wireguard-linux/arch/um/kernel, branch jd/unified-crypt-queue

Merge tag 'for-linus-5.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml

2020-04-07T19:36:09Z

Pull UML updates from Richard Weinberger: - New mode for time travel, external via virtio - Fixes for ubd to make sure no requests can get lost - Fixes for vector networking - Allow CONFIG_STATIC_LINK only when possible - Minor cleanups and fixes * tag 'for-linus-5.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml: um: Remove some unnecessary NULL checks in vector_user.c um: vector: Avoid NULL ptr deference if transport is unset um: Make CONFIG_STATIC_LINK actually static um: Implement cpu_relax() as ndelay(1) for time-travel um: Implement ndelay/udelay in time-travel mode um: Implement time-travel=ext um: virtio: Implement VHOST_USER_PROTOCOL_F_INBAND_NOTIFICATIONS um: time-travel: Rewrite as an event scheduler um: Move timer-internal.h to non-shared hostfs: Use kasprintf() instead of fixed buffer formatting um: falloc.h needs to be directly included for older libc um: ubd: Retry buffer read on any kind of error um: ubd: Prevent buffer overrun on command completion um: Fix overlapping ELF segments when statically linked um: Delete never executed timer um: Don't overwrite ethtool driver version um: Fix len of file in create_pid_file um: Don't use console_drivers directly um: Cleanup CONFIG_IOSCHED_CFQ

mm: allow VM_FAULT_RETRY for multiple times

2020-04-02T16:35:30Z

The idea comes from a discussion between Linus and Andrea [1]. Before this patch we only allow a page fault to retry once. We achieved this by clearing the FAULT_FLAG_ALLOW_RETRY flag when doing handle_mm_fault() the second time. This was majorly used to avoid unexpected starvation of the system by looping over forever to handle the page fault on a single page. However that should hardly happen, and after all for each code path to return a VM_FAULT_RETRY we'll first wait for a condition (during which time we should possibly yield the cpu) to happen before VM_FAULT_RETRY is really returned. This patch removes the restriction by keeping the FAULT_FLAG_ALLOW_RETRY flag when we receive VM_FAULT_RETRY. It means that the page fault handler now can retry the page fault for multiple times if necessary without the need to generate another page fault event. Meanwhile we still keep the FAULT_FLAG_TRIED flag so page fault handler can still identify whether a page fault is the first attempt or not. Then we'll have these combinations of fault flags (only considering ALLOW_RETRY flag and TRIED flag): - ALLOW_RETRY and !TRIED: this means the page fault allows to retry, and this is the first try - ALLOW_RETRY and TRIED: this means the page fault allows to retry, and this is not the first try - !ALLOW_RETRY and !TRIED: this means the page fault does not allow to retry at all - !ALLOW_RETRY and TRIED: this is forbidden and should never be used In existing code we have multiple places that has taken special care of the first condition above by checking against (fault_flags & FAULT_FLAG_ALLOW_RETRY). This patch introduces a simple helper to detect the first retry of a page fault by checking against both (fault_flags & FAULT_FLAG_ALLOW_RETRY) and !(fault_flag & FAULT_FLAG_TRIED) because now even the 2nd try will have the ALLOW_RETRY set, then use that helper in all existing special paths. One example is in __lock_page_or_retry(), now we'll drop the mmap_sem only in the first attempt of page fault and we'll keep it in follow up retries, so old locking behavior will be retained. This will be a nice enhancement for current code [2] at the same time a supporting material for the future userfaultfd-writeprotect work, since in that work there will always be an explicit userfault writeprotect retry for protected pages, and if that cannot resolve the page fault (e.g., when userfaultfd-writeprotect is used in conjunction with swapped pages) then we'll possibly need a 3rd retry of the page fault. It might also benefit other potential users who will have similar requirement like userfault write-protection. GUP code is not touched yet and will be covered in follow up patch. Please read the thread below for more information. [1] https://lore.kernel.org/lkml/20171102193644.GB22686@redhat.com/ [2] https://lore.kernel.org/lkml/20181230154648.GB9832@redhat.com/ 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/20200220160246.9790-1-peterx@redhat.com Signed-off-by: Linus Torvalds

