user/sven/linux.git/kernel/fork.c, branch v5.5.14

mm: fork: fix kernel_stack memcg stats for various stack implementations

2020-04-01T09:00:11Z

commit 8380ce479010f2f779587b462a9b4681934297c3 upstream. Depending on CONFIG_VMAP_STACK and the THREAD_SIZE / PAGE_SIZE ratio the space for task stacks can be allocated using __vmalloc_node_range(), alloc_pages_node() and kmem_cache_alloc_node(). In the first and the second cases page->mem_cgroup pointer is set, but in the third it's not: memcg membership of a slab page should be determined using the memcg_from_slab_page() function, which looks at page->slab_cache->memcg_params.memcg . In this case, using mod_memcg_page_state() (as in account_kernel_stack()) is incorrect: page->mem_cgroup pointer is NULL even for pages charged to a non-root memory cgroup. It can lead to kernel_stack per-memcg counters permanently showing 0 on some architectures (depending on the configuration). In order to fix it, let's introduce a mod_memcg_obj_state() helper, which takes a pointer to a kernel object as a first argument, uses mem_cgroup_from_obj() to get a RCU-protected memcg pointer and calls mod_memcg_state(). It allows to handle all possible configurations (CONFIG_VMAP_STACK and various THREAD_SIZE/PAGE_SIZE values) without spilling any memcg/kmem specifics into fork.c . Note: This is a special version of the patch created for stable backports. It contains code from the following two patches: - mm: memcg/slab: introduce mem_cgroup_from_obj() - mm: fork: fix kernel_stack memcg stats for various stack implementations [guro@fb.com: introduce mem_cgroup_from_obj()] Link: http://lkml.kernel.org/r/20200324004221.GA36662@carbon.dhcp.thefacebook.com Fixes: 4d96ba353075 ("mm: memcg/slab: stop setting page->mem_cgroup pointer for slab pages") Signed-off-by: Roman Gushchin Signed-off-by: Andrew Morton Reviewed-by: Shakeel Butt Acked-by: Johannes Weiner Cc: Michal Hocko Cc: Bharata B Rao Cc: Shakeel Butt Cc: Link: http://lkml.kernel.org/r/20200303233550.251375-1-guro@fb.com Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

clone3: ensure copy_thread_tls is implemented

2020-01-07T12:31:27Z

copy_thread implementations handle CLONE_SETTLS by reading the TLS value from the registers containing the syscall arguments for clone. This doesn't work with clone3 since the TLS value is passed in clone_args instead. Signed-off-by: Amanieu d'Antras Cc: # 5.3.x Link: https://lore.kernel.org/r/20200102172413.654385-8-amanieu@gmail.com Signed-off-by: Christian Brauner

Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2019-12-03T20:20:25Z

Pull timer updates from Ingo Molnar: "The main changes in the timer code in this cycle were: - Clockevent updates: - timer-of framework cleanups. (Geert Uytterhoeven) - Use timer-of for the renesas-ostm and the device name to prevent name collision in case of multiple timers. (Geert Uytterhoeven) - Check if there is an error after calling of_clk_get in asm9260 (Chuhong Yuan) - ABI fix: Zero out high order bits of nanoseconds on compat syscalls. This got broken a year ago, with apparently no side effects so far. Since the kernel would use random data otherwise I don't think we'd have other options but to fix the bug, even if there was a side effect to applications (Dmitry Safonov) - Optimize ns_to_timespec64() on 32-bit systems: move away from div_s64_rem() which can be slow, to div_u64_rem() which is faster (Arnd Bergmann) - Annotate KCSAN-reported false positive data races in hrtimer_is_queued() users by moving timer->state handling over to the READ_ONCE()/WRITE_ONCE() APIs. This documents these accesses (Eric Dumazet) - Misc cleanups and small fixes" [ I undid the "ABI fix" and updated the comments instead. The reason there were apparently no side effects is that the fix was a no-op. The updated comment is to say _why_ it was a no-op. - Linus ] * 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: time: Zero the upper 32-bits in __kernel_timespec on 32-bit time: Rename tsk->real_start_time to ->start_boottime hrtimer: Remove the comment about not used HRTIMER_SOFTIRQ time: Fix spelling mistake in comment time: Optimize ns_to_timespec64() hrtimer: Annotate lockless access to timer->state clocksource/drivers/asm9260: Add a check for of_clk_get clocksource/drivers/renesas-ostm: Use unique device name instead of ostm clocksource/drivers/renesas-ostm: Convert to timer_of clocksource/drivers/timer-of: Use unique device name instead of timer clocksource/drivers/timer-of: Convert last full_name to %pOF

