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2020-07-24io_uring: don't do opcode prep twicePavel Begunkov
Calling into opcode prep handlers may be dangerous, as they re-read SQE but might not re-initialise requests completely. If io_req_defer() passed fast checks and is done with preparations, punt it async. As all other cases are covered with nulling @sqe, this guarantees that io_[opcode]_prep() are visited only once per request. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: clear IORING_SQ_NEED_WAKEUP after executing task worksXiaoguang Wang
In io_sq_thread(), if there are task works to handle, current codes will skip schedule() and go on polling sq again, but forget to clear IORING_SQ_NEED_WAKEUP flag, fix this issue. Also add two helpers to set and clear IORING_SQ_NEED_WAKEUP flag, Signed-off-by: Xiaoguang Wang <xiaoguang.wang@linux.alibaba.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: batch put_task_struct()Pavel Begunkov
As every iopoll request have a task ref, it becomes expensive to put them one by one, instead we can put several at once integrating that into io_req_free_batch(). Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24tasks: add put_task_struct_many()Pavel Begunkov
put_task_struct_many() is as put_task_struct() but puts several references at once. Useful to batching it. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: return locked and pinned page accountingPavel Begunkov
Locked and pinned memory accounting in io_{,un}account_mem() depends on having ->sqo_mm, which is NULL after a recent change for non SQPOLL'ed io_ring. That disables the accounting. Return ->sqo_mm initialisation back, and do __io_sq_thread_acquire_mm() based on IORING_SETUP_SQPOLL flag. Fixes: 8eb06d7e8dd85 ("io_uring: fix missing ->mm on exit") Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: don't miscount pinned memoryPavel Begunkov
io_sqe_buffer_unregister() uses cxt->sqo_mm for memory accounting, but io_ring_ctx_free() drops ->sqo_mm before leaving pinned_vm over-accounted. Postpone mm cleanup for when it's not needed anymore. Fixes: 309758254ea62 ("io_uring: report pinned memory usage") Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: don't open-code recv kbuf managmentPavel Begunkov
Don't implement fast path of kbuf freeing and management inlined into io_recv{,msg}(), that's error prone and duplicates handling. Replace it with a helper io_put_recv_kbuf(), which mimics io_put_rw_kbuf() in the io_read/write(). This also keeps cflags calculation in one place, removing duplication between rw and recv/send. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: extract io_put_kbuf() helperPavel Begunkov
Extract a common helper for cleaning up a selected buffer, this will be used shortly. By the way, correct cflags types to unsigned and, as kbufs are anyway tracked by a flag, remove useless zeroing req->rw.addr. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: move BUFFER_SELECT check into *recv[msg]Pavel Begunkov
Move REQ_F_BUFFER_SELECT flag check out of io_recv_buffer_select(), and do that in its call sites That saves us from double error checking and possibly an extra function call. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: free selected-bufs if error'edPavel Begunkov
io_clean_op() may be skipped even if there is a selected io_buffer, that's because *select_buffer() funcions never set REQ_F_NEED_CLEANUP. Trigger io_clean_op() when REQ_F_BUFFER_SELECTED is set as well, and and clear the flag if was freed out of it. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: don't forget cflags in io_recv()Pavel Begunkov
Instead of returning error from io_recv(), go through generic cleanup path, because it'll retain cflags for userspace. Do the same for io_send() for consistency. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: remove extra checks in send/recvPavel Begunkov
With the return on a bad socket, kmsg is always non-null by the end of the function, prune left extra checks and initialisations. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: indent left {send,recv}[msg]()Pavel Begunkov
Flip over "if (sock)" condition with return on error, the upper layer will take care. That change will be handy later, but already removes an extra jump from hot path. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: simplify file ref tracking in submission statePavel Begunkov
Currently, file refs in struct io_submit_state are tracked with 2 vars: @has_refs -- how many refs were initially taken @used_refs -- number of refs used Replace it with a single variable counting how many refs left at the current moment. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring/io-wq: move RLIMIT_FSIZE to io-wqPavel Begunkov
