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2020-09-01module: Fix up module_notifier return valuesPeter Zijlstra
While auditing all module notifiers I noticed a whole bunch of fail wrt the return value. Notifiers have a 'special' return semantics. As is; NOTIFY_DONE vs NOTIFY_OK is a bit vague; but notifier_from_errno(0) results in NOTIFY_OK and NOTIFY_DONE has a comment that says "Don't care". From this I've used NOTIFY_DONE when the function completely ignores the callback and notifier_to_error() isn't used. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org> Reviewed-by: Robert Richter <rric@kernel.org> Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Link: https://lore.kernel.org/r/20200818135804.385360407@infradead.org
2020-09-01notifier: Fix broken error handling patternPeter Zijlstra
The current notifiers have the following error handling pattern all over the place: int err, nr; err = __foo_notifier_call_chain(&chain, val_up, v, -1, &nr); if (err & NOTIFIER_STOP_MASK) __foo_notifier_call_chain(&chain, val_down, v, nr-1, NULL) And aside from the endless repetition thereof, it is broken. Consider blocking notifiers; both calls take and drop the rwsem, this means that the notifier list can change in between the two calls, making @nr meaningless. Fix this by replacing all the __foo_notifier_call_chain() functions with foo_notifier_call_chain_robust() that embeds the above pattern, but ensures it is inside a single lock region. Note: I switched atomic_notifier_call_chain_robust() to use the spinlock, since RCU cannot provide the guarantee required for the recovery. Note: software_resume() error handling was broken afaict. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Link: https://lore.kernel.org/r/20200818135804.325626653@infradead.org
2020-08-30Merge tag 'x86-urgent-2020-08-30' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Thomas Gleixner: "Three interrupt related fixes for X86: - Move disabling of the local APIC after invoking fixup_irqs() to ensure that interrupts which are incoming are noted in the IRR and not ignored. - Unbreak affinity setting. The rework of the entry code reused the regular exception entry code for device interrupts. The vector number is pushed into the errorcode slot on the stack which is then lifted into an argument and set to -1 because that's regs->orig_ax which is used in quite some places to check whether the entry came from a syscall. But it was overlooked that orig_ax is used in the affinity cleanup code to validate whether the interrupt has arrived on the new target. It turned out that this vector check is pointless because interrupts are never moved from one vector to another on the same CPU. That check is a historical leftover from the time where x86 supported multi-CPU affinities, but not longer needed with the now strict single CPU affinity. Famous last words ... - Add a missing check for an empty cpumask into the matrix allocator. The affinity change added a warning to catch the case where an interrupt is moved on the same CPU to a different vector. This triggers because a condition with an empty cpumask returns an assignment from the allocator as the allocator uses for_each_cpu() without checking the cpumask for being empty. The historical inconsistent for_each_cpu() behaviour of ignoring the cpumask and unconditionally claiming that CPU0 is in the mask struck again. Sigh. plus a new entry into the MAINTAINER file for the HPE/UV platform" * tag 'x86-urgent-2020-08-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: genirq/matrix: Deal with the sillyness of for_each_cpu() on UP x86/irq: Unbreak interrupt affinity setting x86/hotplug: Silence APIC only after all interrupts are migrated MAINTAINERS: Add entry for HPE Superdome Flex (UV) maintainers
2020-08-30Merge tag 'locking-urgent-2020-08-30' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking fixes from Thomas Gleixner: "A set of fixes for lockdep, tracing and RCU: - Prevent recursion by using raw_cpu_* operations - Fixup the interrupt state in the cpu idle code to be consistent - Push rcu_idle_enter/exit() invocations deeper into the idle path so that the lock operations are inside the RCU watching sections - Move trace_cpu_idle() into generic code so it's called before RCU goes idle. - Handle raw_local_irq* vs. local_irq* operations correctly - Move the tracepoints out from under the lockdep recursion handling which turned out to be fragile and inconsistent" * tag 'locking-urgent-2020-08-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: lockdep,trace: Expose tracepoints lockdep: Only trace IRQ edges mips: Implement arch_irqs_disabled() arm64: Implement arch_irqs_disabled() nds32: Implement arch_irqs_disabled() locking/lockdep: Cleanup x86/entry: Remove unused THUNKs cpuidle: Move trace_cpu_idle() into generic code cpuidle: Make CPUIDLE_FLAG_TLB_FLUSHED generic sched,idle,rcu: Push rcu_idle deeper into the idle path cpuidle: Fixup IRQ state lockdep: Use raw_cpu_*() for per-cpu variables
2020-08-30genirq/matrix: Deal with the sillyness of for_each_cpu() on UPThomas Gleixner
Most of the CPU mask operations behave the same way, but for_each_cpu() and it's variants ignore the cpumask argument and claim that CPU0 is always in the mask. This is historical, inconsistent and annoying behaviour. The matrix allocator uses for_each_cpu() and can be called on UP with an empty cpumask. The calling code does not expect that this succeeds but until commit e027fffff799 ("x86/irq: Unbreak interrupt affinity setting") this went unnoticed. That commit added a WARN_ON() to catch cases which move an interrupt from one vector to another on the same CPU. The warning triggers on UP. Add a check for the cpumask being empty to prevent this. Fixes: 2f75d9e1c905 ("genirq: Implement bitmap matrix allocator") Reported-by: kernel test robot <rong.a.chen@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org
