summaryrefslogtreecommitdiffstats
path: root/arch/xtensa/kernel
AgeCommit message (Collapse)Author
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>
2020-08-07Merge branch 'akpm' (patches from Andrew)Linus Torvalds
Merge misc updates from Andrew Morton: - a few MM hotfixes - kthread, tools, scripts, ntfs and ocfs2 - some of MM Subsystems affected by this patch series: kthread, tools, scripts, ntfs, ocfs2 and mm (hofixes, pagealloc, slab-generic, slab, slub, kcsan, debug, pagecache, gup, swap, shmem, memcg, pagemap, mremap, mincore, sparsemem, vmalloc, kasan, pagealloc, hugetlb and vmscan). * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (162 commits) mm: vmscan: consistent update to pgrefill mm/vmscan.c: fix typo khugepaged: khugepaged_test_exit() check mmget_still_valid() khugepaged: retract_page_tables() remember to test exit khugepaged: collapse_pte_mapped_thp() protect the pmd lock khugepaged: collapse_pte_mapped_thp() flush the right range mm/hugetlb: fix calculation of adjust_range_if_pmd_sharing_possible mm: thp: replace HTTP links with HTTPS ones mm/page_alloc: fix memalloc_nocma_{save/restore} APIs mm/page_alloc.c: skip setting nodemask when we are in interrupt mm/page_alloc: fallbacks at most has 3 elements mm/page_alloc: silence a KASAN false positive mm/page_alloc.c: remove unnecessary end_bitidx for [set|get]_pfnblock_flags_mask() mm/page_alloc.c: simplify pageblock bitmap access mm/page_alloc.c: extract the common part in pfn_to_bitidx() mm/page_alloc.c: replace the definition of NR_MIGRATETYPE_BITS with PB_migratetype_bits mm/shuffle: remove dynamic reconfiguration mm/memory_hotplug: document why shuffle_zone() is relevant mm/page_alloc: remove nr_free_pagecache_pages() mm: remove vm_total_pages ...
2020-08-07mm: remove unneeded includes of <asm/pgalloc.h>Mike Rapoport
Patch series "mm: cleanup usage of <asm/pgalloc.h>" Most architectures have very similar versions of pXd_alloc_one() and pXd_free_one() for intermediate levels of page table. These patches add generic versions of these functions in <asm-generic/pgalloc.h> and enable use of the generic functions where appropriate. In addition, functions declared and defined in <asm/pgalloc.h> headers are used mostly by core mm and early mm initialization in arch and there is no actual reason to have the <asm/pgalloc.h> included all over the place. The first patch in this series removes unneeded includes of <asm/pgalloc.h> In the end it didn't work out as neatly as I hoped and moving pXd_alloc_track() definitions to <asm-generic/pgalloc.h> would require unnecessary changes to arches that have custom page table allocations, so I've decided to move lib/ioremap.c to mm/ and make pgalloc-track.h local to mm/. This patch (of 8): In most cases <asm/pgalloc.h> header is required only for allocations of page table memory. Most of the .c files that include that header do not use symbols declared in <asm/pgalloc.h> and do not require that header. As for the other header files that used to include <asm/pgalloc.h>, it is possible to move that include into the .c file that actually uses symbols from <asm/pgalloc.h> and drop the include from the header file. The process was somewhat automated using sed -i -E '/[<"]asm\/pgalloc\.h/d' \ $(grep -L -w -f /tmp/xx \ $(git grep -E -l '[<"]asm/pgalloc\.h')) where /tmp/xx contains all the symbols defined in arch/*/include/asm/pgalloc.h. [rppt@linux.ibm.com: fix powerpc warning] Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Pekka Enberg <penberg@kernel.org> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> [m68k] Cc: Abdul Haleem <abdhalee@linux.vnet.ibm.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Joerg Roedel <joro@8bytes.org> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com> Cc: Stafford Horne <shorne@gmail.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Joerg Roedel <jroedel@suse.de> Cc: Matthew Wilcox <willy@infradead.org> Link: http://lkml.kernel.org/r/20200627143453.31835-1-rppt@kernel.org Link: http://lkml.kernel.org/r/20200627143453.31835-2-rppt@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-07Merge branch 'work.regset' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull ptrace regset updates from Al Viro: "Internal regset API changes: - regularize copy_regset_{to,from}_user() callers - switch to saner calling conventions for ->get() - kill user_regset_copyout() The ->put() side of things will have to wait for the next cycle, unfortunately. The balance is about -1KLoC and replacements for ->get() instances are a lot saner" * 'work.regset' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (41 commits) regset: kill user_regset_copyout{,_zero}() regset(): kill ->get_size() regset: kill ->get() csky: switch to ->regset_get() xtensa: switch to ->regset_get() parisc: switch to ->regset_get() nds32: switch to ->regset_get() nios2: switch to ->regset_get() hexagon: switch to ->regset_get() h8300: switch to ->regset_get() openrisc: switch to ->regset_get() riscv: switch to ->regset_get() c6x: switch to ->regset_get() ia64: switch to ->regset_get() arc: switch to ->regset_get() arm: switch to ->regset_get() sh: convert to ->regset_get() arm64: switch to ->regset_get() mips: switch to ->regset_get() sparc: switch to ->regset_get() ...
2020-08-06Merge tag 'xtensa-20200805' of git://github.com/jcmvbkbc/linux-xtensaLinus Torvalds
Pull Xtensa updates from Max Filippov: - add syscall audit support - add seccomp filter support - clean up make rules under arch/xtensa/boot - fix state management for exclusive access opcodes - fix build with PMU enabled * tag 'xtensa-20200805' of git://github.com/jcmvbkbc/linux-xtensa: xtensa: add missing exclusive access state management xtensa: fix xtensa_pmu_setup prototype xtensa: add boot subdirectories build artifacts to 'targets' xtensa: add uImage and xipImage to targets xtensa: move vmlinux.bin[.gz] to boot subdirectory xtensa: initialize_mmu.h: fix a duplicated word selftests/seccomp: add xtensa support xtensa: add seccomp support xtensa: expose syscall through user_pt_regs xtensa: add audit support
2020-08-04Merge tag 'close-range-v5.9' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux Pull close_range() implementation from Christian Brauner: "This adds the close_range() syscall. It allows to efficiently close a range of file descriptors up to all file descriptors of a calling task. This is coordinated with the FreeBSD folks which have copied our version of this syscall and in the meantime have already merged it in April 2019: https://reviews.freebsd.org/D21627 https://svnweb.freebsd.org/base?view=revision&revision=359836 The syscall originally came up in a discussion around the new mount API and making new file descriptor types cloexec by default. During this discussion, Al suggested the close_range() syscall. First, it helps to close all file descriptors of an exec()ing task. This can be done safely via (quoting Al's example from [1] verbatim): /* that exec is sensitive */ unshare(CLONE_FILES); /* we don't want anything past stderr here */ close_range(3, ~0U); execve(....); The code snippet above is one way of working around the problem that file descriptors are not cloexec by default. This is aggravated by the fact that we can't just switch them over without massively regressing userspace. For a whole class of programs having an in-kernel method of closing all file descriptors is very helpful (e.g. demons, service managers, programming language standard libraries, container managers etc.). Second, it allows userspace to avoid implementing closing all file descriptors by parsing through /proc/<pid>/fd/* and calling close() on each file descriptor and other hacks. From looking at various large(ish) userspace code bases this or similar patterns are very common in service managers, container runtimes, and programming language runtimes/standard libraries such as Python or Rust. In addition, the syscall will also work for tasks that do not have procfs mounted and on kernels that do not have procfs support compiled in. In such situations the only way to make sure that all file descriptors are closed is to call close() on each file descriptor up to UINT_MAX or RLIMIT_NOFILE, OPEN_MAX trickery. Based on Linus' suggestion close_range() also comes with a new flag CLOSE_RANGE_UNSHARE to more elegantly handle file descriptor dropping right before exec. This would usually be expressed in the sequence: unshare(CLONE_FILES); close_range(3, ~0U); as pointed out by Linus it might be desirable to have this be a part of close_range() itself under a new flag CLOSE_RANGE_UNSHARE which gets especially handy when we're closing all file descriptors above a certain threshold. Test-suite as always included" * tag 'close-range-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux: tests: add CLOSE_RANGE_UNSHARE tests close_range: add CLOSE_RANGE_UNSHARE tests: add close_range() tests arch: wire-up close_range() open: add close_range()