mm: introduce FAULT_FLAG_DEFAULT

2020-04-02T16:35:29Z

Although there're tons of arch-specific page fault handlers, most of them are still sharing the same initial value of the page fault flags. Say, merely all of the page fault handlers would allow the fault to be retried, and they also allow the fault to respond to SIGKILL. Let's define a default value for the fault flags to replace those initial page fault flags that were copied over. With this, it'll be far easier to introduce new fault flag that can be used by all the architectures instead of touching all the archs. Signed-off-by: Peter Xu Signed-off-by: Andrew Morton Tested-by: Brian Geffon Reviewed-by: David Hildenbrand Cc: Andrea Arcangeli Cc: Bobby Powers 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/20200220160238.9694-1-peterx@redhat.com Signed-off-by: Linus Torvalds

um: Implement ndelay/udelay in time-travel mode

2020-03-29T21:29:52Z

In external or inf-cpu time-travel mode, ndelay/udelay currently just waste CPU time since the simulation time doesn't advance. Implement them properly in this case. Note that the "if (time_travel_mode == ...)" parts compile out if CONFIG_UML_TIME_TRAVEL_SUPPORT isn't set, time_travel_mode is defined to TT_MODE_OFF in that case. Signed-off-by: Johannes Berg Signed-off-by: Richard Weinberger

um: Implement time-travel=ext

2020-03-29T21:29:08Z

This implements synchronized time-travel mode which - using a special application on a unix socket - lets multiple machines take part in a time-travelling simulation together. The protocol for the unix domain socket is defined in the new file include/uapi/linux/um_timetravel.h. Signed-off-by: Johannes Berg Signed-off-by: Richard Weinberger

um: time-travel: Rewrite as an event scheduler

2020-03-29T21:28:51Z

Instead of tracking all the various timer configurations, modify the time-travel mode to have an event scheduler and use a timer event on the scheduler to handle the different timer configurations. This doesn't change the function right now, but it prepares the code for having different kinds of events in the future (i.e. interrupts coming from other devices that are part of co-simulation.) While at it, also move time_travel_sleep() to time.c to reduce the externally visible API surface. Also, we really should mark time-travel as incompatible with SMP, even if UML doesn't support SMP yet. Finally, I noticed a bug while developing this - if we move time forward due to consuming time while reading the clock, we might move across the next event and that would cause us to go backward in time when we then handle that event. Fix that by invoking the whole event machine in this case, but in order to simplify this, make reading the clock only cost something when interrupts are not disabled. Otherwise, we'd have to hook into the interrupt delivery machinery etc. and that's somewhat intrusive. Signed-off-by: Johannes Berg Signed-off-by: Richard Weinberger

um: Move timer-internal.h to non-shared

2020-03-29T21:28:43Z

This file isn't really shared, it's only used on the kernel side, not on the user side. Remove the include from the user-side and move the file to a better place. While at it, rename it to time-internal.h, it's not really just timers but all kinds of things related to timekeeping. Signed-off-by: Johannes Berg Signed-off-by: Richard Weinberger

um: Fix overlapping ELF segments when statically linked

2020-03-29T21:21:29Z

When statically linked, the .text section in UML kernels is not page aligned, causing it to share a page with the executable headers. As .text and the executable headers have different permissions, this causes the kernel to wish to map the same page twice (once as headers with r-- permissions, once as .text with r-x permissions), causing a segfault, and a nasty message printed to the host kernel's dmesg: "Uhuuh, elf segment at 0000000060000000 requested but the memory is mapped already" By aligning the .text to a page boundary (as in the dynamically linked version in dyn.lds.S), there is no such overlap, and the kernel runs correctly. Signed-off-by: David Gow Reviewed-by: Brendan Higgins Signed-off-by: Richard Weinberger

um: Don't use console_drivers directly

2020-03-29T21:17:10Z

console_drivers is kind of (semi-)private variable to the console code. Direct use of it make us stuck with it being exported here and there. Reduce use of console_drivers by replacing it with for_each_console(). Cc: Thomas Meyer Signed-off-by: Andy Shevchenko Signed-off-by: Richard Weinberger

proc: convert everything to "struct proc_ops"

2020-02-04T03:05:26Z

The most notable change is DEFINE_SHOW_ATTRIBUTE macro split in seq_file.h. Conversion rule is: llseek => proc_lseek unlocked_ioctl => proc_ioctl xxx => proc_xxx delete ".owner = THIS_MODULE" line [akpm@linux-foundation.org: fix drivers/isdn/capi/kcapi_proc.c] [sfr@canb.auug.org.au: fix kernel/sched/psi.c] Link: http://lkml.kernel.org/r/20200122180545.36222f50@canb.auug.org.au Link: http://lkml.kernel.org/r/20191225172546.GB13378@avx2 Signed-off-by: Alexey Dobriyan Signed-off-by: Stephen Rothwell Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds