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* Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds2019-08-102-10/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fixes from Thomas Gleixner: "Three fixlets for the scheduler: - Avoid double bandwidth accounting in the push & pull code - Use a sane FIFO priority for the Pressure Stall Information (PSI) thread. - Avoid permission checks when setting the scheduler params for the PSI thread" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/psi: Do not require setsched permission from the trigger creator sched/psi: Reduce psimon FIFO priority sched/deadline: Fix double accounting of rq/running bw in push & pull
| * sched/psi: Do not require setsched permission from the trigger creatorSuren Baghdasaryan2019-08-061-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When a process creates a new trigger by writing into /proc/pressure/* files, permissions to write such a file should be used to determine whether the process is allowed to do so or not. Current implementation would also require such a process to have setsched capability. Setting of psi trigger thread's scheduling policy is an implementation detail and should not be exposed to the user level. Remove the permission check by using _nocheck version of the function. Suggested-by: Nick Kralevich <nnk@google.com> Signed-off-by: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: lizefan@huawei.com Cc: mingo@redhat.com Cc: akpm@linux-foundation.org Cc: kernel-team@android.com Cc: dennisszhou@gmail.com Cc: dennis@kernel.org Cc: hannes@cmpxchg.org Cc: axboe@kernel.dk Link: https://lkml.kernel.org/r/20190730013310.162367-1-surenb@google.com
| * sched/psi: Reduce psimon FIFO priorityPeter Zijlstra2019-08-061-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | PSI defaults to a FIFO-99 thread, reduce this to FIFO-1. FIFO-99 is the very highest priority available to SCHED_FIFO and it not a suitable default; it would indicate the psi work is the most important work on the machine. Since Real-Time tasks will have pre-allocated memory and locked it in place, Real-Time tasks do not care about PSI. All it needs is to be above OTHER. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Tested-by: Suren Baghdasaryan <surenb@google.com> Cc: Thomas Gleixner <tglx@linutronix.de>
| * sched/deadline: Fix double accounting of rq/running bw in push & pullDietmar Eggemann2019-08-061-8/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | {push,pull}_dl_task() always calls {de,}activate_task() with .flags=0 which sets p->on_rq=TASK_ON_RQ_MIGRATING. {push,pull}_dl_task()->{de,}activate_task()->{de,en}queue_task()-> {de,en}queue_task_dl() calls {sub,add}_{running,rq}_bw() since p->on_rq==TASK_ON_RQ_MIGRATING. So {sub,add}_{running,rq}_bw() in {push,pull}_dl_task() is double-accounting for that task. Fix it by removing rq/running bw accounting in [push/pull]_dl_task(). Fixes: 7dd778841164 ("sched/core: Unify p->on_rq updates") Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Valentin Schneider <valentin.schneider@arm.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Luca Abeni <luca.abeni@santannapisa.it> Cc: Daniel Bristot de Oliveira <bristot@redhat.com> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Qais Yousef <qais.yousef@arm.com> Link: https://lkml.kernel.org/r/20190802145945.18702-2-dietmar.eggemann@arm.com
* | genirq/affinity: Create affinity mask for single vectorMing Lei2019-08-081-4/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since commit c66d4bd110a1f8 ("genirq/affinity: Add new callback for (re)calculating interrupt sets"), irq_create_affinity_masks() returns NULL in case of single vector. This change has caused regression on some drivers, such as lpfc. The problem is that single vector requests can happen in some generic cases: 1) kdump kernel 2) irq vectors resource is close to exhaustion. If in that situation the affinity mask for a single vector is not created, every caller has to handle the special case. There is no reason why the mask cannot be created, so remove the check for a single vector and create the mask. Fixes: c66d4bd110a1f8 ("genirq/affinity: Add new callback for (re)calculating interrupt sets") Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20190805011906.5020-1-ming.lei@redhat.com
* | Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netLinus Torvalds2019-08-061-2/+2
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull networking fixes from David Miller: "Yeah I should have sent a pull request last week, so there is a lot more here than usual: 1) Fix memory leak in ebtables compat code, from Wenwen Wang. 2) Several kTLS bug fixes from Jakub Kicinski (circular close on disconnect etc.) 3) Force slave speed check on link state recovery in bonding 802.3ad mode, from Thomas Falcon. 4) Clear RX descriptor bits before assigning buffers to them in stmmac, from Jose Abreu. 5) Several missing of_node_put() calls, mostly wrt. for_each_*() OF loops, from Nishka Dasgupta. 6) Double kfree_skb() in peak_usb can driver, from Stephane Grosjean. 7) Need to hold sock across skb->destructor invocation, from Cong Wang. 8) IP header length needs to be validated in ipip tunnel xmit, from Haishuang Yan. 9) Use after free in ip6 tunnel driver, also from Haishuang Yan. 10) Do not use MSI interrupts on r8169 chips before RTL8168d, from Heiner Kallweit. 11) Upon bridge device init failure, we need to delete the local fdb. From Nikolay Aleksandrov. 12) Handle erros from of_get_mac_address() properly in stmmac, from Martin Blumenstingl. 13) Handle concurrent rename vs. dump in netfilter ipset, from Jozsef Kadlecsik. 14) Setting NETIF_F_LLTX on mac80211 causes complete breakage with some devices, so revert. From Johannes Berg. 15) Fix deadlock in rxrpc, from David Howells. 16) Fix Kconfig deps of enetc driver, we must have PHYLIB. From Yue Haibing. 17) Fix mvpp2 crash on module removal, from Matteo Croce. 18) Fix race in genphy_update_link, from Heiner Kallweit. 19) bpf_xdp_adjust_head() stopped working with generic XDP when we fixes generic XDP to support stacked devices properly, fix from Jesper Dangaard Brouer. 20) Unbalanced RCU locking in rt6_update_exception_stamp_rt(), from David Ahern. 21) Several memory leaks in new sja1105 driver, from Vladimir Oltean" * git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (214 commits) net: dsa: sja1105: Fix memory leak on meta state machine error path net: dsa: sja1105: Fix memory leak on meta state machine normal path net: dsa: sja1105: Really fix panic on unregistering PTP clock net: dsa: sja1105: Use the LOCKEDS bit for SJA1105 E/T as well net: dsa: sja1105: Fix broken learning with vlan_filtering disabled net: dsa: qca8k: Add of_node_put() in qca8k_setup_mdio_bus() net: sched: sample: allow accessing psample_group with rtnl net: sched: police: allow accessing police->params with rtnl net: hisilicon: Fix dma_map_single failed on arm64 net: hisilicon: fix hip04-xmit never return TX_BUSY net: hisilicon: make hip04_tx_reclaim non-reentrant tc-testing: updated vlan action tests with batch create/delete net sched: update vlan action for batched events operations net: stmmac: tc: Do not return a fragment entry net: stmmac: Fix issues when number of Queues >= 4 net: stmmac: xgmac: Fix XGMAC selftests be2net: disable bh with spin_lock in be_process_mcc net: cxgb3_main: Fix a resource leak in a error path in 'init_one()' net: ethernet: sun4i-emac: Support phy-handle property for finding PHYs net: bridge: move default pvid init/deinit to NETDEV_REGISTER/UNREGISTER ...
| * Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpfDavid S. Miller2019-07-251-2/+2
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Alexei Starovoitov says: ==================== pull-request: bpf 2019-07-25 The following pull-request contains BPF updates for your *net* tree. The main changes are: 1) fix segfault in libbpf, from Andrii. 2) fix gso_segs access, from Eric. 3) tls/sockmap fixes, from Jakub and John. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
| | * bpf: fix narrower loads on s390Ilya Leoshkevich2019-07-231-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The very first check in test_pkt_md_access is failing on s390, which happens because loading a part of a struct __sk_buff field produces an incorrect result. The preprocessed code of the check is: { __u8 tmp = *((volatile __u8 *)&skb->len + ((sizeof(skb->len) - sizeof(__u8)) / sizeof(__u8))); if (tmp != ((*(volatile __u32 *)&skb->len) & 0xFF)) return 2; }; clang generates the following code for it: 0: 71 21 00 03 00 00 00 00 r2 = *(u8 *)(r1 + 3) 1: 61 31 00 00 00 00 00 00 r3 = *(u32 *)(r1 + 0) 2: 57 30 00 00 00 00 00 ff r3 &= 255 3: 5d 23 00 1d 00 00 00 00 if r2 != r3 goto +29 <LBB0_10> Finally, verifier transforms it to: 0: (61) r2 = *(u32 *)(r1 +104) 1: (bc) w2 = w2 2: (74) w2 >>= 24 3: (bc) w2 = w2 4: (54) w2 &= 255 5: (bc) w2 = w2 The problem is that when verifier emits the code to replace a partial load of a struct __sk_buff field (*(u8 *)(r1 + 3)) with a full load of struct sk_buff field (*(u32 *)(r1 + 104)), an optional shift and a bitwise AND, it assumes that the machine is little endian and incorrectly decides to use a shift. Adjust shift count calculation to account for endianness. Fixes: 31fd85816dbe ("bpf: permits narrower load from bpf program context fields") Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* | | memremap: move from kernel/ to mm/Christoph Hellwig2019-08-032-406/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | memremap.c implements MM functionality for ZONE_DEVICE, so it really should be in the mm/ directory, not the kernel/ one. Link: http://lkml.kernel.org/r/20190722094143.18387-1-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com> Acked-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | kernel/signal.c: fix a kernel-doc markupMauro Carvalho Chehab2019-08-031-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The kernel-doc parser doesn't handle expressions with %foo*. Instead, when an asterisk should be part of a constant, it uses an alternative notation: `foo*`. Link: http://lkml.kernel.org/r/7f18c2e0b5e39e6b7eb55ddeb043b8b260b49f2d.1563361575.git.mchehab+samsung@kernel.org Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Cc: Deepa Dinamani <deepa.kernel@gmail.com> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | Merge tag 'arm-swiotlb-5.3' of git://git.infradead.org/users/hch/dma-mappingLinus Torvalds2019-08-021-2/+11
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull arm swiotlb support from Christoph Hellwig: "This fixes a cascade of regressions that originally started with the addition of the ia64 port, but only got fatal once we removed most uses of block layer bounce buffering in Linux 4.18. The reason is that while the original i386/PAE code that was the first architecture that supported > 4GB of memory without an iommu decided to leave bounce buffering to the subsystems, which in those days just mean block and networking as no one else consumed arbitrary userspace memory. Later with ia64, x86_64 and other ports we assumed that either an iommu or something that fakes it up ("software IOTLB" in beautiful Intel speak) is present and that subsystems can rely on that for dealing with addressing limitations in devices. Except that the ARM LPAE scheme that added larger physical address to 32-bit ARM did not follow that scheme and thus only worked by chance and only for block and networking I/O directly to highmem. Long story, short fix - add swiotlb support to arm when build for LPAE platforms, which actuallys turns out to be pretty trivial with the modern dma-direct / swiotlb code to fix the Linux 4.18-ish regression" * tag 'arm-swiotlb-5.3' of git://git.infradead.org/users/hch/dma-mapping: arm: use swiotlb for bounce buffering on LPAE configs dma-mapping: check pfn validity in dma_common_{mmap,get_sgtable}
| * | | dma-mapping: check pfn validity in dma_common_{mmap,get_sgtable}Christoph Hellwig2019-07-241-2/+11
| |/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | Check that the pfn returned from arch_dma_coherent_to_pfn refers to a valid page and reject the mmap / get_sgtable requests otherwise. Based on the arm implementation of the mmap and get_sgtable methods. Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Vignesh Raghavendra <vigneshr@ti.com>
* | | Merge tag 'dma-mapping-5.3-3' of git://git.infradead.org/users/hch/dma-mappingLinus Torvalds2019-08-021-3/+5
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull dma-mapping regression fixes from Christoph Hellwig: "Two related regression fixes for changes from this merge window to fix alignment issues introduced in the CMA allocation rework (Nicolin Chen)" * tag 'dma-mapping-5.3-3' of git://git.infradead.org/users/hch/dma-mapping: dma-contiguous: page-align the size in dma_free_contiguous() dma-contiguous: do not overwrite align in dma_alloc_contiguous()
| * | | dma-contiguous: page-align the size in dma_free_contiguous()Nicolin Chen2019-07-291-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | According to the original dma_direct_alloc_pages() code: { unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT; if (!dma_release_from_contiguous(dev, page, count)) __free_pages(page, get_order(size)); } The count parameter for dma_release_from_contiguous() was page aligned before the right-shifting operation, while the new API dma_free_contiguous() forgets to have PAGE_ALIGN() at the size. So this patch simply adds it to prevent any corner case. Fixes: fdaeec198ada ("dma-contiguous: add dma_{alloc,free}_contiguous() helpers") Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Christoph Hellwig <hch@lst.de>
