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2025-12-02Merge tag 's390-6.19-1' of ↵Linus Torvalds3-736/+412
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Heiko Carstens: - Provide a new interface for dynamic configuration and deconfiguration of hotplug memory, allowing with and without memmap_on_memory support. This makes the way memory hotplug is handled on s390 much more similar to other architectures - Remove compat support. There shouldn't be any compat user space around anymore, therefore get rid of a lot of code which also doesn't need to be tested anymore - Add stackprotector support. GCC 16 will get new compiler options, which allow to generate code required for kernel stackprotector support - Merge pai_crypto and pai_ext PMU drivers into a new driver. This removes a lot of duplicated code. The new driver is also extendable and allows to support new PMUs - Add driver override support for AP queues - Rework and extend zcrypt and AP trace events to allow for tracing of crypto requests - Support block sizes larger than 65535 bytes for CCW tape devices - Since the rework of the virtual kernel address space the module area and the kernel image are within the same 4GB area. This eliminates the need of weak per cpu variables. Get rid of ARCH_MODULE_NEEDS_WEAK_PER_CPU - Various other small improvements and fixes * tag 's390-6.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (92 commits) watchdog: diag288_wdt: Remove KMSG_COMPONENT macro s390/entry: Use lay instead of aghik s390/vdso: Get rid of -m64 flag handling s390/vdso: Rename vdso64 to vdso s390: Rename head64.S to head.S s390/vdso: Use common STABS_DEBUG and DWARF_DEBUG macros s390: Add stackprotector support s390/modules: Simplify module_finalize() slightly s390: Remove KMSG_COMPONENT macro s390/percpu: Get rid of ARCH_MODULE_NEEDS_WEAK_PER_CPU s390/ap: Restrict driver_override versus apmask and aqmask use s390/ap: Rename mutex ap_perms_mutex to ap_attr_mutex s390/ap: Support driver_override for AP queue devices s390/ap: Use all-bits-one apmask/aqmask for vfio in_use() checks s390/debug: Update description of resize operation s390/syscalls: Switch to generic system call table generation s390/syscalls: Remove system call table pointer from thread_struct s390/uapi: Remove 31 bit support from uapi header files s390: Remove compat support tools: Remove s390 compat support ...
2025-11-17s390/syscalls: Switch to generic system call table generationHeiko Carstens3-735/+411
The s390 syscall.tbl format differs slightly from most others, and therefore requires an s390 specific system call table generation script. With compat support gone use the opportunity to switch to generic system call table generation. The abi for all 64 bit system calls is now common, since there is no need to specify if system call entry points are only for 64 bit anymore. Furthermore create the system call table in C instead of assembler code in order to get type checking for all system call functions contained within the table. Reviewed-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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>
2025-07-02fs: 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>
2025-02-12fs: 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>
2024-11-18Merge tag 's390-6.13-1' of ↵Linus Torvalds1-12/+15
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Heiko Carstens: - Add firmware sysfs interface which allows user space to retrieve the dump area size of the machine - Add 'measurement_chars_full' CHPID sysfs attribute to make the complete associated Channel-Measurements Characteristics Block available - Add virtio-mem support - Move gmap aka KVM page fault handling from the main fault handler to KVM code. This is the first step to make s390 KVM page fault handling similar to other architectures. With this first step the main fault handler does not have any special handling anymore, and therefore convert it to support LOCK_MM_AND_FIND_VMA - With gcc 14 s390 support for flag output operand support for inline assemblies was added. This allows for several optimizations: - Provide a cmpxchg inline assembly which makes use of this, and provide all variants of arch_try_cmpxchg() so that the compiler can generate slightly better code - Convert a few cmpxchg() loops to try_cmpxchg() loops - Similar to x86 add a CC_OUT() helper macro (and other macros), and convert all inline assemblies to make use of them, so that depending on compiler version better code can be generated - List installed host-key hashes in sysfs if the machine supports the Query Ultravisor Keys UVC - Add 'Retrieve Secret' ioctl which allows user space in protected execution guests to retrieve previously stored secrets from the Ultravisor - Add pkey-uv module which supports the conversion of Ultravisor retrievable secrets to protected keys - Extend the existing paes cipher to exploit the full AES-XTS hardware acceleration introduced with message-security assist extension 10 - Convert hopefully all sysfs show functions to use sysfs_emit() so that the constant flow of such patches stop - For PCI devices make use of the newly added Topology ID attribute to enable whole card multi-function support despite the change to PCHID per port. Additionally improve the overall robustness and usability of the multifunction support - Various other small improvements, fixes, and cleanups * tag 's390-6.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (133 commits) s390/cio/ioasm: Convert to use flag output macros s390/cio/qdio: Convert to use flag output macros s390/sclp: Convert to use flag output macros s390/dasd: Convert to use flag output macros s390/boot/physmem: Convert to use flag output macros s390/pci: Convert to use flag output macros s390/kvm: Convert to use flag output macros s390/extmem: Convert to use flag output macros s390/string: Convert to use flag output macros s390/diag: Convert to use flag output macros s390/irq: Convert to use flag output macros s390/smp: Convert to use flag output macros s390/uv: Convert to use flag output macros s390/pai: Convert to use flag output macros s390/mm: Convert to use flag output macros s390/cpu_mf: Convert to use flag output macros s390/cpcmd: Convert to use flag output macros s390/topology: Convert to use flag output macros s390/time: Convert to use flag output macros s390/pageattr: Convert to use flag output macros ...
2024-11-12s390/syscalls: Convert filechk to if_changedMasahiro Yamada1-11/+14
The filechk macro always executes the syscalltbl script (and discards the output if there are no changes). Using if_changed is more efficient because it avoids running the script when the target is up-to-date and the command remains unchanged. All other architectures use if_changed for generating syscall headers. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Link: https://lore.kernel.org/r/20241111134603.2063226-3-masahiroy@kernel.org Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-11-12s390/syscalls: Remove unnecessary argument of filechk_syshdrMasahiro Yamada1-3/+3
The filechk_syshdr macro receives $@ in both cases, making the argument redundant. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Link: https://lore.kernel.org/r/20241111134603.2063226-2-masahiroy@kernel.org Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2024-11-12s390/syscalls: Avoid creation of arch/arch/ directoryMasahiro Yamada1-1/+1
Building the kernel with ARCH=s390 creates a weird arch/arch/ directory. $ find arch/arch arch/arch arch/arch/s390 arch/arch/s390/include arch/arch/s390/include/generated arch/arch/s390/include/generated/asm arch/arch/s390/include/generated/uapi arch/arch/s390/include/generated/uapi/asm The root cause is 'targets' in arch/s390/kernel/syscalls/Makefile, where the relative path is incorrect. Strictly speaking, 'targets' was not necessary in the first place because this Makefile uses 'filechk' instead of 'if_changed'. However, this commit keeps it, as it will be useful when converting 'filechk' to 'if_changed' later. Fixes: 5c75824d915e ("s390/syscalls: add Makefile to generate system call header files") Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Link: https://lore.kernel.org/r/20241111134603.2063226-1-masahiroy@kernel.org Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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>
2024-06-25syscalls: fix compat_sys_io_pgetevents_time64 usageArnd Bergmann1-1/+1