RLIMIT_SIZE in needed only for execution from an io-wq context, hence move all preparations from hot path to io-wq work setup. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: alloc ->io in io_req_defer_prep()Pavel Begunkov
Every call to io_req_defer_prep() is prepended with allocating ->io, just do that in the function. And while we're at it, mark error paths with unlikey and replace "if (ret < 0)" with "if (ret)". There is only one change in the observable behaviour, that's instead of killing the head request right away on error, it postpones it until the link is assembled, that looks more preferable. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: remove empty cleanup of OP_OPEN* reqsPavel Begunkov
A switch in __io_clean_op() doesn't have default, it's pointless to list opcodes that doesn't do any cleanup. Remove IORING_OP_OPEN* from there. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: inline io_req_work_grab_env()Pavel Begunkov
The only caller of io_req_work_grab_env() is io_prep_async_work(), and they are both initialising req->work. Inline grab_env(), it's easier to keep this way, moreover there already were bugs with misplacing io_req_init_async(). Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: place cflags into completion dataPavel Begunkov
req->cflags is used only for defer-completion path, just use completion data to store it. With the 4 bytes from the ->sequence patch and compacting io_kiocb, this frees 8 bytes. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: remove sequence from io_kiocbPavel Begunkov
req->sequence is used only for deferred (i.e. DRAIN) requests, but initialised for every request. Remove req->sequence from io_kiocb together with its initialisation in io_init_req(). Replace it with a new field in struct io_defer_entry, that will be calculated only when needed in io_req_defer(), which is a slow path. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: use non-intrusive list for deferPavel Begunkov
The only left user of req->list is DRAIN, hence instead of keeping a separate per request list for it, do that with old fashion non-intrusive lists allocated on demand. That's a really slow path, so that's OK. This removes req->list and so sheds 16 bytes from io_kiocb. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: remove init for unused listPavel Begunkov
poll*() doesn't use req->list, don't init it. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: add req->timeout.listPavel Begunkov
Instead of using shared req->list, hang timeouts up on their own list entry. struct io_timeout have enough extra space for it, but if that will be a problem ->inflight_entry can reused for that. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: use completion list for CQ overflowPavel Begunkov
As with the completion path, also use compl.list for overflowed requests. If cleaned up properly, nobody needs per-op data there anymore. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: use inflight_entry list for iopoll'ingPavel Begunkov
req->inflight_entry is used to track requests that grabbed files_struct. Let's share it with iopoll list, because the only iopoll'ed ops are reads and writes, which don't need a file table. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: rename ctx->poll into ctx->iopollPavel Begunkov
It supports both polling and I/O polling. Rename ctx->poll to clearly show that it's only in I/O poll case. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: share completion list w/ per-op spacePavel Begunkov
Calling io_req_complete(req) means that the request is done, and there is nothing left but to clean it up. That also means that per-op data after that should not be used, so we're free to reuse it in completion path, e.g. to store overflow_list as done in this patch. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: follow **iovec idiom in io_import_iovecPavel Begunkov
As for import_iovec(), return !=NULL iovec from io_import_iovec() only when it should be freed. That includes returning NULL when iovec is already in req->io, because it should be deallocated by other means, e.g. inside op handler. After io_setup_async_rw() local iovec to ->io, just mark it NULL, to follow the idea in io_{read,write} as well. That's easier to follow, and especially useful if we want to reuse per-op space for completion data. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> [axboe: only call kfree() on non-NULL pointer] Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: add a helper for async rw iovec prepPavel Begunkov
Preparing reads/writes for async is a bit tricky. Extract a helper to not repeat it twice. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: simplify io_req_map_rw()Pavel Begunkov