| * | | dma-contiguous: do not overwrite align in dma_alloc_contiguous()Nicolin Chen2019-07-291-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The dma_alloc_contiguous() limits align at CONFIG_CMA_ALIGNMENT for cma_alloc() however it does not restore it for the fallback routine. This will result in a size mismatch between the allocation and free when running into the fallback routines after cma_alloc() fails, if the align is larger than CONFIG_CMA_ALIGNMENT. This patch adds a cma_align to take care of cma_alloc() and prevent the align from being overwritten. Fixes: fdaeec198ada ("dma-contiguous: add dma_{alloc,free}_contiguous() helpers") Reported-by: Dafna Hirschfeld <dafna.hirschfeld@collabora.com> Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
* | | | Merge tag 'trace-v5.3-rc2' of ↵Linus Torvalds2019-07-311-10/+7
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing fixes from Steven Rostedt: "Two minor fixes: - Fix trace event header include guards, as several did not match the #define to the #ifdef - Remove a redundant test to ftrace_graph_notrace_addr() that was accidentally added" * tag 'trace-v5.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: fgraph: Remove redundant ftrace_graph_notrace_addr() test tracing: Fix header include guards in trace event headers
| * | | | fgraph: Remove redundant ftrace_graph_notrace_addr() testChangbin Du2019-07-301-10/+7
| |/ / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We already have tested it before. The second one should be removed. With this change, the performance should have little improvement. Link: http://lkml.kernel.org/r/20190730140850.7927-1-changbin.du@gmail.com Cc: stable@vger.kernel.org Fixes: 9cd2992f2d6c ("fgraph: Have set_graph_notrace only affect function_graph tracer") Signed-off-by: Changbin Du <changbin.du@gmail.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
* | | | exit: make setting exit_state consistentChristian Brauner2019-07-301-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since commit b191d6491be6 ("pidfd: fix a poll race when setting exit_state") we unconditionally set exit_state to EXIT_ZOMBIE before calling into do_notify_parent(). This was done to eliminate a race when querying exit_state in do_notify_pidfd(). Back then we decided to do the absolute minimal thing to fix this and not touch the rest of the exit_notify() function where exit_state is set. Since this fix has not caused any issues change the setting of exit_state to EXIT_DEAD in the autoreap case to account for the fact hat exit_state is set to EXIT_ZOMBIE unconditionally. This fix was planned but also explicitly requested in [1] and makes the whole code more consistent. /* References */ [1]: https://lore.kernel.org/lkml/CAHk-=wigcxGFR2szue4wavJtH5cYTTeNES=toUBVGsmX0rzX+g@mail.gmail.com Signed-off-by: Christian Brauner <christian@brauner.io> Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org>
* | | | pidfd: Add warning if exit_state is 0 during notificationJoel Fernandes (Google)2019-07-291-0/+1
|/ / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Previously a condition got missed where the pidfd waiters are awakened before the exit_state gets set. This can result in a missed notification [1] and the polling thread waiting forever. It is fixed now, however it would be nice to avoid this kind of issue going unnoticed in the future. So just add a warning to catch it in the future. /* References */ [1]: https://lore.kernel.org/lkml/20190717172100.261204-1-joel@joelfernandes.org/ Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> Link: https://lore.kernel.org/r/20190724164816.201099-1-joel@joelfernandes.org Signed-off-by: Christian Brauner <christian@brauner.io>
* | | Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds2019-07-272-44/+102
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fixes from Thomas Gleixner: "Two fixes for the fair scheduling class: - Prevent freeing memory which is accessible by concurrent readers - Make the RCU annotations for numa groups consistent" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/fair: Use RCU accessors consistently for ->numa_group sched/fair: Don't free p->numa_faults with concurrent readers
| * | | sched/fair: Use RCU accessors consistently for ->numa_groupJann Horn2019-07-251-39/+81
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The old code used RCU annotations and accessors inconsistently for ->numa_group, which can lead to use-after-frees and NULL dereferences. Let all accesses to ->numa_group use proper RCU helpers to prevent such issues. Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Petr Mladek <pmladek@suse.com> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will@kernel.org> Fixes: 8c8a743c5087 ("sched/numa: Use {cpu, pid} to create task groups for shared faults") Link: https://lkml.kernel.org/r/20190716152047.14424-3-jannh@google.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | sched/fair: Don't free p->numa_faults with concurrent readersJann Horn2019-07-252-5/+21
| |/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When going through execve(), zero out the NUMA fault statistics instead of freeing them. During execve, the task is reachable through procfs and the scheduler. A concurrent /proc/*/sched reader can read data from a freed ->numa_faults allocation (confirmed by KASAN) and write it back to userspace. I believe that it would also be possible for a use-after-free read to occur through a race between a NUMA fault and execve(): task_numa_fault() can lead to task_numa_compare(), which invokes task_weight() on the currently running task of a different CPU. Another way to fix this would be to make ->numa_faults RCU-managed or add extra locking, but it seems easier to wipe the NUMA fault statistics on execve. Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Petr Mladek <pmladek@suse.com> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will@kernel.org> Fixes: 82727018b0d3 ("sched/numa: Call task_numa_free() from do_execve()") Link: https://lkml.kernel.org/r/20190716152047.14424-1-jannh@google.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds2019-07-271-1/+1