2020-08-04Merge tag 'fork-v5.9' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux Pull fork cleanups from Christian Brauner: "This is cleanup series from when we reworked a chunk of the process creation paths in the kernel and switched to struct {kernel_}clone_args. High-level this does two main things: - Remove the double export of both do_fork() and _do_fork() where do_fork() used the incosistent legacy clone calling convention. Now we only export _do_fork() which is based on struct kernel_clone_args. - Remove the copy_thread_tls()/copy_thread() split making the architecture specific HAVE_COYP_THREAD_TLS config option obsolete. This switches all remaining architectures to select HAVE_COPY_THREAD_TLS and thus to the copy_thread_tls() calling convention. The current split makes the process creation codepaths more convoluted than they need to be. Each architecture has their own copy_thread() function unless it selects HAVE_COPY_THREAD_TLS then it has a copy_thread_tls() function. The split is not needed anymore nowadays, all architectures support CLONE_SETTLS but quite a few of them never bothered to select HAVE_COPY_THREAD_TLS and instead simply continued to use copy_thread() and use the old calling convention. Removing this split cleans up the process creation codepaths and paves the way for implementing clone3() on such architectures since it requires the copy_thread_tls() calling convention. After having made each architectures support copy_thread_tls() this series simply renames that function back to copy_thread(). It also switches all architectures that call do_fork() directly over to _do_fork() and the struct kernel_clone_args calling convention. This is a corollary of switching the architectures that did not yet support it over to copy_thread_tls() since do_fork() is conditional on not supporting copy_thread_tls() (Mostly because it lacks a separate argument for tls which is trivial to fix but there's no need for this function to exist.). The do_fork() removal is in itself already useful as it allows to to remove the export of both do_fork() and _do_fork() we currently have in favor of only _do_fork(). This has already been discussed back when we added clone3(). The legacy clone() calling convention is - as is probably well-known - somewhat odd: # # ABI hall of shame # config CLONE_BACKWARDS config CLONE_BACKWARDS2 config CLONE_BACKWARDS3 that is aggravated by the fact that some architectures such as sparc follow the CLONE_BACKWARDSx calling convention but don't really select the corresponding config option since they call do_fork() directly. So do_fork() enforces a somewhat arbitrary calling convention in the first place that doesn't really help the individual architectures that deviate from it. They can thus simply be switched to _do_fork() enforcing a single calling convention. (I really hope that any new architectures will __not__ try to implement their own calling conventions...) Most architectures already have made a similar switch (m68k comes to mind). Overall this removes more code than it adds even with a good portion of added comments. It simplifies a chunk of arch specific assembly either by moving the code into C or by simply rewriting the assembly. Architectures that have been touched in non-trivial ways have all been actually boot and stress tested: sparc and ia64 have been tested with Debian 9 images. They are the two architectures which have been touched the most. All non-trivial changes to architectures have seen acks from the relevant maintainers. nios2 with a custom built buildroot image. h8300 I couldn't get something bootable to test on but the changes have been fairly automatic and I'm sure we'll hear people yell if I broke something there. All other architectures that have been touched in trivial ways have been compile tested for each single patch of the series via git rebase -x "make ..." v5.8-rc2. arm{64} and x86{_64} have been boot tested even though they have just been trivially touched (removal of the HAVE_COPY_THREAD_TLS macro from their Kconfig) because well they are basically "core architectures" and since it is trivial to get your hands on a useable image" * tag 'fork-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux: arch: rename copy_thread_tls() back to copy_thread() arch: remove HAVE_COPY_THREAD_TLS unicore: switch to copy_thread_tls() sh: switch to copy_thread_tls() nds32: switch to copy_thread_tls() microblaze: switch to copy_thread_tls() hexagon: switch to copy_thread_tls() c6x: switch to copy_thread_tls() alpha: switch to copy_thread_tls() fork: remove do_fork() h8300: select HAVE_COPY_THREAD_TLS, switch to kernel_clone_args nios2: enable HAVE_COPY_THREAD_TLS, switch to kernel_clone_args ia64: enable HAVE_COPY_THREAD_TLS, switch to kernel_clone_args sparc: unconditionally enable HAVE_COPY_THREAD_TLS sparc: share process creation helpers between sparc and sparc64 sparc64: enable HAVE_COPY_THREAD_TLS fork: fold legacy_clone_args_valid() into _do_fork()
2020-07-31xtensa: add missing exclusive access state managementMax Filippov
The result of the s32ex opcode is recorded in the ATOMCTL special register and must be retrieved with the getex opcode. Context switch between s32ex and getex may trash the ATOMCTL register and result in duplicate update or missing update of the atomic variable. Add atomctl8 field to the struct thread_info and use getex to swap ATOMCTL bit 8 as a part of context switch. Clear exclusive access monitor on kernel entry. Cc: stable@vger.kernel.org Fixes: f7c34874f04a ("xtensa: add exclusive atomics support") Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2020-07-31xtensa: fix xtensa_pmu_setup prototypeMax Filippov
Fix the following build error in configurations with CONFIG_XTENSA_VARIANT_HAVE_PERF_EVENTS=y: arch/xtensa/kernel/perf_event.c:420:29: error: passing argument 3 of ‘cpuhp_setup_state’ from incompatible pointer type Cc: stable@vger.kernel.org Fixes: 25a77b55e74c ("xtensa/perf: Convert the hotplug notifier to state machine callbacks") Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2020-07-28xtensa: add seccomp supportMax Filippov
Add SECCOMP to xtensa Kconfig, select HAVE_ARCH_SECCOMP_FILTER, add TIF_SECCOMP and call secure_computing from do_syscall_trace_enter. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2020-07-28xtensa: expose syscall through user_pt_regsMax Filippov
Use one of the reserved slots in struct user_pt_regs to return syscall number in the GPR regset. Update syscall number from the GPR regset only when it's non-zero. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2020-07-28xtensa: add audit supportMax Filippov
All bits needed for syscall audit are present on xtensa. Add audit_syscall_entry and audit_syscall_exit calls and select HAVE_ARCH_AUDITSYSCALL in Kconfig. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2020-07-27xtensa: switch to ->regset_get()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-07-08xtensa: simplify xtensa_pmu_irq_handlerXu Wang
Use for_each_set_bit() instead of open-coding it to simplify the code. Signed-off-by: Xu Wang <vulab@iscas.ac.cn> Message-Id: <20200708062023.7986-1-vulab@iscas.ac.cn> Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2020-07-04arch: rename copy_thread_tls() back to copy_thread()Christian Brauner
Now that HAVE_COPY_THREAD_TLS has been removed, rename copy_thread_tls() back simply copy_thread(). It's a simpler name, and doesn't imply that only tls is copied here. This finishes an outstanding chunk of internal process creation work since we've added clone3(). Cc: linux-arch@vger.kernel.org Acked-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>A Acked-by: Stafford Horne <shorne@gmail.com> Acked-by: Greentime Hu <green.hu@gmail.com> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>A Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2020-07-02xtensa: update *pos in cpuinfo_op.nextMax Filippov
Increment *pos in the cpuinfo_op.next to fix the following warning triggered by cat /proc/cpuinfo: seq_file: buggy .next function c_next did not update position index Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2020-07-02xtensa: fix __sync_fetch_and_{and,or}_4 declarationsMax Filippov