2020-08-27dma-pool: Fix an uninitialized variable bug in atomic_pool_expand()Dan Carpenter
The "page" pointer can be used with out being initialized. Fixes: d7e673ec2c8e ("dma-pool: Only allocate from CMA when in same memory zone") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-08-26lockdep,trace: Expose tracepointsPeter Zijlstra
The lockdep tracepoints are under the lockdep recursion counter, this has a bunch of nasty side effects: - TRACE_IRQFLAGS doesn't work across the entire tracepoint - RCU-lockdep doesn't see the tracepoints either, hiding numerous "suspicious RCU usage" warnings. Pull the trace_lock_*() tracepoints completely out from under the lockdep recursion handling and completely rely on the trace level recusion handling -- also, tracing *SHOULD* not be taking locks in any case. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: Marco Elver <elver@google.com> Link: https://lkml.kernel.org/r/20200821085348.782688941@infradead.org
2020-08-26cpuidle: Move trace_cpu_idle() into generic codePeter Zijlstra
Remove trace_cpu_idle() from the arch_cpu_idle() implementations and put it in the generic code, right before disabling RCU. Gets rid of more trace_*_rcuidle() users. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: Marco Elver <elver@google.com> Link: https://lkml.kernel.org/r/20200821085348.428433395@infradead.org
2020-08-26sched,idle,rcu: Push rcu_idle deeper into the idle pathPeter Zijlstra
Lots of things take locks, due to a wee bug, rcu_lockdep didn't notice that the locking tracepoints were using RCU. Push rcu_idle_{enter,exit}() as deep as possible into the idle paths, this also resolves a lot of _rcuidle()/RCU_NONIDLE() usage. Specifically, sched_clock_idle_wakeup_event() will use ktime which will use seqlocks which will tickle lockdep, and stop_critical_timings() uses lock. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: Marco Elver <elver@google.com> Link: https://lkml.kernel.org/r/20200821085348.310943801@infradead.org
2020-08-26lockdep: Use raw_cpu_*() for per-cpu variablesPeter Zijlstra
Sven reported that commit a21ee6055c30 ("lockdep: Change hardirq{s_enabled,_context} to per-cpu variables") caused trouble on s390 because their this_cpu_*() primitives disable preemption which then lands back tracing. On the one hand, per-cpu ops should use preempt_*able_notrace() and raw_local_irq_*(), on the other hand, we can trivialy use raw_cpu_*() ops for this. Fixes: a21ee6055c30 ("lockdep: Change hardirq{s_enabled,_context} to per-cpu variables") Reported-by: Sven Schnelle <svens@linux.ibm.com> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: Marco Elver <elver@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20200821085348.192346882@infradead.org
2020-08-23treewide: Use fallthrough pseudo-keywordGustavo A. R. Silva
Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-08-23Merge tag 'core-urgent-2020-08-23' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull entry fix from Thomas Gleixner: "A single bug fix for the common entry code. The transcription of the x86 version messed up the reload of the syscall number from pt_regs after ptrace and seccomp which breaks syscall number rewriting" * tag 'core-urgent-2020-08-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: core/entry: Respect syscall number rewrites
2020-08-23Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netLinus Torvalds
Pull networking fixes from David Miller: "Nothing earth shattering here, lots of small fixes (f.e. missing RCU protection, bad ref counting, missing memset(), etc.) all over the place: 1) Use get_file_rcu() in task_file iterator, from Yonghong Song. 2) There are two ways to set remote source MAC addresses in macvlan driver, but only one of which validates things properly. Fix this. From Alvin Šipraga. 3) Missing of_node_put() in gianfar probing, from Sumera Priyadarsini. 4) Preserve device wanted feature bits across multiple netlink ethtool requests, from Maxim Mikityanskiy. 5) Fix rcu_sched stall in task and task_file bpf iterators, from Yonghong Song. 6) Avoid reset after device destroy in ena driver, from Shay Agroskin. 7) Missing memset() in netlink policy export reallocation path, from Johannes Berg. 8) Fix info leak in __smc_diag_dump(), from Peilin Ye. 9) Decapsulate ECN properly for ipv6 in ipv4 tunnels, from Mark Tomlinson. 10) Fix number of data stream negotiation in SCTP, from David Laight. 11) Fix double free in connection tracker action module, from Alaa Hleihel. 12) Don't allow empty NHA_GROUP attributes, from Nikolay Aleksandrov" * git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (46 commits) net: nexthop: don't allow empty NHA_GROUP bpf: Fix two typos in uapi/linux/bpf.h net: dsa: b53: check for timeout tipc: call rcu_read_lock() in tipc_aead_encrypt_done() net/sched: act_ct: Fix skb double-free in tcf_ct_handle_fragments() error flow net: sctp: Fix negotiation of the number of data streams. dt-bindings: net: renesas, ether: Improve schema validation gre6: Fix reception with IP6_TNL_F_RCV_DSCP_COPY hv_netvsc: Fix the queue_mapping in netvsc_vf_xmit() hv_netvsc: Remove "unlikely" from netvsc_select_queue bpf: selftests: global_funcs: Check err_str before strstr bpf: xdp: Fix XDP mode when no mode flags specified selftests/bpf: Remove test_align leftovers tools/resolve_btfids: Fix sections with wrong alignment net/smc: Prevent kernel-infoleak in __smc_diag_dump() sfc: fix build warnings on 32-bit net: phy: mscc: Fix a couple of spelling mistakes "spcified" -> "specified" libbpf: Fix map index used in error message net: gemini: Fix missing free_netdev() in error path of gemini_ethernet_port_probe() net: atlantic: Use readx_poll_timeout() for large timeout ...
