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2022-01-20Merge branch 'akpm' (patches from Andrew)Linus Torvalds
Merge more updates from Andrew Morton: "55 patches. Subsystems affected by this patch series: percpu, procfs, sysctl, misc, core-kernel, get_maintainer, lib, checkpatch, binfmt, nilfs2, hfs, fat, adfs, panic, delayacct, kconfig, kcov, and ubsan" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (55 commits) lib: remove redundant assignment to variable ret ubsan: remove CONFIG_UBSAN_OBJECT_SIZE kcov: fix generic Kconfig dependencies if ARCH_WANTS_NO_INSTR lib/Kconfig.debug: make TEST_KMOD depend on PAGE_SIZE_LESS_THAN_256KB btrfs: use generic Kconfig option for 256kB page size limit arch/Kconfig: split PAGE_SIZE_LESS_THAN_256KB from PAGE_SIZE_LESS_THAN_64KB configs: introduce debug.config for CI-like setup delayacct: track delays from memory compact Documentation/accounting/delay-accounting.rst: add thrashing page cache and direct compact delayacct: cleanup flags in struct task_delay_info and functions use it delayacct: fix incomplete disable operation when switch enable to disable delayacct: support swapin delay accounting for swapping without blkio panic: remove oops_id panic: use error_report_end tracepoint on warnings fs/adfs: remove unneeded variable make code cleaner FAT: use io_schedule_timeout() instead of congestion_wait() hfsplus: use struct_group_attr() for memcpy() region nilfs2: remove redundant pointer sbufs fs/binfmt_elf: use PT_LOAD p_align values for static PIE const_structs.checkpatch: add frequently used ops structs ...
2022-01-20arch/Kconfig: split PAGE_SIZE_LESS_THAN_256KB from PAGE_SIZE_LESS_THAN_64KBNathan Chancellor
Patch series "Fix CONFIG_TEST_KMOD with 256kB page size". The kernel test robot reported a build error [1] from a failed assertion in fs/btrfs/inode.c with a hexagon randconfig that includes CONFIG_PAGE_SIZE_256KB. This error is the same one that was addressed by commit b05fbcc36be1 ("btrfs: disable build on platforms having page size 256K") but CONFIG_TEST_KMOD selects CONFIG_BTRFS without having the "page size less than 256kB dependency", which results in the error reappearing. The first patch introduces CONFIG_PAGE_SIZE_LESS_THAN_256KB by splitting it off from CONFIG_PAGE_SIZE_LESS_THAN_64KB, which was introduced in commit 1f0e290cc5fd ("arch: Add generic Kconfig option indicating page size smaller than 64k") for a similar reason in 5.16-rc3. The second patch uses that configuration option for CONFIG_BTRFS to reduce duplication. The third patch resolves the build error by adding CONFIG_PAGE_SIZE_LESS_THAN_256KB as a dependency to CONFIG_TEST_KMOD so that CONFIG_BTRFS does not get enabled under that invalid configuration. [1]: https://lore.kernel.org/r/202111270255.UYOoN5VN-lkp@intel.com/ This patch (of 3): btrfs requires a page size smaller than 256kB. To use that dependency in other places, introduce CONFIG_PAGE_SIZE_LESS_THAN_256KB and reuse that dependency in CONFIG_PAGE_SIZE_LESS_THAN_64KB. Link: https://lkml.kernel.org/r/20211129230141.228085-1-nathan@kernel.org Link: https://lkml.kernel.org/r/20211129230141.228085-2-nathan@kernel.org Signed-off-by: Nathan Chancellor <nathan@kernel.org> Cc: Chris Mason <clm@fb.com> Cc: Josef Bacik <josef@toxicpanda.com> Cc: David Sterba <dsterba@suse.com> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-01-19Merge tag 'kbuild-v5.17' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild updates from Masahiro Yamada: - Add new kconfig target 'make mod2noconfig', which will be useful to speed up the build and test iteration. - Raise the minimum supported version of LLVM to 11.0.0 - Refactor certs/Makefile - Change the format of include/config/auto.conf to stop double-quoting string type CONFIG options. - Fix ARCH=sh builds in dash - Separate compression macros for general purposes (cmd_bzip2 etc.) and the ones for decompressors (cmd_bzip2_with_size etc.) - Misc Makefile cleanups * tag 'kbuild-v5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (34 commits) kbuild: add cmd_file_size arch: decompressor: remove useless vmlinux.bin.all-y kbuild: rename cmd_{bzip2,lzma,lzo,lz4,xzkern,zstd22} kbuild: drop $(size_append) from cmd_zstd sh: rename suffix-y to suffix_y doc: kbuild: fix default in `imply` table microblaze: use built-in function to get CPU_{MAJOR,MINOR,REV} certs: move scripts/extract-cert to certs/ kbuild: do not quote string values in include/config/auto.conf kbuild: do not include include/config/auto.conf from shell scripts certs: simplify $(srctree)/ handling and remove config_filename macro kbuild: stop using config_filename in scripts/Makefile.modsign certs: remove misleading comments about GCC PR certs: refactor file cleaning certs: remove unneeded -I$(srctree) option for system_certificates.o certs: unify duplicated cmd_extract_certs and improve the log certs: use $< and $@ to simplify the key generation rule kbuild: remove headers_check stub kbuild: move headers_check.pl to usr/include/ certs: use if_changed to re-generate the key when the key type is changed ...
2022-01-15Merge branch 'akpm' (patches from Andrew)Linus Torvalds
Merge misc updates from Andrew Morton: "146 patches. Subsystems affected by this patch series: kthread, ia64, scripts, ntfs, squashfs, ocfs2, vfs, and mm (slab-generic, slab, kmemleak, dax, kasan, debug, pagecache, gup, shmem, frontswap, memremap, memcg, selftests, pagemap, dma, vmalloc, memory-failure, hugetlb, userfaultfd, vmscan, mempolicy, oom-kill, hugetlbfs, migration, thp, ksm, page-poison, percpu, rmap, zswap, zram, cleanups, hmm, and damon)" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (146 commits) mm/damon: hide kernel pointer from tracepoint event mm/damon/vaddr: hide kernel pointer from damon_va_three_regions() failure log mm/damon/vaddr: use pr_debug() for damon_va_three_regions() failure logging mm/damon/dbgfs: remove an unnecessary variable mm/damon: move the implementation of damon_insert_region to damon.h mm/damon: add access checking for hugetlb pages Docs/admin-guide/mm/damon/usage: update for schemes statistics mm/damon/dbgfs: support all DAMOS stats Docs/admin-guide/mm/damon/reclaim: document statistics parameters mm/damon/reclaim: provide reclamation statistics mm/damon/schemes: account how many times quota limit has exceeded mm/damon/schemes: account scheme actions that successfully applied mm/damon: remove a mistakenly added comment for a future feature Docs/admin-guide/mm/damon/usage: update for kdamond_pid and (mk|rm)_contexts Docs/admin-guide/mm/damon/usage: mention tracepoint at the beginning Docs/admin-guide/mm/damon/usage: remove redundant information Docs/admin-guide/mm/damon/usage: update for scheme quotas and watermarks mm/damon: convert macro functions to static inline functions mm/damon: modify damon_rand() macro to static inline function mm/damon: move damon_rand() definition into damon.h ...
2022-01-15mm: page table checkPasha Tatashin
Check user page table entries at the time they are added and removed. Allows to synchronously catch memory corruption issues related to double mapping. When a pte for an anonymous page is added into page table, we verify that this pte does not already point to a file backed page, and vice versa if this is a file backed page that is being added we verify that this page does not have an anonymous mapping We also enforce that read-only sharing for anonymous pages is allowed (i.e. cow after fork). All other sharing must be for file pages. Page table check allows to protect and debug cases where "struct page" metadata became corrupted for some reason. For example, when refcnt or mapcount become invalid. Link: https://lkml.kernel.org/r/20211221154650.1047963-4-pasha.tatashin@soleen.com Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Rientjes <rientjes@google.com> Cc: Frederic Weisbecker <frederic@kernel.org> Cc: Greg Thelen <gthelen@google.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Hugh Dickins <hughd@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiri Slaby <jirislaby@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kees Cook <keescook@chromium.org> Cc: Masahiro Yamada <masahiroy@kernel.org> Cc: Mike Rapoport <rppt@kernel.org> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Paul Turner <pjt@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sami Tolvanen <samitolvanen@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wei Xu <weixugc@google.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-01-10Merge tag 'x86_sgx_for_v5.17_rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 SGX updates from Borislav Petkov: - Add support for handling hw errors in SGX pages: poisoning, recovering from poison memory and error injection into SGX pages - A bunch of changes to the SGX selftests to simplify and allow of SGX features testing without the need of a whole SGX software stack - Add a sysfs attribute which is supposed to show the amount of SGX memory in a NUMA node, similar to what /proc/meminfo is to normal memory - The usual bunch of fixes and cleanups too * tag 'x86_sgx_for_v5.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits) x86/sgx: Fix NULL pointer dereference on non-SGX systems selftests/sgx: Fix corrupted cpuid macro invocation x86/sgx: Add an attribute for the amount of SGX memory in a NUMA node x86/sgx: Fix minor documentation issues selftests/sgx: Add test for multiple TCS entry selftests/sgx: Enable multiple thread support selftests/sgx: Add page permission and exception test selftests/sgx: Rename test properties in preparation for more enclave tests selftests/sgx: Provide per-op parameter structs for the test enclave selftests/sgx: Add a new kselftest: Unclobbered_vdso_oversubscribed selftests/sgx: Move setup_test_encl() to each TEST_F() selftests/sgx: Encpsulate the test enclave creation selftests/sgx: Dump segments and /proc/self/maps only on failure selftests/sgx: Create a heap for the test enclave selftests/sgx: Make data measurement for an enclave segment optional selftests/sgx: Assign source for each segment selftests/sgx: Fix a benign linker warning x86/sgx: Add check for SGX pages to ghes_do_memory_failure() x86/sgx: Add hook to error injection address validation x86/sgx: Hook arch_memory_failure() into mainline code ...
