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2024-01-09Merge tag 'lsm-pr-20240105' of ↵Linus Torvalds
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 Szeredi
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 Schaufler
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 Torvalds
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 Mehta
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 Mehta
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.org
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.org
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.org
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 Dabbelt
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>
2023-06-28Merge tag 'mm-stable-2023-06-24-19-15' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull mm updates from Andrew Morton: - Yosry Ahmed brought back some cgroup v1 stats in OOM logs - Yosry has also eliminated cgroup's atomic rstat flushing - Nhat Pham adds the new cachestat() syscall. It provides userspace with the ability to query pagecache status - a similar concept to mincore() but more powerful and with improved usability - Mel Gorman provides more optimizations for compaction, reducing the prevalence of page rescanning - Lorenzo Stoakes has done some maintanance work on the get_user_pages() interface - Liam Howlett continues with cleanups and maintenance work to the maple tree code. Peng Zhang also does some work on maple tree - Johannes Weiner has done some cleanup work on the compaction code - David Hildenbrand has contributed additional selftests for get_user_pages() - Thomas Gleixner has contributed some maintenance and optimization work for the vmalloc code - Baolin Wang has provided some compaction cleanups, - SeongJae Park continues maintenance work on the DAMON code - Huang Ying has done some maintenance on the swap code's usage of device refcounting - Christoph Hellwig has some cleanups for the filemap/directio code - Ryan Roberts provides two patch series which yield some rationalization of the kernel's access to pte entries - use the provided APIs rather than open-coding accesses - Lorenzo Stoakes has some fixes to the interaction between pagecache and directio access to file mappings - John Hubbard has a series of fixes to the MM selftesting code - ZhangPeng continues the folio conversion campaign - Hugh Dickins has been working on the pagetable handling code, mainly with a view to reducing the load on the mmap_lock - Catalin Marinas has reduced the arm64 kmalloc() minimum alignment from 128 to 8 - Domenico Cerasuolo has improved the zswap reclaim mechanism by reorganizing the LRU management - Matthew Wilcox provides some fixups to make gfs2 work better with the buffer_head code - Vishal Moola also has done some folio conversion work - Matthew Wilcox has removed the remnants of the pagevec code - their functionality is migrated over to struct folio_batch * tag 'mm-stable-2023-06-24-19-15' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (380 commits) mm/hugetlb: remove hugetlb_set_page_subpool() mm: nommu: correct the range of mmap_sem_read_lock in task_mem() hugetlb: revert use of page_cache_next_miss() Revert "page cache: fix page_cache_next/prev_miss off by one" mm/vmscan: fix root proactive reclaim unthrottling unbalanced node mm: memcg: rename and document global_reclaim() mm: kill [add|del]_page_to_lru_list() mm: compaction: convert to use a folio in isolate_migratepages_block() mm: zswap: fix double invalidate with exclusive loads mm: remove unnecessary pagevec includes mm: remove references to pagevec mm: rename invalidate_mapping_pagevec to mapping_try_invalidate mm: remove struct pagevec net: convert sunrpc from pagevec to folio_batch i915: convert i915_gpu_error to use a folio_batch pagevec: rename fbatch_count() mm: remove check_move_unevictable_pages() drm: convert drm_gem_put_pages() to use a folio_batch i915: convert shmem_sg_free_table() to use a folio_batch scatterlist: add sg_set_folio() ...
2023-06-12arm: update in-source documentation referencesJonathan Corbet
The Arm documentation has moved to Documentation/arch/arm; update references within arch/arm to match. Cc: Russell King <linux@armlinux.org.uk> Cc: Alim Akhtar <alim.akhtar@samsung.com> Cc: Patrice Chotard <patrice.chotard@foss.st.com> Cc: linux-doc@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-arch@vger.kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2023-06-09cachestat: wire up cachestat for other architecturesNhat Pham
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>
2022-03-31arch: syscalls: simplify uapi/kapi directory creationMasahiro Yamada
$(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.V
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>
2021-10-07futex,arm: Wire up sys_futex_waitv()André Almeida
Wire up syscall entry point for ARM architectures, for both 32 and 64-bit. Signed-off-by: André Almeida <andrealmeid@collabora.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20210923171111.300673-19-andrealmeid@collabora.com
2021-09-09Merge tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-armLinus Torvalds
Pull ARM development updates from Russell King: - Rename "mod_init" and "mod_exit" so that initcall debug output is actually useful (Randy Dunlap) - Update maintainers entries for linux-arm-kernel to indicate it is moderated for non-subscribers (Randy Dunlap) - Move install rules to arch/arm/Makefile (Masahiro Yamada) - Drop unnecessary ARCH_NR_GPIOS definition (Linus Walleij) - Don't warn about atags_to_fdt() stack size (David Heidelberg) - Speed up unaligned copy_{from,to}_kernel_nofault (Arnd Bergmann) - Get rid of set_fs() usage (Arnd Bergmann) - Remove checks for GCC prior to v4.6 (Geert Uytterhoeven) * tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm: ARM: 9118/1: div64: Remove always-true __div64_const32_is_OK() duplicate ARM: 9117/1: asm-generic: div64: Remove always-true __div64_const32_is_OK() ARM: 9116/1: unified: Remove check for gcc < 4 ARM: 9110/1: oabi-compat: fix oabi epoll sparse warning ARM: 9113/1: uaccess: remove set_fs() implementation ARM: 9112/1: uaccess: add __{get,put}_kernel_nofault ARM: 9111/1: oabi-compat: rework fcntl64() emulation ARM: 9114/1: oabi-compat: rework sys_semtimedop emulation ARM: 9108/1: oabi-compat: rework epoll_wait/epoll_pwait emulation ARM: 9107/1: syscall: always store thread_info->abi_syscall ARM: 9109/1: oabi-compat: add epoll_pwait handler ARM: 9106/1: traps: use get_kernel_nofault instead of set_fs() ARM: 9115/1: mm/maccess: fix unaligned copy_{from,to}_kernel_nofault ARM: 9105/1: atags_to_fdt: don't warn about stack size ARM: 9103/1: Drop ARCH_NR_GPIOS definition ARM: 9102/1: move theinstall rules to arch/arm/Makefile ARM: 9100/1: MAINTAINERS: mark all linux-arm-kernel@infradead list as moderated ARM: 9099/1: crypto: rename 'mod_init' & 'mod_exit' functions to be module-specific