2020-08-21Merge branch 'akpm' (patches from Andrew)Linus Torvalds
Merge misc fixes from Andrew Morton: "11 patches. Subsystems affected by this: misc, mm/hugetlb, mm/vmalloc, mm/misc, romfs, relay, uprobes, squashfs, mm/cma, mm/pagealloc" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: mm, page_alloc: fix core hung in free_pcppages_bulk() mm: include CMA pages in lowmem_reserve at boot squashfs: avoid bio_alloc() failure with 1Mbyte blocks uprobes: __replace_page() avoid BUG in munlock_vma_page() kernel/relay.c: fix memleak on destroy relay channel romfs: fix uninitialized memory leak in romfs_dev_read() mm/rodata_test.c: fix missing function declaration mm/vunmap: add cond_resched() in vunmap_pmd_range khugepaged: adjust VM_BUG_ON_MM() in __khugepaged_enter() hugetlb_cgroup: convert comma to semicolon mailmap: add Andi Kleen
2020-08-21Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpfDavid S. Miller
Alexei Starovoitov says: ==================== pull-request: bpf 2020-08-21 The following pull-request contains BPF updates for your *net* tree. We've added 11 non-merge commits during the last 5 day(s) which contain a total of 12 files changed, 78 insertions(+), 24 deletions(-). The main changes are: 1) three fixes in BPF task iterator logic, from Yonghong. 2) fix for compressed dwarf sections in vmlinux, from Jiri. 3) fix xdp attach regression, from Andrii. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2020-08-21uprobes: __replace_page() avoid BUG in munlock_vma_page()Hugh Dickins
syzbot crashed on the VM_BUG_ON_PAGE(PageTail) in munlock_vma_page(), when called from uprobes __replace_page(). Which of many ways to fix it? Settled on not calling when PageCompound (since Head and Tail are equals in this context, PageCompound the usual check in uprobes.c, and the prior use of FOLL_SPLIT_PMD will have cleared PageMlocked already). Fixes: 5a52c9df62b4 ("uprobe: use FOLL_SPLIT_PMD instead of FOLL_SPLIT") Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Acked-by: Song Liu <songliubraving@fb.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: <stable@vger.kernel.org> [5.4+] Link: http://lkml.kernel.org/r/alpine.LSU.2.11.2008161338360.20413@eggly.anvils Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-21kernel/relay.c: fix memleak on destroy relay channelWei Yongjun
kmemleak report memory leak as follows: unreferenced object 0x607ee4e5f948 (size 8): comm "syz-executor.1", pid 2098, jiffies 4295031601 (age 288.468s) hex dump (first 8 bytes): 00 00 00 00 00 00 00 00 ........ backtrace: relay_open kernel/relay.c:583 [inline] relay_open+0xb6/0x970 kernel/relay.c:563 do_blk_trace_setup+0x4a8/0xb20 kernel/trace/blktrace.c:557 __blk_trace_setup+0xb6/0x150 kernel/trace/blktrace.c:597 blk_trace_ioctl+0x146/0x280 kernel/trace/blktrace.c:738 blkdev_ioctl+0xb2/0x6a0 block/ioctl.c:613 block_ioctl+0xe5/0x120 fs/block_dev.c:1871 vfs_ioctl fs/ioctl.c:48 [inline] __do_sys_ioctl fs/ioctl.c:753 [inline] __se_sys_ioctl fs/ioctl.c:739 [inline] __x64_sys_ioctl+0x170/0x1ce fs/ioctl.c:739 do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 'chan->buf' is malloced in relay_open() by alloc_percpu() but not free while destroy the relay channel. Fix it by adding free_percpu() before return from relay_destroy_channel(). Fixes: 017c59c042d0 ("relay: Use per CPU constructs for the relay channel buffer pointers") Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: David Rientjes <rientjes@google.com> Cc: Michel Lespinasse <walken@google.com> Cc: Daniel Axtens <dja@axtens.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Akash Goel <akash.goel@intel.com> Cc: <stable@vger.kernel.org> Link: http://lkml.kernel.org/r/20200817122826.48518-1-weiyongjun1@huawei.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-21core/entry: Respect syscall number rewritesThomas Gleixner
The transcript of the x86 entry code to the generic version failed to reload the syscall number from ptregs after ptrace and seccomp have run, which both can modify the syscall number in ptregs. It returns the original syscall number instead which is obviously not the right thing to do. Reload the syscall number to fix that. Fixes: 142781e108b1 ("entry: Provide generic syscall entry functionality") Reported-by: Kyle Huey <me@kylehuey.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Kyle Huey <me@kylehuey.com> Tested-by: Kees Cook <keescook@chromium.org> Acked-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/87blj6ifo8.fsf@nanos.tec.linutronix.de
2020-08-20Merge tag 'dma-mapping-5.9-1' of git://git.infradead.org/users/hch/dma-mappingLinus Torvalds
Pull dma-mapping fixes from Christoph Hellwig: "Fix more fallout from the dma-pool changes (Nicolas Saenz Julienne, me)" * tag 'dma-mapping-5.9-1' of git://git.infradead.org/users/hch/dma-mapping: dma-pool: Only allocate from CMA when in same memory zone dma-pool: fix coherent pool allocations for IOMMU mappings
2020-08-18bpf: Avoid visit same object multiple timesYonghong Song
Currently when traversing all tasks, the next tid is always increased by one. This may result in visiting the same task multiple times in a pid namespace. This patch fixed the issue by seting the next tid as pid_nr_ns(pid, ns) + 1, similar to funciton next_tgid(). Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Cc: Rik van Riel <riel@surriel.com> Link: https://lore.kernel.org/bpf/20200818222310.2181500-1-yhs@fb.com
2020-08-18bpf: Fix a rcu_sched stall issue with bpf task/task_file iteratorYonghong Song
In our production system, we observed rcu stalls when 'bpftool prog` is running. rcu: INFO: rcu_sched self-detected stall on CPU rcu: \x097-....: (20999 ticks this GP) idle=302/1/0x4000000000000000 softirq=1508852/1508852 fqs=4913 \x09(t=21031 jiffies g=2534773 q=179750) NMI backtrace for cpu 7 CPU: 7 PID: 184195 Comm: bpftool Kdump: loaded Tainted: G W 5.8.0-00004-g68bfc7f8c1b4 #6 Hardware name: Quanta Twin Lakes MP/Twin Lakes Passive MP, BIOS F09_3A17 05/03/2019 Call Trace: <IRQ> dump_stack+0x57/0x70 nmi_cpu_backtrace.cold+0x14/0x53 ? lapic_can_unplug_cpu.cold+0x39/0x39 nmi_trigger_cpumask_backtrace+0xb7/0xc7 rcu_dump_cpu_stacks+0xa2/0xd0 rcu_sched_clock_irq.cold+0x1ff/0x3d9 ? tick_nohz_handler+0x100/0x100 update_process_times+0x5b/0x90 tick_sched_timer+0x5e/0xf0 __hrtimer_run_queues+0x12a/0x2a0 hrtimer_interrupt+0x10e/0x280 __sysvec_apic_timer_interrupt+0x51/0xe0 asm_call_on_stack+0xf/0x20 </IRQ> sysvec_apic_timer_interrupt+0x6f/0x80 asm_sysvec_apic_timer_interrupt+0x12/0x20 RIP: 0010:task_file_seq_get_next+0x71/0x220 Code: 00 00 8b 53 1c 49 8b 7d 00 89 d6 48 8b 47 20 44 8b 18 41 39 d3 76 75 48 8b 4f 20 8b 01 39 d0 76 61 41 89 d1 49 39 c1 48 19 c0 <48> 8b 49 08 21 d0 48 8d 04 c1 4c 8b 08 4d 85 c9 74 46 49 8b 41 38 RSP: 0018:ffffc90006223e10 EFLAGS: 00000297 RAX: ffffffffffffffff RBX: ffff888f0d172388 RCX: ffff888c8c07c1c0 RDX: 00000000000f017b RSI: 00000000000f017b RDI: ffff888c254702c0 RBP: ffffc90006223e68 R08: ffff888be2a1c140 R09: 00000000000f017b R10: 0000000000000002 R11: 0000000000100000 R12: ffff888f23c24118 R13: ffffc90006223e60 R14: ffffffff828509a0 R15: 00000000ffffffff task_file_seq_next+0x52/0xa0 bpf_seq_read+0xb9/0x320 vfs_read+0x9d/0x180 ksys_read+0x5f/0xe0 do_syscall_64+0x38/0x60 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f8815f4f76e Code: c0 e9 f6 fe ff ff 55 48 8d 3d 76 70 0a 00 48 89 e5 e8 36 06 02 00 66 0f 1f 44 00 00 64 8b 04 25 18 00 00 00 85 c0 75 14 0f 05 <48> 3d 00 f0 ff ff 77 52 c3 66 0f 1f 84 00 00 00 00 00 55 48 89 e5 RSP: 002b:00007fff8f9df578 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 000000000170b9c0 RCX: 00007f8815f4f76e RDX: 0000000000001000 RSI: 00007fff8f9df5b0 RDI: 0000000000000007 RBP: 00007fff8f9e05f0 R08: 0000000000000049 R09: 0000000000000010 R10: 00007f881601fa40 R11: 0000000000000246 R12: 00007fff8f9e05a8 R13: 00007fff8f9e05a8 R14: 0000000001917f90 R15: 000000000000e22e Note that `bpftool prog` actually calls a task_file bpf iterator program to establish an association between prog/map/link/btf anon files and processes. In the case where the above rcu stall occured, we had a process having 1587 tasks and each task having roughly 81305 files. This implied 129 million bpf prog invocations. Unfortunwtely none of these files are prog/map/link/btf files so bpf iterator/prog needs to traverse all these files and not able to return to user space since there are no seq_file buffer overflow. This patch fixed the issue in bpf_seq_read() to limit the number of visited objects. If the maximum number of visited objects is reached, no more objects will be visited in the current syscall. If there is nothing written in the seq_file buffer, -EAGAIN will return to the user so user can try again. The maximum number of visited objects is set at 1 million. In our Intel Xeon D-2191 2.3GHZ 18-core server, bpf_seq_read() visiting 1 million files takes around 0.18 seconds. We did not use cond_resched() since for some iterators, e.g., netlink iterator, where rcu read_lock critical section spans between consecutive seq_ops->next(), which makes impossible to do cond_resched() in the key while loop of function bpf_seq_read(). Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Cc: Paul E. McKenney <paulmck@kernel.org> Link: https://lore.kernel.org/bpf/20200818222309.2181348-1-yhs@fb.com
2020-08-17Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netLinus Torvalds
Pull networking fixes from David Miller: "Another batch of fixes: 1) Remove nft_compat counter flush optimization, it generates warnings from the refcount infrastructure. From Florian Westphal. 2) Fix BPF to search for build id more robustly, from Jiri Olsa. 3) Handle bogus getopt lengths in ebtables, from Florian Westphal. 4) Infoleak and other fixes to j1939 CAN driver, from Eric Dumazet and Oleksij Rempel. 5) Reset iter properly on mptcp sendmsg() error, from Florian Westphal. 6) Show a saner speed in bonding broadcast mode, from Jarod Wilson. 7) Various kerneldoc fixes in bonding and elsewhere, from Lee Jones. 8) Fix double unregister in bonding during namespace tear down, from Cong Wang. 9) Disable RP filter during icmp_redirect selftest, from David Ahern" * git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (75 commits) otx2_common: Use devm_kcalloc() in otx2_config_npa() net: qrtr: fix usage of idr in port assignment to socket selftests: disable rp_filter for icmp_redirect.sh Revert "net: xdp: pull ethernet header off packet after computing skb->protocol" phylink: <linux/phylink.h>: fix function prototype kernel-doc warning mptcp: sendmsg: reset iter on error redux net: devlink: Remove overzealous WARN_ON with snapshots tipc: not enable tipc when ipv6 works as a module tipc: fix uninit skb->data in tipc_nl_compat_dumpit() net: Fix potential wrong skb->protocol in skb_vlan_untag() net: xdp: pull ethernet header off packet after computing skb->protocol ipvlan: fix device features bonding: fix a potential double-unregister can: j1939: add rxtimer for multipacket broadcast session can: j1939: abort multipacket broadcast session when timeout occurs can: j1939: cancel rxtimer on multipacket broadcast session complete can: j1939: fix support for multipacket broadcast message net: fddi: skfp: cfm: Remove seemingly unused variable 'ID_sccs' net: fddi: skfp: cfm: Remove set but unused variable 'oldstate' net: fddi: skfp: smt: Remove seemingly unused variable 'ID_sccs' ...