Using sys_io_pgetevents() as the entry point for compat mode tasks works almost correctly, but misses the sign extension for the min_nr and nr arguments. This was addressed on parisc by switching to compat_sys_io_pgetevents_time64() in commit 6431e92fc827 ("parisc: io_pgetevents_time64() needs compat syscall in 32-bit compat mode"), as well as by using more sophisticated system call wrappers on x86 and s390. However, arm64, mips, powerpc, sparc and riscv still have the same bug. Change all of them over to use compat_sys_io_pgetevents_time64() like parisc already does. This was clearly the intention when the function was originally added, but it got hooked up incorrectly in the tables. Cc: stable@vger.kernel.org Fixes: 48166e6ea47d ("y2038: add 64-bit time_t syscalls to all 32-bit architectures") Acked-by: Heiko Carstens <hca@linux.ibm.com> # s390 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 = 0; j < 1000, j++) mprotect one mapping stop and save the sample delete 1000 mappings calculates all samples. Below tests are performed on Intel(R) Pentium(R) Gold 7505 @ 2.00GHz, 4G memory, Chromebook. Based on the latest upstream code: The first test (measuring time) syscall__ vmas t t_mseal delta_ns per_vma % munmap__ 1 909 944 35 35 104% munmap__ 2 1398 1502 104 52 107% munmap__ 4 2444 2594 149 37 106% munmap__ 8 4029 4323 293 37 107% munmap__ 16 6647 6935 288 18 104% munmap__ 32 11811 12398 587 18 105% mprotect 1 439 465 26 26 106% mprotect 2 1659 1745 86 43 105% mprotect 4 3747 3889 142 36 104% mprotect 8 6755 6969 215 27 103% mprotect 16 13748 14144 396 25 103% mprotect 32 27827 28969 1142 36 104% madvise_ 1 240 262 22 22 109% madvise_ 2 366 442 76 38 121% madvise_ 4 623 751 128 32 121% madvise_ 8 1110 1324 215 27 119% madvise_ 16 2127 2451 324 20 115% madvise_ 32 4109 4642 534 17 113% The second test (measuring cpu cycle) syscall__ vmas cpu cmseal delta_cpu per_vma % munmap__ 1 1790 1890 100 100 106% munmap__ 2 2819 3033 214 107 108% munmap__ 4 4959 5271 312 78 106% munmap__ 8 8262 8745 483 60 106% munmap__ 16 13099 14116 1017 64 108% munmap__ 32 23221 24785 1565 49 107% mprotect 1 906 967 62 62 107% mprotect 2 3019 3203 184 92 106% mprotect 4 6149 6569 420 105 107% mprotect 8 9978 10524 545 68 105% mprotect 16 20448 21427 979 61 105% mprotect 32 40972 42935 1963 61 105% madvise_ 1 434 497 63 63 115% madvise_ 2 752 899 147 74 120% madvise_ 4 1313 1513 200 50 115% madvise_ 8 2271 2627 356 44 116% madvise_ 16 4312 4883 571 36 113% madvise_ 32 8376 9319 943 29 111% Based on the result, for 6.8 kernel, sealing check adds 20-40 nano seconds, or around 50-100 CPU cycles, per VMA. In addition, I applied the sealing to 5.10 kernel: The first test (measuring time) syscall__ vmas t tmseal delta_ns per_vma % munmap__ 1 357 390 33 33 109% munmap__ 2 442 463 21 11 105% munmap__ 4 614 634 20 5 103% munmap__ 8 1017 1137 120 15 112% munmap__ 16 1889 2153 263 16 114% munmap__ 32 4109 4088 -21 -1 99% mprotect 1 235 227 -7 -7 97% mprotect 2 495 464 -30 -15 94% mprotect 4 741 764 24 6 103% mprotect 8 1434 1437 2 0 100% mprotect 16 2958 2991 33 2 101% mprotect 32 6431 6608 177 6 103% madvise_ 1 191 208 16 16 109% madvise_ 2 300 324 24 12 108% madvise_ 4 450 473 23 6 105% madvise_ 8 753 806 53 7 107% madvise_ 16 1467 1592 125 8 108% madvise_ 32 2795 3405 610 19 122% The second test (measuring cpu cycle) syscall__ nbr_vma cpu cmseal delta_cpu per_vma % munmap__ 1 684 715 31 31 105% munmap__ 2 861 898 38 19 104% munmap__ 4 1183 1235 51 13 104% munmap__ 8 1999 2045 46 6 102% munmap__ 16 3839 3816 -23 -1 99% munmap__ 32 7672 7887 216 7 103% mprotect 1 397 443 46 46 112% mprotect 2 738 788 50 25 107% mprotect 4 1221 1256 35 9 103% mprotect 8 2356 2429 72 9 103% mprotect 16 4961 4935 -26 -2 99% mprotect 32 9882 10172 291 9 103% madvise_ 1 351 380 29 29 108% madvise_ 2 565 615 49 25 109% madvise_ 4 872 933 61 15 107% madvise_ 8 1508 1640 132 16 109% madvise_ 16 3078 3323 245 15 108% madvise_ 32 5893 6704 811 25 114% For 5.10 kernel, sealing check adds 0-15 ns in time, or 10-30 CPU cycles, there is even decrease in some cases. It might be interesting to compare 5.10 and 6.8 kernel The first test (measuring time) syscall__ vmas t_5_10 t_6_8 delta_ns per_vma % munmap__ 1 357 909 552 552 254% munmap__ 2 442 1398 956 478 316% munmap__ 4 614 2444 1830 458 398% munmap__ 8 1017 4029 3012 377 396% munmap__ 16 1889 6647 4758 297 352% munmap__ 32 4109 11811 7702 241 287% mprotect 1 235 439 204 204 187% mprotect 2 495 1659 1164 582 335% mprotect 4 741 3747 3006 752 506% mprotect 8 1434 6755 5320 665 471% mprotect 