2021-09-03Merge branch 'akpm' (patches from Andrew)Linus Torvalds
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 Baghdasaryan
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>
2021-08-20ARM: 9108/1: oabi-compat: rework epoll_wait/epoll_pwait emulationArnd Bergmann
The epoll_wait() system call wrapper is one of the remaining users of the set_fs() infrasturcture for Arm. Changing it to not require set_fs() is rather complex unfortunately. The approach I'm taking here is to allow architectures to override the code that copies the output to user space, and let the oabi-compat implementation check whether it is getting called from an EABI or OABI system call based on the thread_info->syscall value. The in_oabi_syscall() check here mirrors the in_compat_syscall() and in_x32_syscall() helpers for 32-bit compat implementations on other architectures. Overall, the amount of code goes down, at least with the newly added sys_oabi_epoll_pwait() helper getting removed again. The downside is added complexity in the source code for the native implementation. There should be no difference in runtime performance except for Arm kernels with CONFIG_OABI_COMPAT enabled that now have to go through an external function call to check which of the two variants to use. Acked-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
2021-08-20ARM: 9109/1: oabi-compat: add epoll_pwait handlerArnd Bergmann
The epoll_wait() syscall has a special version for OABI compat mode to convert the arguments to the EABI structure layout of the kernel. However, the later epoll_pwait() syscall was added in arch/arm in linux-2.6.32 without this conversion. Use the same kind of handler for both. Fixes: 369842658a36 ("ARM: 5677/1: ARM support for TIF_RESTORE_SIGMASK/pselect6/ppoll/epoll_pwait") Cc: stable@vger.kernel.org Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
2021-07-12exit/bdflush: Remove the deprecated bdflush system callEric W. Biederman
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>
2021-07-06Merge tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-armLinus Torvalds
Pull ARM development updates from Russell King: - Make it clear __swp_entry_to_pte() uses PTE_TYPE_FAULT - Updates for setting vmalloc size via command line to resolve an issue with the 8MiB hole not properly being accounted for, and clean up the code. - ftrace support for module PLTs - Spelling fixes - kbuild updates for removing generated files and pattern rules for generating files - Clang/llvm updates - Change the way the kernel is mapped, placing it in vmalloc space instead. - Remove arm_pm_restart from arm and aarch64. * tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm: (29 commits) ARM: 9098/1: ftrace: MODULE_PLT: Fix build problem without DYNAMIC_FTRACE ARM: 9097/1: mmu: Declare section start/end correctly ARM: 9096/1: Remove arm_pm_restart() ARM: 9095/1: ARM64: Remove arm_pm_restart() ARM: 9094/1: Register with kernel restart handler ARM: 9093/1: drivers: firmwapsci: Register with kernel restart handler ARM: 9092/1: xen: Register with kernel restart handler ARM: 9091/1: Revert "mm: qsd8x50: Fix incorrect permission faults" ARM: 9090/1: Map the lowmem and kernel separately ARM: 9089/1: Define kernel physical section start and end ARM: 9088/1: Split KERNEL_OFFSET from PAGE_OFFSET ARM: 9087/1: kprobes: test-thumb: fix for LLVM_IAS=1 ARM: 9086/1: syscalls: use pattern rules to generate syscall headers ARM: 9085/1: remove unneeded abi parameter to syscallnr.sh ARM: 9084/1: simplify the build rule of mach-types.h ARM: 9083/1: uncompress: atags_to_fdt: Spelling s/REturn/Return/ ARM: 9082/1: [v2] mark prepare_page_table as __init ARM: 9079/1: ftrace: Add MODULE_PLTS support ARM: 9078/1: Add warn suppress parameter to arm_gen_branch_link() ARM: 9077/1: PLT: Move struct plt_entries definition to header ...
2021-06-07ARM: 9086/1: syscalls: use pattern rules to generate syscall headersMasahiro Yamada
Use pattern rules to unify similar build rules between OABI and EABI. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2021-06-07ARM: 9085/1: remove unneeded abi parameter to syscallnr.shMasahiro Yamada
You do not need to pass the abi parameter to syscallnr.sh because it parses all the lines of syscall.tbl except comments anyway. Simplify the code. Also, remove unneeded single-quoting. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2021-06-07ARM: 9084/1: simplify the build rule of mach-types.hMasahiro Yamada
The directory of mach-types.h is created a couple of lines above: _dummy := $(shell [ -d '$(kapi)' ] || mkdir -p '$(kapi)') \ The 'mkdir -p' command is redundant. scripts/Kbuild.include defines real-prereqs as a shorthand for $(filter-out $(PHONY),$^). Let's use it to simplify the code. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2021-06-07quota: Wire up quotactl_fd syscallJan Kara
Wire up the quotactl_fd syscall. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz>
2021-05-17quota: Disable quotactl_path syscallJan Kara
In commit fa8b90070a80 ("quota: wire up quotactl_path") we have wired up new quotactl_path syscall. However some people in LWN discussion have objected that the path based syscall is missing dirfd and flags argument which is mostly standard for contemporary path based syscalls. Indeed they have a point and after a discussion with Christian Brauner and Sascha Hauer I've decided to disable the syscall for now and update its API. Since there is no userspace currently using that syscall and it hasn't been released in any major release, we should be fine. CC: Christian Brauner <christian.brauner@ubuntu.com> CC: Sascha Hauer <s.hauer@pengutronix.de> Link: https://lore.kernel.org/lkml/20210512153621.n5u43jsytbik4yze@wittgenstein Signed-off-by: Jan Kara <jack@suse.cz>
2021-05-06Merge tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-armLinus Torvalds