Building xtensa kernel with gcc-10 produces the following warnings: arch/xtensa/kernel/xtensa_ksyms.c:90:15: warning: conflicting types for built-in function ‘__sync_fetch_and_and_4’; expected ‘unsigned int(volatile void *, unsigned int)’ [-Wbuiltin-declaration-mismatch] arch/xtensa/kernel/xtensa_ksyms.c:96:15: warning: conflicting types for built-in function ‘__sync_fetch_and_or_4’; expected ‘unsigned int(volatile void *, unsigned int)’ [-Wbuiltin-declaration-mismatch] Fix declarations of these functions to avoid the warning. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
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
2020-06-09mm: reorder includes after introduction of linux/pgtable.hMike Rapoport
The replacement of <asm/pgrable.h> with <linux/pgtable.h> made the include of the latter in the middle of asm includes. Fix this up with the aid of the below script and manual adjustments here and there. import sys import re if len(sys.argv) is not 3: print "USAGE: %s <file> <header>" % (sys.argv[0]) sys.exit(1) hdr_to_move="#include <linux/%s>" % sys.argv[2] moved = False in_hdrs = False with open(sys.argv[1], "r") as f: lines = f.readlines() for _line in lines: line = _line.rstrip(' ') if line == hdr_to_move: continue if line.startswith("#include <linux/"): in_hdrs = True elif not moved and in_hdrs: moved = True print hdr_to_move print line Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Cain <bcain@codeaurora.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chris Zankel <chris@zankel.net> Cc: "David S. Miller" <davem@davemloft.net> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greentime Hu <green.hu@gmail.com> Cc: Greg Ungerer <gerg@linux-m68k.org> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Guo Ren <guoren@kernel.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ley Foon Tan <ley.foon.tan@intel.com> Cc: Mark Salter <msalter@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Nick Hu <nickhu@andestech.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Richard Weinberger <richard@nod.at> Cc: Rich Felker <dalias@libc.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Vincent Chen <deanbo422@gmail.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Will Deacon <will@kernel.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Link: http://lkml.kernel.org/r/20200514170327.31389-4-rppt@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-09mm: introduce include/linux/pgtable.hMike Rapoport
The include/linux/pgtable.h is going to be the home of generic page table manipulation functions. Start with moving asm-generic/pgtable.h to include/linux/pgtable.h and make the latter include asm/pgtable.h. Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Cain <bcain@codeaurora.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chris Zankel <chris@zankel.net> Cc: "David S. Miller" <davem@davemloft.net> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greentime Hu <green.hu@gmail.com> Cc: Greg Ungerer <gerg@linux-m68k.org> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Guo Ren <guoren@kernel.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ley Foon Tan <ley.foon.tan@intel.com> Cc: Mark Salter <msalter@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Nick Hu <nickhu@andestech.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Richard Weinberger <richard@nod.at> Cc: Rich Felker <dalias@libc.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Vincent Chen <deanbo422@gmail.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Will Deacon <will@kernel.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Link: http://lkml.kernel.org/r/20200514170327.31389-3-rppt@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-09mm: don't include asm/pgtable.h if linux/mm.h is already includedMike Rapoport
Patch series "mm: consolidate definitions of page table accessors", v2. The low level page table accessors (pXY_index(), pXY_offset()) are duplicated across all architectures and sometimes more than once. For instance, we have 31 definition of pgd_offset() for 25 supported architectures. Most of these definitions are actually identical and typically it boils down to, e.g. static inline unsigned long pmd_index(unsigned long address) { return (address >> PMD_SHIFT) & (PTRS_PER_PMD - 1); } static inline pmd_t *pmd_offset(pud_t *pud, unsigned long address) { return (pmd_t *)pud_page_vaddr(*pud) + pmd_index(address); } These definitions can be shared among 90% of the arches provided XYZ_SHIFT, PTRS_PER_XYZ and xyz_page_vaddr() are defined. For architectures that