$needle. In practice, $(prefix)aarch64-linux-gnu/$needle rarely contains executables. To better model how GCC's -B/--prefix takes in effect in practice, newer Clang (since https://github.com/llvm/llvm-project/commit/3452a0d8c17f7166f479706b293caf6ac76ffd90) only searches for $(prefix)$needle. Currently it will find /usr/bin/as instead of /usr/bin/aarch64-linux-gnu-as. Set --prefix= to $(GCC_TOOLCHAIN_DIR)$(notdir $(CROSS_COMPILE)) (/usr/bin/aarch64-linux-gnu-) so that newer Clang can find the appropriate cross compiling GNU as (when -no-integrated-as is in effect). Cc: stable@vger.kernel.org Reported-by: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Fangrui Song <maskray@google.com> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com> Tested-by: Nathan Chancellor <natechancellor@gmail.com> Tested-by: Nick Desaulniers <ndesaulniers@google.com> Link: https://github.com/ClangBuiltLinux/linux/issues/1099 Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-07-19Linux 5.8-rc6Linus Torvalds
2020-07-13Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextDavid S. Miller
Alexei Starovoitov says: ==================== pull-request: bpf-next 2020-07-13 The following pull-request contains BPF updates for your *net-next* tree. We've added 36 non-merge commits during the last 7 day(s) which contain a total of 62 files changed, 2242 insertions(+), 468 deletions(-). The main changes are: 1) Avoid trace_printk warning banner by switching bpf_trace_printk to use its own tracing event, from Alan. 2) Better libbpf support on older kernels, from Andrii. 3) Additional AF_XDP stats, from Ciara. 4) build time resolution of BTF IDs, from Jiri. 5) BPF_CGROUP_INET_SOCK_RELEASE hook, from Stanislav. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-13bpf: Resolve BTF IDs in vmlinux imageJiri Olsa
Using BTF_ID_LIST macro to define lists for several helpers using BTF arguments. And running resolve_btfids on vmlinux elf object during linking, so the .BTF_ids section gets the IDs resolved. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Tested-by: Andrii Nakryiko <andriin@fb.com> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20200711215329.41165-5-jolsa@kernel.org
2020-07-13bpf: Compile resolve_btfids tool at kernel compilation startJiri Olsa
The resolve_btfids tool will be used during the vmlinux linking, so it's necessary it's ready for it. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Tested-by: Andrii Nakryiko <andriin@fb.com> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20200711215329.41165-3-jolsa@kernel.org
2020-07-12Linux 5.8-rc5Linus Torvalds
2020-07-11kbuild: fix single target builds for external modulesMasahiro Yamada
Commit f566e1fbadb6 ("kbuild: make multiple directory targets work") broke single target builds for external modules. Fix this. Fixes: f566e1fbadb6 ("kbuild: make multiple directory targets work") Reported-by: Bjørn Mork <bjorn@mork.no> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Tested-by: Bjørn Mork <bjorn@mork.no>
2020-07-07kbuild: remove cc-option test of -fno-stack-protectorMasahiro Yamada
Some Makefiles already pass -fno-stack-protector unconditionally. For example, arch/arm64/kernel/vdso/Makefile, arch/x86/xen/Makefile. No problem report so far about hard-coding this option. So, we can assume all supported compilers know -fno-stack-protector. GCC 4.8 and Clang support this option (https://godbolt.org/z/_HDGzN) Get rid of cc-option from -fno-stack-protector. Remove CONFIG_CC_HAS_STACKPROTECTOR_NONE, which is always 'y'. Note: arch/mips/vdso/Makefile adds -fno-stack-protector twice, first unconditionally, and second conditionally. I removed the second one. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
2020-07-05Linux 5.8-rc4Linus Torvalds
2020-07-05Merge tag 'kbuild-fixes-v5.8-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild fixes frin Masahiro Yamada: - fix various bugs in xconfig - fix some issues in cross-compilation using Clang - fix documentation * tag 'kbuild-fixes-v5.8-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: .gitignore: Do not track `defconfig` from `make savedefconfig` kbuild: make Clang build userprogs for target architecture kbuild: fix CONFIG_CC_CAN_LINK(_STATIC) for cross-compilation with Clang kconfig: qconf: parse newer types at debug info kconfig: qconf: navigate menus on hyperlinks kconfig: qconf: don't show goback button on splitMode kconfig: qconf: simplify the goBack() logic kconfig: qconf: re-implement setSelected() kconfig: qconf: make debug links work again kconfig: qconf: make search fully work again on split mode kconfig: qconf: cleanup includes docs: kbuild: fix ReST formatting gcc-plugins: fix gcc-plugins directory path in documentation