2020-08-17bpf: Use get_file_rcu() instead of get_file() for task_file iteratorYonghong Song
With latest `bpftool prog` command, we observed the following kernel panic. BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor instruction fetch in kernel mode #PF: error_code(0x0010) - not-present page PGD dfe894067 P4D dfe894067 PUD deb663067 PMD 0 Oops: 0010 [#1] SMP CPU: 9 PID: 6023 ... RIP: 0010:0x0 Code: Bad RIP value. RSP: 0000:ffffc900002b8f18 EFLAGS: 00010286 RAX: ffff8883a405f400 RBX: ffff888e46a6bf00 RCX: 000000008020000c RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff8883a405f400 RBP: ffff888e46a6bf50 R08: 0000000000000000 R09: ffffffff81129600 R10: ffff8883a405f300 R11: 0000160000000000 R12: 0000000000002710 R13: 000000e9494b690c R14: 0000000000000202 R15: 0000000000000009 FS: 00007fd9187fe700(0000) GS:ffff888e46a40000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 0000000de5d33002 CR4: 0000000000360ee0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <IRQ> rcu_core+0x1a4/0x440 __do_softirq+0xd3/0x2c8 irq_exit+0x9d/0xa0 smp_apic_timer_interrupt+0x68/0x120 apic_timer_interrupt+0xf/0x20 </IRQ> RIP: 0033:0x47ce80 Code: Bad RIP value. RSP: 002b:00007fd9187fba40 EFLAGS: 00000206 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000002 RBX: 00007fd931789160 RCX: 000000000000010c RDX: 00007fd9308cdfb4 RSI: 00007fd9308cdfb4 RDI: 00007ffedd1ea0a8 RBP: 00007fd9187fbab0 R08: 000000000000000e R09: 000000000000002a R10: 0000000000480210 R11: 00007fd9187fc570 R12: 00007fd9316cc400 R13: 0000000000000118 R14: 00007fd9308cdfb4 R15: 00007fd9317a9380 After further analysis, the bug is triggered by Commit eaaacd23910f ("bpf: Add task and task/file iterator targets") which introduced task_file bpf iterator, which traverses all open file descriptors for all tasks in the current namespace. The latest `bpftool prog` calls a task_file bpf program to traverse all files in the system in order to associate processes with progs/maps, etc. When traversing files for a given task, rcu read_lock is taken to access all files in a file_struct. But it used get_file() to grab a file, which is not right. It is possible file->f_count is 0 and get_file() will unconditionally increase it. Later put_file() may cause all kind of issues with the above as one of sympotoms. The failure can be reproduced with the following steps in a few seconds: $ cat t.c #include <stdio.h> #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> #include <unistd.h> #define N 10000 int fd[N]; int main() { int i; for (i = 0; i < N; i++) { fd[i] = open("./note.txt", 'r'); if (fd[i] < 0) { fprintf(stderr, "failed\n"); return -1; } } for (i = 0; i < N; i++) close(fd[i]); return 0; } $ gcc -O2 t.c $ cat run.sh #/bin/bash for i in {1..100} do while true; do ./a.out; done & done $ ./run.sh $ while true; do bpftool prog >& /dev/null; done This patch used get_file_rcu() which only grabs a file if the file->f_count is not zero. This is to ensure the file pointer is always valid. The above reproducer did not fail for more than 30 minutes. Fixes: eaaacd23910f ("bpf: Add task and task/file iterator targets") Suggested-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Link: https://lore.kernel.org/bpf/20200817174214.252601-1-yhs@fb.com
2020-08-17watch_queue: Limit the number of watches a user can holdDavid Howells
Impose a limit on the number of watches that a user can hold so that they can't use this mechanism to fill up all the available memory. This is done by putting a counter in user_struct that's incremented when a watch is allocated and decreased when it is released. If the number exceeds the RLIMIT_NOFILE limit, the watch is rejected with EAGAIN. This can be tested by the following means: (1) Create a watch queue and attach it to fd 5 in the program given - in this case, bash: keyctl watch_session /tmp/nlog /tmp/gclog 5 bash (2) In the shell, set the maximum number of files to, say, 99: ulimit -n 99 (3) Add 200 keyrings: for ((i=0; i<200; i++)); do keyctl newring a$i @s || break; done (4) Try to watch all of the keyrings: for ((i=0; i<200; i++)); do echo $i; keyctl watch_add 5 %:a$i || break; done This should fail when the number of watches belonging to the user hits 99. (5) Remove all the keyrings and all of those watches should go away: for ((i=0; i<200; i++)); do keyctl unlink %:a$i; done (6) Kill off the watch queue by exiting the shell spawned by watch_session. Fixes: c73be61cede5 ("pipe: Add general notification queue support") Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-16Merge tag 'io_uring-5.9-2020-08-15' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull io_uring fixes from Jens Axboe: "A few differerent things in here. Seems like syzbot got some more io_uring bits wired up, and we got a handful of reports and the associated fixes are in here. General fixes too, and a lot of them marked for stable. Lastly, a bit of fallout from the async buffered reads, where we now more easily trigger short reads. Some applications don't really like that, so the io_read() code now handles short reads internally, and got a cleanup along the way so that it's now easier to read (and documented). We're now passing tests that failed before" * tag 'io_uring-5.9-2020-08-15' of git://git.kernel.dk/linux-block: io_uring: short circuit -EAGAIN for blocking read attempt io_uring: sanitize double poll handling io_uring: internally retry short reads io_uring: retain iov_iter state over io_read/io_write calls task_work: only grab task signal lock when needed io_uring: enable lookup of links holding inflight files io_uring: fail poll arm on queue proc failure io_uring: hold 'ctx' reference around task_work queue + execute fs: RWF_NOWAIT should imply IOCB_NOIO io_uring: defer file table grabbing request cleanup for locked requests io_uring: add missing REQ_F_COMP_LOCKED for nested requests io_uring: fix recursive completion locking on oveflow flush io_uring: use TWA_SIGNAL for task_work uncondtionally io_uring: account locked memory before potential error case io_uring: set ctx sq/cq entry count earlier io_uring: Fix NULL pointer dereference in loop_rw_iter() io_uring: add comments on how the async buffered read retry works io_uring: io_async_buf_func() need not test page bit
2020-08-15Merge tag 'sh-for-5.9' of git://git.libc.org/linux-shLinus Torvalds
Pull arch/sh updates from Rich Felker: "Cleanup, SECCOMP_FILTER support, message printing fixes, and other changes to arch/sh" * tag 'sh-for-5.9' of git://git.libc.org/linux-sh: (34 commits) sh: landisk: Add missing initialization of sh_io_port_base sh: bring syscall_set_return_value in line with other architectures sh: Add SECCOMP_FILTER sh: Rearrange blocks in entry-common.S sh: switch to copy_thread_tls() sh: use the generic dma coherent remap allocator sh: don't allow non-coherent DMA for NOMMU dma-mapping: consolidate the NO_DMA definition in kernel/dma/Kconfig sh: unexport register_trapped_io and match_trapped_io_handler sh: don't include <asm/io_trapped.h> in <asm/io.h> sh: move the ioremap implementation out of line sh: move ioremap_fixed details out of <asm/io.h> sh: remove __KERNEL__ ifdefs from non-UAPI headers sh: sort the selects for SUPERH alphabetically sh: remove -Werror from Makefiles sh: Replace HTTP links with HTTPS ones arch/sh/configs: remove obsolete CONFIG_SOC_CAMERA* sh: stacktrace: Remove stacktrace_ops.stack() sh: machvec: Modernize printing of kernel messages sh: pci: Modernize printing of kernel messages ...