really need a custom version there is always possibility to override the generic version with the usual ifdefs magic. These patches introduce include/linux/pgtable.h that replaces include/asm-generic/pgtable.h and add the definitions of the page table accessors to the new header. This patch (of 12): The linux/mm.h header includes <asm/pgtable.h> to allow inlining of the functions involving page table manipulations, e.g. pte_alloc() and pmd_alloc(). So, there is no point to explicitly include <asm/pgtable.h> in the files that include <linux/mm.h>. The include statements in such cases are remove with a simple loop: for f in $(git grep -l "include <linux/mm.h>") ; do sed -i -e '/include <asm\/pgtable.h>/ d' $f done Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Cain <bcain@codeaurora.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chris Zankel <chris@zankel.net> Cc: "David S. Miller" <davem@davemloft.net> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greentime Hu <green.hu@gmail.com> Cc: Greg Ungerer <gerg@linux-m68k.org> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Guo Ren <guoren@kernel.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ley Foon Tan <ley.foon.tan@intel.com> Cc: Mark Salter <msalter@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nick Hu <nickhu@andestech.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Richard Weinberger <richard@nod.at> Cc: Rich Felker <dalias@libc.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Vincent Chen <deanbo422@gmail.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Will Deacon <will@kernel.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Link: http://lkml.kernel.org/r/20200514170327.31389-1-rppt@kernel.org Link: http://lkml.kernel.org/r/20200514170327.31389-2-rppt@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-09kernel: rename show_stack_loglvl() => show_stack()Dmitry Safonov
Now the last users of show_stack() got converted to use an explicit log level, show_stack_loglvl() can drop it's redundant suffix and become once again well known show_stack(). Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20200418201944.482088-51-dima@arista.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-09xtensa: add show_stack_loglvl()Dmitry Safonov
Currently, the log-level of show_stack() depends on a platform realization. It creates situations where the headers are printed with lower log level or higher than the stacktrace (depending on a platform or user). Furthermore, it forces the logic decision from user to an architecture side. In result, some users as sysrq/kdb/etc are doing tricks with temporary rising console_loglevel while printing their messages. And in result it not only may print unwanted messages from other CPUs, but also omit printing at all in the unlucky case where the printk() was deferred. Introducing log-level parameter and KERN_UNSUPPRESSED [1] seems an easier approach than introducing more printk buffers. Also, it will consolidate printings with headers. Introduce show_stack_loglvl(), that eventually will substitute show_stack(). [1]: https://lore.kernel.org/lkml/20190528002412.1625-1-dima@arista.com/T/#u Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Chris Zankel <chris@zankel.net> Cc: Max Filippov <jcmvbkbc@gmail.com> Link: http://lkml.kernel.org/r/20200418201944.482088-44-dima@arista.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-09xtensa: add loglvl to show_trace()Dmitry Safonov
Currently, the log-level of show_stack() depends on a platform realization. It creates situations where the headers are printed with lower log level or higher than the stacktrace (depending on a platform or user). Furthermore, it forces the logic decision from user to an architecture side. In result, some users as sysrq/kdb/etc are doing tricks with temporary rising console_loglevel while printing their messages. And in result it not only may print unwanted messages from other CPUs, but also omit printing at all in the unlucky case where the printk() was deferred. Introducing log-level parameter and KERN_UNSUPPRESSED [1] seems an easier approach than introducing more printk buffers. Also, it will consolidate printings with headers. Add log level argument to show_trace() as a preparation for introducing show_stack_loglvl(). [1]: https://lore.kernel.org/lkml/20190528002412.1625-1-dima@arista.com/T/#u [rppt@kernel.org: build fix] Link: http://lkml.kernel.org/r/20200511194534.GA1018386@kernel.org Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Chris Zankel <chris@zankel.net> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Mike Rapoport <rppt@kernel.org> Link: http://lkml.kernel.org/r/20200418201944.482088-43-dima@arista.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-03Merge tag 'xtensa-20200603' of git://github.com/jcmvbkbc/linux-xtensaLinus Torvalds