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Thomas Gleixner: "A pile of perf related fixes: Kernel: - Fix SLOTS PEBS event constraints for Icelake CPUs - Add the missing mask bit to allow counting hardware generated prefetches on L3 for Icelake CPUs - Make the test for hypervisor platforms more accurate (as far as possible) - Handle PMUs correctly which override event->cpu - Yet another missing fallthrough annotation Tools: perf.data: - Fix loading of compressed data split across adjacent records - Fix buffer size setting for processing CPU topology perf.data header. perf stat: - Fix segfault for event group in repeat mode - Always separate "stalled cycles per insn" line, it was being appended to the "instructions" line. perf script: - Fix --max-blocks man page description. - Improve man page description of metrics. - Fix off by one in brstackinsn IPC computation. perf probe: - Avoid calling freeing routine multiple times for same pointer. perf build: - Do not use -Wshadow on gcc < 4.8, avoiding too strict warnings treated as errors, breaking the build" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/x86/intel: Mark expected switch fall-throughs perf/core: Fix creating kernel counters for PMUs that override event->cpu perf/x86: Apply more accurate check on hypervisor platform perf/x86/intel: Fix invalid Bit 13 for Icelake MSR_OFFCORE_RSP_x register perf/x86/intel: Fix SLOTS PEBS event constraint perf build: Do not use -Wshadow on gcc < 4.8 perf probe: Avoid calling freeing routine multiple times for same pointer perf probe: Set pev->nargs to zero after freeing pev->args entries perf session: Fix loading of compressed data split across adjacent records perf stat: Always separate stalled cycles per insn perf stat: Fix segfault for event group in repeat mode perf tools: Fix proper buffer size for feature processing perf script: Fix off by one in brstackinsn IPC computation perf script: Improve man page description of metrics perf script: Fix --max-blocks man page description
| * | | perf/core: Fix creating kernel counters for PMUs that override event->cpuLeonard Crestez2019-07-251-1/+1
| |/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Some hardware PMU drivers will override perf_event.cpu inside their event_init callback. This causes a lockdep splat when initialized through the kernel API: WARNING: CPU: 0 PID: 250 at kernel/events/core.c:2917 ctx_sched_out+0x78/0x208 pc : ctx_sched_out+0x78/0x208 Call trace: ctx_sched_out+0x78/0x208 __perf_install_in_context+0x160/0x248 remote_function+0x58/0x68 generic_exec_single+0x100/0x180 smp_call_function_single+0x174/0x1b8 perf_install_in_context+0x178/0x188 perf_event_create_kernel_counter+0x118/0x160 Fix this by calling perf_install_in_context with event->cpu, just like perf_event_open Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Frank Li <Frank.li@nxp.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will@kernel.org> Link: https://lkml.kernel.org/r/c4ebe0503623066896d7046def4d6b1e06e0eb2e.1563972056.git.leonard.crestez@nxp.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | Merge branch 'locking-urgent-for-linus' of ↵Linus Torvalds2019-07-274-15/+40
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking fixes from Thomas Gleixner: "A set of locking fixes: - Address the fallout of the rwsem rework. Missing ACQUIREs and a sanity check to prevent a use-after-free - Add missing checks for unitialized mutexes when mutex debugging is enabled. - Remove the bogus code in the generic SMP variant of arch_futex_atomic_op_inuser() - Fixup the #ifdeffery in lockdep to prevent compile warnings" * 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: locking/mutex: Test for initialized mutex locking/lockdep: Clean up #ifdef checks locking/lockdep: Hide unused 'class' variable locking/rwsem: Add ACQUIRE comments tty/ldsem, locking/rwsem: Add missing ACQUIRE to read_failed sleep loop lcoking/rwsem: Add missing ACQUIRE to read_slowpath sleep loop locking/rwsem: Add missing ACQUIRE to read_slowpath exit when queue is empty locking/rwsem: Don't call owner_on_cpu() on read-owner futex: Cleanup generic SMP variant of arch_futex_atomic_op_inuser()
| * | | locking/mutex: Test for initialized mutexSebastian Andrzej Siewior2019-07-251-1/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | An uninitialized/ zeroed mutex will go unnoticed because there is no check for it. There is a magic check in the unlock's slowpath path which might go unnoticed if the unlock happens in the fastpath. Add a ->magic check early in the mutex_lock() and mutex_trylock() path. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Will Deacon <will@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190703092125.lsdf4gpsh2plhavb@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | locking/lockdep: Clean up #ifdef checksArnd Bergmann2019-07-251-7/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As Will Deacon points out, CONFIG_PROVE_LOCKING implies TRACE_IRQFLAGS, so the conditions I added in the previous patch, and some others in the same file can be simplified by only checking for the former. No functional change. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Will Deacon <will@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Bart Van Assche <bvanassche@acm.org> Cc: Frederic Weisbecker <frederic@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Waiman Long <longman@redhat.com> Cc: Yuyang Du <duyuyang@gmail.com> Fixes: 886532aee3cd ("locking/lockdep: Move mark_lock() inside CONFIG_TRACE_IRQFLAGS && CONFIG_PROVE_LOCKING") Link: https://lkml.kernel.org/r/20190628102919.2345242-1-arnd@arndb.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | locking/lockdep: Hide unused 'class' variableArnd Bergmann2019-07-251-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The usage is now hidden in an #ifdef, so we need to move the variable itself in there as well to avoid this warning: kernel/locking/lockdep_proc.c:203:21: error: unused variable 'class' [-Werror,-Wunused-variable] Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Bart Van Assche <bvanassche@acm.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Qian Cai <cai@lca.pw> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Waiman Long <longman@redhat.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Yuyang Du <duyuyang@gmail.com> Cc: frederic@kernel.org Fixes: 68d41d8c94a3 ("locking/lockdep: Fix lock used or unused stats error") Link: https://lkml.kernel.org/r/20190715092809.736834-1-arnd@arndb.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | locking/rwsem: Add ACQUIRE commentsPeter Zijlstra2019-07-251-5/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since we just reviewed read_slowpath for ACQUIRE correctness, add a few coments to retain our findings. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Will Deacon <will@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | lcoking/rwsem: Add missing ACQUIRE to read_slowpath sleep loopPeter Zijlstra2019-07-251-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While reviewing another read_slowpath patch, both Will and I noticed another missing ACQUIRE, namely: X = 0; CPU0 CPU1 rwsem_down_read() for (;;) { set_current_state(TASK_UNINTERRUPTIBLE); X = 1; rwsem_up_write(); rwsem_mark_wake() atomic_long_add(adjustment, &sem->count); smp_store_release(&waiter->task, NULL); if (!waiter.task) break; ... } r = X; Allows 'r == 0'. Reported-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reported-by: Will Deacon <will@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Will Deacon <will@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | locking/rwsem: Add missing ACQUIRE to read_slowpath exit when queue is emptyJan Stancek2019-07-251-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | LTP mtest06 has been observed to occasionally hit "still mapped when deleted" and following BUG_ON on arm64. The extra mapcount originated from pagefault handler, which handled pagefault for vma that has already been detached. vma is detached under mmap_sem write lock by detach_vmas_to_be_unmapped(), which also invalidates vmacache. When the pagefault handler (under mmap_sem read lock) calls find_vma(), vmacache_valid() wrongly reports vmacache as valid. After rwsem down_read() returns via 'queue empty' path (as of v5.2), it does so without an ACQUIRE on sem->count: down_read() __down_read() rwsem_down_read_failed() __rwsem_down_read_failed_common() raw_spin_lock_irq(&sem->wait_lock); if (list_empty(&sem->wait_list)) { if (atomic_long_read(&sem->count) >= 0) { raw_spin_unlock_irq(&sem->wait_lock); return sem; The problem can be reproduced by running LTP mtest06 in a loop and building the kernel (-j $NCPUS) in parallel. It does reproduces since v4.20 on arm64 HPE Apollo 70 (224 CPUs, 256GB RAM, 2 nodes). It triggers reliably in about an hour. The patched kernel ran fine for 10+ hours. Signed-off-by: Jan Stancek <jstancek@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Will Deacon <will@kernel.org> Acked-by: Waiman Long <longman@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dbueso@suse.de Fixes: 4b486b535c33 ("locking/rwsem: Exit read lock slowpath if queue empty & no writer") Link: https://lkml.kernel.org/r/50b8914e20d1d62bb2dee42d342836c2c16ebee7.1563438048.git.jstancek@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | locking/rwsem: Don't call owner_on_cpu() on read-ownerWaiman Long2019-07-251-1/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For writer, the owner value is cleared on unlock. For reader, it is left intact on unlock for providing better debugging aid on crash dump and the unlock of one reader may not mean the lock is free. As a result, the owner_on_cpu() shouldn't be used on read-owner as the task pointer value may not be valid and it might have been freed. That is the case in rwsem_spin_on_owner(), but not in rwsem_can_spin_on_owner(). This can lead to use-after-free error from KASAN. For example, BUG: KASAN: use-after-free in rwsem_down_write_slowpath (/home/miguel/kernel/linux/kernel/locking/rwsem.c:669 /home/miguel/kernel/linux/kernel/locking/rwsem.c:1125) Fix this by checking for RWSEM_READER_OWNED flag before calling owner_on_cpu(). Reported-by: Luis Henriques <lhenriques@suse.com> Tested-by: Luis Henriques <lhenriques@suse.com> Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jeff Layton <jlayton@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Will Deacon <will.deacon@arm.com> Cc: huang ying <huang.ying.caritas@gmail.com> Fixes: 94a9717b3c40e ("locking/rwsem: Make rwsem->owner an atomic_long_t") Link: https://lkml.kernel.org/r/81e82d5b-5074-77e8-7204-28479bbe0df0@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | | Merge branch 'access-creds'Linus Torvalds2019-07-251-2/+19
|\ \ \ \ | |_|/ / |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The access() (and faccessat()) credentials change can cause an unnecessary load on the RCU machinery because every access() call ends up freeing the temporary access credential using RCU. This isn't really noticeable on small machines, but if you have hundreds of cores you can cause huge slowdowns due to RCU storms. It's easy to avoid: the temporary access crededntials aren't actually normally accessed using RCU at all, so we can avoid the whole issue by just marking them as such. * access-creds: access: avoid the RCU grace period for the temporary subjective credentials