2020-08-15Merge tag 'x86-urgent-2020-08-15' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Ingo Molnar: "Misc fixes and small updates all around the place: - Fix mitigation state sysfs output - Fix an FPU xstate/sxave code assumption bug triggered by Architectural LBR support - Fix Lightning Mountain SoC TSC frequency enumeration bug - Fix kexec debug output - Fix kexec memory range assumption bug - Fix a boundary condition in the crash kernel code - Optimize porgatory.ro generation a bit - Enable ACRN guests to use X2APIC mode - Reduce a __text_poke() IRQs-off critical section for the benefit of PREEMPT_RT" * tag 'x86-urgent-2020-08-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/alternatives: Acquire pte lock with interrupts enabled x86/bugs/multihit: Fix mitigation reporting when VMX is not in use x86/fpu/xstate: Fix an xstate size check warning with architectural LBRs x86/purgatory: Don't generate debug info for purgatory.ro x86/tsr: Fix tsc frequency enumeration bug on Lightning Mountain SoC kexec_file: Correctly output debugging information for the PT_LOAD ELF header kexec: Improve & fix crash_exclude_mem_range() to handle overlapping ranges x86/crash: Correct the address boundary of function parameters x86/acrn: Remove redundant chars from ACRN signature x86/acrn: Allow ACRN guest to use X2APIC mode
2020-08-15Merge tag 'sched-urgent-2020-08-15' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fixes from Ingo Molnar: "Two fixes: fix a new tracepoint's output value, and fix the formatting of show-state syslog printouts" * tag 'sched-urgent-2020-08-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/debug: Fix the alignment of the show-state debug output sched: Fix use of count for nr_running tracepoint
2020-08-15Merge tag 'perf-urgent-2020-08-15' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Ingo Molnar: "Misc fixes, an expansion of perf syscall access to CAP_PERFMON privileged tools, plus a RAPL HW-enablement for Intel SPR platforms" * tag 'perf-urgent-2020-08-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/x86/rapl: Add support for Intel SPR platform perf/x86/rapl: Support multiple RAPL unit quirks perf/x86/rapl: Fix missing psys sysfs attributes hw_breakpoint: Remove unused __register_perf_hw_breakpoint() declaration kprobes: Remove show_registers() function prototype perf/core: Take over CAP_SYS_PTRACE creds to CAP_PERFMON capability
2020-08-15Merge tag 'locking-urgent-2020-08-15' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking fixlets from Ingo Molnar: "A documentation fix and a 'fallthrough' macro update" * tag 'locking-urgent-2020-08-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: futex: Convert to use the preferred 'fallthrough' macro Documentation/locking/locktypes: Fix a typo
2020-08-15Merge branch 'akpm' (patches from Andrew)Linus Torvalds
Merge more updates from Andrew Morton: "Subsystems affected by this patch series: mm/hotfixes, lz4, exec, mailmap, mm/thp, autofs, sysctl, mm/kmemleak, mm/misc and lib" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (35 commits) virtio: pci: constify ioreadX() iomem argument (as in generic implementation) ntb: intel: constify ioreadX() iomem argument (as in generic implementation) rtl818x: constify ioreadX() iomem argument (as in generic implementation) iomap: constify ioreadX() iomem argument (as in generic implementation) sh: use generic strncpy() sh: clkfwk: remove r8/r16/r32 include/asm-generic/vmlinux.lds.h: align ro_after_init mm: annotate a data race in page_zonenum() mm/swap.c: annotate data races for lru_rotate_pvecs mm/rmap: annotate a data race at tlb_flush_batched mm/mempool: fix a data race in mempool_free() mm/list_lru: fix a data race in list_lru_count_one mm/memcontrol: fix a data race in scan count mm/page_counter: fix various data races at memsw mm/swapfile: fix and annotate various data races mm/filemap.c: fix a data race in filemap_fault() mm/swap_state: mark various intentional data races mm/page_io: mark various intentional data races mm/frontswap: mark various intentional data races mm/kmemleak: silence KCSAN splats in checksum ...
2020-08-14all arch: remove system call sys_sysctlXiaoming Ni
Since commit 61a47c1ad3a4dc ("sysctl: Remove the sysctl system call"), sys_sysctl is actually unavailable: any input can only return an error. We have been warning about people using the sysctl system call for years and believe there are no more users. Even if there are users of this interface if they have not complained or fixed their code by now they probably are not going to, so there is no point in warning them any longer. So completely remove sys_sysctl on all architectures. [nixiaoming@huawei.com: s390: fix build error for sys_call_table_emu] Link: http://lkml.kernel.org/r/20200618141426.16884-1-nixiaoming@huawei.com Signed-off-by: Xiaoming Ni <nixiaoming@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Will Deacon <will@kernel.org> [arm/arm64] Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Aleksa Sarai <cyphar@cyphar.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andi Kleen <ak@linux.intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Bin Meng <bin.meng@windriver.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: chenzefeng <chenzefeng2@huawei.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Christian Brauner <christian@brauner.io> Cc: Chris Zankel <chris@zankel.net> Cc: David Howells <dhowells@redhat.com> Cc: David S. Miller <davem@davemloft.net> Cc: Diego Elio Pettenò <flameeyes@flameeyes.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Dominik Brodowski <linux@dominikbrodowski.net> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Iurii Zaikin <yzaikin@google.com> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Kars de Jong <jongk@linux-m68k.org> Cc: Kees Cook <keescook@chromium.org> Cc: Krzysztof Kozlowski <krzk@kernel.org> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Marco Elver <elver@google.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Martin K. Petersen <martin.petersen@oracle.com> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Miklos Szeredi <mszeredi@redhat.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Cc: Nick Piggin <npiggin@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Olof Johansson <olof@lixom.net> Cc: Paul Burton <paulburton@kernel.org> Cc: "Paul E. McKenney" <paulmck@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com> Cc: Richard Henderson <rth@twiddle.net> Cc: Rich Felker <dalias@libc.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Sami Tolvanen <samitolvanen@google.com> Cc: Sargun Dhillon <sargun@sargun.me> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Sudeep Holla <sudeep.holla@arm.com> Cc: Sven Schnelle <svens@stackframe.org> Cc: Thiago Jung Bauermann <bauerman@linux.ibm.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Zhou Yanjie <zhouyanjie@wanyeetech.com> Link: http://lkml.kernel.org/r/20200616030734.87257-1-nixiaoming@huawei.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-14dma-mapping: consolidate the NO_DMA definition in kernel/dma/KconfigChristoph Hellwig
Have a single definition that architetures can select. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Rich Felker <dalias@libc.org>
2020-08-14Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpfDavid S. Miller
Daniel Borkmann says: ==================== pull-request: bpf 2020-08-15 The following pull-request contains BPF updates for your *net* tree. We've added 23 non-merge commits during the last 4 day(s) which contain a total of 32 files changed, 421 insertions(+), 141 deletions(-). The main changes are: 1) Fix sock_ops ctx access splat due to register override, from John Fastabend. 2) Batch of various fixes to libbpf, bpftool, and selftests when testing build in 32-bit mode, from Andrii Nakryiko. 3) Fix vmlinux.h generation on ARM by mapping GCC built-in types (__Poly*_t) to equivalent ones clang can work with, from Jean-Philippe Brucker. 4) Fix build_id lookup in bpf_get_stackid() helper by walking all NOTE ELF sections instead of just first, from Jiri Olsa. 5) Avoid use of __builtin_offsetof() in libbpf for CO-RE, from Yonghong Song. 6) Fix segfault in test_mmap due to inconsistent length params, from Jianlin Lv. 7) Don't override errno in libbpf when logging errors, from Toke Høiland-Jørgensen. 8) Fix v4_to_v6 sockaddr conversion in sk_lookup test, from Stanislav Fomichev. 9) Add link to bpf-helpers(7) man page to BPF doc, from Joe Stringer. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2020-08-14dma-debug: remove debug_dma_assert_idle() functionLinus Torvalds
This remoes the code from the COW path to call debug_dma_assert_idle(), which was added many years ago. Google shows that it hasn't caught anything in the 6+ years we've had it apart from a false positive, and Hugh just noticed how it had a very unfortunate spinlock serialization in the COW path. He fixed that issue the previous commit (a85ffd59bd36: "dma-debug: fix debug_dma_assert_idle(), use rcu_read_lock()"), but let's see if anybody even notices when we remove this function entirely. NOTE! We keep the dma tracking infrastructure that was added by the commit that introduced it. Partly to make it easier to resurrect this debug code if we ever deside to, and partly because that tracking by pfn and offset looks quite reasonable. The problem with this debug code was simply that it was expensive and didn't seem worth it, not that it was wrong per se. Acked-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-14dma-debug: fix debug_dma_assert_idle(), use rcu_read_lock()Hugh Dickins
Since commit 2a9127fcf229 ("mm: rewrite wait_on_page_bit_common() logic") improved unlock_page(), it has become more noticeable how cow_user_page() in a kernel with CONFIG_DMA_API_DEBUG=y can create and suffer from heavy contention on DMA debug's radix_lock in debug_dma_assert_idle(). It is only doing a lookup: use rcu_read_lock() and rcu_read_unlock() instead; though that does require the static ents[] to be moved onstack... ...but, hold on, isn't that radix_tree_gang_lookup() and loop doing quite the wrong thing: searching CACHELINES_PER_PAGE entries for an exact match with the first cacheline of the page in question? radix_tree_gang_lookup() is the right tool for the job, but we need nothing more than to check the first entry it can find, reporting if that falls anywhere within the page. (Is RCU safe here? As safe as using the spinlock was. The entries are never freed, so don't need to be freed by RCU. They may be reused, and there is a faint chance of a race, with an offending entry reused while printing its error info; but the spinlock did not prevent that either, and I agree that it's not worth worrying about. ] [ Side noe: this patch is a clear improvement to the status quo, but the next patch will be removing this debug function entirely. But just in case we decide we want to resurrect the debugging code some day, I'm first applying this improvement patch so that it doesn't get lost - Linus ] Fixes: 3b7a6418c749 ("dma debug: account for cachelines and read-only mappings in overlap tracking") Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-14Merge tag 'timers-urgent-2020-08-14' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timekeeping updates from Thomas Gleixner: "A set of timekeeping/VDSO updates: - Preparatory work to allow S390 to switch over to the generic VDSO implementation. S390 requires that the VDSO data pointer is handed in to the counter read function when time namespace support is enabled. Adding the pointer is a NOOP for all other architectures because the compiler is supposed to optimize that out when it is unused in the architecture specific inline. The change also solved a similar problem for MIPS which fortunately has time namespaces not yet enabled. S390 needs to update clock related VDSO data independent of the timekeeping updates. This was solved so far with yet another sequence counter in the S390 implementation. A better solution is to utilize the already existing VDSO sequence count for this. The core code now exposes helper functions which allow to serialize against the timekeeper code and against concurrent readers. S390 needs extra data for their clock readout function. The initial common VDSO data structure did not provide a way to add that. It now has an embedded architecture specific struct embedded which defaults to an empty struct. Doing this now avoids tree dependencies and conflicts post rc1 and allows all other architectures which work on generic VDSO support to work from a common upstream base. - A trivial comment fix" * tag 'timers-urgent-2020-08-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: time: Delete repeated words in comments lib/vdso: Allow to add architecture-specific vdso data timekeeping/vsyscall: Provide vdso_update_begin/end() vdso/treewide: Add vdso_data pointer argument to __arch_get_hw_counter()