2021-12-09x86/sgx: Add an attribute for the amount of SGX memory in a NUMA nodeJarkko Sakkinen
== Problem == The amount of SGX memory on a system is determined by the BIOS and it varies wildly between systems. It can be as small as dozens of MB's and as large as many GB's on servers. Just like how applications need to know how much regular RAM is available, enclave builders need to know how much SGX memory an enclave can consume. == Solution == Introduce a new sysfs file: /sys/devices/system/node/nodeX/x86/sgx_total_bytes to enumerate the amount of SGX memory available in each NUMA node. This serves the same function for SGX as /proc/meminfo or /sys/devices/system/node/nodeX/meminfo does for normal RAM. 'sgx_total_bytes' is needed today to help drive the SGX selftests. SGX-specific swap code is exercised by creating overcommitted enclaves which are larger than the physical SGX memory on the system. They currently use a CPUID-based approach which can diverge from the actual amount of SGX memory available. 'sgx_total_bytes' ensures that the selftests can work efficiently and do not attempt stupid things like creating a 100,000 MB enclave on a system with 128 MB of SGX memory. == Implementation Details == Introduce CONFIG_HAVE_ARCH_NODE_DEV_GROUP opt-in flag to expose an arch specific attribute group, and add an attribute for the amount of SGX memory in bytes to each NUMA node: == ABI Design Discussion == As opposed to the per-node ABI, a single, global ABI was considered. However, this would prevent enclaves from being able to size themselves so that they fit on a single NUMA node. Essentially, a single value would rule out NUMA optimizations for enclaves. Create a new "x86/" directory inside each "nodeX/" sysfs directory. 'sgx_total_bytes' is expected to be the first of at least a few sgx-specific files to be placed in the new directory. Just scanning /proc/meminfo, these are the no-brainers that we have for RAM, but we need for SGX: MemTotal: xxxx kB // sgx_total_bytes (implemented here) MemFree: yyyy kB // sgx_free_bytes SwapTotal: zzzz kB // sgx_swapped_bytes So, at *least* three. I think we will eventually end up needing something more along the lines of a dozen. A new directory (as opposed to being in the nodeX/ "root") directory avoids cluttering the root with several "sgx_*" files. Place the new file in a new "nodeX/x86/" directory because SGX is highly x86-specific. It is very unlikely that any other architecture (or even non-Intel x86 vendor) will ever implement SGX. Using "sgx/" as opposed to "x86/" was also considered. But, there is a real chance this can get used for other arch-specific purposes. [ dhansen: rewrite changelog ] Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20211116162116.93081-2-jarkko@kernel.org
2021-12-02arch/Kconfig: Remove CLANG_VERSION check in HAS_LTO_CLANGNathan Chancellor
The minimum supported version of LLVM has been raised to 11.0.0, meaning this check is always true, so it can be dropped. Signed-off-by: Nathan Chancellor <nathan@kernel.org> Reviewed-by: Miguel Ojeda <ojeda@kernel.org> Reviewed-by: Mark Brown <broonie@kernel.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-11-27arch: Add generic Kconfig option indicating page size smaller than 64kGuenter Roeck
NTFS_RW and VMXNET3 require a page size smaller than 64kB. Add generic Kconfig option for use outside architecture code to avoid architecture specific Kconfig options in that code. Suggested-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Cc: Anton Altaparmakov <anton@tuxera.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-01Merge tag 'trace-v5.16' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing updates from Steven Rostedt: - kprobes: Restructured stack unwinder to show properly on x86 when a stack dump happens from a kretprobe callback. - Fix to bootconfig parsing - Have tracefs allow owner and group permissions by default (only denying others). There's been pressure to allow non root to tracefs in a controlled fashion, and using groups is probably the safest. - Bootconfig memory managament updates. - Bootconfig clean up to have the tools directory be less dependent on changes in the kernel tree. - Allow perf to be traced by function tracer. - Rewrite of function graph tracer to be a callback from the function tracer instead of having its own trampoline (this change will happen on an arch by arch basis, and currently only x86_64 implements it). - Allow multiple direct trampolines (bpf hooks to functions) be batched together in one synchronization. - Allow histogram triggers to add variables that can perform calculations against the event's fields. - Use the linker to determine architecture callbacks from the ftrace trampoline to allow for proper parameter prototypes and prevent warnings from the compiler. - Extend histogram triggers to key off of variables. - Have trace recursion use bit magic to determine preempt context over if branches. - Have trace recursion disable preemption as all use cases do anyway. - Added testing for verification of tracing utilities. - Various small clean ups and fixes. * tag 'trace-v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (101 commits) tracing/histogram: Fix semicolon.cocci warnings tracing/histogram: Fix documentation inline emphasis warning tracing: Increase PERF_MAX_TRACE_SIZE to handle Sentinel1 and docker together tracing: Show size of requested perf buffer bootconfig: Initialize ret in xbc_parse_tree() ftrace: do CPU checking after preemption disabled ftrace: disable preemption when recursion locked tracing/histogram: Document expression arithmetic and constants tracing/histogram: Optimize division by a power of 2 tracing/histogram: Covert expr to const if both operands are constants tracing/histogram: Simplify handling of .sym-offset in expressions tracing: Fix operator precedence for hist triggers expression tracing: Add division and multiplication support for hist triggers tracing: Add support for creating hist trigger variables from literal selftests/ftrace: Stop tracing while reading the trace file by default MAINTAINERS: Update KPROBES and TRACING entries test_kprobes: Move it from kernel/ to lib/ docs, kprobes: Remove invalid URL and add new reference samples/kretprobes: Fix return value if register_kretprobe() failed lib/bootconfig: Fix the xbc_get_info kerneldoc ...
2021-11-01Merge tag 'x86_cc_for_v5.16_rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull generic confidential computing updates from Borislav Petkov: "Add an interface called cc_platform_has() which is supposed to be used by confidential computing solutions to query different aspects of the system. The intent behind it is to unify testing of such aspects instead of having each confidential computing solution add its own set of tests to code paths in the kernel, leading to an unwieldy mess" * tag 'x86_cc_for_v5.16_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: treewide: Replace the use of mem_encrypt_active() with cc_platform_has() x86/sev: Replace occurrences of sev_es_active() with cc_platform_has() x86/sev: Replace occurrences of sev_active() with cc_platform_has() x86/sme: Replace occurrences of sme_active() with cc_platform_has() powerpc/pseries/svm: Add a powerpc version of cc_platform_has() x86/sev: Add an x86 version of cc_platform_has() arch/cc: Introduce a function to check for confidential computing features x86/ioremap: Selectively build arch override encryption functions
2021-10-26kprobes: Add a test case for stacktrace from kretprobe handlerMasami Hiramatsu
Add a test case for stacktrace from kretprobe handler and nested kretprobe handlers. This test checks both of stack trace inside kretprobe handler and stack trace from pt_regs. Those stack trace must include actual function return address instead of kretprobe trampoline. The nested kretprobe stacktrace test checks whether the unwinder can correctly unwind the call frame on the stack which has been modified by the kretprobe. Since the stacktrace on kretprobe is correctly fixed only on x86, this introduces a meta kconfig ARCH_CORRECT_STACKTRACE_ON_KRETPROBE which tells user that the stacktrace on kretprobe is correct or not. The test results will be shown like below; TAP version 14 1..1 # Subtest: kprobes_test 1..6 ok 1 - test_kprobe ok 2 - test_kprobes ok 3 - test_kretprobe ok 4 - test_kretprobes ok 5 - test_stacktrace_on_kretprobe ok 6 - test_stacktrace_on_nested_kretprobe # kprobes_test: pass:6 fail:0 skip:0 total:6 # Totals: pass:6 fail:0 skip:0 total:6 ok 1 - kprobes_test Link: https://lkml.kernel.org/r/163516211244.604541.18350507860972214415.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-26signal: Add an optional check for altstack sizeThomas Gleixner
New x86 FPU features will be very large, requiring ~10k of stack in signal handlers. These new features require a new approach called "dynamic features". The kernel currently tries to ensure that altstacks are reasonably sized. Right now, on x86, sys_sigaltstack() requires a size of >=2k. However, that 2k is a constant. Simply raising that 2k requirement to >10k for the new features would break existing apps which have a compiled-in size of 2k. Instead of universally enforcing a larger stack, prohibit a process from using dynamic features without properly-sized altstacks. This must be enforced in two places: * A dynamic feature can not be enabled without an large-enough altstack for each process thread. * Once a dynamic feature is enabled, any request to install a too-small altstack will be rejected The dynamic feature enabling code must examine each thread in a process to ensure that the altstacks are large enough. Add a new lock (sigaltstack_lock()) to ensure that threads can not race and change their altstack after being examined. Add the infrastructure in form of a config option and provide empty stubs for architectures which do not need dynamic altstack size checks. This implementation will be fleshed out for x86 in a future patch called x86/arch_prctl: Add controls for dynamic XSTATE components [dhansen: commit message. ] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20211021225527.10184-2-chang.seok.bae@intel.com
2021-10-04arch/cc: Introduce a function to check for confidential computing featuresTom Lendacky
In preparation for other confidential computing technologies, introduce a generic helper function, cc_platform_has(), that can be used to check for specific active confidential computing attributes, like memory encryption. This is intended to eliminate having to add multiple technology-specific checks to the code (e.g. if (sev_active() || tdx_active() || ... ). [ bp: s/_CC_PLATFORM_H/_LINUX_CC_PLATFORM_H/g ] Co-developed-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Andi Kleen <ak@linux.intel.com> Co-developed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210928191009.32551-3-bp@alien8.de
2021-09-08Merge branch 'akpm' (patches from Andrew)Linus Torvalds
Merge more updates from Andrew Morton: "147 patches, based on 7d2a07b769330c34b4deabeed939325c77a7ec2f. Subsystems affected by this patch series: mm (memory-hotplug, rmap, ioremap, highmem, cleanups, secretmem, kfence, damon, and vmscan), alpha, percpu, procfs, misc, core-kernel, MAINTAINERS, lib, checkpatch, epoll, init, nilfs2, coredump, fork, pids, criu, kconfig, selftests, ipc, and scripts" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (94 commits) scripts: check_extable: fix typo in user error message mm/workingset: correct kernel-doc notations ipc: replace costly bailout check in sysvipc_find_ipc() selftests/memfd: remove unused variable Kconfig.debug: drop selecting non-existing HARDLOCKUP_DETECTOR_ARCH configs: remove the obsolete CONFIG_INPUT_POLLDEV prctl: allow to setup brk for et_dyn executables pid: cleanup the stale comment mentioning pidmap_init(). kernel/fork.c: unexport get_{mm,task}_exe_file coredump: fix memleak in dump_vma_snapshot() fs/coredump.c: log if a core dump is aborted due to changed file permissions nilfs2: use refcount_dec_and_lock() to fix potential UAF nilfs2: fix memory leak in nilfs_sysfs_delete_snapshot_group nilfs2: fix memory leak in nilfs_sysfs_create_snapshot_group nilfs2: fix memory leak in nilfs_sysfs_delete_##name##_group nilfs2: fix memory leak in nilfs_sysfs_create_##name##_group nilfs2: fix NULL pointer in nilfs_##name##_attr_release nilfs2: fix memory leak in nilfs_sysfs_create_device_group trap: cleanup trap_init() init: move usermodehelper_enable() to populate_rootfs() ...
