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2025-10-29compiler_types: Introduce __nocfi_genericNathan Chancellor1-0/+7
There are two different ways that LLVM can expand kCFI operand bundles in LLVM IR: generically in the middle end or using an architecture specific sequence when lowering LLVM IR to machine code in the backend. The generic pass allows any architecture to take advantage of kCFI but the expansion of these bundles in the middle end can mess with optimizations that may turn indirect calls into direct calls when the call target is known at compile time, such as after inlining. Add __nocfi_generic, dependent on an architecture selecting CONFIG_ARCH_USES_CFI_GENERIC_LLVM_PASS, to disable kCFI bundle generation in functions where only the generic kCFI pass may cause problems. Link: https://github.com/ClangBuiltLinux/linux/issues/2124 Signed-off-by: Nathan Chancellor <nathan@kernel.org> Link: https://patch.msgid.link/20251025-idpf-fix-arm-kcfi-build-error-v1-1-ec57221153ae@kernel.org Signed-off-by: Kees Cook <kees@kernel.org>
2025-10-09rust: cfi: only 64-bit arm and x86 support CFI_CLANGConor Dooley1-0/+1
The kernel uses the standard rustc targets for non-x86 targets, and out of those only 64-bit arm's target has kcfi support enabled. For x86, the custom 64-bit target enables kcfi. The HAVE_CFI_ICALL_NORMALIZE_INTEGERS_RUSTC config option that allows CFI_CLANG to be used in combination with RUST does not check whether the rustc target supports kcfi. This breaks the build on riscv (and presumably 32-bit arm) when CFI_CLANG and RUST are enabled at the same time. Ordinarily, a rustc-option check would be used to detect target support but unfortunately rustc-option filters out the target for reasons given in commit 46e24a545cdb4 ("rust: kasan/kbuild: fix missing flags on first build"). As a result, if the host supports kcfi but the target does not, e.g. when building for riscv on x86_64, the build would remain broken. Instead, make HAVE_CFI_ICALL_NORMALIZE_INTEGERS_RUSTC depend on the only two architectures where the target used supports it to fix the build. CC: stable@vger.kernel.org Fixes: ca627e636551e ("rust: cfi: add support for CFI_CLANG with Rust") Signed-off-by: Conor Dooley <conor.dooley@microchip.com> Acked-by: Miguel Ojeda <ojeda@kernel.org> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20250908-distill-lint-1ae78bcf777c@spud Signed-off-by: Paul Walmsley <pjw@kernel.org>
2025-10-01Merge tag 'kbuild-6.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kbuild/linuxLinus Torvalds1-1/+0
Pull Kbuild updates from Nathan Chancellor: - Extend modules.builtin.modinfo to include module aliases from MODULE_DEVICE_TABLE for builtin modules so that userspace tools (such as kmod) can verify that a particular module alias will be handled by a builtin module - Bump the minimum version of LLVM for building the kernel to 15.0.0 - Upgrade several userspace API checks in headers_check.pl to errors - Unify and consolidate CONFIG_WERROR / W=e handling - Turn assembler and linker warnings into errors with CONFIG_WERROR / W=e - Respect CONFIG_WERROR / W=e when building userspace programs (userprogs) - Enable -Werror unconditionally when building host programs (hostprogs) - Support copy_file_range() and data segment alignment in gen_init_cpio to improve performance on filesystems that support reflinks such as btrfs and XFS - Miscellaneous small changes to scripts and configuration files * tag 'kbuild-6.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kbuild/linux: (47 commits) modpost: Initialize builtin_modname to stop SIGSEGVs Documentation: kbuild: note CONFIG_DEBUG_EFI in reproducible builds kbuild: vmlinux.unstripped should always depend on .vmlinux.export.o modpost: Create modalias for builtin modules modpost: Add modname to mod_device_table alias scsi: Always define blogic_pci_tbl structure kbuild: extract modules.builtin.modinfo from vmlinux.unstripped kbuild: keep .modinfo section in vmlinux.unstripped kbuild: always create intermediate vmlinux.unstripped s390: vmlinux.lds.S: Reorder sections KMSAN: Remove tautological checks objtool: Drop noinstr hack for KCSAN_WEAK_MEMORY lib/Kconfig.debug: Drop CLANG_VERSION check from DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT riscv: Remove ld.lld version checks from many TOOLCHAIN_HAS configs riscv: Unconditionally use linker relaxation riscv: Remove version check for LTO_CLANG selects powerpc: Drop unnecessary initializations in __copy_inst_from_kernel_nofault() mips: Unconditionally select ARCH_HAS_CURRENT_STACK_POINTER arm64: Remove tautological LLVM Kconfig conditions ARM: Clean up definition of ARM_HAS_GROUP_RELOCS ...
2025-09-30Merge tag 'timers-vdso-2025-09-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds1-1/+1
Pull VDSO updates from Thomas Gleixner: - Further consolidation of the VDSO infrastructure and the common data store - Simplification of the related Kconfig logic - Improve the VDSO selftest suite * tag 'timers-vdso-2025-09-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: selftests: vDSO: Drop vdso_test_clock_getres selftests: vDSO: vdso_test_abi: Add tests for clock_gettime64() selftests: vDSO: vdso_test_abi: Test CPUTIME clocks selftests: vDSO: vdso_test_abi: Use explicit indices for name array selftests: vDSO: vdso_test_abi: Drop clock availability tests selftests: vDSO: vdso_test_abi: Use ksft_finished() selftests: vDSO: vdso_test_abi: Correctly skip whole test with missing vDSO selftests: vDSO: Fix -Wunitialized in powerpc VDSO_CALL() wrapper vdso: Add struct __kernel_old_timeval forward declaration to gettime.h vdso: Gate VDSO_GETRANDOM behind HAVE_GENERIC_VDSO vdso: Drop Kconfig GENERIC_VDSO_TIME_NS vdso: Drop Kconfig GENERIC_VDSO_DATA_STORE vdso: Drop kconfig GENERIC_COMPAT_VDSO vdso: Drop kconfig GENERIC_VDSO_32 riscv: vdso: Untangle Kconfig logic time: Build generic update_vsyscall() only with generic time vDSO vdso/gettimeofday: Remove !CONFIG_TIME_NS stubs vdso: Move ENABLE_COMPAT_VDSO from core to arm64 ARM: VDSO: Remove cntvct_ok global variable vdso/datastore: Gate time data behind CONFIG_GENERIC_GETTIMEOFDAY
2025-09-30Merge tag 'core-core-2025-09-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds1-0/+4
Pull TIF bit unification updates from Thomas Gleixner: "A set of changes to consolidate the generic TIF (thread info flag) bits accross architectures. All architectures define the same set of generic TIF bits. This makes it pointlessly hard to add a new generic TIF bit or to change an existing one. Provide a generic variant and convert the architectures which utilize the generic entry code over to use it. The TIF space is divided into 16 generic bits and 16 architecture specific bits, which turned out to provide enough space on both sides" * tag 'core-core-2025-09-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: LoongArch: Fix bitflag conflict for TIF_FIXADE riscv: Use generic TIF bits loongarch: Use generic TIF bits s390/entry: Remove unused TIF flags s390: Use generic TIF bits x86: Use generic TIF bits asm-generic: Provide generic TIF infrastructure
2025-09-30Merge tag 'sched-core-2025-09-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds1-0/+38
Pull scheduler updates from Ingo Molnar: "Core scheduler changes: - Make migrate_{en,dis}able() inline, to improve performance (Menglong Dong) - Move STDL_INIT() functions out-of-line (Peter Zijlstra) - Unify the SCHED_{SMT,CLUSTER,MC} Kconfig (Peter Zijlstra) Fair scheduling: - Defer throttling to when tasks exit to user-space, to reduce the chance & impact of throttle-preemption with held locks and other resources (Aaron Lu, Valentin Schneider) - Get rid of sched_domains_curr_level hack for tl->cpumask(), as the warning was getting triggered on certain topologies (Peter Zijlstra) Misc cleanups & fixes: - Header cleanups (Menglong Dong) - Fix race in push_dl_task() (Harshit Agarwal)" * tag 'sched-core-2025-09-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched: Fix some typos in include/linux/preempt.h sched: Make migrate_{en,dis}able() inline rcu: Replace preempt.h with sched.h in include/linux/rcupdate.h arch: Add the macro COMPILE_OFFSETS to all the asm-offsets.c sched/fair: Do not balance task to a throttled cfs_rq sched/fair: Do not special case tasks in throttled hierarchy sched/fair: update_cfs_group() for throttled cfs_rqs sched/fair: Propagate load for throttled cfs_rq sched/fair: Get rid of throttled_lb_pair() sched/fair: Task based throttle time accounting sched/fair: Switch to task based throttle model sched/fair: Implement throttle task work and related helpers sched/fair: Add related data structure for task based throttle sched: Unify the SCHED_{SMT,CLUSTER,MC} Kconfig sched: Move STDL_INIT() functions out-of-line sched/fair: Get rid of sched_domains_curr_level hack for tl->cpumask() sched/deadline: Fix race in push_dl_task()
2025-09-24kcfi: Rename CONFIG_CFI_CLANG to CONFIG_CFIKees Cook1-13/+23
The kernel's CFI implementation uses the KCFI ABI specifically, and is not strictly tied to a particular compiler. In preparation for GCC supporting KCFI, rename CONFIG_CFI_CLANG to CONFIG_CFI (along with associated options). Use new "transitional" Kconfig option for old CONFIG_CFI_CLANG that will enable CONFIG_CFI during olddefconfig. Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Reviewed-by: Nathan Chancellor <nathan@kernel.org> Link: https://lore.kernel.org/r/20250923213422.1105654-3-kees@kernel.org Signed-off-by: Kees Cook <kees@kernel.org>
2025-09-17asm-generic: Provide generic TIF infrastructureThomas Gleixner1-0/+4