| * | | access: avoid the RCU grace period for the temporary subjective credentialsLinus Torvalds2019-07-241-2/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It turns out that 'access()' (and 'faccessat()') can cause a lot of RCU work because it installs a temporary credential that gets allocated and freed for each system call. The allocation and freeing overhead is mostly benign, but because credentials can be accessed under the RCU read lock, the freeing involves a RCU grace period. Which is not a huge deal normally, but if you have a lot of access() calls, this causes a fair amount of seconday damage: instead of having a nice alloc/free patterns that hits in hot per-CPU slab caches, you have all those delayed free's, and on big machines with hundreds of cores, the RCU overhead can end up being enormous. But it turns out that all of this is entirely unnecessary. Exactly because access() only installs the credential as the thread-local subjective credential, the temporary cred pointer doesn't actually need to be RCU free'd at all. Once we're done using it, we can just free it synchronously and avoid all the RCU overhead. So add a 'non_rcu' flag to 'struct cred', which can be set by users that know they only use it in non-RCU context (there are other potential users for this). We can make it a union with the rcu freeing list head that we need for the RCU case, so this doesn't need any extra storage. Note that this also makes 'get_current_cred()' clear the new non_rcu flag, in case we have filesystems that take a long-term reference to the cred and then expect the RCU delayed freeing afterwards. It's not entirely clear that this is required, but it makes for clear semantics: the subjective cred remains non-RCU as long as you only access it synchronously using the thread-local accessors, but you _can_ use it as a generic cred if you want to. It is possible that we should just remove the whole RCU markings for ->cred entirely. Only ->real_cred is really supposed to be accessed through RCU, and the long-term cred copies that nfs uses might want to explicitly re-enable RCU freeing if required, rather than have get_current_cred() do it implicitly. But this is a "minimal semantic changes" change for the immediate problem. Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Eric Dumazet <edumazet@google.com> Acked-by: Paul E. McKenney <paulmck@linux.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Jan Glauber <jglauber@marvell.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: Jayachandran Chandrasekharan Nair <jnair@marvell.com> Cc: Greg KH <greg@kroah.com> Cc: Kees Cook <keescook@chromium.org> Cc: David Howells <dhowells@redhat.com> Cc: Miklos Szeredi <miklos@szeredi.hu> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds2019-07-221-4/+4
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull preemption Kconfig fix from Thomas Gleixner: "The PREEMPT_RT stub config renamed PREEMPT to PREEMPT_LL and defined PREEMPT outside of the menu and made it selectable by both PREEMPT_LL and PREEMPT_RT. Stupid me missed that 114 defconfigs select CONFIG_PREEMPT which obviously can't work anymore. oldconfig builds are affected as well, but it's more obvious as the user gets asked. [old]defconfig silently fixes it up and selects PREEMPT_NONE. Unbreak it by undoing the rename and adding a intermediate config symbol which is selected by both PREEMPT and PREEMPT_RT. That requires to chase down a few #ifdefs, but it's better than tweaking 114 defconfigs and annoying users" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/rt, Kconfig: Unbreak def/oldconfig with CONFIG_PREEMPT=y
| * | | | sched/rt, Kconfig: Unbreak def/oldconfig with CONFIG_PREEMPT=yThomas Gleixner2019-07-221-4/+4
| | |/ / | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The merge of the CONFIG_PREEMPT_RT stub renamed CONFIG_PREEMPT to CONFIG_PREEMPT_LL which causes all defconfigs which have CONFIG_PREEMPT=y set to fall back to CONFIG_PREEMPT_NONE because CONFIG_PREEMPT depends on the preemption mode choice wich defaults to NONE. This also affects oldconfig builds. So rather than changing 114 defconfig files and being an annoyance to users, revert the rename and select a new config symbol PREEMPTION. That keeps everything working smoothly and the revelant ifdef's are going to be fixed up step by step. Reported-by: Mark Rutland <mark.rutland@arm.com> Fixes: a50a3f4b6a31 ("sched/rt, Kconfig: Introduce CONFIG_PREEMPT_RT") Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* / | | pidfd: fix a poll race when setting exit_stateSuren Baghdasaryan2019-07-221-0/+1
|/ / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is a race between reading task->exit_state in pidfd_poll and writing it after do_notify_parent calls do_notify_pidfd. Expected sequence of events is: CPU 0 CPU 1 ------------------------------------------------ exit_notify do_notify_parent do_notify_pidfd tsk->exit_state = EXIT_DEAD pidfd_poll if (tsk->exit_state) However nothing prevents the following sequence: CPU 0 CPU 1 ------------------------------------------------ exit_notify do_notify_parent do_notify_pidfd pidfd_poll if (tsk->exit_state) tsk->exit_state = EXIT_DEAD This causes a polling task to wait forever, since poll blocks because exit_state is 0 and the waiting task is not notified again. A stress test continuously doing pidfd poll and process exits uncovered this bug. To fix it, we make sure that the task's exit_state is always set before calling do_notify_pidfd. Fixes: b53b0b9d9a6 ("pidfd: add polling support") Cc: kernel-team@android.com Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> Link: https://lore.kernel.org/r/20190717172100.261204-1-joel@joelfernandes.org [christian@brauner.io: adapt commit message and drop unneeded changes from wait_task_zombie] Signed-off-by: Christian Brauner <christian@brauner.io>
* | | Merge tag 'dma-mapping-5.3-1' of git://git.infradead.org/users/hch/dma-mappingLinus Torvalds2019-07-202-25/+22
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull dma-mapping fixes from Christoph Hellwig: "Fix various regressions: - force unencrypted dma-coherent buffers if encryption bit can't fit into the dma coherent mask (Tom Lendacky) - avoid limiting request size if swiotlb is not used (me) - fix swiotlb handling in dma_direct_sync_sg_for_cpu/device (Fugang Duan)" * tag 'dma-mapping-5.3-1' of git://git.infradead.org/users/hch/dma-mapping: dma-direct: correct the physical addr in dma_direct_sync_sg_for_cpu/device dma-direct: only limit the mapping size if swiotlb could be used dma-mapping: add a dma_addressing_limited helper dma-direct: Force unencrypted DMA under SME for certain DMA masks