2021-09-08arch: Kconfig: fix spelling mistake "seperate" -> "separate"Colin Ian King
Threre is a spelling mistake in the Kconfig text. Fix it. Link: https://lkml.kernel.org/r/20210704095207.37342-1-colin.king@canonical.com Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-05Merge tag 'trace-v5.15' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing updates from Steven Rostedt: - simplify the Kconfig use of FTRACE and TRACE_IRQFLAGS_SUPPORT - bootconfig can now start histograms - bootconfig supports group/all enabling - histograms now can put values in linear size buckets - execnames can be passed to synthetic events - introduce "event probes" that attach to other events and can retrieve data from pointers of fields, or record fields as different types (a pointer to a string as a string instead of just a hex number) - various fixes and clean ups * tag 'trace-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (35 commits) tracing/doc: Fix table format in histogram code selftests/ftrace: Add selftest for testing duplicate eprobes and kprobes selftests/ftrace: Add selftest for testing eprobe events on synthetic events selftests/ftrace: Add test case to test adding and removing of event probe selftests/ftrace: Fix requirement check of README file selftests/ftrace: Add clear_dynamic_events() to test cases tracing: Add a probe that attaches to trace events tracing/probes: Reject events which have the same name of existing one tracing/probes: Have process_fetch_insn() take a void * instead of pt_regs tracing/probe: Change traceprobe_set_print_fmt() to take a type tracing/probes: Use struct_size() instead of defining custom macros tracing/probes: Allow for dot delimiter as well as slash for system names tracing/probe: Have traceprobe_parse_probe_arg() take a const arg tracing: Have dynamic events have a ref counter tracing: Add DYNAMIC flag for dynamic events tracing: Replace deprecated CPU-hotplug functions. MAINTAINERS: Add an entry for os noise/latency tracepoint: Fix kerneldoc comments bootconfig/tracing/ktest: Update ktest example for boot-time tracing tools/bootconfig: Use per-group/all enable option in ftrace2bconf script ...
2021-08-16tracing: Refactor TRACE_IRQFLAGS_SUPPORT in KconfigMasahiro Yamada
Make architectures select TRACE_IRQFLAGS_SUPPORT instead of having many defines. Link: https://lkml.kernel.org/r/20210731052233.4703-2-masahiroy@kernel.org Acked-by: Heiko Carstens <hca@linux.ibm.com> Acked-by: Vineet Gupta <vgupta@synopsys.com>   #arch/arc Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-07-28sched: Add task_work callback for paranoid L1D flushBalbir Singh
The upcoming paranoid L1D flush infrastructure allows to conditionally (opt-in) flush L1D in switch_mm() as a defense against potential new side channels or for paranoia reasons. As the flush makes only sense when a task runs on a non-SMT enabled core, because SMT siblings share L1, the switch_mm() logic will kill a task which is flagged for L1D flush when it is running on a SMT thread. Add a taskwork callback so switch_mm() can queue a SIG_KILL command which is invoked when the task tries to return to user space. Signed-off-by: Balbir Singh <sblbir@amazon.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20210108121056.21940-1-sblbir@amazon.com
2021-06-22Kconfig: Introduce ARCH_WANTS_NO_INSTR and CC_HAS_NO_PROFILE_FN_ATTRNick Desaulniers
We don't want compiler instrumentation to touch noinstr functions, which are annotated with the no_profile_instrument_function function attribute. Add a Kconfig test for this and make GCOV depend on it, and in the future, PGO. If an architecture is using noinstr, it should denote that via this Kconfig value. That makes Kconfigs that depend on noinstr able to express dependencies in an architecturally agnostic way. Cc: Masahiro Yamada <masahiroy@kernel.org> Link: https://lore.kernel.org/lkml/YMTn9yjuemKFLbws@hirez.programming.kicks-ass.net/ Link: https://lore.kernel.org/lkml/YMcssV%2Fn5IBGv4f0@hirez.programming.kicks-ass.net/ Suggested-by: Nathan Chancellor <nathan@kernel.org> Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com> Reviewed-by: Nathan Chancellor <nathan@kernel.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Heiko Carstens <hca@linux.ibm.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20210621231822.2848305-4-ndesaulniers@google.com
2021-05-01Merge tag 'landlock_v34' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security Pull Landlock LSM from James Morris: "Add Landlock, a new LSM from Mickaël Salaün. Briefly, Landlock provides for unprivileged application sandboxing. From Mickaël's cover letter: "The goal of Landlock is to enable to restrict ambient rights (e.g. global filesystem access) for a set of processes. Because Landlock is a stackable LSM [1], it makes possible to create safe security sandboxes as new security layers in addition to the existing system-wide access-controls. This kind of sandbox is expected to help mitigate the security impact of bugs or unexpected/malicious behaviors in user-space applications. Landlock empowers any process, including unprivileged ones, to securely restrict themselves. Landlock is inspired by seccomp-bpf but instead of filtering syscalls and their raw arguments, a Landlock rule can restrict the use of kernel objects like file hierarchies, according to the kernel semantic. Landlock also takes inspiration from other OS sandbox mechanisms: XNU Sandbox, FreeBSD Capsicum or OpenBSD Pledge/Unveil. In this current form, Landlock misses some access-control features. This enables to minimize this patch series and ease review. This series still addresses multiple use cases, especially with the combined use of seccomp-bpf: applications with built-in sandboxing, init systems, security sandbox tools and security-oriented APIs [2]" The cover letter and v34 posting is here: https://lore.kernel.org/linux-security-module/20210422154123.13086-1-mic@digikod.net/ See also: https://landlock.io/ This code has had extensive design discussion and review over several years" Link: https://lore.kernel.org/lkml/50db058a-7dde-441b-a7f9-f6837fe8b69f@schaufler-ca.com/ [1] Link: https://lore.kernel.org/lkml/f646e1c7-33cf-333f-070c-0a40ad0468cd@digikod.net/ [2] * tag 'landlock_v34' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: landlock: Enable user space to infer supported features landlock: Add user and kernel documentation samples/landlock: Add a sandbox manager example selftests/landlock: Add user space tests landlock: Add syscall implementations arch: Wire up Landlock syscalls fs,security: Add sb_delete hook landlock: Support filesystem access-control LSM: Infrastructure management of the superblock landlock: Add ptrace restrictions landlock: Set up the security framework and manage credentials landlock: Add ruleset and domain management landlock: Add object management
2021-04-30mm/vmalloc: hugepage vmalloc mappingsNicholas Piggin
Support huge page vmalloc mappings. Config option HAVE_ARCH_HUGE_VMALLOC enables support on architectures that define HAVE_ARCH_HUGE_VMAP and supports PMD sized vmap mappings. vmalloc will attempt to allocate PMD-sized pages if allocating PMD size or larger, and fall back to small pages if that was unsuccessful. Architectures must ensure that any arch specific vmalloc allocations that require PAGE_SIZE mappings (e.g., module allocations vs strict module rwx) use the VM_NOHUGE flag to inhibit larger mappings. This can result in more internal fragmentation and memory overhead for a given allocation, an option nohugevmalloc is added to disable at boot. [colin.king@canonical.com: fix read of uninitialized pointer area] Link: https://lkml.kernel.org/r/20210318155955.18220-1-colin.king@canonical.com Link: https://lkml.kernel.org/r/20210317062402.533919-14-npiggin@gmail.com Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Ding Tianhong <dingtianhong@huawei.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Russell King <linux@armlinux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-29Merge tag 'kbuild-v5.13' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild updates from Masahiro Yamada: - Evaluate $(call cc-option,...) etc. only for build targets - Add CONFIG_VMLINUX_MAP to generate .map file when linking vmlinux - Remove unnecessary --gcc-toolchains Clang flag because the --prefix flag finds the toolchains - Do not pass Clang's --prefix flag when using the integrated as - Check the assembler version in Kconfig time - Add new CONFIG options, AS_VERSION, AS_IS_GNU, AS_IS_LLVM to clean up some dependencies in Kconfig - Fix invalid Module.symvers creation when building only modules without vmlinux - Fix false-positive modpost warnings when CONFIG_TRIM_UNUSED_KSYMS is set, but there is no module to build - Refactor module installation Makefile - Support zstd for module compression - Convert alpha and ia64 to use generic shell scripts to generate the syscall headers - Add a new elfnote to indicate if the kernel was built with LTO, which will be used by pahole - Flatten the directory structure under include/config/ so CONFIG options and filenames match - Change the deb source package name from linux-$(KERNELRELEASE) to linux-upstream * tag 'kbuild-v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (42 commits) kbuild: Add $(KBUILD_HOSTLDFLAGS) to 'has_libelf' test kbuild: deb-pkg: change the source package name to linux-upstream tools: do not include scripts/Kbuild.include kbuild: redo fake deps at include/config/*.h kbuild: remove TMPO from try-run MAINTAINERS: add pattern for dummy-tools kbuild: add an elfnote for whether vmlinux is built with lto ia64: syscalls: switch to generic syscallhdr.sh ia64: syscalls: switch to generic syscalltbl.sh alpha: syscalls: switch to generic syscallhdr.sh alpha: syscalls: switch to generic syscalltbl.sh sysctl: use min() helper for namecmp() kbuild: add support for zstd compressed modules kbuild: remove CONFIG_MODULE_COMPRESS kbuild: merge scripts/Makefile.modsign to scripts/Makefile.modinst kbuild: move module strip/compression code into scripts/Makefile.modinst kbuild: refactor scripts/Makefile.modinst kbuild: rename extmod-prefix to extmod_prefix kbuild: check module name conflict for external modules as well kbuild: show the target directory for depmod log ...