Common TIF bits do not have to be defined by every architecture. They can be defined in a generic header. That allows adding generic TIF bits without chasing a gazillion of architecture headers, which is again a unjustified burden on anyone who works on generic infrastructure as it always needs a boat load of work to keep existing architecture code working when adding new stuff. While it is not as horrible as the ignorance of the generic entry infrastructure, it is a welcome mechanism to make architecture people rethink their approach of just leaching generic improvements into architecture code and thereby making it accumulatingly harder to maintain and improve generic code. It's about time that this changes. Provide the infrastructure and split the TIF space in half, 16 generic and 16 architecture specific bits. This could probably be extended by TIF_SINGLESTEP and BLOCKSTEP, but those are only used in architecture specific code. So leave them alone for now. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Acked-by: Arnd Bergmann <arnd@arndb.de>
2025-09-04vdso: Drop Kconfig GENERIC_VDSO_DATA_STOREThomas Weißschuh1-1/+1
All users of the generic vDSO library also use the generic vDSO datastore. Remove the now unnecessary Kconfig symbol. Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/all/20250826-vdso-cleanups-v1-9-d9b65750e49f@linutronix.de
2025-09-03sched: Unify the SCHED_{SMT,CLUSTER,MC} KconfigPeter Zijlstra1-0/+38
Like many Kconfig symbols, SCHED_{SMT,CLUSTER,MC} are duplicated across arch/*/Kconfig. Try and clean up a little. Suggested-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Shrikanth Hegde <sshegde@linux.ibm.com> Tested-by: Shrikanth Hegde <sshegde@linux.ibm.com> # powerpc Link: https://lkml.kernel.org/r/20250826094358.GG3245006@noisy.programming.kicks-ass.net
2025-08-28arch/Kconfig: Drop always true condition from RANDOMIZE_KSTACK_OFFSETNathan Chancellor1-1/+0
Now that the minimum supported version of LLVM for building the kernel has been bumped to 15.0.0, the second depends line in RANDOMIZE_KSTACK_OFFSET is always true, so it can be removed. Reviewed-by: Kees Cook <kees@kernel.org> Link: https://lore.kernel.org/r/20250821-bump-min-llvm-ver-15-v2-2-635f3294e5f0@kernel.org Signed-off-by: Nathan Chancellor <nathan@kernel.org>
2025-08-01Merge tag 'trace-deferred-unwind-v6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-traceLinus Torvalds1-0/+7
Pull initial deferred unwind infrastructure from Steven Rostedt: "This is the core infrastructure for the deferred unwinder that is required for sframes[1]. Several other patch series are based on this work although those patch series are not dependent on each other. In order to simplify the development, having this core series upstream will allow the other series to be worked on in parallel. The other series are: - The two patches to implement x86 support [2] [3] - The s390 work [4] - The perf work [5] - The ftrace work [6] - The sframe work [7] And more is on the way. The core infrastructure adds the following in kernel APIs: - int unwind_user_faultable(struct unwind_stacktrace *trace); Performs a user space stack trace that may fault user pages in. - int unwind_deferred_init(struct unwind_work *work, unwind_callback_t func); Allows a tracer to register with the unwind deferred infrastructure. - int unwind_deferred_request(struct unwind_work *work, u64 *cookie); Used when a tracer request a deferred trace. Can be called from interrupt or NMI context. - void unwind_deferred_cancel(struct unwind_work *work); Called by a tracer to unregister from the deferred unwind infrastructure. - void unwind_deferred_task_exit(struct task_struct *task); Called by task exit code to flush any pending unwind requests. - void unwind_task_init(struct task_struct *task); Called by do_fork() to initialize the task struct for the deferred unwinder. - void unwind_task_free(struct task_struct *task); Called by do_exit() to free up any resources used by the deferred unwinder. None of the above is actually compiled unless an architecture enables it, which none currently do" Link: https://sourceware.org/binutils/wiki/sframe [1] Link: https://lore.kernel.org/linux-trace-kernel/20250717004958.260781923@kernel.org/ [2] Link: https://lore.kernel.org/linux-trace-kernel/20250717004958.432327787@kernel.org/ [3] Link: https://lore.kernel.org/linux-trace-kernel/20250710163522.3195293-1-jremus@linux.ibm.com/ [4] Link: https://lore.kernel.org/linux-trace-kernel/20250718164119.089692174@kernel.org/ [5] Link: https://lore.kernel.org/linux-trace-kernel/20250424192612.505622711@goodmis.org/ [6] Link: https://lore.kernel.org/linux-trace-kernel/20250717012848.927473176@kernel.org/ [7] * tag 'trace-deferred-unwind-v6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: unwind: Finish up unwind when a task exits unwind deferred: Use SRCU unwind_deferred_task_work() unwind: Add USED bit to only have one conditional on way back to user space unwind deferred: Add unwind_completed mask to stop spurious callbacks unwind deferred: Use bitmask to determine which callbacks to call unwind_user/deferred: Make unwind deferral requests NMI-safe unwind_user/deferred: Add deferred unwinding interface unwind_user/deferred: Add unwind cache unwind_user/deferred: Add unwind_user_faultable() unwind_user: Add user space unwinding API with frame pointer support
2025-07-29Merge tag 'x86_bugs_for_v6.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds1-0/+3
Pull x86 CPU mitigation updates from Borislav Petkov: - Untangle the Retbleed from the ITS mitigation on Intel. Allow for ITS to enable stuffing independently from Retbleed, do some cleanups to simplify and streamline the code - Simplify SRSO and make mitigation types selection more versatile depending on the Retbleed mitigation selection. Simplify code some - Add the second part of the attack vector controls which provide a lot friendlier user interface to the speculation mitigations than selecting each one by one as it is now. Instead, the selection of whole attack vectors which are relevant to the system in use can be done and protection against only those vectors is enabled, thus giving back some performance to the users * tag 'x86_bugs_for_v6.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (31 commits) x86/bugs: Print enabled attack vectors x86/bugs: Add attack vector controls for TSA x86/pti: Add attack vector controls for PTI x86/bugs: Add attack vector controls for ITS x86/bugs: Add attack vector controls for SRSO x86/bugs: Add attack vector controls for L1TF x86/bugs: Add attack vector controls for spectre_v2 x86/bugs: Add attack vector controls for BHI x86/bugs: Add attack vector controls for spectre_v2_user x86/bugs: Add attack vector controls for retbleed x86/bugs: Add attack vector controls for spectre_v1 x86/bugs: Add attack vector controls for GDS x86/bugs: Add attack vector controls for SRBDS x86/bugs: Add attack vector controls for RFDS x86/bugs: Add attack vector controls for MMIO x86/bugs: Add attack vector controls for TAA x86/bugs: Add attack vector controls for MDS x86/bugs: Define attack vectors relevant for each bug x86/Kconfig: Add arch attack vector support cpu: Define attack vectors ...
2025-07-29Merge tag 'core-entry-2025-07-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds1-0/+9
Pull generic entry code updates from Thomas Gleixner: - Split the code into syscall and exception/interrupt parts to ease the conversion of ARM[64] to the generic entry infrastructure - Extend syscall user dispatching to support a single intercepted range instead of the default single non-intercepted range. That allows monitoring/analysis of a specific executable range, e.g. a library, and also provides flexibility for sandboxing scenarios - Cleanup and extend the user dispatch selftest * tag 'core-entry-2025-07-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: entry: Split generic entry into generic exception and syscall entry selftests: Add tests for PR_SYS_DISPATCH_INCLUSIVE_ON syscall_user_dispatch: Add PR_SYS_DISPATCH_INCLUSIVE_ON selftests: Fix errno checking in syscall_user_dispatch test
2025-07-29unwind_user: Add user space unwinding API with frame pointer supportJosh Poimboeuf1-0/+7
Introduce a generic API for unwinding user stacks. In order to expand user space unwinding to be able to handle more complex scenarios, such as deferred unwinding and reading user space information, create a generic interface that all architectures can use that support the various unwinding methods. This is an alternative method for handling user space stack traces from the simple stack_trace_save_user() API. This does not replace that interface, but this interface will be used to expand the functionality of user space stack walking. None of the structures introduced will be exposed to user space tooling. Support for frame pointer unwinding is added. For an architecture to support frame pointer unwinding it needs to enable CONFIG_HAVE_UNWIND_USER_FP and define ARCH_INIT_USER_FP_FRAME. By encoding the frame offsets in struct unwind_user_frame, much of this code can also be reused for future unwinder implementations like sframe. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Andrii Nakryiko <andrii@kernel.org> Cc: Indu Bhagat <indu.bhagat@oracle.com> Cc: "Jose E. Marchesi" <jemarch@gnu.org> Cc: Beau Belgrave <beaub@linux.microsoft.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Florian Weimer <fweimer@redhat.com> Cc: Sam James <sam@gentoo.org> Link: https://lore.kernel.org/20250729182404.975790139@kernel.org Reviewed-by: Jens Remus <jremus@linux.ibm.com> Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> Co-developed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/all/20250710164301.3094-2-mathieu.desnoyers@efficios.com/ Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Co-developed-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-07-21stackleak: Rename STACKLEAK to KSTACK_ERASEKees Cook1-2/+2
In preparation for adding Clang sanitizer coverage stack depth tracking that can support stack depth callbacks: - Add the new top-level CONFIG_KSTACK_ERASE option which will be implemented either with the stackleak GCC plugin, or with the Clang stack depth callback support. - Rename CONFIG_GCC_PLUGIN_STACKLEAK as needed to CONFIG_KSTACK_ERASE, but keep it for anything specific to the GCC plugin itself. - Rename all exposed "STACKLEAK" names and files to "KSTACK_ERASE" (named for what it does rather than what it protects against), but leave as many of the internals alone as possible to avoid even more churn. While here, also split "prev_lowest_stack" into CONFIG_KSTACK_ERASE_METRICS, since that's the only place it is referenced from. Suggested-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20250717232519.2984886-1-kees@kernel.org Signed-off-by: Kees Cook <kees@kernel.org>
2025-07-11x86/Kconfig: Add arch attack vector supportDavid Kaplan1-0/+3
ARCH_HAS_CPU_ATTACK_VECTORS should be set for architectures which implement the new attack-vector based controls for CPU mitigations. If an arch does not support attack-vector based controls then an attempt to use them results in a warning. Signed-off-by: David Kaplan <david.kaplan@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/20250707183316.1349127-4-david.kaplan@amd.com
2025-06-30entry: Split generic entry into generic exception and syscall entryJinjie Ruan1-0/+9
Currently CONFIG_GENERIC_ENTRY enables both the generic exception entry logic and the generic syscall entry logic, which are otherwise loosely coupled. Introduce separate config options for these so that architectures can select the two independently. This will make it easier for architectures to migrate to generic entry code. Suggested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Linus Walleij <linus.walleij@linaro.org> Link: https://lore.kernel.org/20250213130007.1418890-2-ruanjinjie@huawei.com Link: https://lore.kernel.org/all/20250624-generic-entry-split-v1-1-53d5ef4f94df@linaro.org [Linus Walleij: rebase onto v6.16-rc1]
2025-05-16fs/resctrl: Add boiler plate for external resctrl codeJames Morse1-0/+8
Add Makefile and Kconfig for fs/resctrl. Add ARCH_HAS_CPU_RESCTRL for the common parts of the resctrl interface and make X86_CPU_RESCTRL select this. Adding an include of asm/resctrl.h to linux/resctrl.h allows the /fs/resctrl files to switch over to using this header instead. Co-developed-by: Dave Martin <Dave.Martin@arm.com> Signed-off-by: Dave Martin <Dave.Martin@arm.com> Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Reviewed-by: Tony Luck <tony.luck@intel.com> Reviewed-by: Fenghua Yu <fenghuay@nvidia.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Tested-by: Fenghua Yu <fenghuay@nvidia.com> Tested-by: Carl Worth <carl@os.amperecomputing.com> # arm64 Tested-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Tested-by: Peter Newman <peternewman@google.com> Tested-by: Amit Singh Tomar <amitsinght@marvell.com> # arm64 Tested-by: Shanker Donthineni <sdonthineni@nvidia.com> # arm64 Tested-by: Babu Moger <babu.moger@amd.com> Tested-by: Tony Luck <tony.luck@intel.com> Link: https://lore.kernel.org/20250515165855.31452-16-james.morse@arm.com
2025-04-05Merge tag 'kbuild-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuildLinus Torvalds1-0/+7
Pull Kbuild updates from Masahiro Yamada: - Improve performance in gendwarfksyms - Remove deprecated EXTRA_*FLAGS and KBUILD_ENABLE_EXTRA_GCC_CHECKS - Support CONFIG_HEADERS_INSTALL for ARCH=um - Use more relative paths to sources files for better reproducibility - Support the loong64 Debian architecture - Add Kbuild bash completion - Introduce intermediate vmlinux.unstripped for architectures that need static relocations to be stripped from the final vmlinux - Fix versioning in Debian packages for -rc releases - Treat missing MODULE_DESCRIPTION() as an error - Convert Nios2 Makefiles to use the generic rule for built-in DTB - Add debuginfo support to the RPM package * tag 'kbuild-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (40 commits) kbuild: rpm-pkg: build a debuginfo RPM kconfig: merge_config: use an empty file as initfile nios2: migrate to the generic rule for built-in DTB rust: kbuild: skip `--remap-path-prefix` for `rustdoc` kbuild: pacman-pkg: hardcode module installation path kbuild: deb-pkg: don't set KBUILD_BUILD_VERSION unconditionally modpost: require a MODULE_DESCRIPTION() kbuild: make all file references relative to source root x86: drop unnecessary prefix map configuration kbuild: deb-pkg: add comment about future removal of KDEB_COMPRESS kbuild: Add a help message for "headers" kbuild: deb-pkg: remove "version" variable in mkdebian kbuild: deb-pkg: fix versioning for -rc releases Documentation/kbuild: Fix indentation in modules.rst example x86: Get rid of Makefile.postlink kbuild: Create intermediate vmlinux build with relocations preserved kbuild: Introduce Kconfig symbol for linking vmlinux with relocations kbuild: link-vmlinux.sh: Make output file name configurable kbuild: do not generate .tmp_vmlinux*.map when CONFIG_VMLINUX_MAP=y Revert "kheaders: Ignore silly-rename files" ...
2025-03-17kbuild: Introduce Kconfig symbol for linking vmlinux with relocationsArd Biesheuvel1-0/+7
Some architectures build vmlinux with static relocations preserved, but strip them again from the final vmlinux image. Arch specific tools consume these static relocations in order to construct relocation tables for KASLR. The fact that vmlinux is created, consumed and subsequently updated goes against the typical, declarative paradigm used by Make, which is based on rules and dependencies. So as a first step towards cleaning this up, introduce a Kconfig symbol to declare that the arch wants to consume the static relocations emitted into vmlinux. This will be wired up further in subsequent patches. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2025-02-21vdso: Add generic architecture-specific data storageThomas Weißschuh1-0/+4
Some architectures need to expose architecture-specific data to the vDSO. Enable the generic vDSO storage mechanism to both store and map this data. Some architectures require more than a single page, like LoongArch, so prepare for that usecase, too. Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/all/20250204-vdso-store-rng-v3-7-13a4669dfc8c@linutronix.de
2024-12-09m68k: Use kernel's generic muldi3 libgcc functionGreg Ungerer1-0/+8
Use the kernels own generic lib/muldi3.c implementation of muldi3 for 68K machines. Some 68K CPUs support 64bit multiplies so move the arch specific umul_ppmm() macro into a header file that is included by lib/muldi3.c. That way it can take advantage of the single instruction when available. There does not appear to be any existing mechanism for the generic lib/muldi3.c code to pick up an external arch definition of umul_ppmm(). Create an arch specific libgcc.h that can optionally be included by the system include/linux/libgcc.h to allow for this. Somewhat oddly there is also a similar definition of umul_ppmm() in the non-architecture code in lib/crypto/mpi/longlong.h for a wide range or machines. Its presence ends up complicating the include setup and means not being able to use something like compiler.h instead. Actually there is a few other defines of umul_ppmm() macros spread around in various architectures, but not directly usable for the m68k case. Signed-off-by: Greg Ungerer <gerg@linux-m68k.org> Link: https://lore.kernel.org/20231113133209.1367286-1-gerg@linux-m68k.org Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
2024-11-30Merge tag 'kbuild-v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuildLinus Torvalds1-0/+39
Pull Kbuild updates from Masahiro Yamada: - Add generic support for built-in boot DTB files - Enable TAB cycling for dialog buttons in nconfig - Fix issues in streamline_config.pl - Refactor Kconfig - Add support for Clang's AutoFDO (Automatic Feedback-Directed Optimization) - Add support for Clang's Propeller, a profile-guided optimization. - Change the working directory to the external module directory for M= builds - Support building external modules in a separate output directory - Enable objtool for *.mod.o and additional kernel objects - Use lz4 instead of deprecated lz4c - Work around a performance issue with "git describe" - Refactor modpost * tag 'kbuild-v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (85 commits) kbuild: rename .tmp_vmlinux.kallsyms0.syms to .tmp_vmlinux0.syms gitignore: Don't ignore 'tags' directory kbuild: add dependency from vmlinux to resolve_btfids modpost: replace tdb_hash() with hash_str() kbuild: deb-pkg: add python3:native to build dependency genksyms: reduce indentation in export_symbol() modpost: improve error messages in device_id_check() modpost: rename alias symbol for MODULE_DEVICE_TABLE() modpost: rename variables in handle_moddevtable() modpost: move strstarts() to modpost.h modpost: convert do_usb_table() to a generic handler modpost: convert do_of_table() to a generic handler modpost: convert do_pnp_device_entry() to a generic handler modpost: convert do_pnp_card_entries() to a generic handler modpost: call module_alias_printf() from all do_*_entry() functions modpost: pass (struct module *) to do_*_entry() functions modpost: remove DEF_FIELD_ADDR_VAR() macro modpost: deduplicate MODULE_ALIAS() for all drivers modpost: introduce module_alias_printf() helper modpost: remove unnecessary check in do_acpi_entry() ...