| * | | dma-direct: correct the physical addr in dma_direct_sync_sg_for_cpu/deviceFugang Duan2019-07-191-7/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | dma_map_sg() may use swiotlb buffer when the kernel command line includes "swiotlb=force" or the dma_addr is out of dev->dma_mask range. After DMA complete the memory moving from device to memory, then user call dma_sync_sg_for_cpu() to sync with DMA buffer, and copy the original virtual buffer to other space. So dma_direct_sync_sg_for_cpu() should use swiotlb physical addr, not the original physical addr from sg_phys(sg). dma_direct_sync_sg_for_device() also has the same issue, correct it as well. Fixes: 55897af63091("dma-direct: merge swiotlb_dma_ops into the dma_direct code") Signed-off-by: Fugang Duan <fugang.duan@nxp.com> Reviewed-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
| * | | dma-direct: only limit the mapping size if swiotlb could be usedChristoph Hellwig2019-07-171-6/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Don't just check for a swiotlb buffer, but also if buffering might be required for this particular device. Fixes: 133d624b1cee ("dma: Introduce dma_max_mapping_size()") Reported-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * | | dma-direct: Force unencrypted DMA under SME for certain DMA masksTom Lendacky2019-07-162-12/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If a device doesn't support DMA to a physical address that includes the encryption bit (currently bit 47, so 48-bit DMA), then the DMA must occur to unencrypted memory. SWIOTLB is used to satisfy that requirement if an IOMMU is not active (enabled or configured in passthrough mode). However, commit fafadcd16595 ("swiotlb: don't dip into swiotlb pool for coherent allocations") modified the coherent allocation support in SWIOTLB to use the DMA direct coherent allocation support. When an IOMMU is not active, this resulted in dma_alloc_coherent() failing for devices that didn't support DMA addresses that included the encryption bit. Addressing this requires changes to the force_dma_unencrypted() function in kernel/dma/direct.c. Since the function is now non-trivial and SME/SEV specific, update the DMA direct support to add an arch override for the force_dma_unencrypted() function. The arch override is selected when CONFIG_AMD_MEM_ENCRYPT is set. The arch override function resides in the arch/x86/mm/mem_encrypt.c file and forces unencrypted DMA when either SEV is active or SME is active and the device does not support DMA to physical addresses that include the encryption bit. Fixes: fafadcd16595 ("swiotlb: don't dip into swiotlb pool for coherent allocations") Suggested-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> [hch: moved the force_dma_unencrypted declaration to dma-mapping.h, fold the s390 fix from Halil Pasic] Signed-off-by: Christoph Hellwig <hch@lst.de>
* | | | Merge branch 'core-urgent-for-linus' of ↵Linus Torvalds2019-07-202-3/+7
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull core fixes from Thomas Gleixner: - A collection of objtool fixes which address recent fallout partially exposed by newer toolchains, clang, BPF and general code changes. - Force USER_DS for user stack traces [ Note: the "objtool fixes" are not all to objtool itself, but for kernel code that triggers objtool warnings. Things like missing function size annotations, or code that confuses the unwinder etc. - Linus] * 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (27 commits) objtool: Support conditional retpolines objtool: Convert insn type to enum objtool: Fix seg fault on bad switch table entry objtool: Support repeated uses of the same C jump table objtool: Refactor jump table code objtool: Refactor sibling call detection logic objtool: Do frame pointer check before dead end check objtool: Change dead_end_function() to return boolean objtool: Warn on zero-length functions objtool: Refactor function alias logic objtool: Track original function across branches objtool: Add mcsafe_handle_tail() to the uaccess safe list bpf: Disable GCC -fgcse optimization for ___bpf_prog_run() x86/uaccess: Remove redundant CLACs in getuser/putuser error paths x86/uaccess: Don't leak AC flag into fentry from mcsafe_handle_tail() x86/uaccess: Remove ELF function annotation from copy_user_handle_tail() x86/head/64: Annotate start_cpu0() as non-callable x86/entry: Fix thunk function ELF sizes x86/kvm: Don't call kvm_spurious_fault() from .fixup x86/kvm: Replace vmx_vmenter()'s call to kvm_spurious_fault() with UD2 ...
| * | | | bpf: Disable GCC -fgcse optimization for ___bpf_prog_run()Josh Poimboeuf2019-07-181-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On x86-64, with CONFIG_RETPOLINE=n, GCC's "global common subexpression elimination" optimization results in ___bpf_prog_run()'s jumptable code changing from this: select_insn: jmp *jumptable(, %rax, 8) ... ALU64_ADD_X: ... jmp *jumptable(, %rax, 8) ALU_ADD_X: ... jmp *jumptable(, %rax, 8) to this: select_insn: mov jumptable, %r12 jmp *(%r12, %rax, 8) ... ALU64_ADD_X: ... jmp *(%r12, %rax, 8) ALU_ADD_X: ... jmp *(%r12, %rax, 8) The jumptable address is placed in a register once, at the beginning of the function. The function execution can then go through multiple indirect jumps which rely on that same register value. This has a few issues: 1) Objtool isn't smart enough to be able to track such a register value across multiple recursive indirect jumps through the jump table. 2) With CONFIG_RETPOLINE enabled, this optimization actually results in a small slowdown. I measured a ~4.7% slowdown in the test_bpf "tcpdump port 22" selftest. This slowdown is actually predicted by the GCC manual: Note: When compiling a program using computed gotos, a GCC extension, you may get better run-time performance if you disable the global common subexpression elimination pass by adding -fno-gcse to the command line. So just disable the optimization for this function. Fixes: e55a73251da3 ("bpf: Fix ORC unwinding in non-JIT BPF code") Reported-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/30c3ca29ba037afcbd860a8672eef0021addf9fe.1563413318.git.jpoimboe@redhat.com
| * | | | Merge branch 'x86/debug' into core/urgentThomas Gleixner2019-07-181-2/+1
| |\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | Pick up the two pending objtool patches as the next round of objtool fixes depend on them.