16 2958 13748 10790 674 465% mprotect 32 6431 27827 21397 669 433% madvise_ 1 191 240 49 49 125% madvise_ 2 300 366 67 33 122% madvise_ 4 450 623 173 43 138% madvise_ 8 753 1110 357 45 147% madvise_ 16 1467 2127 660 41 145% madvise_ 32 2795 4109 1314 41 147% The second test (measuring cpu cycle) syscall__ vmas cpu_5_10 c_6_8 delta_cpu per_vma % munmap__ 1 684 1790 1106 1106 262% munmap__ 2 861 2819 1958 979 327% munmap__ 4 1183 4959 3776 944 419% munmap__ 8 1999 8262 6263 783 413% munmap__ 16 3839 13099 9260 579 341% munmap__ 32 7672 23221 15549 486 303% mprotect 1 397 906 509 509 228% mprotect 2 738 3019 2281 1140 409% mprotect 4 1221 6149 4929 1232 504% mprotect 8 2356 9978 7622 953 423% mprotect 16 4961 20448 15487 968 412% mprotect 32 9882 40972 31091 972 415% madvise_ 1 351 434 82 82 123% madvise_ 2 565 752 186 93 133% madvise_ 4 872 1313 442 110 151% madvise_ 8 1508 2271 763 95 151% madvise_ 16 3078 4312 1234 77 140% madvise_ 32 5893 8376 2483 78 142% From 5.10 to 6.8 munmap: added 250-550 ns in time, or 500-1100 in cpu cycle, per vma. mprotect: added 200-750 ns in time, or 500-1200 in cpu cycle, per vma. madvise: added 33-50 ns in time, or 70-110 in cpu cycle, per vma. In comparison to mseal, which adds 20-40 ns or 50-100 CPU cycles, the increase from 5.10 to 6.8 is significantly larger, approximately ten times greater for munmap and mprotect. When I discuss the mm performance with Brian Makin, an engineer who worked on performance, it was brought to my attention that such performance benchmarks, which measuring millions of mm syscall in a tight loop, may not accurately reflect real-world scenarios, such as that of a database service. Also this is tested using a single HW and ChromeOS, the data from another HW or distribution might be different. It might be best to take this data with a grain of salt. This patch (of 5): Wire up mseal syscall for all architectures. Link: https://lkml.kernel.org/r/20240415163527.626541-1-jeffxu@chromium.org Link: https://lkml.kernel.org/r/20240415163527.626541-2-jeffxu@chromium.org Signed-off-by: Jeff Xu <jeffxu@chromium.org> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guenter Roeck <groeck@chromium.org> Cc: Jann Horn <jannh@google.com> [Bug #2] Cc: Jeff Xu <jeffxu@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Jorge Lucangeli Obes <jorgelo@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Muhammad Usama Anjum <usama.anjum@collabora.com> Cc: Pedro Falcato <pedro.falcato@gmail.com> Cc: Stephen Röttger <sroettger@google.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Amer Al Shanawany <amer.shanawany@gmail.com> Cc: Javier Carrasco <javier.carrasco.cruz@gmail.com> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-10kbuild: use $(src) instead of $(srctree)/$(src) for source directoryMasahiro Yamada1-2/+2
Kbuild conventionally uses $(obj)/ for generated files, and $(src)/ for checked-in source files. It is merely a convention without any functional difference. In fact, $(obj) and $(src) are exactly the same, as defined in scripts/Makefile.build: src := $(obj) When the kernel is built in a separate output directory, $(src) does not accurately reflect the source directory location. While Kbuild resolves this discrepancy by specifying VPATH=$(srctree) to search for source files, it does not cover all cases. For example, when adding a header search path for local headers, -I$(srctree)/$(src) is typically passed to the compiler. This introduces inconsistency between upstream and downstream Makefiles because $(src) is used instead of $(srctree)/$(src) for the latter. To address this inconsistency, this commit changes the semantics of $(src) so that it always points to the directory in the source tree. Going forward, the variables used in Makefiles will have the following meanings: $(obj) - directory in the object tree $(src) - directory in the source tree (changed by this commit) $(objtree) - the top of the kernel object tree $(srctree) - the top of the kernel source tree Consequently, $(srctree)/$(src) in upstream Makefiles need to be replaced with $(src). Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
2024-01-09Merge tag 'lsm-pr-20240105' of ↵Linus Torvalds1-0/+3
git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm Pull security module updates from Paul Moore: - Add three new syscalls: lsm_list_modules(), lsm_get_self_attr(), and lsm_set_self_attr(). The first syscall simply lists the LSMs enabled, while the second and third get and set the current process' LSM attributes. Yes, these syscalls may provide similar functionality to what can be found under /proc or /sys, but they were designed to support multiple, simultaneaous (stacked) LSMs from the start as opposed to the current /proc based solutions which were created at a time when only one LSM was allowed to be active at a given time. We have spent considerable time discussing ways to extend the existing /proc interfaces to support multiple, simultaneaous LSMs and even our best ideas have been far too ugly to support as a kernel API; after +20 years in the kernel, I felt the LSM layer had established itself enough to justify a handful of syscalls. Support amongst the individual LSM developers has been nearly unanimous, with a single objection coming from Tetsuo (TOMOYO) as he is worried that the LSM_ID_XXX token concept will make it more difficult for out-of-tree LSMs to survive. Several members of the LSM community have demonstrated the ability for out-of-tree LSMs to continue to exist by picking high/unused LSM_ID values as well as pointing out that many kernel APIs rely on integer identifiers, e.g. syscalls (!), but unfortunately Tetsuo's objections remain. My personal opinion is that while I have no interest in penalizing out-of-tree LSMs, I'm not going to penalize in-tree development to support out-of-tree development, and I view this as a necessary step forward to support the push for expanded LSM stacking and reduce our reliance on /proc and /sys which has occassionally been problematic for some container users. Finally, we have included the linux-api folks on (all?) recent revisions of the patchset and addressed all of their concerns. - Add a new security_file_ioctl_compat() LSM hook to handle the 32-bit ioctls on 64-bit systems problem. This patch includes support for all of the existing LSMs which provide ioctl hooks, although it turns out only SELinux actually cares about the individual ioctls. It is worth noting that while Casey (Smack) and Tetsuo (TOMOYO) did not give explicit ACKs to this patch, they did both indicate they are okay with the changes. - Fix a potential memory leak in the CALIPSO code when IPv6 is disabled at boot. While it's good that we are fixing this, I doubt this is something users are seeing in the wild as you need to both disable IPv6 and then attempt to configure IPv6 labeled networking via NetLabel/CALIPSO; that just doesn't make much sense. Normally this would go through netdev, but Jakub asked me to take this patch and of all the trees I maintain, the LSM tree seemed like the best fit. - Update the LSM MAINTAINERS entry with additional information about our process docs, patchwork, bug reporting, etc. I also noticed that the Lockdown LSM is missing a dedicated MAINTAINERS entry so I've added that to the pull request. I've been working with one of the major Lockdown authors/contributors to see if they are willing to step up and assume a Lockdown maintainer role; hopefully that will happen soon, but in the meantime I'll continue to look after it. - Add a handful of mailmap entries for Serge Hallyn and myself. * tag 'lsm-pr-20240105' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm: (27 commits) lsm: new security_file_ioctl_compat() hook lsm: Add a __counted_by() annotation to lsm_ctx.ctx calipso: fix memory leak in netlbl_calipso_add_pass() selftests: remove the LSM_ID_IMA check in lsm/lsm_list_modules_test MAINTAINERS: add an entry for the lockdown LSM MAINTAINERS: update the LSM entry mailmap: add entries for Serge Hallyn's dead accounts mailmap: update/replace my old email addresses lsm: mark the lsm_id variables are marked as static lsm: convert security_setselfattr() to use memdup_user() lsm: align based on pointer length in lsm_fill_user_ctx() lsm: consolidate buffer size handling into lsm_fill_user_ctx() lsm: correct error codes in security_getselfattr() lsm: cleanup the size counters in security_getselfattr() lsm: don't yet account for IMA in LSM_CONFIG_COUNT calculation lsm: drop LSM_ID_IMA LSM: selftests for Linux Security Module syscalls SELinux: Add selfattr hooks AppArmor: Add selfattr hooks Smack: implement setselfattr and getselfattr hooks ...