2020-07-02kbuild: make Clang build userprogs for target architectureMasahiro Yamada
Programs added 'userprogs' should be compiled for the target architecture i.e. the same architecture as the kernel. GCC does this correctly since the target architecture is implied by the toolchain prefix. Clang builds userspace programs always for the host architecture because the target triple is currently missing. Fix this. Fixes: 7f3a59db274c ("kbuild: add infrastructure to build userspace programs") Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
2020-06-28Linux 5.8-rc3Linus Torvalds
2020-06-21Linux 5.8-rc2Linus Torvalds
2020-06-22Revert "Makefile: install modules.builtin even if CONFIG_MODULES=n"Masahiro Yamada
This reverts commit e0b250b57dcf403529081e5898a9de717f96b76b, which broke build systems that need to install files to a certain path, but do not set INSTALL_MOD_PATH when invoking 'make install'. $ make INSTALL_PATH=/tmp/destdir install mkdir: cannot create directory ‘/lib/modules/5.8.0-rc1+/’: Permission denied Makefile:1342: recipe for target '_builtin_inst_' failed make: *** [_builtin_inst_] Error 1 While modules.builtin is useful also for CONFIG_MODULES=n, this change in the behavior is quite unexpected. Maybe "make modules_install" can install modules.builtin irrespective of CONFIG_MODULES as Jonas originally suggested. Anyway, that commit should be reverted ASAP. Reported-by: Douglas Anderson <dianders@chromium.org> Reported-by: Guenter Roeck <linux@roeck-us.net> Cc: Jonas Karlman <jonas@kwiboo.se> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Tested-by: Guenter Roeck <linux@roeck-us.net>
2020-06-16security: allow using Clang's zero initialization for stack variablesglider@google.com
In addition to -ftrivial-auto-var-init=pattern (used by CONFIG_INIT_STACK_ALL now) Clang also supports zero initialization for locals enabled by -ftrivial-auto-var-init=zero. The future of this flag is still being debated (see https://bugs.llvm.org/show_bug.cgi?id=45497). Right now it is guarded by another flag, -enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang, which means it may not be supported by future Clang releases. Another possible resolution is that -ftrivial-auto-var-init=zero will persist (as certain users have already started depending on it), but the name of the guard flag will change. In the meantime, zero initialization has proven itself as a good production mitigation measure against uninitialized locals. Unlike pattern initialization, which has a higher chance of triggering existing bugs, zero initialization provides safe defaults for strings, pointers, indexes, and sizes. On the other hand, pattern initialization remains safer for return values. Chrome OS and Android are moving to using zero initialization for production builds. Performance-wise, the difference between pattern and zero initialization is usually negligible, although the generated code for zero initialization is more compact. This patch renames CONFIG_INIT_STACK_ALL to CONFIG_INIT_STACK_ALL_PATTERN and introduces another config option, CONFIG_INIT_STACK_ALL_ZERO, that enables zero initialization for locals if the corresponding flags are supported by Clang. Cc: Kees Cook <keescook@chromium.org> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Alexander Potapenko <glider@google.com> Link: https://lore.kernel.org/r/20200616083435.223038-1-glider@google.com Reviewed-by: Maciej Żenczykowski <maze@google.com> Signed-off-by: Kees Cook <keescook@chromium.org>
2020-06-15Makefile: Improve compressed debug info support detectionArvind Sankar
Commit 10e68b02c861 ("Makefile: support compressed debug info") added support for compressed debug sections. Support is detected by checking - does the compiler support -gz=zlib - does the assembler support --compressed-debug-sections=zlib - does the linker support --compressed-debug-sections=zlib However, the gcc driver's support for this option is somewhat convoluted. The driver's builtin specs are set based on the version of binutils that it was configured with. It reports an error if the configure-time linker/assembler (i.e., not necessarily the actual assembler that will be run) do not support the option, but only if the assembler (or linker) is actually invoked when -gz=zlib is passed. The cc-option check in scripts/Kconfig.include does not invoke the assembler, so the gcc driver reports success even if it does not support the option being passed to the assembler. Because the as-option check passes the option directly to the assembler via -Wa,--compressed-debug-sections=zlib, the gcc driver does not see this option and will never report an error. Combined with an installed version of binutils that is more recent than the one the compiler was built with, it is possible for all three tests to succeed, yet an actual compilation with -gz=zlib to fail. Moreover, it is unnecessary to explicitly pass --compressed-debug-sections=zlib to the assembler via -Wa, since the driver will do that automatically when it supports -gz=zlib. Convert the as-option to just -gz=zlib, simplifying it as well as performing a better test of the gcc driver's capabilities. Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-06-14Linux 5.8-rc1Linus Torvalds