Pull ARM updates from Russell King: - Fix BSS size calculation for LLVM - Improve robustness of kernel entry around v7_invalidate_l1 - Fix and update kprobes assembly - Correct breakpoint overflow handler check - Pause function graph tracer when suspending a CPU - Switch to generic syscallhdr.sh and syscalltbl.sh - Remove now unused set_kernel_text_r[wo] functions - Updates for ptdump (__init marking and using DEFINE_SHOW_ATTRIBUTE) - Fix for interrupted SMC (secure) calls - Remove Compaq Personal Server platform * tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm: ARM: footbridge: remove personal server platform ARM: 9075/1: kernel: Fix interrupted SMC calls ARM: 9074/1: ptdump: convert to DEFINE_SHOW_ATTRIBUTE ARM: 9073/1: ptdump: add __init section marker to three functions ARM: 9072/1: mm: remove set_kernel_text_r[ow]() ARM: 9067/1: syscalls: switch to generic syscallhdr.sh ARM: 9068/1: syscalls: switch to generic syscalltbl.sh ARM: 9066/1: ftrace: pause/unpause function graph tracer in cpu_suspend() ARM: 9064/1: hw_breakpoint: Do not directly check the event's overflow_handler hook ARM: 9062/1: kprobes: rewrite test-arm.c in UAL ARM: 9061/1: kprobes: fix UNPREDICTABLE warnings ARM: 9060/1: kexec: Remove unused kexec_reinit callback ARM: 9059/1: cache-v7: get rid of mini-stack ARM: 9058/1: cache-v7: refactor v7_invalidate_l1 to avoid clobbering r5/r6 ARM: 9057/1: cache-v7: add missing ISB after cache level selection ARM: 9056/1: decompressor: fix BSS size calculation for LLVM ld.lld
2021-05-01Merge tag 'landlock_v34' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security Pull Landlock LSM from James Morris: "Add Landlock, a new LSM from Mickaël Salaün. Briefly, Landlock provides for unprivileged application sandboxing. From Mickaël's cover letter: "The goal of Landlock is to enable to restrict ambient rights (e.g. global filesystem access) for a set of processes. Because Landlock is a stackable LSM [1], it makes possible to create safe security sandboxes as new security layers in addition to the existing system-wide access-controls. This kind of sandbox is expected to help mitigate the security impact of bugs or unexpected/malicious behaviors in user-space applications. Landlock empowers any process, including unprivileged ones, to securely restrict themselves. Landlock is inspired by seccomp-bpf but instead of filtering syscalls and their raw arguments, a Landlock rule can restrict the use of kernel objects like file hierarchies, according to the kernel semantic. Landlock also takes inspiration from other OS sandbox mechanisms: XNU Sandbox, FreeBSD Capsicum or OpenBSD Pledge/Unveil. In this current form, Landlock misses some access-control features. This enables to minimize this patch series and ease review. This series still addresses multiple use cases, especially with the combined use of seccomp-bpf: applications with built-in sandboxing, init systems, security sandbox tools and security-oriented APIs [2]" The cover letter and v34 posting is here: https://lore.kernel.org/linux-security-module/20210422154123.13086-1-mic@digikod.net/ See also: https://landlock.io/ This code has had extensive design discussion and review over several years" Link: https://lore.kernel.org/lkml/50db058a-7dde-441b-a7f9-f6837fe8b69f@schaufler-ca.com/ [1] Link: https://lore.kernel.org/lkml/f646e1c7-33cf-333f-070c-0a40ad0468cd@digikod.net/ [2] * tag 'landlock_v34' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: landlock: Enable user space to infer supported features landlock: Add user and kernel documentation samples/landlock: Add a sandbox manager example selftests/landlock: Add user space tests landlock: Add syscall implementations arch: Wire up Landlock syscalls fs,security: Add sb_delete hook landlock: Support filesystem access-control LSM: Infrastructure management of the superblock landlock: Add ptrace restrictions landlock: Set up the security framework and manage credentials landlock: Add ruleset and domain management landlock: Add object management
2021-04-22arch: Wire up Landlock syscallsMickaël Salaün
Wire up the following system calls for all architectures: * landlock_create_ruleset(2) * landlock_add_rule(2) * landlock_restrict_self(2) Cc: Arnd Bergmann <arnd@arndb.de> Cc: James Morris <jmorris@namei.org> Cc: Jann Horn <jannh@google.com> Cc: Kees Cook <keescook@chromium.org> Cc: Serge E. Hallyn <serge@hallyn.com> Signed-off-by: Mickaël Salaün <mic@linux.microsoft.com> Link: https://lore.kernel.org/r/20210422154123.13086-10-mic@digikod.net Signed-off-by: James Morris <jamorris@linux.microsoft.com>
2021-03-25ARM: 9067/1: syscalls: switch to generic syscallhdr.shMasahiro Yamada
Many architectures duplicate similar shell scripts. This commit converts ARM to use scripts/syscallhdr.sh, and also collects OABI/OEBI syscalls into unistd-eabi.h/unistd-oabi.h, removing unistd-common.h. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2021-03-25ARM: 9068/1: syscalls: switch to generic syscalltbl.shMasahiro Yamada
Many architectures duplicate similar shell scripts. This commit converts ARM to use scripts/syscalltbl.sh. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Acked-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2021-03-17quota: wire up quotactl_pathSascha Hauer
Wire up the quotactl_path syscall added in the previous patch. Link: https://lore.kernel.org/r/20210304123541.30749-3-s.hauer@pengutronix.de Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz>
2021-02-25Merge tag 'kbuild-v5.12' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild updates from Masahiro Yamada: - Fix false-positive build warnings for ARCH=ia64 builds - Optimize dictionary size for module compression with xz - Check the compiler and linker versions in Kconfig - Fix misuse of extra-y - Support DWARF v5 debug info - Clamp SUBLEVEL to 255 because stable releases 4.4.x and 4.9.x exceeded the limit - Add generic syscall{tbl,hdr}.sh for cleanups across arches - Minor cleanups of genksyms - Minor cleanups of Kconfig * tag 'kbuild-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (38 commits) initramfs: Remove redundant dependency of RD_ZSTD on BLK_DEV_INITRD kbuild: remove deprecated 'always' and 'hostprogs-y/m' kbuild: parse C= and M= before changing the working directory kbuild: reuse this-makefile to define abs_srctree kconfig: unify rule of config, menuconfig, nconfig, gconfig, xconfig kconfig: omit --oldaskconfig option for 'make config' kconfig: fix 'invalid option' for help option kconfig: remove dead code in conf_askvalue() kconfig: clean up nested if-conditionals in check_conf() kconfig: Remove duplicate call to sym_get_string_value() Makefile: Remove # characters from compiler string Makefile: reuse CC_VERSION_TEXT kbuild: check the minimum linker version in Kconfig kbuild: remove ld-version macro scripts: add generic syscallhdr.sh scripts: add generic syscalltbl.sh arch: syscalls: remove $(srctree)/ prefix from syscall tables arch: syscalls: add missing FORCE and fix 'targets' to make if_changed work gen_compile_commands: prune some directories kbuild: simplify access to the kernel's version ...