fork: support VMAP_STACK with KASAN_VMALLOC

2019-12-01T20:59:05Z

Supporting VMAP_STACK with KASAN_VMALLOC is straightforward: - clear the shadow region of vmapped stacks when swapping them in - tweak Kconfig to allow VMAP_STACK to be turned on with KASAN Link: http://lkml.kernel.org/r/20191031093909.9228-4-dja@axtens.net Signed-off-by: Daniel Axtens Reviewed-by: Dmitry Vyukov Reviewed-by: Andrey Ryabinin Cc: Alexander Potapenko Cc: Christophe Leroy Cc: Mark Rutland Cc: Vasily Gorbik Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge tag 'for-linus-hmm' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma

2019-11-30T18:33:14Z

Pull hmm updates from Jason Gunthorpe: "This is another round of bug fixing and cleanup. This time the focus is on the driver pattern to use mmu notifiers to monitor a VA range. This code is lifted out of many drivers and hmm_mirror directly into the mmu_notifier core and written using the best ideas from all the driver implementations. This removes many bugs from the drivers and has a very pleasing diffstat. More drivers can still be converted, but that is for another cycle. - A shared branch with RDMA reworking the RDMA ODP implementation - New mmu_interval_notifier API. This is focused on the use case of monitoring a VA and simplifies the process for drivers - A common seq-count locking scheme built into the mmu_interval_notifier API usable by drivers that call get_user_pages() or hmm_range_fault() with the VA range - Conversion of mlx5 ODP, hfi1, radeon, nouveau, AMD GPU, and Xen GntDev drivers to the new API. This deletes a lot of wonky driver code. - Two improvements for hmm_range_fault(), from testing done by Ralph" * tag 'for-linus-hmm' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma: mm/hmm: remove hmm_range_dma_map and hmm_range_dma_unmap mm/hmm: make full use of walk_page_range() xen/gntdev: use mmu_interval_notifier_insert mm/hmm: remove hmm_mirror and related drm/amdgpu: Use mmu_interval_notifier instead of hmm_mirror drm/amdgpu: Use mmu_interval_insert instead of hmm_mirror drm/amdgpu: Call find_vma under mmap_sem nouveau: use mmu_interval_notifier instead of hmm_mirror nouveau: use mmu_notifier directly for invalidate_range_start drm/radeon: use mmu_interval_notifier_insert RDMA/hfi1: Use mmu_interval_notifier_insert for user_exp_rcv RDMA/odp: Use mmu_interval_notifier_insert() mm/hmm: define the pre-processor related parts of hmm.h even if disabled mm/hmm: allow hmm_range to be used with a mmu_interval_notifier or hmm_mirror mm/mmu_notifier: add an interval tree notifier mm/mmu_notifier: define the header pre-processor parts even if disabled mm/hmm: allow snapshot of the special zero page

Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2019-11-27T00:02:40Z

Pull locking updates from Ingo Molnar: "The main changes in this cycle were: - A comprehensive rewrite of the robust/PI futex code's exit handling to fix various exit races. (Thomas Gleixner et al) - Rework the generic REFCOUNT_FULL implementation using atomic_fetch_* operations so that the performance impact of the cmpxchg() loops is mitigated for common refcount operations. With these performance improvements the generic implementation of refcount_t should be good enough for everybody - and this got confirmed by performance testing, so remove ARCH_HAS_REFCOUNT and REFCOUNT_FULL entirely, leaving the generic implementation enabled unconditionally. (Will Deacon) - Other misc changes, fixes, cleanups" * 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (27 commits) lkdtm: Remove references to CONFIG_REFCOUNT_FULL locking/refcount: Remove unused 'refcount_error_report()' function locking/refcount: Consolidate implementations of refcount_t locking/refcount: Consolidate REFCOUNT_{MAX,SATURATED} definitions locking/refcount: Move saturation warnings out of line locking/refcount: Improve performance of generic REFCOUNT_FULL code locking/refcount: Move the bulk of the REFCOUNT_FULL implementation into the header locking/refcount: Remove unused refcount_*_checked() variants locking/refcount: Ensure integer operands are treated as signed locking/refcount: Define constants for saturation and max refcount values futex: Prevent exit livelock futex: Provide distinct return value when owner is exiting futex: Add mutex around futex exit futex: Provide state handling for exec() as well futex: Sanitize exit state handling futex: Mark the begin of futex exit explicitly futex: Set task::futex_state to DEAD right after handling futex exit futex: Split futex_mm_release() for exit/exec exit/exec: Seperate mm_release() futex: Replace PF_EXITPIDONE with a state ...

Merge tag 'threads-v5.5' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux

2019-11-26T02:36:49Z

Pull thread management updates from Christian Brauner: - A pidfd's fdinfo file currently contains the field "Pid:\t" where is the pid of the process in the pid namespace of the procfs instance the fdinfo file for the pidfd was opened in. The fdinfo file has now gained a new "NSpid:\t[\t[...]]" field which lists the pids of the process in all child pid namespaces provided the pid namespace of the procfs instance it is looked up under has an ancestoral relationship with the pid namespace of the process. If it does not 0 will be shown and no further pid namespaces will be listed. Tests included. (Christian Kellner) - If the process the pidfd references has already exited, print -1 for the Pid and NSpid fields in the pidfd's fdinfo file. Tests included. (me) - Add CLONE_CLEAR_SIGHAND. This lets callers clear all signal handler that are not SIG_DFL or SIG_IGN at process creation time. This originated as a feature request from glibc to improve performance and elimate races in their posix_spawn() implementation. Tests included. (me) - Add support for choosing a specific pid for a process with clone3(). This is the feature which was part of the thread update for v5.4 but after a discussion at LPC in Lisbon we decided to delay it for one more cycle in order to make the interface more generic. This has now done. It is now possible to choose a specific pid in a whole pid namespaces (sub)hierarchy instead of just one pid namespace. In order to choose a specific pid the caller must have CAP_SYS_ADMIN in all owning user namespaces of the target pid namespaces. Tests included. (Adrian Reber) - Test improvements and extensions. (Andrei Vagin, me) * tag 'threads-v5.5' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux: selftests/clone3: skip if clone3() is ENOSYS selftests/clone3: check that all pids are released on error paths selftests/clone3: report a correct number of fails selftests/clone3: flush stdout and stderr before clone3() and _exit() selftests: add tests for clone3() with *set_tid fork: extend clone3() to support setting a PID selftests: add tests for clone3() tests: test CLONE_CLEAR_SIGHAND clone3: add CLONE_CLEAR_SIGHAND pid: use pid_has_task() in pidfd_open() exit: use pid_has_task() in do_wait() pid: use pid_has_task() in __change_pid() test: verify fdinfo for pidfd of reaped process pidfd: check pid has attached task in fdinfo pidfd: add tests for NSpid info in fdinfo pidfd: add NSpid entries to fdinfo

Merge branch 'timers/urgent' into timers/core, to pick up fix

2019-11-25T14:43:15Z

Signed-off-by: Ingo Molnar

mm/hmm: define the pre-processor related parts of hmm.h even if disabled

2019-11-23T23:56:44Z

Only the function calls are stubbed out with static inlines that always fail. This is the standard way to write a header for an optional component and makes it easier for drivers that only optionally need HMM_MIRROR. Link: https://lore.kernel.org/r/20191112202231.3856-5-jgg@ziepe.ca Reviewed-by: Jérôme Glisse Tested-by: Ralph Campbell Reviewed-by: Christoph Hellwig Signed-off-by: Jason Gunthorpe

fork: fix pidfd_poll()'s return type

2019-11-20T10:48:50Z

pidfd_poll() is defined as returning 'unsigned int' but the .poll method is declared as returning '__poll_t', a bitwise type. Fix this by using the proper return type and using the EPOLL constants instead of the POLL ones, as required for __poll_t. Fixes: b53b0b9d9a61 ("pidfd: add polling support") Cc: Joel Fernandes (Google) Cc: stable@vger.kernel.org # 5.3 Signed-off-by: Luc Van Oostenryck Reviewed-by: Christian Brauner Link: https://lore.kernel.org/r/20191120003320.31138-1-luc.vanoostenryck@gmail.com Signed-off-by: Christian Brauner