aboutsummaryrefslogtreecommitdiff
path: root/arch/sh/kernel
AgeCommit message (Collapse)AuthorFilesLines
3 daystreewide: Update email addressThomas Gleixner1-1/+1
In a vain attempt to consolidate the email zoo switch everything to the kernel.org account. Signed-off-by: Thomas Gleixner <tglx@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2025-11-03arch: hookup listns() system callChristian Brauner1-0/+1
Add the listns() system call to all architectures. Link: https://patch.msgid.link/20251029-work-namespace-nstree-listns-v4-20-2e6f823ebdc0@kernel.org Tested-by: syzbot@syzkaller.appspotmail.com Reviewed-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-09-30Merge tag 'sched-core-2025-09-26' of ↵Linus Torvalds1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 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()
2025-09-25arch: Add the macro COMPILE_OFFSETS to all the asm-offsets.cMenglong Dong1-0/+1
The include/generated/asm-offsets.h is generated in Kbuild during compiling from arch/SRCARCH/kernel/asm-offsets.c. When we want to generate another similar offset header file, circular dependency can happen. For example, we want to generate a offset file include/generated/test.h, which is included in include/sched/sched.h. If we generate asm-offsets.h first, it will fail, as include/sched/sched.h is included in asm-offsets.c and include/generated/test.h doesn't exist; If we generate test.h first, it can't success neither, as include/generated/asm-offsets.h is included by it. In x86_64, the macro COMPILE_OFFSETS is used to avoid such circular dependency. We can generate asm-offsets.h first, and if the COMPILE_OFFSETS is defined, we don't include the "generated/test.h". And we define the macro COMPILE_OFFSETS for all the asm-offsets.c for this purpose. Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2025-09-01arch: copy_thread: pass clone_flags as u64Simon Schuster1-1/+1
With the introduction of clone3 in commit 7f192e3cd316 ("fork: add clone3") the effective bit width of clone_flags on all architectures was increased from 32-bit to 64-bit, with a new type of u64 for the flags. However, for most consumers of clone_flags the interface was not changed from the previous type of unsigned long. While this works fine as long as none of the new 64-bit flag bits (CLONE_CLEAR_SIGHAND and CLONE_INTO_CGROUP) are evaluated, this is still undesirable in terms of the principle of least surprise. Thus, this commit fixes all relevant interfaces of the copy_thread function that is called from copy_process to consistently pass clone_flags as u64, so that no truncation to 32-bit integers occurs on 32-bit architectures. Signed-off-by: Simon Schuster <schuster.simon@siemens-energy.com> Link: https://lore.kernel.org/20250901-nios2-implement-clone3-v2-3-53fcf5577d57@siemens-energy.com Fixes: c5febea0956fd387 ("fork: Pass struct kernel_clone_args into copy_thread") Acked-by: Guo Ren (Alibaba Damo Academy) <guoren@kernel.org> Acked-by: Andreas Larsson <andreas@gaisler.com> # sparc Acked-by: David Hildenbrand <david@redhat.com> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> # m68k Reviewed-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-08-03Merge tag 'mm-nonmm-stable-2025-08-03-12-47' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull non-MM updates from Andrew Morton: "Significant patch series in this pull request: - "squashfs: Remove page->mapping references" (Matthew Wilcox) gets us closer to being able to remove page->mapping - "relayfs: misc changes" (Jason Xing) does some maintenance and minor feature addition work in relayfs - "kdump: crashkernel reservation from CMA" (Jiri Bohac) switches us from static preallocation of the kdump crashkernel's working memory over to dynamic allocation. So the difficulty of a-priori estimation of the second kernel's needs is removed and the first kernel obtains extra memory - "generalize panic_print's dump function to be used by other kernel parts" (Feng Tang) implements some consolidation and rationalization of the various ways in which a failing kernel splats information at the operator * tag 'mm-nonmm-stable-2025-08-03-12-47' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (80 commits) tools/getdelays: add backward compatibility for taskstats version kho: add test for kexec handover delaytop: enhance error logging and add PSI feature description samples: Kconfig: fix spelling mistake "instancess" -> "instances" fat: fix too many log in fat_chain_add() scripts/spelling.txt: add notifer||notifier to spelling.txt xen/xenbus: fix typo "notifer" net: mvneta: fix typo "notifer" drm/xe: fix typo "notifer" cxl: mce: fix typo "notifer" KVM: x86: fix typo "notifer" MAINTAINERS: add maintainers for delaytop ucount: use atomic_long_try_cmpxchg() in atomic_long_inc_below() ucount: fix atomic_long_inc_below() argument type kexec: enable CMA based contiguous allocation stackdepot: make max number of pools boot-time configurable lib/xxhash: remove unused functions init/Kconfig: restore CONFIG_BROKEN help text lib/raid6: update recov_rvv.c zero page usage docs: update docs after introducing delaytop ...
2025-07-28Merge tag 'execve-v6.17' of ↵Linus Torvalds1-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull execve updates from Kees Cook: - Introduce regular REGSET note macros arch-wide (Dave Martin) - Remove arbitrary 4K limitation of program header size (Yin Fengwei) - Reorder function qualifiers for copy_clone_args_from_user() (Dishank Jogi) * tag 'execve-v6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (25 commits) fork: reorder function qualifiers for copy_clone_args_from_user binfmt_elf: remove the 4k limitation of program header size binfmt_elf: Warn on missing or suspicious regset note names xtensa: ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note names um: ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note names x86/ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note names sparc: ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note names sh: ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note names s390/ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note names riscv: ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note names powerpc/ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note names parisc: ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note names openrisc: ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note names nios2: ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note names MIPS: ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note names m68k: ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note names LoongArch: ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note names hexagon: ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note names csky: ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note names arm64: ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note names ...