Don't deref req->io->rw every time, but put it in a local variable. This looks prettier, generates less instructions, and doesn't break alias analysis. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: replace rw->task_work with rq->task_workPavel Begunkov
io_kiocb::task_work was de-unionised, and is not planned to be shared back, because it's too useful and commonly used. Hence, instead of keeping a separate task_work in struct io_async_rw just reuse req->task_work. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: extract io_sendmsg_copy_hdr()Pavel Begunkov
Don't repeat send msg initialisation code, it's error prone. Extract and use a helper function. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: use more specific type in rcv/snd msg cpPavel Begunkov
send/recv msghdr initialisation works with struct io_async_msghdr, but pulls the whole struct io_async_ctx for no reason. That complicates it with composite accessing, e.g. io->msg. Use and pass the most specific type, which is struct io_async_msghdr. It is the larget field in union io_async_ctx and doesn't save stack space, but looks clearer. The most of the changes are replacing "io->msg." with "iomsg->" Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: rename sr->msg into umsgPavel Begunkov
Every second field in send/recv is called msg, make it a bit more understandable by renaming ->msg, which is a user provided ptr, to ->umsg. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: fix sq array offset calculationDmitry Vyukov
rings_size() sets sq_offset to the total size of the rings (the returned value which is used for memory allocation). This is wrong: sq array should be located within the rings, not after them. Set sq_offset to where it should be. Fixes: 75b28affdd6a ("io_uring: allocate the two rings together") Signed-off-by: Dmitry Vyukov <dvyukov@google.com> Acked-by: Hristo Venev <hristo@venev.name> Cc: io-uring@vger.kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24Merge branch 'io_uring-5.8' into for-5.9/io_uringJens Axboe
Merge in io_uring-5.8 fixes, as changes/cleanups to how we do locked mem accounting require a fixup, and only one of the spots are noticed by git as the other merges cleanly. The flags fix from io_uring-5.8 also causes a merge conflict, the leak fix for recvmsg, the double poll fix, and the link failure locking fix. * io_uring-5.8: io_uring: fix lockup in io_fail_links() io_uring: fix ->work corruption with poll_add io_uring: missed req_init_async() for IOSQE_ASYNC io_uring: always allow drain/link/hardlink/async sqe flags io_uring: ensure double poll additions work with both request types io_uring: fix recvmsg memory leak with buffer selection io_uring: fix not initialised work->flags io_uring: fix missing msg_name assignment io_uring: account user memory freed when exit has been queued io_uring: fix memleak in io_sqe_files_register() io_uring: fix memleak in __io_sqe_files_update() io_uring: export cq overflow status to userspace Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: fix lockup in io_fail_links()Pavel Begunkov
io_fail_links() doesn't consider REQ_F_COMP_LOCKED leading to nested spin_lock(completion_lock) and lockup. [ 197.680409] rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 6-... } 18239 jiffies s: 1421 root: 0x40/. [ 197.680411] rcu: blocking rcu_node structures: [ 197.680412] Task dump for CPU 6: [ 197.680413] link-timeout R running task 0 1669 1 0x8000008a [ 197.680414] Call Trace: [ 197.680420] ? io_req_find_next+0xa0/0x200 [ 197.680422] ? io_put_req_find_next+0x2a/0x50 [ 197.680423] ? io_poll_task_func+0xcf/0x140 [ 197.680425] ? task_work_run+0x67/0xa0 [ 197.680426] ? do_exit+0x35d/0xb70 [ 197.680429] ? syscall_trace_enter+0x187/0x2c0 [ 197.680430] ? do_group_exit+0x43/0xa0 [ 197.680448] ? __x64_sys_exit_group+0x18/0x20 [ 197.680450] ? do_syscall_64+0x52/0xa0 [ 197.680452] ? entry_SYSCALL_64_after_hwframe+0x44/0xa9 Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24io_uring: fix ->work corruption with poll_addPavel Begunkov
req->work might be already initialised by the time it gets into __io_arm_poll_handler(), which will corrupt it by using fields that are in an union with req->work. Luckily, the only side effect is missing put_creds(). Clean req->work before going there. Suggested-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-24arm64: enable time namespace supportAndrei Vagin
CONFIG_TIME_NS is dependes on GENERIC_VDSO_TIME_NS. Signed-off-by: Andrei Vagin <avagin@gmail.com> Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Reviewed-by: Dmitry Safonov <dima@arista.com> Link: https://lore.kernel.org/r/20200624083321.144975-7-avagin@gmail.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-07-24arm64/vdso: Restrict splitting VVAR VMAAndrei Vagin