2021-04-27Merge tag 'cfi-v5.13-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull CFI on arm64 support from Kees Cook: "This builds on last cycle's LTO work, and allows the arm64 kernels to be built with Clang's Control Flow Integrity feature. This feature has happily lived in Android kernels for almost 3 years[1], so I'm excited to have it ready for upstream. The wide diffstat is mainly due to the treewide fixing of mismatched list_sort prototypes. Other things in core kernel are to address various CFI corner cases. The largest code portion is the CFI runtime implementation itself (which will be shared by all architectures implementing support for CFI). The arm64 pieces are Acked by arm64 maintainers rather than coming through the arm64 tree since carrying this tree over there was going to be awkward. CFI support for x86 is still under development, but is pretty close. There are a handful of corner cases on x86 that need some improvements to Clang and objtool, but otherwise works well. Summary: - Clean up list_sort prototypes (Sami Tolvanen) - Introduce CONFIG_CFI_CLANG for arm64 (Sami Tolvanen)" * tag 'cfi-v5.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: arm64: allow CONFIG_CFI_CLANG to be selected KVM: arm64: Disable CFI for nVHE arm64: ftrace: use function_nocfi for ftrace_call arm64: add __nocfi to __apply_alternatives arm64: add __nocfi to functions that jump to a physical address arm64: use function_nocfi with __pa_symbol arm64: implement function_nocfi psci: use function_nocfi for cpu_resume lkdtm: use function_nocfi treewide: Change list_sort to use const pointers bpf: disable CFI in dispatcher functions kallsyms: strip ThinLTO hashes from static functions kthread: use WARN_ON_FUNCTION_MISMATCH workqueue: use WARN_ON_FUNCTION_MISMATCH module: ensure __cfi_check alignment mm: add generic function_nocfi macro cfi: add __cficanonical add support for Clang CFI
2021-04-25kbuild: check the minimum assembler version in KconfigMasahiro Yamada
Documentation/process/changes.rst defines the minimum assembler version (binutils version), but we have never checked it in the build time. Kbuild never invokes 'as' directly because all assembly files in the kernel tree are *.S, hence must be preprocessed. I do not expect raw assembly source files (*.s) would be added to the kernel tree. Therefore, we always use $(CC) as the assembler driver, and commit aa824e0c962b ("kbuild: remove AS variable") removed 'AS'. However, we are still interested in the version of the assembler acting behind. As usual, the --version option prints the version string. $ as --version | head -n 1 GNU assembler (GNU Binutils for Ubuntu) 2.35.1 But, we do not have $(AS). So, we can add the -Wa prefix so that $(CC) passes --version down to the backing assembler. $ gcc -Wa,--version | head -n 1 gcc: fatal error: no input files compilation terminated. OK, we need to input something to satisfy gcc. $ gcc -Wa,--version -c -x assembler /dev/null -o /dev/null | head -n 1 GNU assembler (GNU Binutils for Ubuntu) 2.35.1 The combination of Clang and GNU assembler works in the same way: $ clang -no-integrated-as -Wa,--version -c -x assembler /dev/null -o /dev/null | head -n 1 GNU assembler (GNU Binutils for Ubuntu) 2.35.1 Clang with the integrated assembler fails like this: $ clang -integrated-as -Wa,--version -c -x assembler /dev/null -o /dev/null | head -n 1 clang: error: unsupported argument '--version' to option 'Wa,' For the last case, checking the error message is fragile. If the proposal for -Wa,--version support [1] is accepted, this may not be even an error in the future. One easy way is to check if -integrated-as is present in the passed arguments. We did not pass -integrated-as to CLANG_FLAGS before, but we can make it explicit. Nathan pointed out -integrated-as is the default for all of the architectures/targets that the kernel cares about, but it goes along with "explicit is better than implicit" policy. [2] With all this in my mind, I implemented scripts/as-version.sh to check the assembler version in Kconfig time. $ scripts/as-version.sh gcc GNU 23501 $ scripts/as-version.sh clang -no-integrated-as GNU 23501 $ scripts/as-version.sh clang -integrated-as LLVM 0 [1]: https://github.com/ClangBuiltLinux/linux/issues/1320 [2]: https://lore.kernel.org/linux-kbuild/20210307044253.v3h47ucq6ng25iay@archlinux-ax161/ Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nathan Chancellor <nathan@kernel.org>
2021-04-22landlock: Support filesystem access-controlMickaël Salaün
Using Landlock objects and ruleset, it is possible to tag inodes according to a process's domain. To enable an unprivileged process to express a file hierarchy, it first needs to open a directory (or a file) and pass this file descriptor to the kernel through landlock_add_rule(2). When checking if a file access request is allowed, we walk from the requested dentry to the real root, following the different mount layers. The access to each "tagged" inodes are collected according to their rule layer level, and ANDed to create access to the requested file hierarchy. This makes possible to identify a lot of files without tagging every inodes nor modifying the filesystem, while still following the view and understanding the user has from the filesystem. Add a new ARCH_EPHEMERAL_INODES for UML because it currently does not keep the same struct inodes for the same inodes whereas these inodes are in use. This commit adds a minimal set of supported filesystem access-control which doesn't enable to restrict all file-related actions. This is the result of multiple discussions to minimize the code of Landlock to ease review. Thanks to the Landlock design, extending this access-control without breaking user space will not be a problem. Moreover, seccomp filters can be used to restrict the use of syscall families which may not be currently handled by Landlock. Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: James Morris <jmorris@namei.org> Cc: Jann Horn <jannh@google.com> Cc: Jeff Dike <jdike@addtoit.com> Cc: Kees Cook <keescook@chromium.org> Cc: Richard Weinberger <richard@nod.at> Cc: Serge E. Hallyn <serge@hallyn.com> Signed-off-by: Mickaël Salaün <mic@linux.microsoft.com> Link: https://lore.kernel.org/r/20210422154123.13086-8-mic@digikod.net Signed-off-by: James Morris <jamorris@linux.microsoft.com>
2021-04-08add support for Clang CFISami Tolvanen
This change adds support for Clang’s forward-edge Control Flow Integrity (CFI) checking. With CONFIG_CFI_CLANG, the compiler injects a runtime check before each indirect function call to ensure the target is a valid function with the correct static type. This restricts possible call targets and makes it more difficult for an attacker to exploit bugs that allow the modification of stored function pointers. For more details, see: https://clang.llvm.org/docs/ControlFlowIntegrity.html Clang requires CONFIG_LTO_CLANG to be enabled with CFI to gain visibility to possible call targets. Kernel modules are supported with Clang’s cross-DSO CFI mode, which allows checking between independently compiled components. With CFI enabled, the compiler injects a __cfi_check() function into the kernel and each module for validating local call targets. For cross-module calls that cannot be validated locally, the compiler calls the global __cfi_slowpath_diag() function, which determines the target module and calls the correct __cfi_check() function. This patch includes a slowpath implementation that uses __module_address() to resolve call targets, and with CONFIG_CFI_CLANG_SHADOW enabled, a shadow map that speeds up module look-ups by ~3x. Clang implements indirect call checking using jump tables and offers two methods of generating them. With canonical jump tables, the compiler renames each address-taken function to <function>.cfi and points the original symbol to a jump table entry, which passes __cfi_check() validation. This isn’t compatible with stand-alone assembly code, which the compiler doesn’t instrument, and would result in indirect calls to assembly code to fail. Therefore, we default to using non-canonical jump tables instead, where the compiler generates a local jump table entry <function>.cfi_jt for each address-taken function, and replaces all references to the function with the address of the jump table entry. Note that because non-canonical jump table addresses are local to each component, they break cross-module function address equality. Specifically, the address of a global function will be different in each module, as it's replaced with the address of a local jump table entry. If this address is passed to a different module, it won’t match the address of the same function taken there. This may break code that relies on comparing addresses passed from other components. CFI checking can be disabled in a function with the __nocfi attribute. Additionally, CFI can be disabled for an entire compilation unit by filtering out CC_FLAGS_CFI. By default, CFI failures result in a kernel panic to stop a potential exploit. CONFIG_CFI_PERMISSIVE enables a permissive mode, where the kernel prints out a rate-limited warning instead, and allows execution to continue. This option is helpful for locating type mismatches, but should only be enabled during development. Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Tested-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20210408182843.1754385-2-samitolvanen@google.com
2021-04-08stack: Optionally randomize kernel stack offset each syscallKees Cook