2025-07-19Add a new optional ",cma" suffix to the crashkernel= command line optionJiri Bohac1-1/+1
Patch series "kdump: crashkernel reservation from CMA", v5. This series implements a way to reserve additional crash kernel memory using CMA. Currently, all the memory for the crash kernel is not usable by the 1st (production) kernel. It is also unmapped so that it can't be corrupted by the fault that will eventually trigger the crash. This makes sense for the memory actually used by the kexec-loaded crash kernel image and initrd and the data prepared during the load (vmcoreinfo, ...). However, the reserved space needs to be much larger than that to provide enough run-time memory for the crash kernel and the kdump userspace. Estimating the amount of memory to reserve is difficult. Being too careful makes kdump likely to end in OOM, being too generous takes even more memory from the production system. Also, the reservation only allows reserving a single contiguous block (or two with the "low" suffix). I've seen systems where this fails because the physical memory is fragmented. By reserving additional crashkernel memory from CMA, the main crashkernel reservation can be just large enough to fit the kernel and initrd image, minimizing the memory taken away from the production system. Most of the run-time memory for the crash kernel will be memory previously available to userspace in the production system. As this memory is no longer wasted, the reservation can be done with a generous margin, making kdump more reliable. Kernel memory that we need to preserve for dumping is normally not allocated from CMA, unless it is explicitly allocated as movable. Currently this is only the case for memory ballooning and zswap. Such movable memory will be missing from the vmcore. User data is typically not dumped by makedumpfile. When dumping of user data is intended this new CMA reservation cannot be used. There are five patches in this series: The first adds a new ",cma" suffix to the recenly introduced generic crashkernel parsing code. parse_crashkernel() takes one more argument to store the cma reservation size. The second patch implements reserve_crashkernel_cma() which performs the reservation. If the requested size is not available in a single range, multiple smaller ranges will be reserved. The third patch updates Documentation/, explicitly mentioning the potential DMA corruption of the CMA-reserved memory. The fourth patch adds a short delay before booting the kdump kernel, allowing pending DMA transfers to finish. The fifth patch enables the functionality for x86 as a proof of concept. There are just three things every arch needs to do: - call reserve_crashkernel_cma() - include the CMA-reserved ranges in the physical memory map - exclude the CMA-reserved ranges from the memory available through /proc/vmcore by excluding them from the vmcoreinfo PT_LOAD ranges. Adding other architectures is easy and I can do that as soon as this series is merged. With this series applied, specifying crashkernel=100M craskhernel=1G,cma on the command line will make a standard crashkernel reservation of 100M, where kexec will load the kernel and initrd. An additional 1G will be reserved from CMA, still usable by the production system. The crash kernel will have 1.1G memory available. The 100M can be reliably predicted based on the size of the kernel and initrd. The new cma suffix is completely optional. When no crashkernel=size,cma is specified, everything works as before. This patch (of 5): Add a new cma_size parameter to parse_crashkernel(). When not NULL, call __parse_crashkernel to parse the CMA reservation size from "crashkernel=size,cma" and store it in cma_size. Set cma_size to NULL in all calls to parse_crashkernel(). Link: https://lkml.kernel.org/r/aEqnxxfLZMllMC8I@dwarf.suse.cz Link: https://lkml.kernel.org/r/aEqoQckgoTQNULnh@dwarf.suse.cz Signed-off-by: Jiri Bohac <jbohac@suse.cz> Cc: Baoquan He <bhe@redhat.com> Cc: Dave Young <dyoung@redhat.com> Cc: Donald Dutile <ddutile@redhat.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Philipp Rudo <prudo@redhat.com> Cc: Pingfan Liu <piliu@redhat.com> Cc: Tao Liu <ltao@redhat.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-14sh: ptrace: Use USER_REGSET_NOTE_TYPE() to specify regset note namesDave Martin1-2/+2
Instead of having the core code guess the note name for each regset, use USER_REGSET_NOTE_TYPE() to pick the correct name from elf.h. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Rich Felker <dalias@libc.org> Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Kees Cook <kees@kernel.org> Cc: Akihiko Odaki <akihiko.odaki@daynix.com> Cc: linux-sh@vger.kernel.org Reviewed-by: Akihiko Odaki <odaki@rsg.ci.i.u-tokyo.ac.jp> Link: https://lore.kernel.org/r/20250701135616.29630-19-Dave.Martin@arm.com Signed-off-by: Kees Cook <kees@kernel.org>
2025-07-02fs: introduce file_getattr and file_setattr syscallsAndrey Albershteyn1-0/+2
Introduce file_getattr() and file_setattr() syscalls to manipulate inode extended attributes. The syscalls takes pair of file descriptor and pathname. Then it operates on inode opened accroding to openat() semantics. The struct file_attr is passed to obtain/change extended attributes. This is an alternative to FS_IOC_FSSETXATTR ioctl with a difference that file don't need to be open as we can reference it with a path instead of fd. By having this we can manipulated inode extended attributes not only on regular files but also on special ones. This is not possible with FS_IOC_FSSETXATTR ioctl as with special files we can not call ioctl() directly on the filesystem inode using fd. This patch adds two new syscalls which allows userspace to get/set extended inode attributes on special files by using parent directory and a path - *at() like syscall. CC: linux-api@vger.kernel.org CC: linux-fsdevel@vger.kernel.org CC: linux-xfs@vger.kernel.org Signed-off-by: Andrey Albershteyn <aalbersh@kernel.org> Link: https://lore.kernel.org/20250630-xattrat-syscall-v6-6-c4e3bc35227b@kernel.org Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-06-07Merge tag 'kbuild-v6.16' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild updates from Masahiro Yamada: - Add support for the EXPORT_SYMBOL_GPL_FOR_MODULES() macro, which exports a symbol only to specified modules - Improve ABI handling in gendwarfksyms - Forcibly link lib-y objects to vmlinux even if CONFIG_MODULES=n - Add checkers for redundant or missing <linux/export.h> inclusion - Deprecate the extra-y syntax - Fix a genksyms bug when including enum constants from *.symref files * tag 'kbuild-v6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (28 commits) genksyms: Fix enum consts from a reference affecting new values arch: use always-$(KBUILD_BUILTIN) for vmlinux.lds kbuild: set y instead of 1 to KBUILD_{BUILTIN,MODULES} efi/libstub: use 'targets' instead of extra-y in Makefile module: make __mod_device_table__* symbols static scripts/misc-check: check unnecessary #include <linux/export.h> when W=1 scripts/misc-check: check missing #include <linux/export.h> when W=1 scripts/misc-check: add double-quotes to satisfy shellcheck kbuild: move W=1 check for scripts/misc-check to top-level Makefile scripts/tags.sh: allow to use alternative ctags implementation kconfig: introduce menu type enum docs: symbol-namespaces: fix reST warning with literal block kbuild: link lib-y objects to vmlinux forcibly even when CONFIG_MODULES=n tinyconfig: enable CONFIG_LD_DEAD_CODE_DATA_ELIMINATION docs/core-api/symbol-namespaces: drop table of contents and section numbering modpost: check forbidden MODULE_IMPORT_NS("module:") at compile time kbuild: move kbuild syntax processing to scripts/Makefile.build Makefile: remove dependency on archscripts for header installation Documentation/kbuild: Add new gendwarfksyms kABI rules Documentation/kbuild: Drop section numbers ...
2025-06-07sh: kprobes: Remove unused variables in kprobe_exceptions_notify()Mike Rapoport1-4/+0
kbuild reports the following warning: arch/sh/kernel/kprobes.c: In function 'kprobe_exceptions_notify': >> arch/sh/kernel/kprobes.c:412:24: warning: variable 'p' set but not used [-Wunused-but-set-variable] 412 | struct kprobe *p = NULL; | ^ The variable 'p' is indeed unused since the commit fa5a24b16f94 ("sh/kprobes: Don't call the ->break_handler() in SH kprobes code") Remove that variable along with 'kprobe_opcode_t *addr' which also becomes unused after 'p' is removed. Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202505151341.EuRFR22l-lkp@intel.com/ Fixes: fa5a24b16f94 ("sh/kprobes: Don't call the ->break_handler() in SH kprobes code") Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Reviewed-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
2025-06-07arch: use always-$(KBUILD_BUILTIN) for vmlinux.ldsMasahiro Yamada1-1/+1
The extra-y syntax is deprecated. Instead, use always-$(KBUILD_BUILTIN), which behaves equivalently. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Acked-by: Johannes Berg <johannes@sipsolutions.net> Reviewed-by: Nicolas Schier <n.schier@avm.de>
2025-04-06Merge tag 'sh-for-v6.15-tag1' of ↵Linus Torvalds1-1/+14
git://git.kernel.org/pub/scm/linux/kernel/git/glaubitz/sh-linux Pull sh updates from John Paul Adrian Glaubitz: "One important fix and one small configuration update. The first patch by Artur Rojek fixes an issue with the J2 firmware loader not being able to find the location of the device tree blob due to insufficient alignment of the .bss section which rendered J2 boards unbootable. The second patch by Johan Korsnes updates the defconfigs on sh to drop the CONFIG_NET_CLS_TCINDEX configuration option which became obsolete after 8c710f75256b ("net/sched: Retire tcindex classifier"). Summary: - sh: defconfig: Drop obsolete CONFIG_NET_CLS_TCINDEX - sh: Align .bss section padding to 8-byte boundary" * tag 'sh-for-v6.15-tag1' of git://git.kernel.org/pub/scm/linux/kernel/git/glaubitz/sh-linux: sh: defconfig: Drop obsolete CONFIG_NET_CLS_TCINDEX sh: Align .bss section padding to 8-byte boundary
2025-04-05sh: Align .bss section padding to 8-byte boundaryArtur Rojek1-1/+14
J2-based devices expect to find a device tree blob at the end of the .bss section. As of a77725a9a3c5 ("scripts/dtc: Update to upstream version v1.6.1-19-g0a3a9d3449c8"), libfdt enforces 8-byte alignment for the DTB, causing J2 devices to fail early in sh_fdt_init(). As the J2 loader firmware calculates the DTB location based on the kernel image .bss section size rather than the __bss_stop symbol offset, the required alignment can't be enforced with BSS_SECTION(0, PAGE_SIZE, 8). To fix this, inline a modified version of the above macro which grows .bss by the required size. While this change affects all existing SH boards, it should be benign on platforms which don't need this alignment. Signed-off-by: Artur Rojek <contact@artur-rojek.eu> Reviewed-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Tested-by: Rob Landley <rob@landley.net> Signed-off-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
2025-03-27Merge tag 'asm-generic-6.15-2' of ↵Linus Torvalds3-170/+0
git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic Pull asm-generic updates from Arnd Bergmann: "This is mainly set of cleanups of asm-generic/io.h, resolving problems with inconsistent semantics of ioread64/iowrite64 that were causing runtime and build issues. The "GENERIC_IOMAP" version that switches between inb()/outb() and readb()/writeb() style accessors is now only used on architectures that have PC-style ISA devices that are not memory mapped (x86, uml, m68k-q40 and powerpc-powernv), while alpha and parisc use a more complicated variant and everything else just maps the ioread interfaces to plan MMIO (readb/writeb etc). In addition there are two small changes from Raag Jadav to simplify the asm-generic/io.h indirect inclusions and from Jann Horn to fix a corner case with read_word_at_a_time" * tag 'asm-generic-6.15-2' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic: rwonce: fix crash by removing READ_ONCE() for unaligned read rwonce: handle KCSAN like KASAN in read_word_at_a_time() m68k: coldfire: select PCI_IOMAP for PCI mips: export pci_iounmap() mips: fix PCI_IOBASE definition m68k/nommu: stop using GENERIC_IOMAP mips: drop GENERIC_IOMAP wrapper powerpc: asm/io.h: remove split ioread64/iowrite64 helpers parisc: stop using asm-generic/iomap.h sh: remove duplicate ioread/iowrite helpers alpha: stop using asm-generic/iomap.h io.h: drop unused headers drm/draw: include missing headers asm-generic/io.h: rework split ioread64/iowrite64 helpers
2025-03-26Merge tag 'sysctl-6.15-rc1' of ↵Linus Torvalds1-0/+21
git://git.kernel.org/pub/scm/linux/kernel/git/sysctl/sysctl Pull sysctl updates from Joel Granados: - Move vm_table members out of kernel/sysctl.c All vm_table array members have moved to their respective subsystems leading to the removal of vm_table from kernel/sysctl.c. This increases modularity by placing the ctl_tables closer to where they are actually used and at the same time reducing the chances of merge conflicts in kernel/sysctl.c. - ctl_table range fixes Replace the proc_handler function that checks variable ranges in coredump_sysctls and vdso_table with the one that actually uses the extra{1,2} pointers as min/max values. This tightens the range of the values that users can pass into the kernel effectively preventing {under,over}flows. - Misc fixes Correct grammar errors and typos in test messages. Update sysctl files in MAINTAINERS. Constified and removed array size in declaration for alignment_tbl * tag 'sysctl-6.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/sysctl/sysctl: (22 commits) selftests/sysctl: fix wording of help messages selftests: fix spelling/grammar errors in sysctl/sysctl.sh MAINTAINERS: Update sysctl file list in MAINTAINERS sysctl: Fix underflow value setting risk in vm_table coredump: Fixes core_pipe_limit sysctl proc_handler sysctl: remove unneeded include sysctl: remove the vm_table sh: vdso: move the sysctl to arch/sh/kernel/vsyscall/vsyscall.c x86: vdso: move the sysctl to arch/x86/entry/vdso/vdso32-setup.c fs: dcache: move the sysctl to fs/dcache.c sunrpc: simplify rpcauth_cache_shrink_count() fs: drop_caches: move sysctl to fs/drop_caches.c fs: fs-writeback: move sysctl to fs/fs-writeback.c mm: nommu: move sysctl to mm/nommu.c security: min_addr: move sysctl to security/min_addr.c mm: mmap: move sysctl to mm/mmap.c mm: util: move sysctls to mm/util.c mm: vmscan: move vmscan sysctls to mm/vmscan.c mm: swap: move sysctl to mm/swap.c mm: filemap: move sysctl to mm/filemap.c ...