2023-12-14wire up syscalls for statmount/listmountMiklos Szeredi1-0/+2
Wire up all archs. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Link: https://lore.kernel.org/r/20231025140205.3586473-7-mszeredi@redhat.com Reviewed-by: Ian Kent <raven@themaw.net> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-11-12LSM: wireup Linux Security Module syscallsCasey Schaufler1-0/+3
Wireup lsm_get_self_attr, lsm_set_self_attr and lsm_list_modules system calls. Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Arnd Bergmann <arnd@arndb.de> Cc: linux-api@vger.kernel.org Reviewed-by: Mickaël Salaün <mic@digikod.net> [PM: forward ported beyond v6.6 due merge window changes] Signed-off-by: Paul Moore <paul@paul-moore.com>
2023-11-01Merge tag 'asm-generic-6.7' of ↵Linus Torvalds1-2/+3
git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic Pull ia64 removal and asm-generic updates from Arnd Bergmann: - The ia64 architecture gets its well-earned retirement as planned, now that there is one last (mostly) working release that will be maintained as an LTS kernel. - The architecture specific system call tables are updated for the added map_shadow_stack() syscall and to remove references to the long-gone sys_lookup_dcookie() syscall. * tag 'asm-generic-6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic: hexagon: Remove unusable symbols from the ptrace.h uapi asm-generic: Fix spelling of architecture arch: Reserve map_shadow_stack() syscall number for all architectures syscalls: Cleanup references to sys_lookup_dcookie() Documentation: Drop or replace remaining mentions of IA64 lib/raid6: Drop IA64 support Documentation: Drop IA64 from feature descriptions kernel: Drop IA64 support from sig_fault handlers arch: Remove Itanium (IA-64) architecture
2023-10-06arch: Reserve map_shadow_stack() syscall number for all architecturesSohil Mehta1-0/+1
commit c35559f94ebc ("x86/shstk: Introduce map_shadow_stack syscall") recently added support for map_shadow_stack() but it is limited to x86 only for now. There is a possibility that other architectures (namely, arm64 and RISC-V), that are implementing equivalent support for shadow stacks, might need to add support for it. Independent of that, reserving arch-specific syscall numbers in the syscall tables of all architectures is good practice and would help avoid future conflicts. map_shadow_stack() is marked as a conditional syscall in sys_ni.c. Adding it to the syscall tables of other architectures is harmless and would return ENOSYS when exercised. Note, map_shadow_stack() was assigned #453 during the merge process since #452 was taken by fchmodat2(). For Powerpc, map it to sys_ni_syscall() as is the norm for Powerpc syscall tables. For Alpha, map_shadow_stack() takes up #563 as Alpha still diverges from the common syscall numbering system in the other architectures. Link: https://lore.kernel.org/lkml/20230515212255.GA562920@debug.ba.rivosinc.com/ Link: https://lore.kernel.org/lkml/b402b80b-a7c6-4ef0-b977-c0f5f582b78a@sirena.org.uk/ Signed-off-by: Sohil Mehta <sohil.mehta@intel.com> Reviewed-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2023-10-03syscalls: Cleanup references to sys_lookup_dcookie()Sohil Mehta1-1/+1
commit 'be65de6b03aa ("fs: Remove dcookies support")' removed the syscall definition for lookup_dcookie. However, syscall tables still point to the old sys_lookup_dcookie() definition. Update syscall tables of all architectures to directly point to sys_ni_syscall() instead. Signed-off-by: Sohil Mehta <sohil.mehta@intel.com> Reviewed-by: Randy Dunlap <rdunlap@infradead.org> Acked-by: Namhyung Kim <namhyung@kernel.org> # for perf Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2023-09-21futex: Add sys_futex_requeue()peterz@infradead.org1-0/+1