This provides the ability for architectures to enable kernel stack base address offset randomization. This feature is controlled by the boot param "randomize_kstack_offset=on/off", with its default value set by CONFIG_RANDOMIZE_KSTACK_OFFSET_DEFAULT. This feature is based on the original idea from the last public release of PaX's RANDKSTACK feature: https://pax.grsecurity.net/docs/randkstack.txt All the credit for the original idea goes to the PaX team. Note that the design and implementation of this upstream randomize_kstack_offset feature differs greatly from the RANDKSTACK feature (see below). Reasoning for the feature: This feature aims to make harder the various stack-based attacks that rely on deterministic stack structure. We have had many such attacks in past (just to name few): https://jon.oberheide.org/files/infiltrate12-thestackisback.pdf https://jon.oberheide.org/files/stackjacking-infiltrate11.pdf https://googleprojectzero.blogspot.com/2016/06/exploiting-recursion-in-linux-kernel_20.html As Linux kernel stack protections have been constantly improving (vmap-based stack allocation with guard pages, removal of thread_info, STACKLEAK), attackers have had to find new ways for their exploits to work. They have done so, continuing to rely on the kernel's stack determinism, in situations where VMAP_STACK and THREAD_INFO_IN_TASK_STRUCT were not relevant. For example, the following recent attacks would have been hampered if the stack offset was non-deterministic between syscalls: https://repositorio-aberto.up.pt/bitstream/10216/125357/2/374717.pdf (page 70: targeting the pt_regs copy with linear stack overflow) https://a13xp0p0v.github.io/2020/02/15/CVE-2019-18683.html (leaked stack address from one syscall as a target during next syscall) The main idea is that since the stack offset is randomized on each system call, it is harder for an attack to reliably land in any particular place on the thread stack, even with address exposures, as the stack base will change on the next syscall. Also, since randomization is performed after placing pt_regs, the ptrace-based approach[1] to discover the randomized offset during a long-running syscall should not be possible. Design description: During most of the kernel's execution, it runs on the "thread stack", which is pretty deterministic in its structure: it is fixed in size, and on every entry from userspace to kernel on a syscall the thread stack starts construction from an address fetched from the per-cpu cpu_current_top_of_stack variable. The first element to be pushed to the thread stack is the pt_regs struct that stores all required CPU registers and syscall parameters. Finally the specific syscall function is called, with the stack being used as the kernel executes the resulting request. The goal of randomize_kstack_offset feature is to add a random offset after the pt_regs has been pushed to the stack and before the rest of the thread stack is used during the syscall processing, and to change it every time a process issues a syscall. The source of randomness is currently architecture-defined (but x86 is using the low byte of rdtsc()). Future improvements for different entropy sources is possible, but out of scope for this patch. Further more, to add more unpredictability, new offsets are chosen at the end of syscalls (the timing of which should be less easy to measure from userspace than at syscall entry time), and stored in a per-CPU variable, so that the life of the value does not stay explicitly tied to a single task. As suggested by Andy Lutomirski, the offset is added using alloca() and an empty asm() statement with an output constraint, since it avoids changes to assembly syscall entry code, to the unwinder, and provides correct stack alignment as defined by the compiler. In order to make this available by default with zero performance impact for those that don't want it, it is boot-time selectable with static branches. This way, if the overhead is not wanted, it can just be left turned off with no performance impact. The generated assembly for x86_64 with GCC looks like this: ... ffffffff81003977: 65 8b 05 02 ea 00 7f mov %gs:0x7f00ea02(%rip),%eax # 12380 <kstack_offset> ffffffff8100397e: 25 ff 03 00 00 and $0x3ff,%eax ffffffff81003983: 48 83 c0 0f add $0xf,%rax ffffffff81003987: 25 f8 07 00 00 and $0x7f8,%eax ffffffff8100398c: 48 29 c4 sub %rax,%rsp ffffffff8100398f: 48 8d 44 24 0f lea 0xf(%rsp),%rax ffffffff81003994: 48 83 e0 f0 and $0xfffffffffffffff0,%rax ... As a result of the above stack alignment, this patch introduces about 5 bits of randomness after pt_regs is spilled to the thread stack on x86_64, and 6 bits on x86_32 (since its has 1 fewer bit required for stack alignment). The amount of entropy could be adjusted based on how much of the stack space we wish to trade for security. My measure of syscall performance overhead (on x86_64): lmbench: /usr/lib/lmbench/bin/x86_64-linux-gnu/lat_syscall -N 10000 null randomize_kstack_offset=y Simple syscall: 0.7082 microseconds randomize_kstack_offset=n Simple syscall: 0.7016 microseconds So, roughly 0.9% overhead growth for a no-op syscall, which is very manageable. And for people that don't want this, it's off by default. There are two gotchas with using the alloca() trick. First, compilers that have Stack Clash protection (-fstack-clash-protection) enabled by default (e.g. Ubuntu[3]) add pagesize stack probes to any dynamic stack allocations. While the randomization offset is always less than a page, the resulting assembly would still contain (unreachable!) probing routines, bloating the resulting assembly. To avoid this, -fno-stack-clash-protection is unconditionally added to the kernel Makefile since this is the only dynamic stack allocation in the kernel (now that VLAs have been removed) and it is provably safe from Stack Clash style attacks. The second gotcha with alloca() is a negative interaction with -fstack-protector*, in that it sees the alloca() as an array allocation, which triggers the unconditional addition of the stack canary function pre/post-amble which slows down syscalls regardless of the static branch. In order to avoid adding this unneeded check and its associated performance impact, architectures need to carefully remove uses of -fstack-protector-strong (or -fstack-protector) in the compilation units that use the add_random_kstack() macro and to audit the resulting stack mitigation coverage (to make sure no desired coverage disappears). No change is visible for this on x86 because the stack protector is already unconditionally disabled for the compilation unit, but the change is required on arm64. There is, unfortunately, no attribute that can be used to disable stack protector for specific functions. Comparison to PaX RANDKSTACK feature: The RANDKSTACK feature randomizes the location of the stack start (cpu_current_top_of_stack), i.e. including the location of pt_regs structure itself on the stack. Initially this patch followed the same approach, but during the recent discussions[2], it has been determined to be of a little value since, if ptrace functionality is available for an attacker, they can use PTRACE_PEEKUSR/PTRACE_POKEUSR to read/write different offsets in the pt_regs struct, observe the cache behavior of the pt_regs accesses, and figure out the random stack offset. Another difference is that the random offset is stored in a per-cpu variable, rather than having it be per-thread. As a result, these implementations differ a fair bit in their implementation details and results, though obviously the intent is similar. [1] https://lore.kernel.org/kernel-hardening/2236FBA76BA1254E88B949DDB74E612BA4BC57C1@IRSMSX102.ger.corp.intel.com/ [2] https://lore.kernel.org/kernel-hardening/20190329081358.30497-1-elena.reshetova@intel.com/ [3] https://lists.ubuntu.com/archives/ubuntu-devel/2019-June/040741.html Co-developed-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20210401232347.2791257-4-keescook@chromium.org
2021-03-11kbuild: remove LLVM=1 test from HAS_LTO_CLANGMasahiro Yamada
As Documentation/kbuild/llvm.rst notes, LLVM=1 switches the default of tools, but you can still override CC, LD, etc. individually. This LLVM=1 check is unneeded because each tool is already checked separately. "make CC=clang LD=ld.lld NM=llvm-nm AR=llvm-ar LLVM_IAS=1 menuconfig" should be able to enable Clang LTO. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nathan Chancellor <nathan@kernel.org>
2021-03-11kbuild: Allow LTO to be selected with KASAN_HW_TAGSSami Tolvanen
While LTO with KASAN is normally not useful, hardware tag-based KASAN can be used also in production kernels with ARM64_MTE. Therefore, allow KASAN_HW_TAGS to be selected together with HAS_LTO_CLANG. Reported-by: Alistair Delva <adelva@google.com> Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-02-24Merge tag 'x86-entry-2021-02-24' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 irq entry updates from Thomas Gleixner: "The irq stack switching was moved out of the ASM entry code in course of the entry code consolidation. It ended up being suboptimal in various ways. This reworks the X86 irq stack handling: - Make the stack switching inline so the stackpointer manipulation is not longer at an easy to find place. - Get rid of the unnecessary indirect call. - Avoid the double stack switching in interrupt return and reuse the interrupt stack for softirq handling. - A objtool fix for CONFIG_FRAME_POINTER=y builds where it got confused about the stack pointer manipulation" * tag 'x86-entry-2021-02-24' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: objtool: Fix stack-swizzle for FRAME_POINTER=y um: Enforce the usage of asm-generic/softirq_stack.h x86/softirq/64: Inline do_softirq_own_stack() softirq: Move do_softirq_own_stack() to generic asm header softirq: Move __ARCH_HAS_DO_SOFTIRQ to Kconfig x86: Select CONFIG_HAVE_IRQ_EXIT_ON_IRQ_STACK x86/softirq: Remove indirection in do_softirq_own_stack() x86/entry: Use run_sysvec_on_irqstack_cond() for XEN upcall x86/entry: Convert device interrupts to inline stack switching x86/entry: Convert system vectors to irq stack macro x86/irq: Provide macro for inlining irq stack switching x86/apic: Split out spurious handling code x86/irq/64: Adjust the per CPU irq stack pointer by 8 x86/irq: Sanitize irq stack tracking x86/entry: Fix instrumentation annotation