2024-11-27kbuild: Add Propeller configuration for kernel buildRong Xu1-0/+19
Add the build support for using Clang's Propeller optimizer. Like AutoFDO, Propeller uses hardware sampling to gather information about the frequency of execution of different code paths within a binary. This information is then used to guide the compiler's optimization decisions, resulting in a more efficient binary. The support requires a Clang compiler LLVM 19 or later, and the create_llvm_prof tool (https://github.com/google/autofdo/releases/tag/v0.30.1). This commit is limited to x86 platforms that support PMU features like LBR on Intel machines and AMD Zen3 BRS. Here is an example workflow for building an AutoFDO+Propeller optimized kernel: 1) Build the kernel on the host machine, with AutoFDO and Propeller build config CONFIG_AUTOFDO_CLANG=y CONFIG_PROPELLER_CLANG=y then $ make LLVM=1 CLANG_AUTOFDO_PROFILE=<autofdo_profile> “<autofdo_profile>” is the profile collected when doing a non-Propeller AutoFDO build. This step builds a kernel that has the same optimization level as AutoFDO, plus a metadata section that records basic block information. This kernel image runs as fast as an AutoFDO optimized kernel. 2) Install the kernel on test/production machines. 3) Run the load tests. The '-c' option in perf specifies the sample event period. We suggest using a suitable prime number, like 500009, for this purpose. For Intel platforms: $ perf record -e BR_INST_RETIRED.NEAR_TAKEN:k -a -N -b -c <count> \ -o <perf_file> -- <loadtest> For AMD platforms: The supported system are: Zen3 with BRS, or Zen4 with amd_lbr_v2 # To see if Zen3 support LBR: $ cat proc/cpuinfo | grep " brs" # To see if Zen4 support LBR: $ cat proc/cpuinfo | grep amd_lbr_v2 # If the result is yes, then collect the profile using: $ perf record --pfm-events RETIRED_TAKEN_BRANCH_INSTRUCTIONS:k -a \ -N -b -c <count> -o <perf_file> -- <loadtest> 4) (Optional) Download the raw perf file to the host machine. 5) Generate Propeller profile: $ create_llvm_prof --binary=<vmlinux> --profile=<perf_file> \ --format=propeller --propeller_output_module_name \ --out=<propeller_profile_prefix>_cc_profile.txt \ --propeller_symorder=<propeller_profile_prefix>_ld_profile.txt “create_llvm_prof” is the profile conversion tool, and a prebuilt binary for linux can be found on https://github.com/google/autofdo/releases/tag/v0.30.1 (can also build from source). "<propeller_profile_prefix>" can be something like "/home/user/dir/any_string". This command generates a pair of Propeller profiles: "<propeller_profile_prefix>_cc_profile.txt" and "<propeller_profile_prefix>_ld_profile.txt". 6) Rebuild the kernel using the AutoFDO and Propeller profile files. CONFIG_AUTOFDO_CLANG=y CONFIG_PROPELLER_CLANG=y and $ make LLVM=1 CLANG_AUTOFDO_PROFILE=<autofdo_profile> \ CLANG_PROPELLER_PROFILE_PREFIX=<propeller_profile_prefix> Co-developed-by: Han Shen <shenhan@google.com> Signed-off-by: Han Shen <shenhan@google.com> Signed-off-by: Rong Xu <xur@google.com> Suggested-by: Sriraman Tallam <tmsriram@google.com> Suggested-by: Krzysztof Pszeniczny <kpszeniczny@google.com> Suggested-by: Nick Desaulniers <ndesaulniers@google.com> Suggested-by: Stephane Eranian <eranian@google.com> Tested-by: Yonghong Song <yonghong.song@linux.dev> Tested-by: Nathan Chancellor <nathan@kernel.org> Reviewed-by: Kees Cook <kees@kernel.org> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-11-23Merge tag 'powerpc-6.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linuxLinus Torvalds1-0/+6
Pull powerpc updates from Michael Ellerman: - Rework kfence support for the HPT MMU to work on systems with >= 16TB of RAM. - Remove the powerpc "maple" platform, used by the "Yellow Dog Powerstation". - Add support for DYNAMIC_FTRACE_WITH_CALL_OPS, DYNAMIC_FTRACE_WITH_DIRECT_CALLS & BPF Trampolines. - Add support for running KVM nested guests on Power11. - Other small features, cleanups and fixes. Thanks to Amit Machhiwal, Arnd Bergmann, Christophe Leroy, Costa Shulyupin, David Hunter, David Wang, Disha Goel, Gautam Menghani, Geert Uytterhoeven, Hari Bathini, Julia Lawall, Kajol Jain, Keith Packard, Lukas Bulwahn, Madhavan Srinivasan, Markus Elfring, Michal Suchanek, Ming Lei, Mukesh Kumar Chaurasiya, Nathan Chancellor, Naveen N Rao, Nicholas Piggin, Nysal Jan K.A, Paulo Miguel Almeida, Pavithra Prakash, Ritesh Harjani (IBM), Rob Herring (Arm), Sachin P Bappalige, Shen Lichuan, Simon Horman, Sourabh Jain, Thomas Weißschuh, Thorsten Blum, Thorsten Leemhuis, Venkat Rao Bagalkote, Zhang Zekun, and zhang jiao. * tag 'powerpc-6.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (89 commits) EDAC/powerpc: Remove PPC_MAPLE drivers powerpc/perf: Add per-task/process monitoring to vpa_pmu driver powerpc/kvm: Add vpa latency counters to kvm_vcpu_arch docs: ABI: sysfs-bus-event_source-devices-vpa-pmu: Document sysfs event format entries for vpa_pmu powerpc/perf: Add perf interface to expose vpa counters MAINTAINERS: powerpc: Mark Maddy as "M" powerpc/Makefile: Allow overriding CPP powerpc-km82xx.c: replace of_node_put() with __free ps3: Correct some typos in comments powerpc/kexec: Fix return of uninitialized variable macintosh: Use common error handling code in via_pmu_led_init() powerpc/powermac: Use of_property_match_string() in pmac_has_backlight_type() powerpc: remove dead config options for MPC85xx platform support powerpc/xive: Use cpumask_intersects() selftests/powerpc: Remove the path after initialization. powerpc/xmon: symbol lookup length fixed powerpc/ep8248e: Use %pa to format resource_size_t powerpc/ps3: Reorganize kerneldoc parameter names KVM: PPC: Book3S HV: Fix kmv -> kvm typo powerpc/sstep: make emulate_vsx_load and emulate_vsx_store static ...
2024-11-23Merge tag 'mm-stable-2024-11-18-19-27' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mmLinus Torvalds1-0/+8
Pull MM updates from Andrew Morton: - The series "zram: optimal post-processing target selection" from Sergey Senozhatsky improves zram's post-processing selection algorithm. This leads to improved memory savings. - Wei Yang has gone to town on the mapletree code, contributing several series which clean up the implementation: - "refine mas_mab_cp()" - "Reduce the space to be cleared for maple_big_node" - "maple_tree: simplify mas_push_node()" - "Following cleanup after introduce mas_wr_store_type()" - "refine storing null" - The series "selftests/mm: hugetlb_fault_after_madv improvements" from David Hildenbrand fixes this selftest for s390. - The series "introduce pte_offset_map_{ro|rw}_nolock()" from Qi Zheng implements some rationaizations and cleanups in the page mapping code. - The series "mm: optimize shadow entries removal" from Shakeel Butt optimizes the file truncation code by speeding up the handling of shadow entries. - The series "Remove PageKsm()" from Matthew Wilcox completes the migration of this flag over to being a folio-based flag. - The series "Unify hugetlb into arch_get_unmapped_area functions" from Oscar Salvador implements a bunch of consolidations and cleanups in the hugetlb code. - The series "Do not shatter hugezeropage on wp-fault" from Dev Jain takes away the wp-fault time practice of turning a huge zero page into small pages. Instead we replace the whole thing with a THP. More consistent cleaner and potentiall saves a large number of pagefaults. - The series "percpu: Add a test case and fix for clang" from Andy Shevchenko enhances and fixes the kernel's built in percpu test code. - The series "mm/mremap: Remove extra vma tree walk" from Liam Howlett optimizes mremap() by avoiding doing things which we didn't need to do. - The series "Improve the tmpfs large folio read performance" from Baolin Wang teaches tmpfs to copy data into userspace at the folio size rather than as individual pages. A 20% speedup was observed. - The series "mm/damon/vaddr: Fix issue in damon_va_evenly_split_region()" fro Zheng Yejian fixes DAMON splitting. - The series "memcg-v1: fully deprecate charge moving" from Shakeel Butt removes the long-deprecated memcgv2 charge moving feature. - The series "fix error handling in mmap_region() and refactor" from Lorenzo Stoakes cleanup up some of the mmap() error handling and addresses some potential performance issues. - The series "x86/module: use large ROX pages for text allocations" from Mike Rapoport teaches x86 to use large pages for read-only-execute module text. - The series "page allocation tag compression" from Suren Baghdasaryan is followon maintenance work for the new page allocation profiling feature. - The series "page->index removals in mm" from Matthew Wilcox remove most references to page->index in mm/. A slow march towards shrinking struct page. - The series "damon/{self,kunit}tests: minor fixups for DAMON debugfs interface tests" from Andrew Paniakin performs maintenance work for DAMON's self testing code. - The series "mm: zswap swap-out of large folios" from Kanchana Sridhar improves zswap's batching of compression and decompression. It is a step along the way towards using Intel IAA hardware acceleration for this zswap operation. - The series "kasan: migrate the last module test to kunit" from Sabyrzhan Tasbolatov completes the migration of the KASAN built-in tests over to the KUnit framework. - The series "implement lightweight guard pages" from Lorenzo Stoakes permits userapace to place fault-generating guard pages within a single VMA, rather than requiring that multiple VMAs be created for this. Improved efficiencies for userspace memory allocators are expected. - The series "memcg: tracepoint for flushing stats" from JP Kobryn uses tracepoints to provide increased visibility into memcg stats flushing activity. - The series "zram: IDLE flag handling fixes" from Sergey Senozhatsky fixes a zram buglet which potentially affected performance. - The series "mm: add more kernel parameters to control mTHP" from Maíra Canal enhances our ability to control/configuremultisize THP from the kernel boot command line. - The series "kasan: few improvements on kunit tests" from Sabyrzhan Tasbolatov has a couple of fixups for the KASAN KUnit tests. - The series "mm/list_lru: Split list_lru lock into per-cgroup scope" from Kairui Song optimizes list_lru memory utilization when lockdep is enabled. * tag 'mm-stable-2024-11-18-19-27' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (215 commits) cma: enforce non-zero pageblock_order during cma_init_reserved_mem() mm/kfence: add a new kunit test test_use_after_free_read_nofault() zram: fix NULL pointer in comp_algorithm_show() memcg/hugetlb: add hugeTLB counters to memcg vmstat: call fold_vm_zone_numa_events() before show per zone NUMA event mm: mmap_lock: check trace_mmap_lock_$type_enabled() instead of regcount zram: ZRAM_DEF_COMP should depend on ZRAM MAINTAINERS/MEMORY MANAGEMENT: add document files for mm Docs/mm/damon: recommend academic papers to read and/or cite mm: define general function pXd_init() kmemleak: iommu/iova: fix transient kmemleak false positive mm/list_lru: simplify the list_lru walk callback function mm/list_lru: split the lock to per-cgroup scope mm/list_lru: simplify reparenting and initial allocation mm/list_lru: code clean up for reparenting mm/list_lru: don't export list_lru_add mm/list_lru: don't pass unnecessary key parameters kasan: add kunit tests for kmalloc_track_caller, kmalloc_node_track_caller kasan: change kasan_atomics kunit test as KUNIT_CASE_SLOW kasan: use EXPORT_SYMBOL_IF_KUNIT to export symbols ...
2024-11-19Merge tag 'timers-vdso-2024-11-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds1-1/+1
Pull vdso data page handling updates from Thomas Gleixner: "First steps of consolidating the VDSO data page handling. The VDSO data page handling is architecture specific for historical reasons, but there is no real technical reason to do so. Aside of that VDSO data has become a dump ground for various mechanisms and fail to provide a clear separation of the functionalities. Clean this up by: - consolidating the VDSO page data by getting rid of architecture specific warts especially in x86 and PowerPC. - removing the last includes of header files which are pulling in other headers outside of the VDSO namespace. - seperating timekeeping and other VDSO data accordingly. Further consolidation of the VDSO page handling is done in subsequent changes scheduled for the next merge window. This also lays the ground for expanding the VDSO time getters for independent PTP clocks in a generic way without making every architecture add support seperately" * tag 'timers-vdso-2024-11-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (42 commits) x86/vdso: Add missing brackets in switch case vdso: Rename struct arch_vdso_data to arch_vdso_time_data powerpc: Split systemcfg struct definitions out from vdso powerpc: Split systemcfg data out of vdso data page powerpc: Add kconfig option for the systemcfg page powerpc/pseries/lparcfg: Use num_possible_cpus() for potential processors powerpc/pseries/lparcfg: Fix printing of system_active_processors powerpc/procfs: Propagate error of remap_pfn_range() powerpc/vdso: Remove offset comment from 32bit vdso_arch_data x86/vdso: Split virtual clock pages into dedicated mapping x86/vdso: Delete vvar.h x86/vdso: Access vdso data without vvar.h x86/vdso: Move the rng offset to vsyscall.h x86/vdso: Access rng vdso data without vvar.h x86/vdso: Access timens vdso data without vvar.h x86/vdso: Allocate vvar page from C code x86/vdso: Access rng data from kernel without vvar x86/vdso: Place vdso_data at beginning of vvar page x86/vdso: Use __arch_get_vdso_data() to access vdso data x86/mm/mmap: Remove arch_vma_name() ...
2024-11-19Merge tag 'perf-core-2024-11-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds1-0/+1
Pull performance events updates from Ingo Molnar: "Uprobes: - Add BPF session support (Jiri Olsa) - Switch to RCU Tasks Trace flavor for better performance (Andrii Nakryiko) - Massively increase uretprobe SMP scalability by SRCU-protecting the uretprobe lifetime (Andrii Nakryiko) - Kill xol_area->slot_count (Oleg Nesterov) Core facilities: - Implement targeted high-frequency profiling by adding the ability for an event to "pause" or "resume" AUX area tracing (Adrian Hunter) VM profiling/sampling: - Correct perf sampling with guest VMs (Colton Lewis) New hardware support: - x86/intel: Add PMU support for Intel ArrowLake-H CPUs (Dapeng Mi) Misc fixes and enhancements: - x86/intel/pt: Fix buffer full but size is 0 case (Adrian Hunter) - x86/amd: Warn only on new bits set (Breno Leitao) - x86/amd/uncore: Avoid a false positive warning about snprintf truncation in amd_uncore_umc_ctx_init (Jean Delvare) - uprobes: Re-order struct uprobe_task to save some space (Christophe JAILLET) - x86/rapl: Move the pmu allocation out of CPU hotplug (Kan Liang) - x86/rapl: Clean up cpumask and hotplug (Kan Liang) - uprobes: Deuglify xol_get_insn_slot/xol_free_insn_slot paths (Oleg Nesterov)" * tag 'perf-core-2024-11-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (32 commits) perf/core: Correct perf sampling with guest VMs perf/x86: Refactor misc flag assignments perf/powerpc: Use perf_arch_instruction_pointer() perf/core: Hoist perf_instruction_pointer() and perf_misc_flags() perf/arm: Drop unused functions uprobes: Re-order struct uprobe_task to save some space perf/x86/amd/uncore: Avoid a false positive warning about snprintf truncation in amd_uncore_umc_ctx_init perf/x86/intel: Do not enable large PEBS for events with aux actions or aux sampling perf/x86/intel/pt: Add support for pause / resume perf/core: Add aux_pause, aux_resume, aux_start_paused perf/x86/intel/pt: Fix buffer full but size is 0 case uprobes: SRCU-protect uretprobe lifetime (with timeout) uprobes: allow put_uprobe() from non-sleepable softirq context perf/x86/rapl: Clean up cpumask and hotplug perf/x86/rapl: Move the pmu allocation out of CPU hotplug uprobe: Add support for session consumer uprobe: Add data pointer to consumer handlers perf/x86/amd: Warn only on new bits set uprobes: fold xol_take_insn_slot() into xol_get_insn_slot() uprobes: kill xol_area->slot_count ...
2024-11-07execmem: add support for cache of large ROX pagesMike Rapoport (Microsoft)1-0/+8
Using large pages to map text areas reduces iTLB pressure and improves performance. Extend execmem_alloc() with an ability to use huge pages with ROX permissions as a cache for smaller allocations. To populate the cache, a writable large page is allocated from vmalloc with VM_ALLOW_HUGE_VMAP, filled with invalid instructions and then remapped as ROX. The direct map alias of that large page is exculded from the direct map. Portions of that large page are handed out to execmem_alloc() callers without any changes to the permissions. When the memory is freed with execmem_free() it is invalidated again so that it won't contain stale instructions. An architecture has to implement execmem_fill_trapping_insns() callback and select ARCH_HAS_EXECMEM_ROX configuration option to be able to use the ROX cache. The cache is enabled on per-range basis when an architecture sets EXECMEM_ROX_CACHE flag in definition of an execmem_range. Link: https://lkml.kernel.org/r/20241023162711.2579610-8-rppt@kernel.org Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Tested-by: kdevops <kdevops@lists.linux.dev> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Petkov (AMD) <bp@alien8.de> Cc: Brian Cain <bcain@quicinc.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Christoph Hellwig <hch@lst.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Guo Ren <guoren@kernel.org> Cc: Helge Deller <deller@gmx.de> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Cc: Kent Overstreet <kent.overstreet@linux.dev> Cc: Liam R. Howlett <Liam.Howlett@Oracle.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Richard Weinberger <richard@nod.at> Cc: Russell King <linux@armlinux.org.uk> Cc: Song Liu <song@kernel.org> Cc: Stafford Horne <shorne@gmail.com> Cc: Steven Rostedt (Google) <rostedt@goodmis.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Vineet Gupta <vgupta@kernel.org> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-11-06kbuild: Add AutoFDO support for Clang buildRong Xu1-0/+20
Add the build support for using Clang's AutoFDO. Building the kernel with AutoFDO does not reduce the optimization level from the compiler. AutoFDO uses hardware sampling to gather information about the frequency of execution of different code paths within a binary. This information is then used to guide the compiler's optimization decisions, resulting in a more efficient binary. Experiments showed that the kernel can improve up to 10% in latency. The support requires a Clang compiler after LLVM 17. This submission is limited to x86 platforms that support PMU features like LBR on Intel machines and AMD Zen3 BRS. Support for SPE on ARM 1, and BRBE on ARM 1 is part of planned future work. Here is an example workflow for AutoFDO kernel: 1) Build the kernel on the host machine with LLVM enabled, for example, $ make menuconfig LLVM=1 Turn on AutoFDO build config: CONFIG_AUTOFDO_CLANG=y With a configuration that has LLVM enabled, use the following command: scripts/config -e AUTOFDO_CLANG After getting the config, build with $ make LLVM=1 2) Install the kernel on the test machine. 3) Run the load tests. The '-c' option in perf specifies the sample event period. We suggest using a suitable prime number, like 500009, for this purpose. For Intel platforms: $ perf record -e BR_INST_RETIRED.NEAR_TAKEN:k -a -N -b -c <count> \ -o <perf_file> -- <loadtest> For AMD platforms: The supported system are: Zen3 with BRS, or Zen4 with amd_lbr_v2 For Zen3: $ cat proc/cpuinfo | grep " brs" For Zen4: $ cat proc/cpuinfo | grep amd_lbr_v2 $ perf record --pfm-events RETIRED_TAKEN_BRANCH_INSTRUCTIONS:k -a \ -N -b -c <count> -o <perf_file> -- <loadtest> 4) (Optional) Download the raw perf file to the host machine. 5) To generate an AutoFDO profile, two offline tools are available: create_llvm_prof and llvm_profgen. The create_llvm_prof tool is part of the AutoFDO project and can be found on GitHub (https://github.com/google/autofdo), version v0.30.1 or later. The llvm_profgen tool is included in the LLVM compiler itself. It's important to note that the version of llvm_profgen doesn't need to match the version of Clang. It needs to be the LLVM 19 release or later, or from the LLVM trunk. $ llvm-profgen --kernel --binary=<vmlinux> --perfdata=<perf_file> \ -o <profile_file> or $ create_llvm_prof --binary=<vmlinux> --profile=<perf_file> \ --format=extbinary --out=<profile_file> Note that multiple AutoFDO profile files can be merged into one via: $ llvm-profdata merge -o <profile_file> <profile_1> ... <profile_n> 6) Rebuild the kernel using the AutoFDO profile file with the same config as step 1, (Note CONFIG_AUTOFDO_CLANG needs to be enabled): $ make LLVM=1 CLANG_AUTOFDO_PROFILE=<profile_file> Co-developed-by: Han Shen <shenhan@google.com> Signed-off-by: Han Shen <shenhan@google.com> Signed-off-by: Rong Xu <xur@google.com> Suggested-by: Sriraman Tallam <tmsriram@google.com> Suggested-by: Krzysztof Pszeniczny <kpszeniczny@google.com> Suggested-by: Nick Desaulniers <ndesaulniers@google.com> Suggested-by: Stephane Eranian <eranian@google.com> Tested-by: Yonghong Song <yonghong.song@linux.dev> Tested-by: Yabin Cui <yabinc@google.com> Tested-by: Nathan Chancellor <nathan@kernel.org> Reviewed-by: Kees Cook <kees@kernel.org> Tested-by: Peter Jung <ptr1337@cachyos.org> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-11-02vdso: Rename struct arch_vdso_data to arch_vdso_time_dataNam Cao1-1/+1