2025-03-11sh: remove duplicate ioread/iowrite helpersArnd Bergmann3-170/+0
The ioread/iowrite functions on sh only do memory mapped I/O like the generic verion, and never map onto non-MMIO inb/outb variants, so they just add complexity. In particular, the use of asm-generic/iomap.h ties the declaration to the x86 implementation. Remove the custom versions and use the architecture-independent fallback code instead. Some of the calling conventions on sh are different here, so fix that by adding 'volatile' keywords where required by the generic implementation and change the cpg clock driver to no longer depend on the interesting choice of return types for ioread8/ioread16/ioread32. Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2025-02-17sysctl: Fix underflow value setting risk in vm_tableNicolas Bouchinet1-1/+2
Commit 3b3376f222e3 ("sysctl.c: fix underflow value setting risk in vm_table") fixes underflow value setting risk in vm_table but misses vdso_enabled sysctl. vdso_enabled sysctl is initialized with .extra1 value as SYSCTL_ZERO to avoid negative value writes but the proc_handler is proc_dointvec and not proc_dointvec_minmax and thus do not uses .extra1 and .extra2. The following command thus works : `# echo -1 > /proc/sys/vm/vdso_enabled` This patch properly sets the proc_handler to proc_dointvec_minmax. In addition to .extra1, .extra2 is set to SYSCTL_ONE. The sysctl is thus bounded between 0 and 1. Fixes: 3b3376f222e3 ("sysctl.c: fix underflow value setting risk in vm_table") Signed-off-by: Nicolas Bouchinet <nicolas.bouchinet@ssi.gouv.fr> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Kees Cook <kees@kernel.org> Signed-off-by: Joel Granados <joel.granados@kernel.org>
2025-02-12fs: add open_tree_attr()Christian Brauner1-0/+1
Add open_tree_attr() which allow to atomically create a detached mount tree and set mount options on it. If OPEN_TREE_CLONE is used this will allow the creation of a detached mount with a new set of mount options without it ever being exposed to userspace without that set of mount options applied. Link: https://lore.kernel.org/r/20250128-work-mnt_idmap-update-v2-v1-3-c25feb0d2eb3@kernel.org Reviewed-by: "Seth Forshee (DigitalOcean)" <sforshee@kernel.org> Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-02-07sh: vdso: move the sysctl to arch/sh/kernel/vsyscall/vsyscall.cKaixiong Yu1-0/+20
When CONFIG_SUPERH and CONFIG_VSYSCALL are defined, vdso_enabled belongs to arch/sh/kernel/vsyscall/vsyscall.c. So, move it into its own file. To avoid failure when registering the vdso_table, move the call to register_sysctl_init() into its own fs_initcall(). Signed-off-by: Kaixiong Yu <yukaixiong@huawei.com> Reviewed-by: Kees Cook <kees@kernel.org> Signed-off-by: Joel Granados <joel.granados@kernel.org>
2025-02-01sh: Migrate to the generic rule for built-in DTBMasahiro Yamada1-2/+2
Commit 654102df2ac2 ("kbuild: add generic support for built-in boot DTBs") introduced generic support for built-in DTBs. Select GENERIC_BUILTIN_DTB when built-in DTB support is enabled. To keep consistency across architectures, this commit also renames CONFIG_USE_BUILTIN_DTB to CONFIG_BUILTIN_DTB, and CONFIG_BUILTIN_DTB_SOURCE to CONFIG_BUILTIN_DTB_NAME. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Signed-off-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
2025-02-01sh: irq: Use seq_put_decimal_ull_width() for decimal valuesDavid Wang1-2/+2
On a system with n CPUs and m interrupts, there will be n*m decimal values yielded via seq_printf(.."%10u "..) which has significant costs parsing format string and is less efficient than seq_put_decimal_ull_width(). Stress reading /proc/interrupts indicates ~30% performance improvement with this patch. Signed-off-by: David Wang <00107082@163.com> Reviewed-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Signed-off-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
2024-11-30Merge tag 'sh-for-v6.13-tag1' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/glaubitz/sh-linux Pull sh updates from John Paul Adrian Glaubitz: "Two small fixes. The first one by Huacai Chen addresses a runtime warning when CONFIG_CPUMASK_OFFSTACK and CONFIG_DEBUG_PER_CPU_MAPS are selected which occurs because the cpuinfo code on sh incorrectly uses NR_CPUS when iterating CPUs instead of the runtime limit nr_cpu_ids. A second fix by Dan Carpenter fixes a use-after-free bug in register_intc_controller() which occurred as a result of improper error handling in the interrupt controller driver code when registering an interrupt controller during plat_irq_setup() on sh" * tag 'sh-for-v6.13-tag1' of git://git.kernel.org/pub/scm/linux/kernel/git/glaubitz/sh-linux: sh: intc: Fix use-after-free bug in register_intc_controller() sh: cpuinfo: Fix a warning for CONFIG_CPUMASK_OFFSTACK