2021-02-23Merge tag 'clang-lto-v5.12-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull clang LTO updates from Kees Cook: "Clang Link Time Optimization. This is built on the work done preparing for LTO by arm64 folks, tracing folks, etc. This includes the core changes as well as the remaining pieces for arm64 (LTO has been the default build method on Android for about 3 years now, as it is the prerequisite for the Control Flow Integrity protections). While x86 LTO enablement is done, it depends on some pending objtool clean-ups. It's possible that I'll send a "part 2" pull request for LTO that includes x86 support. For merge log posterity, and as detailed in commit dc5723b02e52 ("kbuild: add support for Clang LTO"), here is the lt;dr to do an LTO build: make LLVM=1 LLVM_IAS=1 defconfig scripts/config -e LTO_CLANG_THIN make LLVM=1 LLVM_IAS=1 (To do a cross-compile of arm64, add "CROSS_COMPILE=aarch64-linux-gnu-" and "ARCH=arm64" to the "make" command lines.) Summary: - Clang LTO build infrastructure and arm64-specific enablement (Sami Tolvanen) - Recursive build CC_FLAGS_LTO fix (Alexander Lobakin)" * tag 'clang-lto-v5.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: kbuild: prevent CC_FLAGS_LTO self-bloating on recursive rebuilds arm64: allow LTO to be selected arm64: disable recordmcount with DYNAMIC_FTRACE_WITH_REGS arm64: vdso: disable LTO drivers/misc/lkdtm: disable LTO for rodata.o efi/libstub: disable LTO scripts/mod: disable LTO for empty.c modpost: lto: strip .lto from module names PCI: Fix PREL32 relocations for LTO init: lto: fix PREL32 relocations init: lto: ensure initcall ordering kbuild: lto: add a default list of used symbols kbuild: lto: merge module sections kbuild: lto: limit inlining kbuild: lto: fix module versioning kbuild: add support for Clang LTO tracing: move function tracer options to Kconfig
2021-02-22Merge tag 'docs-5.12' of git://git.lwn.net/linuxLinus Torvalds
Pull documentation updates from Jonathan Corbet: "It has been a relatively quiet cycle in docsland. - As promised, the minimum Sphinx version to build the docs is now 1.7, and we have dropped support for Python 2 entirely. That allowed the removal of a bunch of compatibility code. - A set of treewide warning fixups from Mauro that I applied after it became clear nobody else was going to deal with them. - The automarkup mechanism can now create cross-references from relative paths to RST files. - More translations, typo fixes, and warning fixes" * tag 'docs-5.12' of git://git.lwn.net/linux: (75 commits) docs: kernel-hacking: be more civil docs: Remove the Microsoft rhetoric Documentation/admin-guide: kernel-parameters: Update nohlt section doc/admin-guide: fix spelling mistake: "perfomance" -> "performance" docs: Document cross-referencing using relative path docs: Enable usage of relative paths to docs on automarkup docs: thermal: fix spelling mistakes Documentation: admin-guide: Update kvm/xen config option docs: Make syscalls' helpers naming consistent coding-style.rst: Avoid comma statements Documentation: /proc/loadavg: add 3 more field descriptions Documentation/submitting-patches: Add blurb about backtraces in commit messages Docs: drop Python 2 support Move our minimum Sphinx version to 1.7 Documentation: input: define ABS_PRESSURE/ABS_MT_PRESSURE resolution as grams scripts/kernel-doc: add internal hyperlink to DOC: sections Update Documentation/admin-guide/sysctl/fs.rst docs: Update DTB format references docs: zh_CN: add iio index.rst translation docs/zh_CN: add iio ep93xx_adc.rst translation ...
2021-02-21Merge tag 's390-5.12-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Vasily Gorbik: - Convert to using the generic entry infrastructure. - Add vdso time namespace support. - Switch s390 and alpha to 64-bit ino_t. As discussed at https://lore.kernel.org/linux-mm/YCV7QiyoweJwvN+m@osiris/ - Get rid of expensive stck (store clock) usages where possible. Utilize cpu alternatives to patch stckf when supported. - Make tod_clock usage less error prone by converting it to a union and rework code which is using it. - Machine check handler fixes and cleanups. - Drop couple of minor inline asm optimizations to fix clang build. - Default configs changes notably to make libvirt happy. - Various changes to rework and improve qdio code. - Other small various fixes and improvements all over the code. * tag 's390-5.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (68 commits) s390/qdio: remove 'merge_pending' mechanism s390/qdio: improve handling of PENDING buffers for QEBSM devices s390/qdio: rework q->qdio_error indication s390/qdio: inline qdio_kick_handler() s390/time: remove get_tod_clock_ext() s390/crypto: use store_tod_clock_ext() s390/hypfs: use store_tod_clock_ext() s390/debug: use union tod_clock s390/kvm: use union tod_clock s390/vdso: use union tod_clock s390/time: convert tod_clock_base to union s390/time: introduce new store_tod_clock_ext() s390/time: rename store_tod_clock_ext() and use union tod_clock s390/time: introduce union tod_clock s390,alpha: switch to 64-bit ino_t s390: split cleanup_sie s390: use r13 in cleanup_sie as temp register s390: fix kernel asce loading when sie is interrupted s390: add stack for machine check handler s390: use WRITE_ONCE when re-allocating async stack ...
2021-02-21Merge tag 'sched-core-2021-02-17' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler updates from Ingo Molnar: "Core scheduler updates: - Add CONFIG_PREEMPT_DYNAMIC: this in its current form adds the preempt=none/voluntary/full boot options (default: full), to allow distros to build a PREEMPT kernel but fall back to close to PREEMPT_VOLUNTARY (or PREEMPT_NONE) runtime scheduling behavior via a boot time selection. There's also the /debug/sched_debug switch to do this runtime. This feature is implemented via runtime patching (a new variant of static calls). The scope of the runtime patching can be best reviewed by looking at the sched_dynamic_update() function in kernel/sched/core.c. ( Note that the dynamic none/voluntary mode isn't 100% identical, for example preempt-RCU is available in all cases, plus the preempt count is maintained in all models, which has runtime overhead even with the code patching. ) The PREEMPT_VOLUNTARY/PREEMPT_NONE models, used by the vast majority of distributions, are supposed to be unaffected. - Fix ignored rescheduling after rcu_eqs_enter(). This is a bug that was found via rcutorture triggering a hang. The bug is that rcu_idle_enter() may wake up a NOCB kthread, but this happens after the last generic need_resched() check. Some cpuidle drivers fix it by chance but many others don't. In true 2020 fashion the original bug fix has grown into a 5-patch scheduler/RCU fix series plus another 16 RCU patches to address the underlying issue of missed preemption events. These are the initial fixes that should fix current incarnations of the bug. - Clean up rbtree usage in the scheduler, by providing & using the following consistent set of rbtree APIs: partial-order; less() based: - rb_add(): add a new entry to the rbtree - rb_add_cached(): like rb_add(), but for a rb_root_cached total-order; cmp() based: - rb_find(): find an entry in an rbtree - rb_find_add(): find an entry, and add if not found - rb_find_first(): find the first (leftmost) matching entry - rb_next_match(): continue from rb_find_first() - rb_for_each(): iterate a sub-tree using the previous two - Improve the SMP/NUMA load-balancer: scan for an idle sibling in a single pass. This is a 4-commit series where each commit improves one aspect of the idle sibling scan logic. - Improve the cpufreq cooling driver by getting the effective CPU utilization metrics from the scheduler - Improve the fair scheduler's active load-balancing logic by reducing the number of active LB attempts & lengthen the load-balancing interval. This improves stress-ng mmapfork performance. - Fix CFS's estimated utilization (util_est) calculation bug that can result in too high utilization values Misc updates & fixes: - Fix the HRTICK reprogramming & optimization feature - Fix SCHED_SOFTIRQ raising race & warning in the CPU offlining code - Reduce dl_add_task_root_domain() overhead - Fix uprobes refcount bug - Process pending softirqs in flush_smp_call_function_from_idle() - Clean up task priority related defines, remove *USER_*PRIO and USER_PRIO() - Simplify the sched_init_numa() deduplication sort - Documentation updates - Fix EAS bug in update_misfit_status(), which degraded the quality of energy-balancing - Smaller cleanups" * tag 'sched-core-2021-02-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (51 commits) sched,x86: Allow !PREEMPT_DYNAMIC entry/kvm: Explicitly flush pending rcuog wakeup before last rescheduling point entry: Explicitly flush pending rcuog wakeup before last rescheduling point rcu/nocb: Trigger self-IPI on late deferred wake up before user resume rcu/nocb: Perform deferred wake up before last idle's need_resched() check rcu: Pull deferred rcuog wake up to rcu_eqs_enter() callers sched/features: Distinguish between NORMAL and DEADLINE hrtick sched/features: Fix hrtick reprogramming sched/deadline: Reduce rq lock contention in dl_add_task_root_domain() uprobes: (Re)add missing get_uprobe() in __find_uprobe() smp: Process pending softirqs in flush_smp_call_function_from_idle() sched: Harden PREEMPT_DYNAMIC static_call: Allow module use without exposing static_call_key sched: Add /debug/sched_preempt preempt/dynamic: Support dynamic preempt with preempt= boot option preempt/dynamic: Provide irqentry_exit_cond_resched() static call preempt/dynamic: Provide preempt_schedule[_notrace]() static calls preempt/dynamic: Provide cond_resched() and might_resched() static calls preempt: Introduce CONFIG_PREEMPT_DYNAMIC static_call: Provide DEFINE_STATIC_CALL_RET0() ...