The struct arch_vdso_data is only about vdso time data. So rename it to arch_vdso_time_data to make it obvious. Non time-related data will be migrated out of these structs soon. Signed-off-by: Nam Cao <namcao@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Heiko Carstens <hca@linux.ibm.com> # s390 Link: https://lore.kernel.org/all/20241010-vdso-generic-base-v1-28-b64f0842d512@linutronix.de
2024-10-31kbuild: Add generic hook for architectures to use before the final vmlinux linkNaveen N Rao1-0/+6
On powerpc, we would like to be able to make a pass on vmlinux.o and generate a new object file to be linked into vmlinux. Add a generic pass in Makefile.vmlinux that architectures can use for this purpose. Architectures need to select CONFIG_ARCH_WANTS_PRE_LINK_VMLINUX and must provide arch/<arch>/tools/Makefile with .arch.vmlinux.o target, which will be invoked prior to the final vmlinux link step. Acked-by: Masahiro Yamada <masahiroy@kernel.org> Signed-off-by: Naveen N Rao <naveen@kernel.org> Signed-off-by: Hari Bathini <hbathini@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://patch.msgid.link/20241030070850.1361304-12-hbathini@linux.ibm.com
2024-10-31cfi: tweak llvm version for HAVE_CFI_ICALL_NORMALIZE_INTEGERSAlice Ryhl1-2/+2
The llvm fix [1] did not make it for 19.0.0, but ended up getting backported to llvm 19.1.3 [2]. Thus, fix the version requirement to correctly specify which versions have the bug. Link: https://github.com/llvm/llvm-project/pull/104826 [1] Link: https://github.com/llvm/llvm-project/pull/113938 [2] Reported-by: kernel test robot <oliver.sang@intel.com> Closes: https://lore.kernel.org/oe-lkp/202410281414.c351044e-oliver.sang@intel.com Fixes: 8b8ca9c25fe6 ("cfi: fix conditions for HAVE_CFI_ICALL_NORMALIZE_INTEGERS") Signed-off-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Sami Tolvanen <samitolvanen@google.com> Link: https://lore.kernel.org/r/20241030-cfi-icall-1913-v1-1-ab8a26e13733@google.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-10-13cfi: fix conditions for HAVE_CFI_ICALL_NORMALIZE_INTEGERSAlice Ryhl1-14/+12
The HAVE_CFI_ICALL_NORMALIZE_INTEGERS option has some tricky conditions when KASAN or GCOV are turned on, as in that case we need some clang and rustc fixes [1][2] to avoid boot failures. The intent with the current setup is that you should be able to override the check and turn on the option if your clang/rustc has the fix. However, this override does not work in practice. Thus, use the new RUSTC_LLVM_VERSION to correctly implement the check for whether the fix is available. Additionally, remove KASAN_HW_TAGS from the list of incompatible options. The CFI_ICALL_NORMALIZE_INTEGERS option is incompatible with KASAN because LLVM will emit some constructors when using KASAN that are assigned incorrect CFI tags. These constructors are emitted due to use of -fsanitize=kernel-address or -fsanitize=kernel-hwaddress that are respectively passed when KASAN_GENERIC or KASAN_SW_TAGS are enabled. However, the KASAN_HW_TAGS option relies on hardware support for MTE instead and does not pass either flag. (Note also that KASAN_HW_TAGS does not `select CONSTRUCTORS`.) Link: https://github.com/llvm/llvm-project/pull/104826 [1] Link: https://github.com/rust-lang/rust/pull/129373 [2] Fixes: 4c66f8307ac0 ("cfi: encode cfi normalized integers + kasan/gcov bug in Kconfig") Signed-off-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Sami Tolvanen <samitolvanen@google.com> Link: https://lore.kernel.org/r/20241010-icall-detect-vers-v1-2-8f114956aa88@google.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-10-07uprobes: switch to RCU Tasks Trace flavor for better performanceAndrii Nakryiko1-0/+1
This patch switches uprobes SRCU usage to RCU Tasks Trace flavor, which is optimized for more lightweight and quick readers (at the expense of slower writers, which for uprobes is a fine tradeof) and has better performance and scalability with number of CPUs. Similarly to baseline vs SRCU, we've benchmarked SRCU-based implementation vs RCU Tasks Trace implementation. SRCU ==== uprobe-nop ( 1 cpus): 3.276 ± 0.005M/s ( 3.276M/s/cpu) uprobe-nop ( 2 cpus): 4.125 ± 0.002M/s ( 2.063M/s/cpu) uprobe-nop ( 4 cpus): 7.713 ± 0.002M/s ( 1.928M/s/cpu) uprobe-nop ( 8 cpus): 8.097 ± 0.006M/s ( 1.012M/s/cpu) uprobe-nop (16 cpus): 6.501 ± 0.056M/s ( 0.406M/s/cpu) uprobe-nop (32 cpus): 4.398 ± 0.084M/s ( 0.137M/s/cpu) uprobe-nop (64 cpus): 6.452 ± 0.000M/s ( 0.101M/s/cpu) uretprobe-nop ( 1 cpus): 2.055 ± 0.001M/s ( 2.055M/s/cpu) uretprobe-nop ( 2 cpus): 2.677 ± 0.000M/s ( 1.339M/s/cpu) uretprobe-nop ( 4 cpus): 4.561 ± 0.003M/s ( 1.140M/s/cpu) uretprobe-nop ( 8 cpus): 5.291 ± 0.002M/s ( 0.661M/s/cpu) uretprobe-nop (16 cpus): 5.065 ± 0.019M/s ( 0.317M/s/cpu) uretprobe-nop (32 cpus): 3.622 ± 0.003M/s ( 0.113M/s/cpu) uretprobe-nop (64 cpus): 3.723 ± 0.002M/s ( 0.058M/s/cpu) RCU Tasks Trace =============== uprobe-nop ( 1 cpus): 3.396 ± 0.002M/s ( 3.396M/s/cpu) uprobe-nop ( 2 cpus): 4.271 ± 0.006M/s ( 2.135M/s/cpu) uprobe-nop ( 4 cpus): 8.499 ± 0.015M/s ( 2.125M/s/cpu) uprobe-nop ( 8 cpus): 10.355 ± 0.028M/s ( 1.294M/s/cpu) uprobe-nop (16 cpus): 7.615 ± 0.099M/s ( 0.476M/s/cpu) uprobe-nop (32 cpus): 4.430 ± 0.007M/s ( 0.138M/s/cpu) uprobe-nop (64 cpus): 6.887 ± 0.020M/s ( 0.108M/s/cpu) uretprobe-nop ( 1 cpus): 2.174 ± 0.001M/s ( 2.174M/s/cpu) uretprobe-nop ( 2 cpus): 2.853 ± 0.001M/s ( 1.426M/s/cpu) uretprobe-nop ( 4 cpus): 4.913 ± 0.002M/s ( 1.228M/s/cpu) uretprobe-nop ( 8 cpus): 5.883 ± 0.002M/s ( 0.735M/s/cpu) uretprobe-nop (16 cpus): 5.147 ± 0.001M/s ( 0.322M/s/cpu) uretprobe-nop (32 cpus): 3.738 ± 0.008M/s ( 0.117M/s/cpu) uretprobe-nop (64 cpus): 4.397 ± 0.002M/s ( 0.069M/s/cpu) Peak throughput for uprobes increases from 8 mln/s to 10.3 mln/s (+28%!), and for uretprobes from 5.3 mln/s to 5.8 mln/s (+11%), as we have more work to do on uretprobes side. Even single-thread (no contention) performance is slightly better: 3.276 mln/s to 3.396 mln/s (+3.5%) for uprobes, and 2.055 mln/s to 2.174 mln/s (+5.8%) for uretprobes. We also select TASKS_TRACE_RCU for UPROBES in Kconfig due to the new dependency. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Link: https://lkml.kernel.org/r/20240910174312.3646590-1-andrii@kernel.org
2024-09-26cfi: encode cfi normalized integers + kasan/gcov bug in KconfigAlice Ryhl1-1/+17
There is a bug in the LLVM implementation of KASAN and GCOV that makes these options incompatible with the CFI_ICALL_NORMALIZE_INTEGERS option. The bug has already been fixed in llvm/clang [1] and rustc [2]. However, Kconfig currently has no way to gate features on the LLVM version inside rustc, so we cannot write down a precise `depends on` clause in this case. Instead, a `def_bool` option is defined for whether CFI_ICALL_NORMALIZE_INTEGERS is available, and its default value is set to false when GCOV or KASAN are turned on. End users using a patched clang/rustc can turn on the HAVE_CFI_ICALL_NORMALIZE_INTEGERS option directly to override this. An alternative solution is to inspect a binary created by clang or rustc to see whether the faulty CFI tags are in the binary. This would be a precise check, but it would involve hard-coding the *hashed* version of the CFI tag. This is because there's no way to get clang or rustc to output the unhased version of the CFI tag. Relying on the precise hashing algorithm using by CFI seems too fragile, so I have not pursued this option. Besides, this kind of hack is exactly what lead to the LLVM bug in the first place. If the CFI_ICALL_NORMALIZE_INTEGERS option is used without CONFIG_RUST, then we actually can perform a precise check today: just compare the clang version number. This works since clang and llvm are always updated in lockstep. However, encoding this in Kconfig would give the HAVE_CFI_ICALL_NORMALIZE_INTEGERS option a dependency on CONFIG_RUST, which is not possible as the reverse dependency already exists. HAVE_CFI_ICALL_NORMALIZE_INTEGERS is defined to be a `def_bool` instead of `bool` to avoid asking end users whether they want to turn on the option. Turning it on explicitly is something only experts should do, so making it hard to do so is not an issue. I added a `depends on CFI_CLANG` clause to the new Kconfig option. I'm not sure whether that makes sense or not, but it doesn't seem to make a big difference. In a future kernel release, I would like to add a Kconfig option similar to CLANG_VERSION/RUSTC_VERSION for inspecting the version of the LLVM inside rustc. Once that feature lands, this logic will be replaced with a precise version check. This check is not being introduced here to avoid introducing a new _VERSION constant in a fix. Link: https://github.com/llvm/llvm-project/pull/104826 [1] Link: https://github.com/rust-lang/rust/pull/129373 [2] Fixes: ce4a2620985c ("cfi: add CONFIG_CFI_ICALL_NORMALIZE_INTEGERS") Reported-by: kernel test robot <oliver.sang@intel.com> Closes: https://lore.kernel.org/oe-lkp/202409231044.4f064459-oliver.sang@intel.com Signed-off-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Sami Tolvanen <samitolvanen@google.com> Link: https://lore.kernel.org/r/20240925-cfi-norm-kasan-fix-v1-1-0328985cdf33@google.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-09-25Merge tag 'rust-6.12' of https://github.com/Rust-for-Linux/linuxLinus Torvalds1-0/+16