Finish off the 'simple' futex2 syscall group by adding sys_futex_requeue(). Unlike sys_futex_{wait,wake}() its arguments are too numerous to fit into a regular syscall. As such, use struct futex_waitv to pass the 'source' and 'destination' futexes to the syscall. This syscall implements what was previously known as FUTEX_CMP_REQUEUE and uses {val, uaddr, flags} for source and {uaddr, flags} for destination. This design explicitly allows requeueing between different types of futex by having a different flags word per uaddr. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Link: https://lore.kernel.org/r/20230921105248.511860556@noisy.programming.kicks-ass.net
2023-09-21futex: Add sys_futex_wait()peterz@infradead.org1-0/+1
To complement sys_futex_waitv()/wake(), add sys_futex_wait(). This syscall implements what was previously known as FUTEX_WAIT_BITSET except it uses 'unsigned long' for the value and bitmask arguments, takes timespec and clockid_t arguments for the absolute timeout and uses FUTEX2 flags. The 'unsigned long' allows FUTEX2_SIZE_U64 on 64bit platforms. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Link: https://lore.kernel.org/r/20230921105248.164324363@noisy.programming.kicks-ass.net
2023-09-21futex: Add sys_futex_wake()peterz@infradead.org1-0/+1
To complement sys_futex_waitv() add sys_futex_wake(). This syscall implements what was previously known as FUTEX_WAKE_BITSET except it uses 'unsigned long' for the bitmask and takes FUTEX2 flags. The 'unsigned long' allows FUTEX2_SIZE_U64 on 64bit platforms. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Link: https://lore.kernel.org/r/20230921105247.936205525@noisy.programming.kicks-ass.net
2023-07-27arch: Register fchmodat2, usually as syscall 452Palmer Dabbelt1-0/+1
This registers the new fchmodat2 syscall in most places as nuber 452, with alpha being the exception where it's 562. I found all these sites by grepping for fspick, which I assume has found me everything. Signed-off-by: Palmer Dabbelt <palmer@sifive.com> Signed-off-by: Alexey Gladkov <legion@kernel.org> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Message-Id: <a677d521f048e4ca439e7080a5328f21eb8e960e.1689092120.git.legion@kernel.org> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-06-09cachestat: wire up cachestat for other architecturesNhat Pham1-0/+1
cachestat is previously only wired in for x86 (and architectures using the generic unistd.h table): https://lore.kernel.org/lkml/20230503013608.2431726-1-nphamcs@gmail.com/ This patch wires cachestat in for all the other architectures. [nphamcs@gmail.com: wire up cachestat for arm64] Link: https://lkml.kernel.org/r/20230511092843.3896327-1-nphamcs@gmail.com Link: https://lkml.kernel.org/r/20230510195806.2902878-1-nphamcs@gmail.com Signed-off-by: Nhat Pham <nphamcs@gmail.com> Tested-by: Michael Ellerman <mpe@ellerman.id.au> [powerpc] Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> [m68k] Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Heiko Carstens <hca@linux.ibm.com> [s390] Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Chris Zankel <chris@zankel.net> Cc: David S. Miller <davem@davemloft.net> Cc: Helge Deller <deller@gmx.de> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michal Simek <monstr@monstr.eu> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Richard Henderson <richard.henderson@linaro.org> Cc: Rich Felker <dalias@libc.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-20s390: wire up memfd_secret system callHeiko Carstens1-1/+1
s390 supports ARCH_HAS_SET_DIRECT_MAP, therefore wire up the memfd_secret system call, which depends on it. Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-03-31arch: syscalls: simplify uapi/kapi directory creationMasahiro Yamada1-2/+1
$(shell ...) expands to empty. There is no need to assign it to _dummy. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
2022-01-15mm/mempolicy: wire up syscall set_mempolicy_home_nodeAneesh Kumar K.V1-0/+1