Pull Xtensa updates from Max Filippov: - fix __user annotations in asm/uaccess.h - fix comments in entry.S * tag 'xtensa-20200603' of git://github.com/jcmvbkbc/linux-xtensa: xtensa: Fix spelling/grammar in comment xtensa: add missing __user annotations to asm/uaccess.h xtensa: fix error paths in __get_user_{check,size} xtensa: fix type conversion in __get_user_size xtensa: add missing __user annotations to __{get,put}_user_check
2020-05-25xtensa: Fix spelling/grammar in commentChris Packham
Change 'excpetion' to 'exception', 'handeled' to 'handled' and 'the the' to 'the'. Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz> Message-Id: <20200525230413.15551-1-chris.packham@alliedtelesis.co.nz> Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
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>
2020-04-10Merge tag 'xtensa-20200410' of git://github.com/jcmvbkbc/linux-xtensaLinus Torvalds
Pull xtensa updates from Max Filippov: - replace setup_irq() by request_irq() - cosmetic fixes in xtensa Kconfig and boot/Makefile * tag 'xtensa-20200410' of git://github.com/jcmvbkbc/linux-xtensa: arch/xtensa: fix grammar in Kconfig help text xtensa: remove meaningless export ccflags-y xtensa: replace setup_irq() by request_irq()
2020-04-07asm-generic: fix unistd_32.h generation formatMichal Simek
Generated files are also checked by sparse that's why add newline to remove sparse (C=1) warning. The issue was found on Microblaze and reported like this: ./arch/microblaze/include/generated/uapi/asm/unistd_32.h:438:45: warning: no newline at end of file Mips and PowerPC have it already but let's align with style used by m68k. Signed-off-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Stefan Asserhall <stefan.asserhall@xilinx.com> Acked-by: Max Filippov <jcmvbkbc@gmail.com> (xtensa) Cc: Arnd Bergmann <arnd@arndb.de> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Chris Zankel <chris@zankel.net> Cc: David S. Miller <davem@davemloft.net> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Helge Deller <deller@gmx.de> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Burton <paulburton@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Rich Felker <dalias@libc.org> Cc: Richard Henderson <rth@twiddle.net> Cc: Tony Luck <tony.luck@intel.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Link: http://lkml.kernel.org/r/4d32ab4e1fb2edb691d2e1687e8fb303c09fd023.1581504803.git.michal.simek@xilinx.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-04Merge tag 'dma-mapping-5.7' of git://git.infradead.org/users/hch/dma-mappingLinus Torvalds
Pull dma-mapping updates from Christoph Hellwig: - fix an integer overflow in the coherent pool (Kevin Grandemange) - provide support for in-place uncached remapping and use that for openrisc - fix the arm coherent allocator to take the bus limit into account * tag 'dma-mapping-5.7' of git://git.infradead.org/users/hch/dma-mapping: ARM/dma-mapping: merge __dma_supported into arm_dma_supported ARM/dma-mapping: take the bus limit into account in __dma_alloc ARM/dma-mapping: remove get_coherent_dma_mask openrisc: use the generic in-place uncached DMA allocator dma-direct: provide a arch_dma_clear_uncached hook dma-direct: make uncached_kernel_address more general dma-direct: consolidate the error handling in dma_direct_alloc_pages dma-direct: remove the cached_kernel_address hook dma-coherent: fix integer overflow in the reserved-memory dma allocation
2020-03-25.gitignore: add SPDX License IdentifierMasahiro Yamada
Add SPDX License Identifier to all .gitignore files. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-16dma-direct: make uncached_kernel_address more generalChristoph Hellwig