| | * | | | bpf: Fix ORC unwinding in non-JIT BPF codeJosh Poimboeuf2019-07-091-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Objtool previously ignored ___bpf_prog_run() because it didn't understand the jump table. This resulted in the ORC unwinder not being able to unwind through non-JIT BPF code. Now that objtool knows how to read jump tables, remove the whitelist and annotate the jump table so objtool can recognize it. Also add an additional "const" to the jump table definition to clarify that the text pointers are constant. Otherwise GCC sets the section writable flag and the assembler spits out warnings. Fixes: d15d356887e7 ("perf/x86: Make perf callchains work without CONFIG_FRAME_POINTER") Reported-by: Song Liu <songliubraving@fb.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Alexei Starovoitov <ast@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Kairui Song <kasong@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Daniel Borkmann <daniel@iogearbox.net> Link: https://lkml.kernel.org/r/881939122b88f32be4c374d248c09d7527a87e35.1561685471.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | | stacktrace: Force USER_DS for stack_trace_save_user()Peter Zijlstra2019-07-181-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When walking userspace stacks, USER_DS needs to be set, otherwise access_ok() will not function as expected. Reported-by: Vegard Nossum <vegard.nossum@oracle.com> Reported-by: Eiichi Tsukata <devel@etsukata.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Vegard Nossum <vegard.nossum@oracle.com> Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org> Link: https://lkml.kernel.org/r/20190718085754.GM3402@hirez.programming.kicks-ass.net
* | | | | | Merge branch 'smp-urgent-for-linus' of ↵Linus Torvalds2019-07-201-0/+16
|\ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull smp fix from Thomas Gleixner: "Add warnings to the smp function calls so callers from wrong contexts get detected" * 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: smp: Warn on function calls from softirq context
| * | | | | | smp: Warn on function calls from softirq contextPeter Zijlstra2019-07-201-0/+16
| |/ / / / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It's clearly documented that smp function calls cannot be invoked from softirq handling context. Unfortunately nothing enforces that or emits a warning. A single function call can be invoked from softirq context only via smp_call_function_single_async(). The only legit context is task context, so add a warning to that effect. Reported-by: luferry <luferry@163.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190718160601.GP3402@hirez.programming.kicks-ass.net
* | | | | | Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds2019-07-201-2/+23
|\ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull CONFIG_PREEMPT_RT stub config from Thomas Gleixner: "The real-time preemption patch set exists for almost 15 years now and while the vast majority of infrastructure and enhancements have found their way into the mainline kernel, the final integration of RT is still missing. Over the course of the last few years, we have worked on reducing the intrusivenness of the RT patches by refactoring kernel infrastructure to be more real-time friendly. Almost all of these changes were benefitial to the mainline kernel on their own, so there was no objection to integrate them. Though except for the still ongoing printk refactoring, the remaining changes which are required to make RT a first class mainline citizen are not longer arguable as immediately beneficial for the mainline kernel. Most of them are either reordering code flows or adding RT specific functionality. But this now has hit a wall and turned into a classic hen and egg problem: Maintainers are rightfully wary vs. these changes as they make only sense if the final integration of RT into the mainline kernel takes place. Adding CONFIG_PREEMPT_RT aims to solve this as a clear sign that RT will be fully integrated into the mainline kernel. The final integration of the missing bits and pieces will be of course done with the same careful approach as we have used in the past. While I'm aware that you are not entirely enthusiastic about that, I think that RT should receive the same treatment as any other widely used out of tree functionality, which we have accepted into mainline over the years. RT has become the de-facto standard real-time enhancement and is shipped by enterprise, embedded and community distros. It's in use throughout a wide range of industries: telecommunications, industrial automation, professional audio, medical devices, data acquisition, automotive - just to name a few major use cases. RT development is backed by a Linuxfoundation project which is supported by major stakeholders of this technology. The funding will continue over the actual inclusion into mainline to make sure that the functionality is neither introducing regressions, regressing itself, nor becomes subject to bitrot. There is also a lifely user community around RT as well, so contrary to the grim situation 5 years ago, it's a healthy project. As RT is still a good vehicle to exercise rarely used code paths and to detect hard to trigger issues, you could at least view it as a QA tool if nothing else" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/rt, Kconfig: Introduce CONFIG_PREEMPT_RT
| * | | | | | sched/rt, Kconfig: Introduce CONFIG_PREEMPT_RTThomas Gleixner2019-07-181-2/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a new entry to the preemption menu which enables the real-time support for the kernel. The choice is only enabled when an architecture supports it. It selects PREEMPT as the RT features depend on it. To achieve that the existing PREEMPT choice is renamed to PREEMPT_LL which select PREEMPT as well. No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Paul E. McKenney <paulmck@linux.ibm.com> Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Acked-by: Clark Williams <williams@redhat.com> Acked-by: Daniel Bristot de Oliveira <bristot@redhat.com> Acked-by: Frederic Weisbecker <frederic@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Daniel Wagner <wagi@monom.org> Acked-by: Luis Claudio R. Goncalves <lgoncalv@redhat.com> Acked-by: Julia Cartwright <julia@ni.com> Acked-by: Tom Zanussi <tom.zanussi@linux.intel.com> Acked-by: Gratian Crisan <gratian.crisan@ni.com> Acked-by: Sebastian Siewior <bigeasy@linutronix.de> Cc: Andrew Morton <akpm@linuxfoundation.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Tejun Heo <tj@kernel.org> Link: http://lkml.kernel.org/r/alpine.DEB.2.21.1907172200190.1778@nanos.tec.linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>