Forbid splitting VVAR VMA resulting in a stricter ABI and reducing the amount of corner-cases to consider while working further on VDSO time namespace support. As the offset from timens to VVAR page is computed compile-time, the pages in VVAR should stay together and not being partically mremap()'ed. Signed-off-by: Andrei Vagin <avagin@gmail.com> Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Reviewed-by: Dmitry Safonov <dima@arista.com> Link: https://lore.kernel.org/r/20200624083321.144975-6-avagin@gmail.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-07-24arm64/vdso: Handle faults on timens pageAndrei Vagin
If a task belongs to a time namespace then the VVAR page which contains the system wide VDSO data is replaced with a namespace specific page which has the same layout as the VVAR page. Signed-off-by: Andrei Vagin <avagin@gmail.com> Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Reviewed-by: Dmitry Safonov <dima@arista.com> Link: https://lore.kernel.org/r/20200624083321.144975-5-avagin@gmail.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-07-24ALSA: hda/realtek: typo_fix: enable headset mic of ASUS ROG Zephyrus ↵Armas Spann
G14(GA401) series with ALC289 This patch fixes a small typo I accidently submitted with the initial patch. The board should be named GA401 not G401. Fixes: ff53664daff2 ("ALSA: hda/realtek: enable headset mic of ASUS ROG Zephyrus G14(G401) series with ALC289") Signed-off-by: Armas Spann <zappel@retarded.farm> Cc: <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20200724140837.302763-1-zappel@retarded.farm Signed-off-by: Takashi Iwai <tiwai@suse.de>
2020-07-24ALSA: hda/realtek: enable headset mic of ASUS ROG Zephyrus G15(GA502) series ↵Armas Spann
with ALC289 This patch adds support for headset mic to the ASUS ROG Zephyrus G15(GA502) notebook series by adding the corresponding vendor/pci_device id, as well as adding a new fixup for the used realtek ALC289. The fixup stets the correct pin to get the headset mic correctly recognized on audio-jack. Signed-off-by: Armas Spann <zappel@retarded.farm> Cc: <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20200724140616.298892-1-zappel@retarded.farm Signed-off-by: Takashi Iwai <tiwai@suse.de>
2020-07-24Merge tag 'mvebu-fixes-5.8-1' of ↵Arnd Bergmann
git://git.kernel.org/pub/scm/linux/kernel/git/gclement/mvebu into arm/fixes mvebu fixes for 5.8 (part 1) - DT change for Armada 38x allowing to add the register needed to fix NETA lockup when repeatedly switching speed. * tag 'mvebu-fixes-5.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/gclement/mvebu: ARM: dts: armada-38x: fix NETA lockup when repeatedly switching speeds
2020-07-24uprobes: Change handle_swbp() to send SIGTRAP with si_code=SI_KERNEL, to fix ↵Oleg Nesterov
GDB regression If a tracee is uprobed and it hits int3 inserted by debugger, handle_swbp() does send_sig(SIGTRAP, current, 0) which means si_code == SI_USER. This used to work when this code was written, but then GDB started to validate si_code and now it simply can't use breakpoints if the tracee has an active uprobe: # cat test.c void unused_func(void) { } int main(void) { return 0; } # gcc -g test.c -o test # perf probe -x ./test -a unused_func # perf record -e probe_test:unused_func gdb ./test -ex run GNU gdb (GDB) 10.0.50.20200714-git ... Program received signal SIGTRAP, Trace/breakpoint trap. 0x00007ffff7ddf909 in dl_main () from /lib64/ld-linux-x86-64.so.2 (gdb) The tracee hits the internal breakpoint inserted by GDB to monitor shared library events but GDB misinterprets this SIGTRAP and reports a signal. Change handle_swbp() to use force_sig(SIGTRAP), this matches do_int3_user() and fixes the problem. This is the minimal fix for -stable, arch/x86/kernel/uprobes.c is equally wrong; it should use send_sigtrap(TRAP_TRACE) instead of send_sig(SIGTRAP), but this doesn't confuse GDB and needs another x86-specific patch. Reported-by: Aaron Merey <amerey@redhat.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20200723154420.GA32043@redhat.com
2020-07-24sched: Warn if garbage is passed to default_wake_function()Chris Wilson
Since the default_wake_function() passes its flags onto try_to_wake_up(), warn if those flags collide with internal values. Given that the supplied flags are garbage, no repair can be done but at least alert the user to the damage they are causing. In the belief that these errors should be picked up during testing, the warning is only compiled in under CONFIG_SCHED_DEBUG. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: https://lore.kernel.org/r/20200723201042.18861-1-chris@chris-wilson.co.uk
2020-07-24arm64/vdso: Add time namespace pageAndrei Vagin