2024-11-30sh: cpuinfo: Fix a warning for CONFIG_CPUMASK_OFFSTACKHuacai Chen1-1/+1
When CONFIG_CPUMASK_OFFSTACK and CONFIG_DEBUG_PER_CPU_MAPS are selected, cpu_max_bits_warn() generates a runtime warning similar as below when showing /proc/cpuinfo. Fix this by using nr_cpu_ids (the runtime limit) instead of NR_CPUS to iterate CPUs. [ 3.052463] ------------[ cut here ]------------ [ 3.059679] WARNING: CPU: 3 PID: 1 at include/linux/cpumask.h:108 show_cpuinfo+0x5e8/0x5f0 [ 3.070072] Modules linked in: efivarfs autofs4 [ 3.076257] CPU: 0 PID: 1 Comm: systemd Not tainted 5.19-rc5+ #1052 [ 3.099465] Stack : 9000000100157b08 9000000000f18530 9000000000cf846c 9000000100154000 [ 3.109127] 9000000100157a50 0000000000000000 9000000100157a58 9000000000ef7430 [ 3.118774] 90000001001578e8 0000000000000040 0000000000000020 ffffffffffffffff [ 3.128412] 0000000000aaaaaa 1ab25f00eec96a37 900000010021de80 900000000101c890 [ 3.138056] 0000000000000000 0000000000000000 0000000000000000 0000000000aaaaaa [ 3.147711] ffff8000339dc220 0000000000000001 0000000006ab4000 0000000000000000 [ 3.157364] 900000000101c998 0000000000000004 9000000000ef7430 0000000000000000 [ 3.167012] 0000000000000009 000000000000006c 0000000000000000 0000000000000000 [ 3.176641] 9000000000d3de08 9000000001639390 90000000002086d8 00007ffff0080286 [ 3.186260] 00000000000000b0 0000000000000004 0000000000000000 0000000000071c1c [ 3.195868] ... [ 3.199917] Call Trace: [ 3.203941] [<90000000002086d8>] show_stack+0x38/0x14c [ 3.210666] [<9000000000cf846c>] dump_stack_lvl+0x60/0x88 [ 3.217625] [<900000000023d268>] __warn+0xd0/0x100 [ 3.223958] [<9000000000cf3c90>] warn_slowpath_fmt+0x7c/0xcc [ 3.231150] [<9000000000210220>] show_cpuinfo+0x5e8/0x5f0 [ 3.238080] [<90000000004f578c>] seq_read_iter+0x354/0x4b4 [ 3.245098] [<90000000004c2e90>] new_sync_read+0x17c/0x1c4 [ 3.252114] [<90000000004c5174>] vfs_read+0x138/0x1d0 [ 3.258694] [<90000000004c55f8>] ksys_read+0x70/0x100 [ 3.265265] [<9000000000cfde9c>] do_syscall+0x7c/0x94 [ 3.271820] [<9000000000202fe4>] handle_syscall+0xc4/0x160 [ 3.281824] ---[ end trace 8b484262b4b8c24c ]--- Cc: stable@vger.kernel.org Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> Reviewed-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Tested-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Signed-off-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
2024-11-20Merge tag 'devicetree-for-6.13' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux Pull devicetree updates from Rob Herring: "Bindings: - Enable dtc "interrupt_provider" warnings for binding examples. Fix the warnings in fsl,mu-msi and ti,sci-inta due to this. - Convert zii,rave-sp-wdt, zii,rave-sp-pwrbutton, and altr,fpga-passive-serial to DT schema format - Add some documentation on the different forms of YAML text blocks which are a constant source of review comments - Fix some schema errors in constraints for arrays - Add compatibles for qcom,sar2130p-pdc and onnn,adt7462 DT core: - Allow overlay kunit tests to run CONFIG_OF_OVERLAY=n - Add some warnings on deprecated address handling - Rework early_init_dt_scan() so the arch can pass in the phys address of the DTB as __pa() is not always valid to use. This fixes a warning for arm64 with kexec. - Add and use some new DT graph iterators for iterating over ports and endpoints - Rework reserved-memory handling to be sized dynamically for fixed regions - Optimize of_modalias() to avoid a strlen() call - Constify struct device_node and property pointers where ever possible" * tag 'devicetree-for-6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux: (36 commits) of: Allow overlay kunit tests to run CONFIG_OF_OVERLAY=n dt-bindings: interrupt-controller: qcom,pdc: Add SAR2130P compatible of/address: Rework bus matching to avoid warnings of: WARN on deprecated #address-cells/#size-cells handling of/fdt: Don't use default address cell sizes for address translation dt-bindings: Enable dtc "interrupt_provider" warnings of/fdt: add dt_phys arg to early_init_dt_scan and early_init_dt_verify dt-bindings: cache: qcom,llcc: Fix X1E80100 reg entries dt-bindings: watchdog: convert zii,rave-sp-wdt.txt to yaml format dt-bindings: input: convert zii,rave-sp-pwrbutton.txt to yaml media: xilinx-tpg: use new of_graph functions fbdev: omapfb: use new of_graph functions gpu: drm: omapdrm: use new of_graph functions ASoC: audio-graph-card2: use new of_graph functions ASoC: audio-graph-card: use new of_graph functions ASoC: test-component: use new of_graph functions of: property: use new of_graph functions of: property: add of_graph_get_next_port_endpoint() of: property: add of_graph_get_next_port() of: module: remove strlen() call in of_modalias() ...