2020-06-13Merge tag 'kbuild-v5.8-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull more Kbuild updates from Masahiro Yamada: - fix build rules in binderfs sample - fix build errors when Kbuild recurses to the top Makefile - covert '---help---' in Kconfig to 'help' * tag 'kbuild-v5.8-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: treewide: replace '---help---' in Kconfig files with 'help' kbuild: fix broken builds because of GZIP,BZIP2,LZOP variables samples: binderfs: really compile this sample and fix build issues
2020-06-11Rebase locking/kcsan to locking/urgentThomas Gleixner
Merge the state of the locking kcsan branch before the read/write_once() and the atomics modifications got merged. Squash the fallout of the rebase on top of the read/write once and atomic fallback work into the merge. The history of the original branch is preserved in tag locking-kcsan-2020-06-02. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2020-06-11kbuild: fix broken builds because of GZIP,BZIP2,LZOP variablesDenis Efremov
Redefine GZIP, BZIP2, LZOP variables as KGZIP, KBZIP2, KLZOP resp. GZIP, BZIP2, LZOP env variables are reserved by the tools. The original attempt to redefine them internally doesn't work in makefiles/scripts intercall scenarios, e.g., "make GZIP=gzip bindeb-pkg" and results in broken builds. There can be other broken build commands because of this, so the universal solution is to use non-reserved env variables for the compression tools. Fixes: 8dfb61dcbace ("kbuild: add variables for compression tools") Signed-off-by: Denis Efremov <efremov@linux.com> Tested-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-06-06Merge tag 'kbuild-v5.8' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild updates from Masahiro Yamada: - fix warnings in 'make clean' for ARCH=um, hexagon, h8300, unicore32 - ensure to rebuild all objects when the compiler is upgraded - exclude system headers from dependency tracking and fixdep processing - fix potential bit-size mismatch between the kernel and BPF user-mode helper - add the new syntax 'userprogs' to build user-space programs for the target architecture (the same arch as the kernel) - compile user-space sample code under samples/ for the target arch instead of the host arch - make headers_install fail if a CONFIG option is leaked to user-space - sanitize the output format of scripts/checkstack.pl - handle ARM 'push' instruction in scripts/checkstack.pl - error out before modpost if a module name conflict is found - error out when multiple directories are passed to M= because this feature is broken for a long time - add CONFIG_DEBUG_INFO_COMPRESSED to support compressed debug info - a lot of cleanups of modpost - dump vmlinux symbols out into vmlinux.symvers, and reuse it in the second pass of modpost - do not run the second pass of modpost if nothing in modules is updated - install modules.builtin(.modinfo) by 'make install' as well as by 'make modules_install' because it is useful even when CONFIG_MODULES=n - add new command line variables, GZIP, BZIP2, LZOP, LZMA, LZ4, and XZ to allow users to use alternatives such as pigz, pbzip2, etc. * tag 'kbuild-v5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (96 commits) kbuild: add variables for compression tools Makefile: install modules.builtin even if CONFIG_MODULES=n mksysmap: Fix the mismatch of '.L' symbols in System.map kbuild: doc: rename LDFLAGS to KBUILD_LDFLAGS modpost: change elf_info->size to size_t modpost: remove is_vmlinux() helper modpost: strip .o from modname before calling new_module() modpost: set have_vmlinux in new_module() modpost: remove mod->skip struct member modpost: add mod->is_vmlinux struct member modpost: remove is_vmlinux() call in check_for_{gpl_usage,unused}() modpost: remove mod->is_dot_o struct member modpost: move -d option in scripts/Makefile.modpost modpost: remove -s option modpost: remove get_next_text() and make {grab,release_}file static modpost: use read_text_file() and get_line() for reading text files modpost: avoid false-positive file open error modpost: fix potential mmap'ed file overrun in get_src_version() modpost: add read_text_file() and get_line() helpers modpost: do not call get_modinfo() for vmlinux(.o) ...