2021-02-22arch: syscalls: remove $(srctree)/ prefix from syscall tablesMasahiro Yamada
The 'syscall' variables are not directly used in the commands. Remove the $(srctree)/ prefix because we can rely on VPATH. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-01-24fs: add mount_setattr()Christian Brauner
This implements the missing mount_setattr() syscall. While the new mount api allows to change the properties of a superblock there is currently no way to change the properties of a mount or a mount tree using file descriptors which the new mount api is based on. In addition the old mount api has the restriction that mount options cannot be applied recursively. This hasn't changed since changing mount options on a per-mount basis was implemented in [1] and has been a frequent request not just for convenience but also for security reasons. The legacy mount syscall is unable to accommodate this behavior without introducing a whole new set of flags because MS_REC | MS_REMOUNT | MS_BIND | MS_RDONLY | MS_NOEXEC | [...] only apply the mount option to the topmost mount. Changing MS_REC to apply to the whole mount tree would mean introducing a significant uapi change and would likely cause significant regressions. The new mount_setattr() syscall allows to recursively clear and set mount options in one shot. Multiple calls to change mount options requesting the same changes are idempotent: int mount_setattr(int dfd, const char *path, unsigned flags, struct mount_attr *uattr, size_t usize); Flags to modify path resolution behavior are specified in the @flags argument. Currently, AT_EMPTY_PATH, AT_RECURSIVE, AT_SYMLINK_NOFOLLOW, and AT_NO_AUTOMOUNT are supported. If useful, additional lookup flags to restrict path resolution as introduced with openat2() might be supported in the future. The mount_setattr() syscall can be expected to grow over time and is designed with extensibility in mind. It follows the extensible syscall pattern we have used with other syscalls such as openat2(), clone3(), sched_{set,get}attr(), and others. The set of mount options is passed in the uapi struct mount_attr which currently has the following layout: struct mount_attr { __u64 attr_set; __u64 attr_clr; __u64 propagation; __u64 userns_fd; }; The @attr_set and @attr_clr members are used to clear and set mount options. This way a user can e.g. request that a set of flags is to be raised such as turning mounts readonly by raising MOUNT_ATTR_RDONLY in @attr_set while at the same time requesting that another set of flags is to be lowered such as removing noexec from a mount tree by specifying MOUNT_ATTR_NOEXEC in @attr_clr. Note, since the MOUNT_ATTR_<atime> values are an enum starting from 0, not a bitmap, users wanting to transition to a different atime setting cannot simply specify the atime setting in @attr_set, but must also specify MOUNT_ATTR__ATIME in the @attr_clr field. So we ensure that MOUNT_ATTR__ATIME can't be partially set in @attr_clr and that @attr_set can't have any atime bits set if MOUNT_ATTR__ATIME isn't set in @attr_clr. The @propagation field lets callers specify the propagation type of a mount tree. Propagation is a single property that has four different settings and as such is not really a flag argument but an enum. Specifically, it would be unclear what setting and clearing propagation settings in combination would amount to. The legacy mount() syscall thus forbids the combination of multiple propagation settings too. The goal is to keep the semantics of mount propagation somewhat simple as they are overly complex as it is. The @userns_fd field lets user specify a user namespace whose idmapping becomes the idmapping of the mount. This is implemented and explained in detail in the next patch. [1]: commit 2e4b7fcd9260 ("[PATCH] r/o bind mounts: honor mount writer counts at remount") Link: https://lore.kernel.org/r/20210121131959.646623-35-christian.brauner@ubuntu.com Cc: David Howells <dhowells@redhat.com> Cc: Aleksa Sarai <cyphar@cyphar.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: linux-fsdevel@vger.kernel.org Cc: linux-api@vger.kernel.org Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2020-12-19epoll: wire up syscall epoll_pwait2Willem de Bruijn
Split off from prev patch in the series that implements the syscall. Link: https://lkml.kernel.org/r/20201121144401.3727659-4-willemdebruijn.kernel@gmail.com Signed-off-by: Willem de Bruijn <willemb@google.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-18mm/madvise: introduce process_madvise() syscall: an external memory hinting APIMinchan Kim
There is usecase that System Management Software(SMS) want to give a memory hint like MADV_[COLD|PAGEEOUT] to other processes and in the case of Android, it is the ActivityManagerService. The information required to make the reclaim decision is not known to the app. Instead, it is known to the centralized userspace daemon(ActivityManagerService), and that daemon must be able to initiate reclaim on its own without any app involvement. To solve the issue, this patch introduces a new syscall process_madvise(2). It uses pidfd of an external process to give the hint. It also supports vector address range because Android app has thousands of vmas due to zygote so it's totally waste of CPU and power if we should call the syscall one by one for each vma.(With testing 2000-vma syscall vs 1-vector syscall, it showed 15% performance improvement. I think it would be bigger in real practice because the testing ran very cache friendly environment). Another potential use case for the vector range is to amortize the cost ofTLB shootdowns for multiple ranges when using MADV_DONTNEED; this could benefit users like TCP receive zerocopy and malloc implementations. In future, we could find more usecases for other advises so let's make it happens as API since we introduce a new syscall at this moment. With that, existing madvise(2) user could replace it with process_madvise(2) with their own pid if they want to have batch address ranges support feature. ince it could affect other process's address range, only privileged process(PTRACE_MODE_ATTACH_FSCREDS) or something else(e.g., being the same UID) gives it the right to ptrace the process could use it successfully. The flag argument is reserved for future use if we need to extend the API. I think supporting all hints madvise has/will supported/support to process_madvise is rather risky. Because we are not sure all hints make sense from external process and implementation for the hint may rely on the caller being in the current context so it could be error-prone. Thus, I just limited hints as MADV_[COLD|PAGEOUT] in this patch. If someone want to add other hints, we could hear the usecase and review it for each hint. It's safer for maintenance rather than introducing a buggy syscall but hard to fix it later. So finally, the API is as follows, ssize_t process_madvise(int pidfd, const struct iovec *iovec, unsigned long vlen, int advice, unsigned int flags); DESCRIPTION The process_madvise() system call is used to give advice or directions to the kernel