commit 9ca365c0c8bdd8552ec064f0e696600cf7ea66dd Author: Sasha Levin Date: Sat Oct 22 16:05:53 2016 -0400 Linux 4.1.35 Signed-off-by: Sasha Levin commit 3b244a6e53dc33f6701bfde8601d7677c0c6e9e8 Author: Mathias Nyman Date: Fri Dec 11 14:38:06 2015 +0200 xhci: fix usb2 resume timing and races. [ Upstream commit f69115fdbc1ac0718e7d19ad3caa3da2ecfe1c96 ] According to USB 2 specs ports need to signal resume for at least 20ms, in practice even longer, before moving to U0 state. Both host and devices can initiate resume. On device initiated resume, a port status interrupt with the port in resume state in issued. The interrupt handler tags a resume_done[port] timestamp with current time + USB_RESUME_TIMEOUT, and kick roothub timer. Root hub timer requests for port status, finds the port in resume state, checks if resume_done[port] timestamp passed, and set port to U0 state. On host initiated resume, current code sets the port to resume state, sleep 20ms, and finally sets the port to U0 state. This should also be changed to work in a similar way as the device initiated resume, with timestamp tagging, but that is not yet tested and will be a separate fix later. There are a few issues with this approach 1. A host initiated resume will also generate a resume event. The event handler will find the port in resume state, believe it's a device initiated resume, and act accordingly. 2. A port status request might cut the resume signalling short if a get_port_status request is handled during the host resume signalling. The port will be found in resume state. The timestamp is not set leading to time_after_eq(jiffies, timestamp) returning true, as timestamp = 0. get_port_status will proceed with moving the port to U0. 3. If an error, or anything else happens to the port during device initiated resume signalling it will leave all the device resume parameters hanging uncleared, preventing further suspend, returning -EBUSY, and cause the pm thread to busyloop trying to enter suspend. Fix this by using the existing resuming_ports bitfield to indicate that resume signalling timing is taken care of. Check if the resume_done[port] is set before using it for timestamp comparison, and also clear out any resume signalling related variables if port is not in U0 or Resume state This issue was discovered when a PM thread busylooped, trying to runtime suspend the xhci USB 2 roothub on a Dell XPS Cc: stable Reported-by: Daniel J Blueman Tested-by: Daniel J Blueman Signed-off-by: Mathias Nyman Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin commit c865f98df72112a3997b219bf711bc46c1e90706 Author: Linus Torvalds Date: Thu Oct 13 13:07:36 2016 -0700 mm: remove gup_flags FOLL_WRITE games from __get_user_pages() [ Upstream commit 19be0eaffa3ac7d8eb6784ad9bdbc7d67ed8e619 ] This is an ancient bug that was actually attempted to be fixed once (badly) by me eleven years ago in commit 4ceb5db9757a ("Fix get_user_pages() race for write access") but that was then undone due to problems on s390 by commit f33ea7f404e5 ("fix get_user_pages bug"). In the meantime, the s390 situation has long been fixed, and we can now fix it by checking the pte_dirty() bit properly (and do it better). The s390 dirty bit was implemented in abf09bed3cce ("s390/mm: implement software dirty bits") which made it into v3.9. Earlier kernels will have to look at the page state itself. Also, the VM has become more scalable, and what used a purely theoretical race back then has become easier to trigger. To fix it, we introduce a new internal FOLL_COW flag to mark the "yes, we already did a COW" rather than play racy games with FOLL_WRITE that is very fundamental, and then use the pte dirty flag to validate that the FOLL_COW flag is still valid. Reported-and-tested-by: Phil "not Paul" Oester Acked-by: Hugh Dickins Reviewed-by: Michal Hocko Cc: Andy Lutomirski Cc: Kees Cook Cc: Oleg Nesterov Cc: Willy Tarreau Cc: Nick Piggin Cc: Greg Thelen Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin commit 4edf04a3a307195be345f8189e37501ac247f68b Author: John Stultz Date: Tue Oct 4 19:55:48 2016 -0700 timekeeping: Fix __ktime_get_fast_ns() regression [ Upstream commit 58bfea9532552d422bde7afa207e1a0f08dffa7d ] In commit 27727df240c7 ("Avoid taking lock in NMI path with CONFIG_DEBUG_TIMEKEEPING"), I changed the logic to open-code the timekeeping_get_ns() function, but I forgot to include the unit conversion from cycles to nanoseconds, breaking