BMC/Intel-BMC/linux.git/include/linux/sched/signal.h, branch dev-5.7

Merge branch 'akpm' (patches from Andrew)

2020-04-02T20:55:34+00:00

Merge updates from Andrew Morton: "A large amount of MM, plenty more to come. Subsystems affected by this patch series: - tools - kthread - kbuild - scripts - ocfs2 - vfs - mm: slub, kmemleak, pagecache, gup, swap, memcg, pagemap, mremap, sparsemem, kasan, pagealloc, vmscan, compaction, mempolicy, hugetlbfs, hugetlb" * emailed patches from Andrew Morton : (155 commits) include/linux/huge_mm.h: check PageTail in hpage_nr_pages even when !THP mm/hugetlb: fix build failure with HUGETLB_PAGE but not HUGEBTLBFS selftests/vm: fix map_hugetlb length used for testing read and write mm/hugetlb: remove unnecessary memory fetch in PageHeadHuge() mm/hugetlb.c: clean code by removing unnecessary initialization hugetlb_cgroup: add hugetlb_cgroup reservation docs hugetlb_cgroup: add hugetlb_cgroup reservation tests hugetlb: support file_region coalescing again hugetlb_cgroup: support noreserve mappings hugetlb_cgroup: add accounting for shared mappings hugetlb: disable region_add file_region coalescing hugetlb_cgroup: add reservation accounting for private mappings mm/hugetlb_cgroup: fix hugetlb_cgroup migration hugetlb_cgroup: add interface for charge/uncharge hugetlb reservations hugetlb_cgroup: add hugetlb_cgroup reservation counter hugetlbfs: Use i_mmap_rwsem to address page fault/truncate race hugetlbfs: use i_mmap_rwsem for more pmd sharing synchronization mm/memblock.c: remove redundant assignment to variable max_addr mm: mempolicy: require at least one nodeid for MPOL_PREFERRED mm: mempolicy: use VM_BUG_ON_VMA in queue_pages_test_walk() ...

mm: return faster for non-fatal signals in user mode faults

2020-04-02T16:35:29+00:00

The idea comes from the upstream discussion between Linus and Andrea: https://lore.kernel.org/lkml/20171102193644.GB22686@redhat.com/ A summary to the issue: there was a special path in handle_userfault() in the past that we'll return a VM_FAULT_NOPAGE when we detected non-fatal signals when waiting for userfault handling. We did that by reacquiring the mmap_sem before returning. However that brings a risk in that the vmas might have changed when we retake the mmap_sem and even we could be holding an invalid vma structure. This patch is a preparation of removing that special path by allowing the page fault to return even faster if we were interrupted by a non-fatal signal during a user-mode page fault handling routine. Suggested-by: Linus Torvalds Suggested-by: Andrea Arcangeli Signed-off-by: Peter Xu Signed-off-by: Andrew Morton Tested-by: Brian Geffon Cc: Bobby Powers Cc: David Hildenbrand Cc: Denis Plotnikov Cc: "Dr . David Alan Gilbert" Cc: Hugh Dickins Cc: Jerome Glisse Cc: Johannes Weiner Cc: "Kirill A . Shutemov" Cc: Martin Cracauer Cc: Marty McFadden Cc: Matthew Wilcox Cc: Maya Gokhale Cc: Mel Gorman Cc: Mike Kravetz Cc: Mike Rapoport Cc: Pavel Emelyanov Link: http://lkml.kernel.org/r/20200220160230.9598-1-peterx@redhat.com Signed-off-by: Linus Torvalds

mm: introduce fault_signal_pending()

2020-04-02T16:35:29+00:00

For most architectures, we've got a quick path to detect fatal signal after a handle_mm_fault(). Introduce a helper for that quick path. It cleans the current codes a bit so we don't need to duplicate the same check across archs. More importantly, this will be an unified place that we handle the signal immediately right after an interrupted page fault, so it'll be much easier for us if we want to change the behavior of handling signals later on for all the archs. Note that currently only part of the archs are using this new helper, because some archs have their own way to handle signals. In the follow up patches, we'll try to apply this helper to all the rest of archs. Another note is that the "regs" parameter in the new helper is not used yet. It'll be used very soon. Now we kept it in this patch only to avoid touching all the archs again in the follow up patches. [peterx@redhat.com: fix sparse warnings] Link: http://lkml.kernel.org/r/20200311145921.GD479302@xz-x1 Signed-off-by: Peter Xu Signed-off-by: Andrew Morton Tested-by: Brian Geffon Cc: Andrea Arcangeli Cc: Bobby Powers Cc: David Hildenbrand Cc: Denis Plotnikov Cc: "Dr . David Alan Gilbert" Cc: Hugh Dickins Cc: Jerome Glisse Cc: Johannes Weiner Cc: "Kirill A . Shutemov" Cc: Martin Cracauer Cc: Marty McFadden Cc: Matthew Wilcox Cc: Maya Gokhale Cc: Mel Gorman Cc: Mike Kravetz Cc: Mike Rapoport Cc: Pavel Emelyanov Link: http://lkml.kernel.org/r/20200220155353.8676-4-peterx@redhat.com Signed-off-by: Linus Torvalds

exec: Add exec_update_mutex to replace cred_guard_mutex

2020-03-25T15:03:36+00:00

The cred_guard_mutex is problematic as it is held over possibly indefinite waits for userspace. The possible indefinite waits for userspace that I have identified are: The cred_guard_mutex is held in PTRACE_EVENT_EXIT waiting for the tracer. The cred_guard_mutex is held over "put_user(0, tsk->clear_child_tid)" in exit_mm(). The cred_guard_mutex is held over "get_user(futex_offset, ...") in exit_robust_list. The cred_guard_mutex held over copy_strings. The functions get_user and put_user can trigger a page fault which can potentially wait indefinitely in the case of userfaultfd or if userspace implements part of the page fault path. In any of those cases the userspace process that the kernel is waiting for might make a different system call that winds up taking the cred_guard_mutex and result in deadlock. Holding a mutex over any of those possibly indefinite waits for userspace does not appear necessary. Add exec_update_mutex that will just cover updating the process during exec where the permissions and the objects pointed to by the task struct may be out of sync. The plan is to switch the users of cred_guard_mutex to exec_update_mutex one by one. This lets us move forward while still being careful and not introducing any regressions. Link: https://lore.kernel.org/lkml/20160921152946.GA24210@dhcp22.suse.cz/ Link: https://lore.kernel.org/lkml/AM6PR03MB5170B06F3A2B75EFB98D071AE4E60@AM6PR03MB5170.eurprd03.prod.outlook.com/ Link: https://lore.kernel.org/linux-fsdevel/20161102181806.GB1112@redhat.com/ Link: https://lore.kernel.org/lkml/20160923095031.GA14923@redhat.com/ Link: https://lore.kernel.org/lkml/20170213141452.GA30203@redhat.com/ Ref: 45c1a159b85b ("Add PTRACE_O_TRACEVFORKDONE and PTRACE_O_TRACEEXIT facilities.") Ref: 456f17cd1a28 ("[PATCH] user-vm-unlock-2.5.31-A2") Reviewed-by: Kirill Tkhai Signed-off-by: "Eric W. Biederman" Signed-off-by: Bernd Edlinger Signed-off-by: Eric W. Biederman

posix-cpu-timers: Move state tracking to struct posix_cputimers

2019-08-28T09:50:42+00:00

Put it where it belongs and clean up the ifdeffery in fork completely. Signed-off-by: Thomas Gleixner Link: https://lkml.kernel.org/r/20190821192922.743229404@linutronix.de

posix-cpu-timers: Move expiry cache into struct posix_cputimers

2019-08-28T09:50:35+00:00

The expiry cache belongs into the posix_cputimers container where the other cpu timers information is. Signed-off-by: Thomas Gleixner Reviewed-by: Frederic Weisbecker Link: https://lkml.kernel.org/r/20190821192921.014444012@linutronix.de

posix-cpu-timers: Create a container struct

2019-08-28T09:50:33+00:00

Per task/process data of posix CPU timers is all over the place which makes the code hard to follow and requires ifdeffery. Create a container to hold all this information in one place, so data is consolidated and the ifdeffery can be confined to the posix timer header file and removed from places like fork. As a first step, move the cpu_timers list head array into the new struct and clean up the initializers and simplify fork. The remaining #ifdef in fork will be removed later. Signed-off-by: Thomas Gleixner Reviewed-by: Frederic Weisbecker Link: https://lkml.kernel.org/r/20190821192920.819418976@linutronix.de

signal: simplify set_user_sigmask/restore_user_sigmask

2019-07-17T02:23:24+00:00

task->saved_sigmask and ->restore_sigmask are only used in the ret-from- syscall paths. This means that set_user_sigmask() can save ->blocked in ->saved_sigmask and do set_restore_sigmask() to indicate that ->blocked was modified. This way the callers do not need 2 sigset_t's passed to set/restore and restore_user_sigmask() renamed to restore_saved_sigmask_unless() turns into the trivial helper which just calls restore_saved_sigmask(). Link: http://lkml.kernel.org/r/20190606113206.GA9464@redhat.com Signed-off-by: Oleg Nesterov Cc: Deepa Dinamani Cc: Arnd Bergmann Cc: Jens Axboe Cc: Davidlohr Bueso Cc: Eric Wong Cc: Jason Baron Cc: Thomas Gleixner Cc: Al Viro Cc: Eric W. Biederman Cc: David Laight Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