2021-02-21Merge tag 'oprofile-removal-5.12' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vireshk/linux Pull oprofile and dcookies removal from Viresh Kumar: "Remove oprofile and dcookies support The 'oprofile' user-space tools don't use the kernel OPROFILE support any more, and haven't in a long time. User-space has been converted to the perf interfaces. The dcookies stuff is only used by the oprofile code. Now that oprofile's support is getting removed from the kernel, there is no need for dcookies as well. Remove kernel's old oprofile and dcookies support" * tag 'oprofile-removal-5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/vireshk/linux: fs: Remove dcookies support drivers: Remove CONFIG_OPROFILE support arch: xtensa: Remove CONFIG_OPROFILE support arch: x86: Remove CONFIG_OPROFILE support arch: sparc: Remove CONFIG_OPROFILE support arch: sh: Remove CONFIG_OPROFILE support arch: s390: Remove CONFIG_OPROFILE support arch: powerpc: Remove oprofile arch: powerpc: Stop building and using oprofile arch: parisc: Remove CONFIG_OPROFILE support arch: mips: Remove CONFIG_OPROFILE support arch: microblaze: Remove CONFIG_OPROFILE support arch: ia64: Remove rest of perfmon support arch: ia64: Remove CONFIG_OPROFILE support arch: hexagon: Don't select HAVE_OPROFILE arch: arc: Remove CONFIG_OPROFILE support arch: arm: Remove CONFIG_OPROFILE support arch: alpha: Remove CONFIG_OPROFILE support
2021-02-21Merge branch 'work.elf-compat' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull ELF compat updates from Al Viro: "Sanitizing ELF compat support, especially for triarch architectures: - X32 handling cleaned up - MIPS64 uses compat_binfmt_elf.c both for O32 and N32 now - Kconfig side of things regularized Eventually I hope to have compat_binfmt_elf.c killed, with both native and compat built from fs/binfmt_elf.c, with -DELF_BITS={64,32} passed by kbuild, but that's a separate story - not included here" * 'work.elf-compat' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: get rid of COMPAT_ELF_EXEC_PAGESIZE compat_binfmt_elf: don't bother with undef of ELF_ARCH Kconfig: regularize selection of CONFIG_BINFMT_ELF mips compat: switch to compat_binfmt_elf.c mips: don't bother with ELF_CORE_EFLAGS mips compat: don't bother with ELF_ET_DYN_BASE mips: KVM_GUEST makes no sense for 64bit builds... mips: kill unused definitions in binfmt_elf[on]32.c mips binfmt_elf*32.c: use elfcore-compat.h x32: make X32, !IA32_EMULATION setups able to execute x32 binaries [amd64] clean PRSTATUS_SIZE/SET_PR_FPVALID up properly elf_prstatus: collect the common part (everything before pr_reg) into a struct binfmt_elf: partially sanitize PRSTATUS_SIZE and SET_PR_FPVALID
2021-02-17preempt: Introduce CONFIG_PREEMPT_DYNAMICMichal Hocko
Preemption mode selection is currently hardcoded on Kconfig choices. Introduce a dedicated option to tune preemption flavour at boot time, This will be only available on architectures efficiently supporting static calls in order not to tempt with the feature against additional overhead that might be prohibitive or undesirable. CONFIG_PREEMPT_DYNAMIC is automatically selected by CONFIG_PREEMPT if the architecture provides the necessary support (CONFIG_STATIC_CALL_INLINE, CONFIG_GENERIC_ENTRY, and provide with __preempt_schedule_function() / __preempt_schedule_notrace_function()). Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Frederic Weisbecker <frederic@kernel.org> [peterz: relax requirement to HAVE_STATIC_CALL] Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lkml.kernel.org/r/20210118141223.123667-5-frederic@kernel.org
2021-02-13s390,alpha: switch to 64-bit ino_tHeiko Carstens
s390 and alpha are the only 64 bit architectures with a 32-bit ino_t. Since this is quite unusual this causes bugs from time to time. See e.g. commit ebce3eb2f7ef ("ceph: fix inode number handling on arches with 32-bit ino_t") for an example. This (obviously) also prevents s390 and alpha to use 64-bit ino_t for tmpfs. See commit b85a7a8bb573 ("tmpfs: disallow CONFIG_TMPFS_INODE64 on s390"). Therefore switch both s390 and alpha to 64-bit ino_t. This should only have an effect on the ustat system call. To prevent ABI breakage define struct ustat compatible to the old layout and change sys_ustat() accordingly. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-02-10softirq: Move __ARCH_HAS_DO_SOFTIRQ to KconfigThomas Gleixner
To prepare for inlining do_softirq_own_stack() replace __ARCH_HAS_DO_SOFTIRQ with a Kconfig switch and select it in the affected architectures. This allows in the next step to move the function prototype and the inline stub into a seperate asm-generic header file which is required to avoid include recursion. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20210210002513.181713427@linutronix.de
2021-01-29drivers: Remove CONFIG_OPROFILE supportViresh Kumar
The "oprofile" user-space tools don't use the kernel OPROFILE support any more, and haven't in a long time. User-space has been converted to the perf interfaces. Remove kernel's old oprofile support. Suggested-by: Christoph Hellwig <hch@infradead.org> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Acked-by: Robert Richter <rric@kernel.org> Acked-by: Paul E. McKenney <paulmck@kernel.org> #RCU Acked-by: William Cohen <wcohen@redhat.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Acked-by: Thomas Gleixner <tglx@linutronix.de>
2021-01-21arch/Kconfig: update a broken file referenceLukas Bulwahn
Commit adab66b71abf ("Revert: "ring-buffer: Remove HAVE_64BIT_ALIGNED_ACCESS"") added the config HAVE_64BIT_ALIGNED_ACCESS back into arch/Kconfig with this revert. In the meantime, commit c9b54d6f362c ("docs: move other kAPI documents to core-api") changed ./Documentation/unaligned-memory-access.txt to ./Documentation/core-api/unaligned-memory-access.rst. Fortunately, ./scripts/documentation-file-ref-check detects this and warns about this broken reference. Update the file reference in arch/Kconfig. Fixes: adab66b71abf ("Revert: "ring-buffer: Remove HAVE_64BIT_ALIGNED_ACCESS"") Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com> Link: https://lore.kernel.org/r/20210119095326.13896-1-lukas.bulwahn@gmail.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-01-14kbuild: lto: fix module versioningSami Tolvanen
With CONFIG_MODVERSIONS, version information is linked into each compilation unit that exports symbols. With LTO, we cannot use this method as all C code is compiled into LLVM bitcode instead. This change collects symbol versions into .symversions files and merges them in link-vmlinux.sh where they are all linked into vmlinux.o at the same time. Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20201211184633.3213045-4-samitolvanen@google.com
2021-01-14kbuild: add support for Clang LTOSami Tolvanen
This change adds build system support for Clang's Link Time Optimization (LTO). With -flto, instead of ELF object files, Clang produces LLVM bitcode, which is compiled into native code at link time, allowing the final binary to be optimized globally. For more details, see: https://llvm.org/docs/LinkTimeOptimization.html The Kconfig option CONFIG_LTO_CLANG is implemented as a choice, which defaults to LTO being disabled. To use LTO, the architecture must select ARCH_SUPPORTS_LTO_CLANG and support: - compiling with Clang, - compiling all assembly code with Clang's integrated assembler, - and linking with LLD. While using CONFIG_LTO_CLANG_FULL results in the best runtime performance, the compilation is not scalable in time or memory. CONFIG_LTO_CLANG_THIN enables ThinLTO, which allows parallel optimization and faster incremental builds. ThinLTO is used by default if the architecture also selects ARCH_SUPPORTS_LTO_CLANG_THIN: https://clang.llvm.org/docs/ThinLTO.html To enable LTO, LLVM tools must be used to handle bitcode files, by passing LLVM=1 and LLVM_IAS=1 options to make: $ make LLVM=1 LLVM_IAS=1 defconfig $ scripts/config -e LTO_CLANG_THIN $ make LLVM=1 LLVM_IAS=1 To prepare for LTO support with other compilers, common parts are gated behind the CONFIG_LTO option, and LTO can be disabled for specific files by filtering out CC_FLAGS_LTO. Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20201211184633.3213045-3-samitolvanen@google.com
2021-01-06[amd64] clean PRSTATUS_SIZE/SET_PR_FPVALID up properlyAl Viro