Link: https://lkml.kernel.org/r/20211202123810.267175-4-aneesh.kumar@linux.ibm.com Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Ben Widawsky <ben.widawsky@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Feng Tang <feng.tang@intel.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Andi Kleen <ak@linux.intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Huang Ying <ying.huang@intel.com> Cc: <linux-api@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-16s390: wire up sys_futex_waitv system callVasily Gorbik1-0/+1
Tested with futex kselftests. Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2021-09-08compat: remove some compat entry pointsArnd Bergmann1-5/+5
These are all handled correctly when calling the native system call entry point, so remove the special cases. Link: https://lkml.kernel.org/r/20210727144859.4150043-6-arnd@kernel.org Signed-off-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Eric Biederman <ebiederm@xmission.com> Cc: Feng Tang <feng.tang@intel.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03Merge branch 'akpm' (patches from Andrew)Linus Torvalds1-0/+2
Merge misc updates from Andrew Morton: "173 patches. Subsystems affected by this series: ia64, ocfs2, block, and mm (debug, pagecache, gup, swap, shmem, memcg, selftests, pagemap, mremap, bootmem, sparsemem, vmalloc, kasan, pagealloc, memory-failure, hugetlb, userfaultfd, vmscan, compaction, mempolicy, memblock, oom-kill, migration, ksm, percpu, vmstat, and madvise)" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (173 commits) mm/madvise: add MADV_WILLNEED to process_madvise() mm/vmstat: remove unneeded return value mm/vmstat: simplify the array size calculation mm/vmstat: correct some wrong comments mm/percpu,c: remove obsolete comments of pcpu_chunk_populated() selftests: vm: add COW time test for KSM pages selftests: vm: add KSM merging time test mm: KSM: fix data type selftests: vm: add KSM merging across nodes test selftests: vm: add KSM zero page merging test selftests: vm: add KSM unmerge test selftests: vm: add KSM merge test mm/migrate: correct kernel-doc notation mm: wire up syscall process_mrelease mm: introduce process_mrelease system call memblock: make memblock_find_in_range method private mm/mempolicy.c: use in_task() in mempolicy_slab_node() mm/mempolicy: unify the create() func for bind/interleave/prefer-many policies mm/mempolicy: advertise new MPOL_PREFERRED_MANY mm/hugetlb: add support for mempolicy MPOL_PREFERRED_MANY ...
2021-09-03mm: wire up syscall process_mreleaseSuren Baghdasaryan1-0/+2
Split off from prev patch in the series that implements the syscall. Link: https://lkml.kernel.org/r/20210809185259.405936-2-surenb@google.com Signed-off-by: Suren Baghdasaryan <surenb@google.com> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Christian Brauner <christian.brauner@ubuntu.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: David Hildenbrand <david@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Florian Weimer <fweimer@redhat.com> Cc: Jan Engelhardt <jengelh@inai.de> Cc: Jann Horn <jannh@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Rik van Riel <riel@surriel.com> Cc: Roman Gushchin <guro@fb.com> Cc: Shakeel Butt <shakeelb@google.com> Cc: Tim Murray <timmurray@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-12exit/bdflush: Remove the deprecated bdflush system callEric W. Biederman1-1/+1
The bdflush system call has been deprecated for a very long time. Recently Michael Schmitz tested[1] and found that the last known caller of of the bdflush system call is unaffected by it's removal. Since the code is not needed delete it. [1] https://lkml.kernel.org/r/36123b5d-daa0-6c2b-f2d4-a942f069fd54@gmail.com Link: https://lkml.kernel.org/r/87sg10quue.fsf_-_@disp2133 Tested-by: Michael Schmitz <schmitzmic@gmail.com> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Cyril Hrubis <chrubis@suse.cz> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>