Allocate the time namespace page among VVAR pages. Provide __arch_get_timens_vdso_data() helper for VDSO code to get the code-relative position of VVARs on that special page. If a task belongs to a time namespace then the VVAR page which contains the system wide VDSO data is replaced with a namespace specific page which has the same layout as the VVAR page. That page has vdso_data->seq set to 1 to enforce the slow path and vdso_data->clock_mode set to VCLOCK_TIMENS to enforce the time namespace handling path. The extra check in the case that vdso_data->seq is odd, e.g. a concurrent update of the VDSO data is in progress, is not really affecting regular tasks which are not part of a time namespace as the task is spin waiting for the update to finish and vdso_data->seq to become even again. If a time namespace task hits that code path, it invokes the corresponding time getter function which retrieves the real VVAR page, reads host time and then adds the offset for the requested clock which is stored in the special VVAR page. The time-namespace page isn't allocated on !CONFIG_TIME_NAMESPACE, but vma is the same size, which simplifies criu/vdso migration between different kernel configs. Signed-off-by: Andrei Vagin <avagin@gmail.com> Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Reviewed-by: Dmitry Safonov <dima@arista.com> Cc: Mark Rutland <mark.rutland@arm.com> Link: https://lore.kernel.org/r/20200624083321.144975-4-avagin@gmail.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-07-24arm64/vdso: Zap vvar pages when switching to a time namespaceAndrei Vagin
The order of vvar pages depends on whether a task belongs to the root time namespace or not. In the root time namespace, a task doesn't have a per-namespace page. In a non-root namespace, the VVAR page which contains the system-wide VDSO data is replaced with a namespace specific page that contains clock offsets. Whenever a task changes its namespace, the VVAR page tables are cleared and then they will be re-faulted with a corresponding layout. A task can switch its time namespace only if its ->mm isn't shared with another task. Signed-off-by: Andrei Vagin <avagin@gmail.com> Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Reviewed-by: Dmitry Safonov <dima@arista.com> Reviewed-by: Christian Brauner <christian.brauner@ubuntu.com> Link: https://lore.kernel.org/r/20200624083321.144975-3-avagin@gmail.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-07-24arm64/vdso: use the fault callback to map vvar pagesAndrei Vagin
Currently the vdso has no awareness of time namespaces, which may apply distinct offsets to processes in different namespaces. To handle this within the vdso, we'll need to expose a per-namespace data page. As a preparatory step, this patch separates the vdso data page from the code pages, and has it faulted in via its own fault callback. Subsquent patches will extend this to support distinct pages per time namespace. The vvar vma has to be installed with the VM_PFNMAP flag to handle faults via its vma fault callback. Signed-off-by: Andrei Vagin <avagin@gmail.com> Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Reviewed-by: Dmitry Safonov <dima@arista.com> Link: https://lore.kernel.org/r/20200624083321.144975-2-avagin@gmail.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-07-24compiler.h: Move instrumentation_begin()/end() to new ↵Ingo Molnar
<linux/instrumentation.h> header Linus pointed out that compiler.h - which is a key header that gets included in every single one of the 28,000+ kernel files during a kernel build - was bloated in: 655389666643: ("vmlinux.lds.h: Create section for protection against instrumentation") Linus noted: > I have pulled this, but do we really want to add this to a header file > that is _so_ core that it gets included for basically every single > file built? > > I don't even see those instrumentation_begin/end() things used > anywhere right now. > > It seems excessive. That 53 lines is maybe not a lot, but it pushed > that header file to over 12kB, and while it's mostly comments, it's > extra IO and parsing basically for _every_ single file compiled in the > kernel. > > For what appears to be absolutely zero upside right now, and I really > don't see why this should be in such a core header file! Move these primitives into a new header: <linux/instrumentation.h>, and include that header in the headers that make use of it. Unfortunately one of these headers is asm-generic/bug.h, which does get included in a lot of places, similarly to compiler.h. So the de-bloating effect isn't as good as we'd like it to be - but at least the interfaces are defined separately. No change to functionality intended. Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20200604071921.GA1361070@gmail.com Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Peter Zijlstra <peterz@infradead.org>