signal: reorder struct sighand_struct

2019-07-17T02:23:24+00:00

struct sighand_struct::siglock field is the most used field by far, put it first so that is can be accessed without IMM8 or IMM32 encoding on x86_64. Space savings (on trimmed down VM test config): add/remove: 0/0 grow/shrink: 8/68 up/down: 49/-1147 (-1098) Function old new delta complete_signal 512 533 +21 do_signalfd4 335 346 +11 __cleanup_sighand 39 43 +4 unhandled_signal 49 52 +3 prepare_signal 692 695 +3 ignore_signals 37 40 +3 __tty_check_change.part 248 251 +3 ksys_unshare 780 781 +1 sighand_ctor 33 29 -4 ptrace_trap_notify 60 56 -4 sigqueue_free 98 91 -7 run_posix_cpu_timers 1389 1382 -7 proc_pid_status 2448 2441 -7 proc_pid_limits 344 337 -7 posix_cpu_timer_rearm 222 215 -7 posix_cpu_timer_get 249 242 -7 kill_pid_info_as_cred 243 236 -7 freeze_task 197 190 -7 flush_old_exec 1873 1866 -7 do_task_stat 3363 3356 -7 do_send_sig_info 98 91 -7 do_group_exit 147 140 -7 init_sighand 2088 2080 -8 do_notify_parent_cldstop 399 391 -8 signalfd_cleanup 50 41 -9 do_notify_parent 557 545 -12 __send_signal 1029 1017 -12 ptrace_stop 590 577 -13 get_signal 1576 1563 -13 __lock_task_sighand 112 99 -13 zap_pid_ns_processes 391 377 -14 update_rlimit_cpu 78 64 -14 tty_signal_session_leader 413 399 -14 tty_open_proc_set_tty 149 135 -14 tty_jobctrl_ioctl 936 922 -14 set_cpu_itimer 339 325 -14 ptrace_resume 226 212 -14 ptrace_notify 110 96 -14 proc_clear_tty 81 67 -14 posix_cpu_timer_del 229 215 -14 kernel_sigaction 156 142 -14 getrusage 977 963 -14 get_current_tty 98 84 -14 force_sigsegv 89 75 -14 force_sig_info 205 191 -14 flush_signals 83 69 -14 flush_itimer_signals 85 71 -14 do_timer_create 1120 1106 -14 do_sigpending 88 74 -14 do_signal_stop 537 523 -14 cgroup_init_fs_context 644 630 -14 call_usermodehelper_exec_async 402 388 -14 calculate_sigpending 58 44 -14 __x64_sys_timer_delete 248 234 -14 __set_current_blocked 80 66 -14 __ptrace_unlink 310 296 -14 __ptrace_detach.part 187 173 -14 send_sigqueue 362 347 -15 get_cpu_itimer 214 199 -15 signalfd_poll 175 159 -16 dequeue_signal 340 323 -17 do_getitimer 192 174 -18 release_task.part 1060 1040 -20 ptrace_peek_siginfo 408 387 -21 posix_cpu_timer_set 827 806 -21 exit_signals 437 416 -21 do_sigaction 541 520 -21 do_setitimer 485 464 -21 disassociate_ctty.part 545 517 -28 __x64_sys_rt_sigtimedwait 721 679 -42 __x64_sys_ptrace 1319 1277 -42 ptrace_request 1828 1782 -46 signalfd_read 507 459 -48 wait_consider_task 2027 1971 -56 do_coredump 3672 3616 -56 copy_process.part 6936 6871 -65 Link: http://lkml.kernel.org/r/20190503192800.GA18004@avx2 Signed-off-by: Alexey Dobriyan Cc: Michal Hocko Cc: Oleg Nesterov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

signal: Remove the signal number and task parameters from force_sig_info

2019-05-29T14:31:44+00:00

force_sig_info always delivers to the current task and the signal parameter always matches info.si_signo. So remove those parameters to make it a simpler less error prone interface, and to make it clear that none of the callers are doing anything clever. This guarantees that force_sig_info will not grow any new buggy callers that attempt to call force_sig on a non-current task, or that pass an signal number that does not match info.si_signo. Signed-off-by: "Eric W. Biederman"