2024-11-18Merge tag 'pull-xattr' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfsLinus Torvalds1-0/+4
Pull xattr updates from Al Viro: "Sanitize xattr and io_uring interactions with it, add *xattrat() syscalls, sanitize struct filename handling in there" * tag 'pull-xattr' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: xattr: remove redundant check on variable err fs/xattr: add *at family syscalls new helpers: file_removexattr(), filename_removexattr() new helpers: file_listxattr(), filename_listxattr() replace do_getxattr() with saner helpers. replace do_setxattr() with saner helpers. new helper: import_xattr_name() fs: rename struct xattr_ctx to kernel_xattr_ctx xattr: switch to CLASS(fd) io_[gs]etxattr_prep(): just use getname() io_uring: IORING_OP_F[GS]ETXATTR is fine with REQ_F_FIXED_FILE getname_maybe_null() - the third variant of pathname copy-in teach filename_lookup() to treat NULL filename as ""
2024-11-06fs/xattr: add *at family syscallsChristian Göttsche1-0/+4
Add the four syscalls setxattrat(), getxattrat(), listxattrat() and removexattrat(). Those can be used to operate on extended attributes, especially security related ones, either relative to a pinned directory or on a file descriptor without read access, avoiding a /proc/<pid>/fd/<fd> detour, requiring a mounted procfs. One use case will be setfiles(8) setting SELinux file contexts ("security.selinux") without race conditions and without a file descriptor opened with read access requiring SELinux read permission. Use the do_{name}at() pattern from fs/open.c. Pass the value of the extended attribute, its length, and for setxattrat(2) the command (XATTR_CREATE or XATTR_REPLACE) via an added struct xattr_args to not exceed six syscall arguments and not merging the AT_* and XATTR_* flags. [AV: fixes by Christian Brauner folded in, the entire thing rebased on top of {filename,file}_...xattr() primitives, treatment of empty pathnames regularized. As the result, AT_EMPTY_PATH+NULL handling is cheap, so f...(2) can use it] Signed-off-by: Christian Göttsche <cgzones@googlemail.com> Link: https://lore.kernel.org/r/20240426162042.191916-1-cgoettsche@seltendoof.de Reviewed-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Christian Brauner <brauner@kernel.org> CC: x86@kernel.org CC: linux-alpha@vger.kernel.org CC: linux-kernel@vger.kernel.org CC: linux-arm-kernel@lists.infradead.org CC: linux-ia64@vger.kernel.org CC: linux-m68k@lists.linux-m68k.org CC: linux-mips@vger.kernel.org CC: linux-parisc@vger.kernel.org CC: linuxppc-dev@lists.ozlabs.org CC: linux-s390@vger.kernel.org CC: linux-sh@vger.kernel.org CC: sparclinux@vger.kernel.org CC: linux-fsdevel@vger.kernel.org CC: audit@vger.kernel.org CC: linux-arch@vger.kernel.org CC: linux-api@vger.kernel.org CC: linux-security-module@vger.kernel.org CC: selinux@vger.kernel.org [brauner: slight tweaks] Signed-off-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2024-10-29of/fdt: add dt_phys arg to early_init_dt_scan and early_init_dt_verifyUsama Arif1-1/+1
__pa() is only intended to be used for linear map addresses and using it for initial_boot_params which is in fixmap for arm64 will give an incorrect value. Hence save the physical address when it is known at boot time when calling early_init_dt_scan for arm64 and use it at kexec time instead of converting the virtual address using __pa(). Note that arm64 doesn't need the FDT region reserved in the DT as the kernel explicitly reserves the passed in FDT. Therefore, only a debug warning is fixed with this change. Reported-by: Breno Leitao <leitao@debian.org> Suggested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Usama Arif <usamaarif642@gmail.com> Fixes: ac10be5cdbfa ("arm64: Use common of_kexec_alloc_and_setup_fdt()") Link: https://lore.kernel.org/r/20241023171426.452688-1-usamaarif642@gmail.com Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
2024-10-02move asm/unaligned.h to linux/unaligned.hAl Viro2-2/+2
asm/unaligned.h is always an include of asm-generic/unaligned.h; might as well move that thing to linux/unaligned.h and include that - there's nothing arch-specific in that header. auto-generated by the following: for i in `git grep -l -w asm/unaligned.h`; do sed -i -e "s/asm\/unaligned.h/linux\/unaligned.h/" $i done for i in `git grep -l -w asm-generic/unaligned.h`; do sed -i -e "s/asm-generic\/unaligned.h/linux\/unaligned.h/" $i done git mv include/asm-generic/unaligned.h include/linux/unaligned.h git mv tools/include/asm-generic/unaligned.h tools/include/linux/unaligned.h sed -i -e "/unaligned.h/d" include/asm-generic/Kbuild sed -i -e "s/__ASM_GENERIC/__LINUX/" include/linux/unaligned.h tools/include/linux/unaligned.h
2024-09-01mm: remove legacy install_special_mapping() codeLinus Torvalds1-3/+11
All relevant architectures had already been converted to the new interface (which just has an underscore in front of the name - not very imaginative naming), this just force-converts the stragglers. The modern interface is almost identical to the old one, except instead of the page pointer it takes a "struct vm_special_mapping" that describes the mapping (and contains the page pointer as one member), and it returns the resulting 'vma' instead of just the error code. Getting rid of the old interface also gets rid of some special casing, which had caused problems with the mremap extensions to "struct vm_special_mapping". [akpm@linux-foundation.org: coding-style cleanups] Link: https://lkml.kernel.org/r/CAHk-=whvR+z=0=0gzgdfUiK70JTa-=+9vxD-4T=3BagXR6dciA@mail.gmail.comTested-by: Rob Landley <rob@landley.net> # arch/sh/ Link: https://lore.kernel.org/all/20240819195120.GA1113263@thelio-3990X/ Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Nathan Chancellor <nathan@kernel.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: Brian Cain <bcain@quicinc.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Guo Ren <guoren@kernel.org> Cc: Jeff Xu <jeffxu@google.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Pedro Falcato <pedro.falcato@gmail.com> Cc: Richard Weinberger <richard@nod.at> Cc: Rich Felker <dalias@libc.org> Cc: Rob Landley <rob@landley.net> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-06-25sh: rework sync_file_range ABIArnd Bergmann2-1/+13