To get rid of hardcoded size/offset in those macros we need to have a definition of i386 variant of struct elf_prstatus. However, we can't do that in asm/compat.h - the types needed for that are not there and adding an include of asm/user32.h into asm/compat.h would cause a lot of mess. That could be conveniently done in elfcore-compat.h, but currently there is nowhere to put arch-dependent parts of it - no asm/elfcore-compat.h. So we introduce a new file (asm/elfcore-compat.h, present on architectures that have CONFIG_ARCH_HAS_ELFCORE_COMPAT set, currently only on x86), have it pulled by linux/elfcore-compat.h and move the definitions there. As a side benefit, we don't need to worry about accidental inclusion of that file into binfmt_elf.c itself, so we don't need the dance with COMPAT_PRSTATUS_SIZE, etc. - only fs/compat_binfmt_elf.c will see that header. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-12-28fanotify: Fix sys_fanotify_mark() on native x86-32Brian Gerst
Commit 121b32a58a3a ("x86/entry/32: Use IA32-specific wrappers for syscalls taking 64-bit arguments") converted native x86-32 which take 64-bit arguments to use the compat handlers to allow conversion to passing args via pt_regs. sys_fanotify_mark() was however missed, as it has a general compat handler. Add a config option that will use the syscall wrapper that takes the split args for native 32-bit. [ bp: Fix typo in Kconfig help text. ] Fixes: 121b32a58a3a ("x86/entry/32: Use IA32-specific wrappers for syscalls taking 64-bit arguments") Reported-by: Paweł Jasiak <pawel@jasiak.xyz> Signed-off-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Jan Kara <jack@suse.cz> Acked-by: Andy Lutomirski <luto@kernel.org> Link: https://lkml.kernel.org/r/20201130223059.101286-1-brgerst@gmail.com
2020-12-22kasan: allow VMAP_STACK for HW_TAGS modeAndrey Konovalov
Even though hardware tag-based mode currently doesn't support checking vmalloc allocations, it doesn't use shadow memory and works with VMAP_STACK as is. Change VMAP_STACK definition accordingly. Link: https://lkml.kernel.org/r/ecdb2a1658ebd88eb276dee2493518ac0e82de41.1606162397.git.andreyknvl@google.com Link: https://linux-review.googlesource.com/id/I3552cbc12321dec82cd7372676e9372a2eb452ac Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Marco Elver <elver@google.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Dmitry Vyukov <dvyukov@google.com> Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Branislav Rankov <Branislav.Rankov@arm.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Kevin Brodsky <kevin.brodsky@arm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-17Merge tag 'trace-v5.11' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing updates from Steven Rostedt: "The major update to this release is that there's a new arch config option called CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS. Currently, only x86_64 enables it. All the ftrace callbacks now take a struct ftrace_regs instead of a struct pt_regs. If the architecture has HAVE_DYNAMIC_FTRACE_WITH_ARGS enabled, then the ftrace_regs will have enough information to read the arguments of the function being traced, as well as access to the stack pointer. This way, if a user (like live kernel patching) only cares about the arguments, then it can avoid using the heavier weight "regs" callback, that puts in enough information in the struct ftrace_regs to simulate a breakpoint exception (needed for kprobes). A new config option that audits the timestamps of the ftrace ring buffer at most every event recorded. Ftrace recursion protection has been cleaned up to move the protection to the callback itself (this saves on an extra function call for those callbacks). Perf now handles its own RCU protection and does not depend on ftrace to do it for it (saving on that extra function call). New debug option to add "recursed_functions" file to tracefs that lists all the places that triggered the recursion protection of the function tracer. This will show where things need to be fixed as recursion slows down the function tracer. The eval enum mapping updates done at boot up are now offloaded to a work queue, as it caused a noticeable pause on slow embedded boards. Various clean ups and last minute fixes" * tag 'trace-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (33 commits) tracing: Offload eval map updates to a work queue Revert: "ring-buffer: Remove HAVE_64BIT_ALIGNED_ACCESS" ring-buffer: Add rb_check_bpage in __rb_allocate_pages ring-buffer: Fix two typos in comments tracing: Drop unneeded assignment in ring_buffer_resize() tracing: Disable ftrace selftests when any tracer is running seq_buf: Avoid type mismatch for seq_buf_init ring-buffer: Fix a typo in function description ring-buffer: Remove obsolete rb_event_is_commit() ring-buffer: Add test to validate the time stamp deltas ftrace/documentation: Fix RST C code blocks tracing: Clean up after filter logic rewriting tracing: Remove the useless value assignment in test_create_synth_event() livepatch: Use the default ftrace_ops instead of REGS when ARGS is available ftrace/x86: Allow for arguments to be passed in to ftrace_regs by default ftrace: Have the callbacks receive a struct ftrace_regs instead of pt_regs MAINTAINERS: assign ./fs/tracefs to TRACING tracing: Fix some typos in comments ftrace: Remove unused varible 'ret' ring-buffer: Add recording of ring buffer recursion into recursed_functions ...
2020-12-16Merge tag 'seccomp-v5.11-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull seccomp updates from Kees Cook: "The major change here is finally gaining seccomp constant-action bitmaps, which internally reduces the seccomp overhead for many real-world syscall filters to O(1), as discussed at Plumbers this year. - Improve seccomp performance via constant-action bitmaps (YiFei Zhu & Kees Cook) - Fix bogus __user annotations (Jann Horn) - Add missed CONFIG for improved selftest coverage (Mickaël Salaün)" * tag 'seccomp-v5.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: selftests/seccomp: Update kernel config seccomp: Remove bogus __user annotations seccomp/cache: Report cache data through /proc/pid/seccomp_cache xtensa: Enable seccomp architecture tracking sh: Enable seccomp architecture tracking s390: Enable seccomp architecture tracking riscv: Enable seccomp architecture tracking powerpc: Enable seccomp architecture tracking parisc: Enable seccomp architecture tracking csky: Enable seccomp architecture tracking arm: Enable seccomp architecture tracking arm64: Enable seccomp architecture tracking selftests/seccomp: Compare bitmap vs filter overhead x86: Enable seccomp architecture tracking seccomp/cache: Add "emulator" to check if filter is constant allow seccomp/cache: Lookup syscall allowlist bitmap for fast path
2020-12-15Merge tag 'irq-core-2020-12-15' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull irq updates from Thomas Gleixner: "Generic interrupt and irqchips subsystem updates. Unusually, there is not a single completely new irq chip driver, just new DT bindings and extensions of existing drivers to accomodate new variants! Core: - Consolidation and robustness changes for irq time accounting - Cleanup and consolidation of irq stats - Remove the fasteoi IPI flow which has been proved useless - Provide an interface for converting legacy interrupt mechanism into irqdomains Drivers: - Preliminary support for managed interrupts on platform devices - Correctly identify allocation of MSIs proxyied by another device - Generalise the Ocelot support to new SoCs - Improve GICv4.1 vcpu entry, matching the corresponding KVM optimisation - Work around spurious interrupts on Qualcomm PDC - Random fixes and cleanups" * tag 'irq-core-2020-12-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (54 commits) irqchip/qcom-pdc: Fix phantom irq when changing between rising/falling driver core: platform: Add devm_platform_get_irqs_affinity() ACPI: Drop acpi_dev_irqresource_disabled() resource: Add irqresource_disabled() genirq/affinity: Add irq_update_affinity_desc() irqchip/gic-v3-its: Flag device allocation as proxied if behind a PCI bridge irqchip/gic-v3-its: Tag ITS device as shared if allocating for a proxy device platform-msi: Track shared domain allocation irqchip/ti-sci-intr: Fix freeing of irqs irqchip/ti-sci-inta: Fix printing of inta id on probe success drivers/irqchip: Remove EZChip NPS interrupt controller Revert "genirq: Add fasteoi IPI flow" irqchip/hip04: Make IPIs use handle_percpu_devid_irq() irqchip/bcm2836: Make IPIs use handle_percpu_devid_irq() irqchip/armada-370-xp: Make IPIs use handle_percpu_devid_irq() irqchip/gic, gic-v3: Make SGIs use handle_percpu_devid_irq() irqchip/ocelot: Add support for Jaguar2 platforms irqchip/ocelot: Add support for Serval platforms irqchip/ocelot: Add support for Luton platforms irqchip/ocelot: prepare to support more SoC ...