Rename the symbol to arch_dma_set_uncached, and pass a size to it as well as allow an error return. That will allow reusing this hook for in-place pagetable remapping. As the in-place remap doesn't always require an explicit cache flush, also detangle ARCH_HAS_DMA_PREP_COHERENT from ARCH_HAS_DMA_SET_UNCACHED. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Robin Murphy <robin.murphy@arm.com>
2020-03-16dma-direct: remove the cached_kernel_address hookChristoph Hellwig
dma-direct now finds the kernel address for coherent allocations based on the dma address, so the cached_kernel_address hooks is unused and can be removed entirely. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Robin Murphy <robin.murphy@arm.com>
2020-03-03xtensa: replace setup_irq() by request_irq()afzal mohammed
request_irq() is preferred over setup_irq(). Invocations of setup_irq() occur after memory allocators are ready. Per tglx[1], setup_irq() existed in olden days when allocators were not ready by the time early interrupts were initialized. Hence replace setup_irq() by request_irq(). [1] https://lkml.kernel.org/r/alpine.DEB.2.20.1710191609480.1971@nanos Signed-off-by: afzal mohammed <afzal.mohd.ma@gmail.com> Message-Id: <20200304004112.3848-1-afzal.mohd.ma@gmail.com> Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2020-02-07Merge tag 'xtensa-20200206' of git://github.com/jcmvbkbc/linux-xtensaLinus Torvalds
Pull xtensa updates from Max Filippov: - reorganize exception vectors placement - small cleanups (drop unused functions/headers/defconfig entries, spelling fixes) * tag 'xtensa-20200206' of git://github.com/jcmvbkbc/linux-xtensa: xtensa: ISS: improve simcall assembly xtensa: reorganize vectors placement xtensa: separate SMP and XIP support xtensa: move fast exception handlers close to vectors arch/xtensa: fix Kconfig typos for HAVE_SMP xtensa: clean up optional XCHAL_* definitions xtensa: drop unused function fast_coprocessor_double xtensa: drop empty platform_* functions from platforms xtensa: clean up platform headers xtensa: drop set_except_vector declaration xtensa: configs: Cleanup old Kconfig IO scheduler options
2020-02-04xtensa: reorganize vectors placementMax Filippov
Allow vectors to be either merged into the kernel .text or put at a fixed virtual address independently of XIP option. Drop option that puts vectors at a fixed offset from the kernel text. Add choice to Kconfig. Vectors at fixed virtual address may be useful for XIP-aware MTD support and for noMMU configurations with available IRAM. Configurations without VECBASE register must put their vectors at specific locations regardless of the selected option. All other configurations should happily use merged vectors. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2020-02-04xtensa: separate SMP and XIP supportMax Filippov
There's no real dependency between SMP and XIP, allow them to be selected together. Always define 2- and 4-argument SECTION_VECTOR macros, always use 4-argument macro for the secondary reset vector and always define relocation entry for it. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2020-02-04xtensa: move fast exception handlers close to vectorsMax Filippov
On XIP kernels it makes sense to have exception vectors and fast exception handlers together (in a fast memory). In addition, with MTD XIP support both vectors and fast exception handlers must be outside of the FLASH. Add section .exception.text and move fast exception handlers to it. Put it together with vectors when vectors are outside of the .text. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2020-02-01xtensa: drop unused function fast_coprocessor_doubleMax Filippov
fast_coprocessor_double is not used since commit c658eac628aa ("[XTENSA] Add support for configurable registers and coprocessors"). Remove it. There should be no coprocessor exceptions generated in the exception handling paths while PS.EXCM is set. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2020-01-31xtensa: drop empty platform_* functions from platformsMax Filippov
Provide missing default implementation for platform_init and drop copies of default platform_init, platform_setup and platform_heartbeet from platforms/*/setup.c Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2020-01-31xtensa: clean up platform headersMax Filippov
Drop include directives for irrelevant headers in asm/platform.h and its users. Sort remaining headers. Signed-off-by: Max Filippov <jcmvbkbc@gmail.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 u