The unusual function calling conventions on SuperH ended up causing sync_file_range to have the wrong argument order, with the 'flags' argument getting sorted before 'nbytes' by the compiler. In userspace, I found that musl, glibc, uclibc and strace all expect the normal calling conventions with 'nbytes' last, so changing the kernel to match them should make all of those work. In order to be able to also fix libc implementations to work with existing kernels, they need to be able to tell which ABI is used. An easy way to do this is to add yet another system call using the sync_file_range2 ABI that works the same on all architectures. Old user binaries can now work on new kernels, and new binaries can try the new sync_file_range2() to work with new kernels or fall back to the old sync_file_range() version if that doesn't exist. Cc: stable@vger.kernel.org Fixes: 75c92acdd5b1 ("sh: Wire up new syscalls.") Acked-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2024-05-23mseal: wire up mseal syscallJeff Xu1-0/+1
Patch series "Introduce mseal", v10. This patchset proposes a new mseal() syscall for the Linux kernel. In a nutshell, mseal() protects the VMAs of a given virtual memory range against modifications, such as changes to their permission bits. Modern CPUs support memory permissions, such as the read/write (RW) and no-execute (NX) bits. Linux has supported NX since the release of kernel version 2.6.8 in August 2004 [1]. The memory permission feature improves the security stance on memory corruption bugs, as an attacker cannot simply write to arbitrary memory and point the code to it. The memory must be marked with the X bit, or else an exception will occur. Internally, the kernel maintains the memory permissions in a data structure called VMA (vm_area_struct). mseal() additionally protects the VMA itself against modifications of the selected seal type. Memory sealing is useful to mitigate memory corruption issues where a corrupted pointer is passed to a memory management system. For example, such an attacker primitive can break control-flow integrity guarantees since read-only memory that is supposed to be trusted can become writable or .text pages can get remapped. Memory sealing can automatically be applied by the runtime loader to seal .text and .rodata pages and applications can additionally seal security critical data at runtime. A similar feature already exists in the XNU kernel with the VM_FLAGS_PERMANENT [3] flag and on OpenBSD with the mimmutable syscall [4]. Also, Chrome wants to adopt this feature for their CFI work [2] and this patchset has been designed to be compatible with the Chrome use case. Two system calls are involved in sealing the map: mmap() and mseal(). The new mseal() is an syscall on 64 bit CPU, and with following signature: int mseal(void addr, size_t len, unsigned long flags) addr/len: memory range. flags: reserved. mseal() blocks following operations for the given memory range. 1> Unmapping, moving to another location, and shrinking the size, via munmap() and mremap(), can leave an empty space, therefore can be replaced with a VMA with a new set of attributes. 2> Moving or expanding a different VMA into the current location, via mremap(). 3> Modifying a VMA via mmap(MAP_FIXED). 4> Size expansion, via mremap(), does not appear to pose any specific risks to sealed VMAs. It is included anyway because the use case is unclear. In any case, users can rely on merging to expand a sealed VMA. 5> mprotect() and pkey_mprotect(). 6> Some destructive madvice() behaviors (e.g. MADV_DONTNEED) for anonymous memory, when users don't have write permission to the memory. Those behaviors can alter region contents by discarding pages, effectively a memset(0) for anonymous memory. The idea that inspired this patch comes from Stephen Röttger’s work in V8 CFI [5]. Chrome browser in ChromeOS will be the first user of this API. Indeed, the Chrome browser has very specific requirements for sealing, which are distinct from those of most applications. For example, in the case of libc, sealing is only applied to read-only (RO) or read-execute (RX) memory segments (such as .text and .RELRO) to prevent them from becoming writable, the lifetime of those mappings are tied to the lifetime of the process. Chrome wants to seal two large address space reservations that are managed by different allocators. The memory is mapped RW- and RWX respectively but write access to it is restricted using pkeys (or in the future ARM permission overlay extensions). The lifetime of those mappings are not tied to the lifetime of the process, therefore, while the memory is sealed, the allocators still need to free or discard the unused memory. For example, with madvise(DONTNEED). However, always allowing madvise(DONTNEED) on this range poses a security risk. For example if a jump instruction crosses a page boundary and the second page gets discarded, it will overwrite the target bytes with zeros and change the control flow. Checking write-permission before the discard operation allows us to control when the operation is valid. In this case, the madvise will only succeed if the executing thread has PKEY write permissions and PKRU changes are protected in software by control-flow integrity. Although the initial version of this patch series is targeting the Chrome browser as its first user, it became evident during upstream discussions that we would also want to ensure that the patch set eventually is a complete solution for memory sealing and compatible with other use cases. The specific scenario currently in mind is glibc's use case of loading and sealing ELF executables. To this end, Stephen is working on a change to glibc to add sealing support to the dynamic linker, which will seal all non-writable segments at startup. Once this work is completed, all applications will be able to automatically benefit from these new protections. In closing, I would like to formally acknowledge the valuable contributions received during the RFC process, which were instrumental in shaping this patch: Jann Horn: raising awareness and providing valuable insights on the destructive madvise operations. Liam R. Howlett: perf optimization. Linus Torvalds: assisting in defining system call signature and scope. Theo de Raadt: sharing the experiences and insight gained from implementing mimmutable() in OpenBSD. MM perf benchmarks ================== This patch adds a loop in the mprotect/munmap/madvise(DONTNEED) to check the VMAs’ sealing flag, so that no partial update can be made, when any segment within the given memory range is sealed. To measure the performance impact of this loop, two tests are developed. [8] The first is measuring the time taken for a particular system call, by using clock_gettime(CLOCK_MONOTONIC). The second is using PERF_COUNT_HW_REF_CPU_CYCLES (exclude user space). Both tests have similar results. The tests have roughly below sequence: for (i = 0; i < 1000, i++) create 1000 mappings (1 page per VMA) start the sampling for (j