Pull Rust updates from Miguel Ojeda: "Toolchain and infrastructure: - Support 'MITIGATION_{RETHUNK,RETPOLINE,SLS}' (which cleans up objtool warnings), teach objtool about 'noreturn' Rust symbols and mimic '___ADDRESSABLE()' for 'module_{init,exit}'. With that, we should be objtool-warning-free, so enable it to run for all Rust object files. - KASAN (no 'SW_TAGS'), KCFI and shadow call sanitizer support. - Support 'RUSTC_VERSION', including re-config and re-build on change. - Split helpers file into several files in a folder, to avoid conflicts in it. Eventually those files will be moved to the right places with the new build system. In addition, remove the need to manually export the symbols defined there, reusing existing machinery for that. - Relax restriction on configurations with Rust + GCC plugins to just the RANDSTRUCT plugin. 'kernel' crate: - New 'list' module: doubly-linked linked list for use with reference counted values, which is heavily used by the upcoming Rust Binder. This includes 'ListArc' (a wrapper around 'Arc' that is guaranteed unique for the given ID), 'AtomicTracker' (tracks whether a 'ListArc' exists using an atomic), 'ListLinks' (the prev/next pointers for an item in a linked list), 'List' (the linked list itself), 'Iter' (an iterator over a 'List'), 'Cursor' (a cursor into a 'List' that allows to remove elements), 'ListArcField' (a field exclusively owned by a 'ListArc'), as well as support for heterogeneous lists. - New 'rbtree' module: red-black tree abstractions used by the upcoming Rust Binder. This includes 'RBTree' (the red-black tree itself), 'RBTreeNode' (a node), 'RBTreeNodeReservation' (a memory reservation for a node), 'Iter' and 'IterMut' (immutable and mutable iterators), 'Cursor' (bidirectional cursor that allows to remove elements), as well as an entry API similar to the Rust standard library one. - 'init' module: add 'write_[pin_]init' methods and the 'InPlaceWrite' trait. Add the 'assert_pinned!' macro. - 'sync' module: implement the 'InPlaceInit' trait for 'Arc' by introducing an associated type in the trait. - 'alloc' module: add 'drop_contents' method to 'BoxExt'. - 'types' module: implement the 'ForeignOwnable' trait for 'Pin<Box<T>>' and improve the trait's documentation. In addition, add the 'into_raw' method to the 'ARef' type. - 'error' module: in preparation for the upcoming Rust support for 32-bit architectures, like arm, locally allow Clippy lint for those. Documentation: - https://rust.docs.kernel.org has been announced, so link to it. - Enable rustdoc's "jump to definition" feature, making its output a bit closer to the experience in a cross-referencer. - Debian Testing now also provides recent Rust releases (outside of the freeze period), so add it to the list. MAINTAINERS: - Trevor is joining as reviewer of the "RUST" entry. And a few other small bits" * tag 'rust-6.12' of https://github.com/Rust-for-Linux/linux: (54 commits) kasan: rust: Add KASAN smoke test via UAF kbuild: rust: Enable KASAN support rust: kasan: Rust does not support KHWASAN kbuild: rust: Define probing macros for rustc kasan: simplify and clarify Makefile rust: cfi: add support for CFI_CLANG with Rust cfi: add CONFIG_CFI_ICALL_NORMALIZE_INTEGERS rust: support for shadow call stack sanitizer docs: rust: include other expressions in conditional compilation section kbuild: rust: replace proc macros dependency on `core.o` with the version text kbuild: rust: rebuild if the version text changes kbuild: rust: re-run Kconfig if the version text changes kbuild: rust: add `CONFIG_RUSTC_VERSION` rust: avoid `box_uninit_write` feature MAINTAINERS: add Trevor Gross as Rust reviewer rust: rbtree: add `RBTree::entry` rust: rbtree: add cursor rust: rbtree: add mutable iterator rust: rbtree: add iterator rust: rbtree: add red-black tree implementation backed by the C version ...
2024-09-19Merge tag 'dma-mapping-6.12-2024-09-19' of git://git.infradead.org/users/hch/dma-mappingLinus Torvalds1-0/+9
Pull dma-mapping updates from Christoph Hellwig: - support DMA zones for arm64 systems where memory starts at > 4GB (Baruch Siach, Catalin Marinas) - support direct calls into dma-iommu and thus obsolete dma_map_ops for many common configurations (Leon Romanovsky) - add DMA-API tracing (Sean Anderson) - remove the not very useful return value from various dma_set_* APIs (Christoph Hellwig) - misc cleanups and minor optimizations (Chen Y, Yosry Ahmed, Christoph Hellwig) * tag 'dma-mapping-6.12-2024-09-19' of git://git.infradead.org/users/hch/dma-mapping: dma-mapping: reflow dma_supported dma-mapping: reliably inform about DMA support for IOMMU dma-mapping: add tracing for dma-mapping API calls dma-mapping: use IOMMU DMA calls for common alloc/free page calls dma-direct: optimize page freeing when it is not addressable dma-mapping: clearly mark DMA ops as an architecture feature vdpa_sim: don't select DMA_OPS arm64: mm: keep low RAM dma zone dma-mapping: don't return errors from dma_set_max_seg_size dma-mapping: don't return errors from dma_set_seg_boundary dma-mapping: don't return errors from dma_set_min_align_mask scsi: check that busses support the DMA API before setting dma parameters arm64: mm: fix DMA zone when dma-ranges is missing dma-mapping: direct calls for dma-iommu dma-mapping: call ->unmap_page and ->unmap_sg unconditionally arm64: support DMA zone above 4GB dma-mapping: replace zone_dma_bits by zone_dma_limit dma-mapping: use bit masking to check VM_DMA_COHERENT
2024-09-13cfi: add CONFIG_CFI_ICALL_NORMALIZE_INTEGERSAlice Ryhl1-0/+16
Introduce a Kconfig option for enabling the experimental option to normalize integer types. This ensures that integer types of the same size and signedness are considered compatible by the Control Flow Integrity sanitizer. The security impact of this flag is minimal. When Sami Tolvanen looked into it, he found that integer normalization reduced the number of unique type hashes in the kernel by ~1%, which is acceptable. This option exists for compatibility with Rust, as C and Rust do not have the same set of integer types. There are cases where C has two different integer types of the same size and signedness, but Rust only has one integer type of that size and signedness. When Rust calls into C functions using such types in their signature, this results in CFI failures. One example is 'unsigned long long' and 'unsigned long' which are both 64-bit on LP64 targets, so on those targets this flag will give both types the same CFI tag. This flag changes the ABI heavily. It is not applied automatically when CONFIG_RUST is turned on to make sure that the CONFIG_RUST option does not change the ABI of C code. For example, some build may need to make other changes atomically with toggling this flag. Having it be a separate option makes it possible to first turn on normalized integer tags, and then later turn on CONFIG_RUST. Similarly, when turning on CONFIG_RUST in a build, you may need a few attempts where the RUST=y commit gets reverted a few times. It is inconvenient if reverting RUST=y also requires reverting the changes you made to support normalized integer tags. To avoid having this flag impact builds that don't care about this, the next patch in this series will make CONFIG_RUST turn on this option using `select` rather than `depends on`. Signed-off-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Sami Tolvanen <samitolvanen@google.com> Tested-by: Gatlin Newhouse <gatlin.newhouse@gmail.com> Acked-by: Kees Cook <kees@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20240801-kcfi-v2-1-c93caed3d121@google.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-09-04dma-mapping: clearly mark DMA ops as an architecture featureChristoph Hellwig1-0/+9
DMA ops are a helper for architectures and not for drivers to override the DMA implementation. Unfortunately driver authors keep ignoring this. Make the fact more clear by renaming the symbol to ARCH_HAS_DMA_OPS and having the two drivers overriding their dma_ops depend on that. These drivers should probably be marked broken, but we can give them a bit of a grace period for that. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com> # for IPU6 Acked-by: Robin Murphy <robin.murphy@arm.com>
2024-07-29treewide: context_tracking: Rename CONTEXT_* into CT_STATE_*Valentin Schneider1-1/+1
Context tracking state related symbols currently use a mix of the CONTEXT_ (e.g. CONTEXT_KERNEL) and CT_SATE_ (e.g. CT_STATE_MASK) prefixes. Clean up the naming and make the ctx_state enum use the CT_STATE_ prefix. Suggested-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Valentin Schneider <vschneid@redhat.com> Acked-by: Frederic Weisbecker <frederic@kernel.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Neeraj Upadhyay <neeraj.upadhyay@kernel.org>
2024-06-17Revert "mm: mmap: allow for the maximum number of bits for randomizing mmap_base by default"Linus Torvalds1-12/+0
This reverts commit 3afb76a66b5559a7b595155803ce23801558a7a9. This was a wrongheaded workaround for an issue that had already been fixed much better by commit 4ef9ad19e176 ("mm: huge_memory: don't force huge page alignment on 32 bit"). Asking users questions at kernel compile time that they can't make sense of is not a viable strategy. And the fact that even the kernel VM maintainers apparently didn't catch that this "fix" is not a fix any more pretty much proves the point that people can't be expected to understand the implications of the question. It may well be the case that we could improve things further, and that __thp_get_unmapped_area() should take the mapping randomization into account even for 64-bit kernels. Maybe we should not be so eager to use THP mappings. But in no case should this be a kernel config option. Cc: Rafael Aquini <aquini@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Jiri Slaby <jirislaby@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2024-06-15mm: mmap: allow for the maximum number of bits for randomizing mmap_base by defaultRafael Aquini1-0/+12
An ASLR regression was noticed [1] and tracked down to file-mapped areas being backed by THP in recent kernels. The 21-bit alignment constraint for such mappings reduces the entropy for randomizing the placement of 64-bit library mappings and breaks ASLR completely for 32-bit libraries. The reported issue is easily addressed by increasing vm.mmap_rnd_bits and vm.mmap_rnd_compat_bits. This patch just provides a simple way to set ARCH_MMAP_RND_BITS and ARCH_MMAP_RND_COMPAT_BITS to their maximum values allowed by the architecture at build time. [1] https://zolutal.github.io/aslrnt/ [akpm@linux-foundation.org: default to `y' if 32-bit, per Rafael] Link: https://lkml.kernel.org/r/20240606180622.102099-1-aquini@redhat.com Fixes: 1854bc6e2420 ("mm/readahead: Align file mappings for non-DAX") Signed-off-by: Rafael Aquini <aquini@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Petr Mladek <pmladek@suse.com> Cc: Samuel Holland <samuel.holland@sifive.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-19arch: add ARCH_HAS_KERNEL_FPU_SUPPORTSamuel Holland1-0/+6
Several architectures provide an API to enable the FPU and run floating-point SIMD code in kernel space. However, the function names, header locations, and semantics are inconsistent across architectures, and FPU support may be gated behind other Kconfig options. provide a standard way for architectures to declare that kernel space FPU support is available. Architectures selecting this option must implement what is currently the most common API (kernel_fpu_begin() and kernel_fpu_end(), plus a new function kernel_fpu_available()) and provide the appropriate CFLAGS for compiling floating-point C code. Link: https://lkml.kernel.org/r/20240329072441.591471-2-samuel.holland@sifive.com Signed-off-by: Samuel Holland <samuel.holland@sifive.com> Suggested-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: Christian König <christian.koenig@amd.com> Cc: Alex Deucher <alexander.deucher@amd.com> Cc: Borislav Petkov (AMD) <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Masahiro Yamada <masahiroy@kernel.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nathan Chancellor <nathan@kernel.org> Cc: Nicolas Schier <nicolas@fjasle.eu> Cc: Palmer Dabbelt <palmer@rivosinc.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: WANG Xuerui <git@xen0n.name> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-14kprobes: remove dependency on CONFIG_MODULESMike Rapoport (IBM)1-1/+1
kprobes depended on CONFIG_MODULES because it has to allocate memory for code. Since code allocations are now implemented with execmem, kprobes can be enabled in non-modular kernels. Add #ifdef CONFIG_MODULE guards for the code dealing with kprobes inside modules, make CONFIG_KPROBES select CONFIG_EXECMEM and drop the dependency of CONFIG_KPROBES on CONFIG_MODULES. Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> [mcgrof: rebase in light of NEED_TASKS_RCU ] Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2024-05-14mm/execmem, arch: convert remaining overrides of module_alloc to execmemMike Rapoport (IBM)1-0/+8
Extend execmem parameters to accommodate more complex overrides of module_alloc() by architectures. This includes specification of a fallback range required by arm, arm64 and powerpc, EXECMEM_MODULE_DATA type required by powerpc, support for allocation of KASAN shadow required by s390 and x86 and support for late initialization of execmem required by arm64. The core implementation of execmem_alloc() takes care of suppressing warnings when the initial allocation fails but there is a fallback range defined. Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org> Acked-by: Will Deacon <will@kernel.org> Acked-by: Song Liu <song@kernel.org> Tested-by: Liviu Dudau <liviu@dudau.co.uk> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2024-05-13Merge tag 'execve-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linuxLinus Torvalds1-0/+9
Pull execve updates from Kees Cook: - Provide knob to change (previously fixed) coredump NOTES size (Allen Pais) - Add sched_prepare_exec tracepoint (Marco Elver) - Make /proc/$pid/auxv work under binfmt_elf_fdpic (Max Filippov) - Convert ARCH_HAVE_EXTRA_ELF_NOTES to proper Kconfig (Vignesh Balasubramanian) - Leave a gap between .bss and brk * tag 'execve-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: fs/coredump: Enable dynamic configuration of max file note size binfmt_elf_fdpic: fix /proc/<pid>/auxv binfmt_elf: Leave a gap between .bss and brk Replace macro "ARCH_HAVE_EXTRA_ELF_NOTES" with kconfig tracing: Add sched_prepare_exec tracepoint
2024-05-13Merge tag 'cmpxchg.2024.05.11a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcuLinus Torvalds1-0/+3
Pull cmpxchg updates from Paul McKenney: "Provide one-byte and two-byte cmpxchg() support on sparc32, parisc, and csky This provides native one-byte and two-byte cmpxchg() support for sparc32 and parisc, courtesy of Al Viro. This support is provided by the same hashed-array-of-locks technique used for the other atomic operations provided for these two platforms. There is also emulated one-byte cmpxchg() support for csky using a new cmpxchg_emu_u8() function that uses a four-byte cmpxchg() to emulate the one-byte variant. Similar patches for emulation of one-byte cmpxchg() for arc, sh, and xtensa have not yet received maintainer acks, so they are slated for the v6.11 merge window" * tag 'cmpxchg.2024.05.11a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu: csky: Emulate one-byte cmpxchg lib: Add one-byte emulation function parisc: add u16 support to cmpxchg() parisc: add missing export of __cmpxchg_u8() parisc: unify implementations of __cmpxchg_u{8,32,64} parisc: __cmpxchg_u32(): lift conversion into the callers sparc32: add __cmpxchg_u{8,16}() and teach __cmpxchg() to handle those sizes sparc32: unify __cmpxchg_u{32,64} sparc32: make the first argument of __cmpxchg_u64() volatile u64 * sparc32: make __cmpxchg_u32() return u32
2024-05-13Merge tag 'rcu.next.v6.10' of https://github.com/urezki/linuxLinus Torvalds1-2/+2
Pull RCU updates from Uladzislau Rezki: - Fix a lockdep complain for lazy-preemptible kernel, remove redundant BH disable for TINY_RCU, remove redundant READ_ONCE() in tree.c, fix false positives KCSAN splat and fix buffer overflow in the print_cpu_stall_info(). - Misc updates related to bpf, tracing and update the MAINTAINERS file. - An improvement of a normal synchronize_rcu() call in terms of latency. It maintains a separate track for sync. users only. This approach bypasses per-cpu nocb-lists thus sync-users do not depend on nocb-list length and how fast regular callbacks are processed. - RCU tasks: switch tasks RCU grace periods to sleep at TASK_IDLE priority, fix some comments, add some diagnostic warning to the exit_tasks_rcu_start() and fix a buffer overflow in the show_rcu_tasks_trace_gp_kthread(). - RCU torture: Increase memory to guest OS, fix a Tasks Rude RCU testing, some updates for TREE09, dump mode information to debug GP kthread state, remove redundant READ_ONCE(), fix some comments about RCU_TORTURE_PIPE_LEN and pipe_count, remove some redundant pointer initialization, fix a hung splat task by when the rcutorture tests start to exit, fix invalid context warning, add '--do-kvfree' parameter to torture test and use slow register unregister callbacks only for rcutype test. * tag 'rcu.next.v6.10' of https://github.com/urezki/linux: (48 commits) rcutorture: Use rcu_gp_slow_register/unregister() only for rcutype test torture: Scale --do-kvfree test time rcutorture: Fix invalid context warning when enable srcu barrier testing rcutorture: Make stall-tasks directly exit when rcutorture tests end rcutorture: Removing redundant function pointer initialization rcutorture: Make rcutorture support print rcu-tasks gp state rcutorture: Use the gp_kthread_dbg operation specified by cur_ops rcutorture: Re-use value stored to ->rtort_pipe_count instead of re-reading rcutorture: Fix rcu_torture_one_read() pipe_count overflow comment rcutorture: Remove extraneous rcu_torture_pipe_update_one() READ_ONCE() rcu: Allocate WQ with WQ_MEM_RECLAIM bit set rcu: Support direct wake-up of synchronize_rcu() users rcu: Add a trace event for synchronize_rcu_normal() rcu: Reduce synchronize_rcu() latency rcu: Fix buffer overflow in print_cpu_stall_info() rcu: Mollify sparse with RCU guard rcu-tasks: Fix show_rcu_tasks_trace_gp_kthread buffer overflow rcu-tasks: Fix the comments for tasks_rcu_exit_srcu_stall_timer rcu-tasks: Replace exit_tasks_rcu_start() initialization with WARN_ON_ONCE() rcu: Remove redundant CONFIG_PROVE_RCU #if condition ...