2020-06-06kbuild: add variables for compression toolsDenis Efremov
Allow user to use alternative implementations of compression tools, such as pigz, pbzip2, pxz. For example, multi-threaded tools to speed up the build: $ make GZIP=pigz BZIP2=pbzip2 Variables _GZIP, _BZIP2, _LZOP are used internally because original env vars are reserved by the tools. The use of GZIP in gzip tool is obsolete since 2015. However, alternative implementations (e.g., pigz) still rely on it. BZIP2, BZIP, LZOP vars are not obsolescent. The credit goes to @grsecurity. As a sidenote, for multi-threaded lzma, xz compression one can use: $ export XZ_OPT="--threads=0" Signed-off-by: Denis Efremov <efremov@linux.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-06-06Makefile: install modules.builtin even if CONFIG_MODULES=nJonas Zeiger
Many applications check for available kernel features via: - /proc/modules (loaded modules, present if CONFIG_MODULES=y) - $(MODLIB)/modules.builtin (builtin modules) They fail to detect features if the kernel was built with CONFIG_MODULES=n and modules.builtin isn't installed. Therefore, add the target "_builtin_inst_" and make "install" and "modules_install" depend on it. Tests results: - make install: kernel image is copied as before, modules.builtin copied - make modules_install: (CONFIG_MODULES=n) nothing is copied, exit 1 Signed-off-by: Jonas Zeiger <jonas.zeiger@talpidae.net> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-06-06modpost: show warning if any of symbol dump files is missingMasahiro Yamada
If modpost fails to load a symbol dump file, it cannot check unresolved symbols, hence module dependency will not be added. Nor CRCs can be added. Currently, external module builds check only $(objtree)/Module.symvers, but it should check files specified by KBUILD_EXTRA_SYMBOLS as well. Move the warning message from the top Makefile to scripts/Makefile.modpost and print the warning if any dump file is missing. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-06-06modpost: generate vmlinux.symvers and reuse it for the second modpostMasahiro Yamada
The full build runs modpost twice, first for vmlinux.o and second for modules. The first pass dumps all the vmlinux symbols into Module.symvers, but the second pass parses vmlinux again instead of reusing the dump file, presumably because it needs to avoid accumulating stale symbols. Loading symbol info from a dump file is faster than parsing an ELF object. Besides, modpost deals with various issues to parse vmlinux in the second pass. A solution is to make the first pass dumps symbols into a separate file, vmlinux.symvers. The second pass reads it, and parses module .o files. The merged symbol information is dumped into Module.symvers in the same way as before. This makes further modpost cleanups possible. Also, it fixes the problem of 'make vmlinux', which previously overwrote Module.symvers, throwing away module symbols. I slightly touched scripts/link-vmlinux.sh so that vmlinux is re-linked when you cross this commit. Otherwise, vmlinux.symvers would not be generated. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-06-03kbuild: update modules.order only when contained modules are updatedMasahiro Yamada
Make modules.order depend on $(obj-m), and use if_changed to build it. This will avoid unneeded update of modules.order, which will be useful to optimize the modpost stage. Currently, the second pass of modpost is always invoked. By checking the timestamp of modules.order, we can avoid the unneeded modpost. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-06-03kbuild: refactor KBUILD_VMLINUX_{OBJS,LIBS} calculationMasahiro Yamada
Do not overwrite core-y or drivers-y. Remove libs-y1 and libs-y2. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>