about the address ranges from external process as well as local process. It provides the advice to address ranges of process described by iovec and vlen. The goal of such advice is to improve system or application performance. The pidfd selects the process referred to by the PID file descriptor specified in pidfd. (See pidofd_open(2) for further information) The pointer iovec points to an array of iovec structures, defined in <sys/uio.h> as: struct iovec { void *iov_base; /* starting address */ size_t iov_len; /* number of bytes to be advised */ }; The iovec describes address ranges beginning at address(iov_base) and with size length of bytes(iov_len). The vlen represents the number of elements in iovec. The advice is indicated in the advice argument, which is one of the following at this moment if the target process specified by pidfd is external. MADV_COLD MADV_PAGEOUT Permission to provide a hint to external process is governed by a ptrace access mode PTRACE_MODE_ATTACH_FSCREDS check; see ptrace(2). The process_madvise supports every advice madvise(2) has if target process is in same thread group with calling process so user could use process_madvise(2) to extend existing madvise(2) to support vector address ranges. RETURN VALUE On success, process_madvise() returns the number of bytes advised. This return value may be less than the total number of requested bytes, if an error occurred. The caller should check return value to determine whether a partial advice occurred. FAQ: Q.1 - Why does any external entity have better knowledge? Quote from Sandeep "For Android, every application (including the special SystemServer) are forked from Zygote. The reason of course is to share as many libraries and classes between the two as possible to benefit from the preloading during boot. After applications start, (almost) all of the APIs end up calling into this SystemServer process over IPC (binder) and back to the application. In a fully running system, the SystemServer monitors every single process periodically to calculate their PSS / RSS and also decides which process is "important" to the user for interactivity. So, because of how these processes start _and_ the fact that the SystemServer is looping to monitor each process, it does tend to *know* which address range of the application is not used / useful. Besides, we can never rely on applications to clean things up themselves. We've had the "hey app1, the system is low on memory, please trim your memory usage down" notifications for a long time[1]. They rely on applications honoring the broadcasts and very few do. So, if we want to avoid the inevitable killing of the application and restarting it, some way to be able to tell the OS about unimportant memory in these applications will be useful. - ssp Q.2 - How to guarantee the race(i.e., object validation) between when giving a hint from an external process and get the hint from the target process? process_madvise operates on the target process's address space as it exists at the instant that process_madvise is called. If the space target process can run between the time the process_madvise process inspects the target process address space and the time that process_madvise is actually called, process_madvise may operate on memory regions that the calling process does not expect. It's the responsibility of the process calling process_madvise to close this race condition. For example, the calling process can suspend the target process with ptrace, SIGSTOP, or the freezer cgroup so that it doesn't have an opportunity to change its own address space before process_madvise is called. Another option is to operate on memory regions that the caller knows a priori will be unchanged in the target process. Yet another option is to accept the race for certain process_madvise calls after reasoning that mistargeting will do no harm. The suggested API itself does not provide synchronization. It also apply other APIs like move_pages, process_vm_write. The race isn't really a problem though. Why is it so wrong to require that callers do their own synchronization in some manner? Nobody objects to write(2) merely because it's possible for two processes to open the same file and clobber each other's writes --- instead, we tell people to use flock or something. Think about mmap. It never guarantees newly allocated address space is still valid when the user tries to access it because other threads could unmap the memory right before. That's where we need synchronization by using other API or design from userside. It shouldn't be part of API itself. If someone needs more fine-grained synchronization rather than process level, there were two ideas suggested - cookie[2] and anon-fd[3]. Both are applicable via using last reserved argument of the API but I don't think it's necessary right now since we have already ways to prevent the race so don't want to add additional complexity with more fine-grained optimization model. To make the API extend, it reserved an unsigned long as last argument so we could support it in future if someone really needs it. Q.3 - Why doesn't ptrace work? Injecting an madvise in the target process using ptrace would not work for us because such injected madvise would have to be executed by the target process, which means that process would have to be runnable and that creates the risk of the abovementioned race and hinting a wrong VMA. Furthermore, we want to act the hint in caller's context, not the callee's, because the callee is usually limited in cpuset/cgroups or even freezed state so they can't act by themselves quick enough, which causes more thrashing/kill. It doesn't work if the target process are ptraced(e.g., strace, debugger, minidump) because a process can have at most one ptracer. [1] https://developer.android.com/topic/performance/memory" [2] process_getinfo for getting the cookie which is updated whenever vma of process address layout are changed - Daniel Colascione - https://lore.kernel.org/lkml/20190520035254.57579-1-minchan@kernel.org/T/#m7694416fd179b2066a2c62b5b139b14e3894e224 [3] anonymous fd which is used for the object(i.e., address range) validation - Michal Hocko - https://lore.kernel.org/lkml/20200120112722.GY18451@dhcp22.suse.cz/ [minchan@kernel.org: fix process_madvise build break for arm64] Link: http://lkml.kernel.org/r/20200303145756.GA219683@google.com [minchan@kernel.org: fix build error for mips of process_madvise] Link: http://lkml.kernel.org/r/20200508052517.GA197378@google.com [akpm@linux-foundation.org: fix patch ordering issue] [akpm@linux-foundation.org: fix arm64 whoops] [minchan@kernel.org: make process_madvise() vlen arg have type size_t, per Florian] [akpm@linux-foundation.org: fix i386 build] [sfr@canb.auug.org.au: fix syscall numbering] Link: https://lkml.kernel.org/r/20200905142639.49fc3f1a@canb.auug.org.au [sfr@canb.auug.org.au: madvise.c needs compat.h] Link: https://lkml.kernel.org/r/20200908204547.285646b4@canb.auug.org.au [minchan@kernel.org: fix mips build] Link: https://lkml.kernel.org/r/20200909173655.GC2435453@google.com [yuehaibing@huawei.com: remove duplicate header which is included twice] Link: https://lkml.kernel.org/r/20200915121550.30584-1-yuehaibing@huawei.com [minchan@kernel.org: do not use helper functions for process_madvise] Link: https://lkml.kernel.org/r/20200921175539.GB387368@google.com [akpm@linux-foundation.org: pidfd_get_pid() gained an argument] [sfr@canb.auug.org.au: fix up for "iov_iter: transparently handle compat iovecs in import_iovec"] Link: https://lkml.kernel.org/r/20200928212542.468e1fef@canb.auug.org.au Signed-off-by: Minchan Kim <minchan@kernel.org> Signed-off-by: YueHaibing <yuehaibing@huawei.com> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Suren Baghdasaryan <surenb@google.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: David Rientjes <rientjes@google.com> Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com> Cc: Brian Geffon <bgeffon@google.com> Cc: Christian Brauner <christian@brauner.io> Cc: Daniel Colascione <dancol@google.com> Cc: Jann Horn <jannh@google.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Joel Fernandes <joel@joelfernandes.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: John Dias <joaodias@google.com> Cc: Kirill Tkhai <ktkhai@virtuozzo.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Oleksandr Natalenko <oleksandr@redhat.com> Cc: Sandeep Patil <sspatil@google.com> Cc: SeongJae Park <sj38.park@gmail.com> Cc: SeongJae Park <sjpark@amazon.de> Cc: Shakeel Butt <shakeelb@google.com> Cc: Sonny Rao <sonnyrao@google.com> Cc: Tim Murray <timmurray@google.com> Cc: Christian Brauner <christian.brauner@ubuntu.com> Cc: Florian Weimer <fw@deneb.enyo.de> Cc: <linux-man@vger.kernel.org> Link: http://lkml.kernel.org/r/20200302193630.68771-3-minchan@kernel.org Link: http://lkml.kernel.org/r/20200508183320.GA125527@google.com Link: http://lkml.kernel.org/r/20200622192900.22757-4-minchan@kernel.org Link: https://lkml.kernel.org/r/20200901000633.1920247-4-minchan@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-14all arch: remove system call sys_sysctlXiaoming Ni
Since commit 61a47c1ad3a4dc ("sysctl: Remove the sysctl system call"), sys_sysctl is actually unavailable: any input can only return an error. We have been warning about people using the sysctl system call for years and believe there are no more users. Even if there are users of this interface if they have not complained or fixed their code by now they probably are not going to, so there is no point in warning them any longer. So completely remove sys_sysctl on all architectures. [nixiaoming@huawei.com: s390: fix build error for sys_call_table_emu] Link: http://lkml.kernel.org/r/20200618141426.16884-1-nixiaoming@huawei.com Signed-off-by: Xiaoming Ni <nixiaoming@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Will Deacon <will@kernel.org> [arm/arm64] Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Aleksa Sarai <cyphar@cyphar.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andi Kleen <ak@linux.intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Bin Meng <bin.meng@windriver.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: chenzefeng <chenzefeng2@huawei.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Christian Brauner <christian@brauner.io> Cc: Chris Zankel <chris@zankel.net> Cc: David Howells <dhowells@redhat.com> Cc: David S. Miller <davem@davemloft.net> Cc: Diego Elio Pettenò <flameeyes@flameeyes.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Dominik Brodowski <linux@dominikbrodowski.net> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Iurii Zaikin <yzaikin@google.com> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Kars de Jong <jongk@linux-m68k.org> Cc: Kees Cook <keescook@chromium.org> Cc: Krzysztof Kozlowski <krzk@kernel.org> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Marco Elver <elver@google.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Martin K. Petersen <martin.petersen@oracle.com> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Miklos Szeredi <mszeredi@redhat.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Cc: Nick Piggin <npiggin@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Olof Johansson <olof@lixom.net> Cc: Paul Burton <paulburton@kernel.org> Cc: "Paul E. McKenney" <paulmck@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com> Cc: Richard Henderson <rth@twiddle.net> Cc: Rich Felker <dalias@libc.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Sami Tolvanen <samitolvanen@google.com> Cc: Sargun Dhillon <sargun@sargun.me> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Sudeep Holla <sudeep.holla@arm.com> Cc: Sven Schnelle <svens@stackframe.org> Cc: Thiago Jung Bauermann <bauerman@linux.ibm.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Zhou Yanjie <zhouyanjie@wanyeetech.com> Link: http://lkml.kernel.org/r/20200616030734.87257-1-nixiaoming@huawei.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-17arch: wire-up close_range()Christian Brauner
This wires up the close_range() syscall into all arches at once. Suggested-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Cc: Jann Horn <jannh@google.com> Cc: David Howells <dhowells@redhat.com> Cc: Dmitry V. Levin <ldv@altlinux.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Florian Weimer <fweimer@redhat.com> Cc: linux-api@vger.kernel.org Cc: linux-alpha@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-xtensa@linux-xtensa.org Cc: linux-arch@vger.kernel.org Cc: x86@kernel.org
2020-05-14vfs: add faccessat2 syscallMiklos Szeredi
POSIX defines faccessat() as having a fourth "flags" argument, while the linux syscall doesn't have it. Glibc tries to emulate AT_EACCESS and AT_SYMLINK_NOFOLLOW, but AT_EACCESS emulation is broken. Add a new faccessat(2) syscall with the added flags argument and implement both flags. The value of AT_EACCESS is defined in glibc headers to be the same as AT_REMOVEDIR. Use this value for the kernel interface as well, together with the explanatory comment. Also add AT_EMPTY_PATH support, which is not documented by POSIX, but can be useful and is trivial to implement. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-01-29Merge tag 'threads-v5.6' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux Pull thread management updates from Christian Brauner: "Sargun Dhillon over the last cycle has worked on the pidfd_getfd() syscall. This syscall allows for the retrieval of file descriptors of a process based on its pidfd. A task needs to have ptrace_may_access() permissions with PTRACE_MODE_ATTACH_REALCREDS (suggested by Oleg and Andy) on the target. One of the main use-cases is in combination with seccomp's user notification feature. As a reminder, seccomp's user notification feature was made available in v5.0. It allows a task to retrieve a file descriptor for its seccomp filter. The file descriptor is usually handed of to a more privileged supervising process. The supervisor can then listen for syscall events caught by the seccomp filter of the supervisee and perform actions in lieu of the supervisee, usually emulating syscalls. pidfd_getfd() is needed to expand its uses. There are currently two major users that wait on pidfd_getfd() and one future user: - Netflix, Sargun said, is working on a service mesh where users should be able to connect to a dns-based VIP. When a user connects to e.g. 1.2.3.4:80 that runs e.g. service "foo" they will be redirected to an envoy process. This service mesh uses seccomp user notifications and pidfd to intercept all connect calls and instead of connecting them to 1.2.3.4:80 connects them to e.g. 127.0.0.1:8080. - LXD uses the seccomp notifier heavily to intercept and emulate mknod() and mount() syscalls for unprivileged containers/processes. With pidfd_getfd() more uses-cases e.g. bridging socket connections will be possible. - The patchset has also seen some interest from the browser corner. Right now, Firefox is using a SECCOMP_RET_TRAP sandbox managed by a broker process. In the future glibc will start blocking all signals during dlopen() rendering this type of sandbox impossible. Hence, in the future Firefox will switch to a seccomp-user-nofication based sandbox which also makes use of file descriptor retrieval. The thread for this can be found at https://sourceware.org/ml/libc-alpha/2019-12/msg00079.html With pidfd_getfd() it is e.g. possible to bridge socket connections for the supervisee (binding to a privileged port) and taking actions on file descriptors on behalf of the supervisee in general. Sargun's first version was using an ioctl on pidfds but various people pushed for it to be a proper syscall which he duely implemented as well over various review cycles. Selftests are of course included. I've also added instructions how to deal with merge conflicts below. There's also a small fix coming from the kernel mentee project to correctly annotate struct sighand_struct with __rcu to fix various sparse warnings. We've received a few more such fixes and even though they are mostly trivial I've decided to postpone them until after -rc1 since they came in rather late and I don't want to risk introducing build warnings. Finally, there's a new prctl() command PR_{G,S}ET_IO_FLUSHER which is needed to avoid allocation recursions triggerable by storage drivers that have userspace parts that run in the IO path (e.g. dm-multipath, iscsi, etc). These allocation recursions deadlock the device. The new prctl() allows such privileged userspace components to avoid allocation recursions by setting the PF_MEMALLOC_NOIO and PF_LESS_THROTTLE flags. The patch carries the necessary acks from the relevant maintainers and is routed here as part of prctl() thread-management." * tag 'threads-v5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux: prctl: PR_{G,S}ET_IO_FLUSHER to support controlling memory reclaim sched.h: Annotate sighand_struct with __rcu test: Add test for pidfd getfd arch: wire up pidfd_getfd syscall pid: Implement pidfd_getfd syscall vfs, fdtable: Add fget_task helper
2020-01-18open: introduce openat2(2) syscallAleksa Sarai
/* Background. */ For a very long time, extending openat(2) with new features has been incredibly frustrating. This stems from the fact that openat(2) is possibly the most famous counter-example to the mantra "don't silently accept garbage from userspace" -- it doesn't check whether unknown flags are present[1]. This means that (generally) the addition of new flags to openat(2) has been fraught with backwards-compatibility issues (O_TMPFILE has to be defined as __O_TMPFILE|O_DIRECTORY|[O_RDWR or O_WRONLY] to ensure old kernels gave errors, since it's insecure to silently ignore the flag[2]). All new security-related flags therefore have a tough road to being added to openat(2). Userspace also has a hard time figuring out whether a particular flag is supported on a particular kernel. While it is now possible with contemporary kernels (thanks to [3]), older kernels will expose unknown flag bits through fcntl(F_GETFL). Giving a clear -EINVAL during openat(2) time matches modern syscall designs and is far more fool-proof. In addition, the newly-added path resolution restriction LOOKUP flags (which we would like to expose to user-space) don't feel related to the pre-existing O_* flag set -- they affect all components of path lookup. We'd therefore like to add a new flag argument. Adding a new syscall allows us to finally fix the flag-ignoring problem, and we can make it extensible enough so that we will hopefully never need an openat3(2). /* Syscall Prototype. */ /* * open_how is an extensible structure (similar in interface to * clone3(2) or sched_setattr(2)). The size parameter must be set to * sizeof(struct open_how), to allow for future extensions. All future * extensions will be appended to open_how, with their zero value * acting as a no-op default. */ struct open_how { /* ... */ }; int openat2(int dfd, const char *pathname, struct open_how *how, size_t size); /* Description. */ The initial version of 'struct open_how' contains the following fields: flags Used to specify openat(2)-style flags. However, any unknown flag bits or otherwise incorrect flag combinations (like O_PATH|O_RDWR) will result in -EINVAL. In addition, this field is 64-bits wide to allow for more O_ flags than currently permitted with openat(2). mode The file mode for O_CREAT or O_TMPFILE. Must be set to zero if flags does not contain O_CREAT or O_TMPFILE. resolve Restrict path resolution (in contrast to O_* flags they affect all path components). The current set of flags are as follows (at the moment, all of the RESOLVE_ flags are implemented as just passing the corresponding LOOKUP_ flag). RESOLVE_NO_XDEV => LOOKUP_NO_XDEV RESOLVE_NO_SYMLINKS => LOOKUP_NO_SYMLINKS RESOLVE_NO_MAGICLINKS => LOOKUP_NO_MAGICLINKS RESOLVE_BENEATH => LOOKUP_BENEATH RESOLVE_IN_ROOT => LOOKUP_IN_ROOT open_how does not contain an embedded size field, because it is of little benefit (userspace can figure out the kernel open_how size at runtime fairly easily without it). It also only contains u64s (even though ->mode arguably should be a u16) to avoid having padding fields which are never used in the future. Note that as a result of the new how->flags handling, O_PATH|O_TMPFILE is no longer permitted for openat(2). As far as I can tell, this has always been a bug and appears to not be used by userspace (and I've not seen any problems on my machines by disallowing it). If it turns out this breaks something, we can special-case it and only permit it for openat(2) but not openat2(2). After input from Florian Weimer, the new open_how and flag definitions are inside a separate header from uapi/linux/fcntl.h, to avoid problems that glibc has with importing that header. /* Testing. */ In a follow-up patch there are over 200 selftests which ensure that this syscall has the correct semantics and will correctly handle several attack scenarios. In addition, I've written a userspace library[4] which provides convenient wrappers around openat2(RESOLVE_IN_ROOT) (this is necessary because no other syscalls support RESOLVE_IN_ROOT, and thus lots of care must be taken when using RESOLVE_IN_ROOT'd file descriptors with other syscalls). During the development of this patch, I've run numerous verification tests using libpathrs (showing that the API is reasonably usable by userspace). /* Future Work. */ Additional RESOLVE_ flags have been suggested during the review period. These can be easily implemented separately (such as blocking auto-mount during resolution). Furthermore, there are some other proposed changes to the openat(2) interface (the most obvious example is magic-link hardening[5]) which would be a good opportunity to add a way for userspace to restrict how O_PATH file descriptors can be re-opened. Another possible avenue of future work would be some kind of CHECK_FIELDS[6] flag which causes the kernel to indicate to userspace which openat2(2) flags and fields are supported by the current kernel (to avoid userspace having to go through several guesses to figure it out). [1]: https://lwn.net/Articles/588444/ [2]: https://lore.kernel.org/lkml/CA+55aFyyxJL1LyXZeBsf2ypriraj5ut1XkNDsunRBqgVjZU_6Q@mail.gmail.com [3]: commit 629e014bb834 ("fs: completely ignore unknown open flags") [4]: https://sourceware.org/bugzilla/show_bug.cgi?id=17523 [5]: https://lore.kernel.org/lkml/20190930183316.10190-2-cyphar@cyphar.com/ [6]: https://youtu.be/ggD-eb3yPVs Suggested-by: Christian Brauner <christian.brauner@ubuntu.com> Signed-off-by: Aleksa Sarai <cyphar@cyphar.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-01-13arch: wire up pidfd_getfd syscallSargun Dhillon
This wires up the pidfd_getfd syscall for all architectures. Signed-off-by: Sargun Dhillon <sargun@sargun.me> Acked-by: Christian Brauner <christian.brauner@ubuntu.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Link: https://lore.kernel.org/r/20200107175927.4558-4-sargun@sargun.me Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2019-07-15docs: arm: convert docs to ReST and rename to *.rstMauro Carvalho Chehab
Converts ARM the text files to ReST, preparing them to be an architecture book. The conversion is actually: - add blank lines and identation in order to identify paragraphs; - fix tables markups; - add some lists markups; - mark literal blocks; - adjust title markups. At its new index.rst, let's add a :orphan: while this is not linked to the main index.rst file, in order to avoid build warnings. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Reviewed-by Corentin Labbe <clabbe.montjoie@gmail.com> # For sun4i-ss
2019-07-11Merge tag 'clone3-v5.3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux Pull clone3 system call from Christian Brauner: "This adds the clone3 syscall which is an extensible successor to clone after we snagged the last flag with CLONE_PIDFD during the 5.2 merge window for clone(). It cleanly supports all of the flags from clone() and thus all legacy workloads. There are few user visible differences between clone3 and clone. First, CLONE_DETACHED will cause EINVAL with clone3 so we can reuse this flag. Second, the CSIGNAL flag is deprecated and will cause EINVAL to be reported. It is superseeded by a dedicated "exit_signal" argument in struct clone_args thus freeing up even more flags. And third, clone3 gives CLONE_PIDFD a dedicated return argument in struct clone_args instead of abusing CLONE_PARENT_SETTID's parent_tidptr argument. The clone3 uapi is designed to be easy to handle on 32- and 64 bit: /* uapi */ struct clone_args { __aligned_u64 flags; __aligned_u64 pidfd; __aligned_u64 child_tid; __aligned_u64 parent_tid; __aligned_u64 exit_signal; __aligned_u64 stack; __aligned_u64 stack_size; __aligned_u64 tls; }; and a separate kernel struct is used that uses proper kernel typing: /* kernel internal */ struct kernel_clone_args { u64 flags; int __user *pidfd; int __user *child_tid; int __user *parent_tid; int exit_signal; unsigned long stack; unsigned long stack_size; unsigned long tls; }; The system call comes with a size argument which enables the kernel to detect what version of clone_args userspace is passing in. clone3 validates that any additional bytes a given kernel does not know about are set to zero and that the size never exceeds a page. A nice feature is that this patchset allowed us to cleanup and simplify various core kernel codepaths in kernel/fork.c by making the internal _do_fork() function take struct kernel_clone_args even for legacy clone(). This patch also unblocks the time namespace patchset which wants to introduce a new CLONE_TIMENS flag. Note, that clone3 has only been wired up for x86{_32,64}, arm{64}, and xtensa. These were the architectures that did not require special massaging. Other architectures treat fork-like system calls individually and after some back and forth neither Arnd nor I felt confident that we dared to add clone3 unconditionally to all architectures. We agreed to leave this up to individual architecture maintainers. This is why there's an additional patch that introduces __ARCH_WANT_SYS_CLONE3 which any architecture can set once it has implemented support for clone3. The patch also adds a cond_syscall(clone3) for architectures such as nios2 or h8300 that generate their syscall table by simply including asm-generic/unistd.h. The hope is to get rid of __ARCH_WANT_SYS_CLONE3 and cond_syscall() rather soon" * tag 'clone3-v5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux: arch: handle arches who do not yet define clone3 arch: wire-up clone3() syscall fork: add clone3
2019-06-28arch: wire-up pidfd_open()Christian Brauner
This wires up the pidfd_open() syscall into all arches at once. Signed-off-by: Christian Brauner <christian@brauner.io> Reviewed-by: David Howells <dhowells@redhat.com> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Kees Cook <keescook@chromium.org> Cc: Joel Fernandes (Google) <joel@joelfernandes.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Jann Horn <jannh@google.com> Cc: Andy Lutomirsky <luto@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Aleksa Sarai <cyphar@cyphar.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: linux-api@vger.kernel.org Cc: linux-alpha@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-xtensa@linux-xtensa.org Cc: linux-arch@vger.kernel.org Cc: x86@kernel.org
2019-06-09arch: wire-up clone3() syscallChristian Brauner
Wire up the clone3() call on all arches that don't require hand-rolled assembly. Some of the arches look like they need special assembly massaging and it is probably smarter if the appropriate arch maintainers would do the actual wiring. Arches that are wired-up are: - x86{_32,64} - arm{64} - xtensa Signed-off-by: Christian Brauner <christian@brauner.io> Acked-by: Arnd Bergmann <arnd@arndb.de> Cc: Kees Cook <keescook@chromium.org> Cc: David Howells <dhowells@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Adrian Reber <adrian@lisas.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Florian Weimer <fweimer@redhat.com> Cc: linux-api@vger.kernel.org Cc: linux-arch@vger.kernel.org Cc: x86@kernel.org
2019-05-16uapi: Wire up the mount API syscalls on non-x86 arches [ver #2]David Howells
Wire up the mount API syscalls on non-x86 arches. Reported-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>