the function's output, which impacts users like perf. This results in bogus perf timestamps like: swapper 0 [000] 253.427536: 111111111 cpu-clock: ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms]) swapper 0 [000] 254.426573: 111111111 cpu-clock: ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms]) swapper 0 [000] 254.426687: 111111111 cpu-clock: ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms]) swapper 0 [000] 254.426800: 111111111 cpu-clock: ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms]) swapper 0 [000] 254.426905: 111111111 cpu-clock: ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms]) swapper 0 [000] 254.427022: 111111111 cpu-clock: ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms]) swapper 0 [000] 254.427127: 111111111 cpu-clock: ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms]) swapper 0 [000] 254.427239: 111111111 cpu-clock: ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms]) swapper 0 [000] 254.427346: 111111111 cpu-clock: ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms]) swapper 0 [000] 254.427463: 111111111 cpu-clock: ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms]) swapper 0 [000] 255.426572: 111111111 cpu-clock: ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms]) Instead of more reasonable expected timestamps like: swapper 0 [000] 39.953768: 111111111 cpu-clock: ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms]) swapper 0 [000] 40.064839: 111111111 cpu-clock: ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms]) swapper 0 [000] 40.175956: 111111111 cpu-clock: ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms]) swapper 0 [000] 40.287103: 111111111 cpu-clock: ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms]) swapper 0 [000] 40.398217: 111111111 cpu-clock: ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms]) swapper 0 [000] 40.509324: 111111111 cpu-clock: ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms]) swapper 0 [000] 40.620437: 111111111 cpu-clock: ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms]) swapper 0 [000] 40.731546: 111111111 cpu-clock: ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms]) swapper 0 [000] 40.842654: 111111111 cpu-clock: ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms]) swapper 0 [000] 40.953772: 111111111 cpu-clock: ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms]) swapper 0 [000] 41.064881: 111111111 cpu-clock: ffffffff810a0de6 native_safe_halt+0x6 ([kernel.kallsyms]) Add the proper use of timekeeping_delta_to_ns() to convert the cycle delta to nanoseconds as needed. Thanks to Brendan and Alexei for finding this quickly after the v4.8 release. Unfortunately the problematic commit has landed in some -stable trees so they'll need this fix as well. Many apologies for this mistake. I'll be looking to add a perf-clock sanity test to the kselftest timers tests soon. Fixes: 27727df240c7 "timekeeping: Avoid taking lock in NMI path with CONFIG_DEBUG_TIMEKEEPING" Reported-by: Brendan Gregg Reported-by: Alexei Starovoitov Tested-and-reviewed-by: Mathieu Desnoyers Signed-off-by: John Stultz Cc: Peter Zijlstra Cc: stable Cc: Steven Rostedt Link: http://lkml.kernel.org/r/1475636148-26539-1-git-send-email-john.stultz@linaro.org Signed-off-by: Thomas Gleixner Signed-off-by: Sasha Levin commit 486eeb6d6755a573829e6c5438eb7aae18891bb1 Author: Christopher S. Hall Date: Mon Feb 22 03:15:19 2016 -0800 time: Add cycles to nanoseconds translation [ Upstream commit 6bd58f09e1d8cc6c50a824c00bf0d617919986a1 ] The timekeeping code does not currently provide a way to translate externally provided clocksource cycles to system time. The cycle count is always provided by the result clocksource read() method internal to the timekeeping code. The added function timekeeping_cycles_to_ns() calculated a nanosecond value from a cycle count that can be added to tk_read_base.base value yielding the current system time. This allows clocksource cycle values external to the timekeeping code to provide a cycle count that can be transformed to system time. Cc: Prarit Bhargava Cc: Richard Cochran Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Andy Lutomirski Cc: kevin.b.stanton@intel.com Cc: kevin.j.clarke@intel.com Cc: hpa@zytor.com Cc: jeffrey.t.kirsher@intel.com Cc: netdev@vger.kernel.org Reviewed-by: Thomas Gleixner Signed-off-by: Christopher S. Hall Signed-off-by: John Stultz Signed-off-by: Sasha Levin