2020-08-14Merge tag 'timers-core-2020-08-14' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull more timer updates from Thomas Gleixner: "A set of posix CPU timer changes which allows to defer the heavy work of posix CPU timers into task work context. The tick interrupt is reduced to a quick check which queues the work which is doing the heavy lifting before returning to user space or going back to guest mode. Moving this out is deferring the signal delivery slightly but posix CPU timers are inaccurate by nature as they depend on the tick so there is no real damage. The relevant test cases all passed. This lifts the last offender for RT out of the hard interrupt context tick handler, but it also has the general benefit that the actual heavy work is accounted to the task/process and not to the tick interrupt itself. Further optimizations are possible to break long sighand lock hold and interrupt disabled (on !RT kernels) times when a massive amount of posix CPU timers (which are unpriviledged) is armed for a task/process. This is currently only enabled for x86 because the architecture has to ensure that task work is handled in KVM before entering a guest, which was just established for x86 with the new common entry/exit code which got merged post 5.8 and is not the case for other KVM architectures" * tag 'timers-core-2020-08-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86: Select POSIX_CPU_TIMERS_TASK_WORK posix-cpu-timers: Provide mechanisms to defer timer handling to task_work posix-cpu-timers: Split run_posix_cpu_timers()
2020-08-14Merge tag 'irq-urgent-2020-08-14' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull irq fixes from Thomas Gleixner: "Two fixes in the core interrupt code which ensure that all error exits unlock the descriptor lock" * tag 'irq-urgent-2020-08-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: genirq: Unlock irq descriptor after errors genirq/PM: Always unlock IRQ descriptor in rearm_wake_irq()
2020-08-14Merge tag 'modules-for-v5.9' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux Pull module updates from Jessica Yu: "The most important change would be Christoph Hellwig's patch implementing proprietary taint inheritance, in an effort to discourage the creation of GPL "shim" modules that interface between GPL symbols and proprietary symbols. Summary: - Have modules that use symbols from proprietary modules inherit the TAINT_PROPRIETARY_MODULE taint, in an effort to prevent GPL shim modules that are used to circumvent _GPL exports. These are modules that claim to be GPL licensed while also using symbols from proprietary modules. Such modules will be rejected while non-GPL modules will inherit the proprietary taint. - Module export space cleanup. Unexport symbols that are unused outside of module.c or otherwise used in only built-in code" * tag 'modules-for-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux: modules: inherit TAINT_PROPRIETARY_MODULE modules: return licensing information from find_symbol modules: rename the licence field in struct symsearch to license modules: unexport __module_address modules: unexport __module_text_address modules: mark each_symbol_section static modules: mark find_symbol static modules: mark ref_module static modules: linux/moduleparam.h: drop duplicated word in a comment
2020-08-14dma-pool: Only allocate from CMA when in same memory zoneNicolas Saenz Julienne
There is no guarantee to CMA's placement, so allocating a zone specific atomic pool from CMA might return memory from a completely different memory zone. To get around this double check CMA's placement before allocating from it. Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de> Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-08-14dma-pool: fix coherent pool allocations for IOMMU mappingsChristoph Hellwig
When allocating coherent pool memory for an IOMMU mapping we don't care about the DMA mask. Move the guess for the initial GFP mask into the dma_direct_alloc_pages and pass dma_coherent_ok as a function pointer argument so that it doesn't get applied to the IOMMU case. Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Amit Pundir <amit.pundir@linaro.org>
2020-08-14sched/debug: Fix the alignment of the show-state debug outputLibing Zhou
Current sysrq(t) output task fields name are not aligned with actual task fields value, e.g.: kernel: sysrq: Show State kernel: task PC stack pid father kernel: systemd S12456 1 0 0x00000000 kernel: Call Trace: kernel: ? __schedule+0x240/0x740 To make it more readable, print fields name together with task fields value in the same line, with fixed width: kernel: sysrq: Show State kernel: task:systemd state:S stack:12920 pid: 1 ppid: 0 flags:0x00000000 kernel: Call Trace: kernel: __schedule+0x282/0x620 Signed-off-by: Libing Zhou <libing.zhou@nokia-sbell.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20200814030236.37835-1-libing.zhou@nokia-sbell.com
2020-08-13Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netLinus Torvalds
Pull networking fixes from David Miller: "Some merge window fallout, some longer term fixes: 1) Handle headroom properly in lapbether and x25_asy drivers, from Xie He. 2) Fetch MAC address from correct r8152 device node, from Thierry Reding. 3) In the sw kTLS path we should allow MSG_CMSG_COMPAT in sendmsg, from Rouven Czerwinski. 4) Correct fdputs in socket layer, from Miaohe Lin. 5) Revert troublesome sockptr_t optimization, from Christoph Hellwig. 6) Fix TCP TFO key reading on big endian, from Jason Baron. 7) Missing CAP_NET_RAW check in nfc, from Qingyu Li. 8) Fix inet fastreuse optimization with tproxy sockets, from Tim Froidcoeur. 9) Fix 64-bit divide in new SFC driver, from Edward Cree. 10) Add a tracepoint for prandom_u32 so that we can more easily perform usage analysis. From Eric Dumazet. 11) Fix rwlock imbalance in AF_PACKET, from John Ogness" * git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (49 commits) net: openvswitch: introduce common code for flushing flows af_packet: TPACKET_V3: fix fill status rwlock imbalance random32: add a tracepoint for prandom_u32() Revert "ipv4: tunnel: fix compilation on ARCH=um" net: accept an empty mask in /sys/class/net/*/queues/rx-*/rps_cpus net: ethernet: stmmac: Disable hardware multicast filter net: stmmac: dwmac1000: provide multicast filter fallback ipv4: tunnel: fix compilation on ARCH=um vsock: fix potential null pointer dereference in vsock_poll() sfc: fix ef100 design-param checking net: initialize fastreuse on inet_inherit_port net: refactor bind_bucket fastreuse into helper net: phy: marvell10g: fix null pointer dereference net: Fix potential memory leak in proto_register() net: qcom/emac: add missed clk_disable_unprepare in error path of emac_clks_phase1_init ionic_lif: Use devm_kcalloc() in ionic_qcq_alloc() net/nfc/rawsock.c: add CAP_NET_RAW check. hinic: fix strncpy output truncated compile warnings drivers/net/wan/x25_asy: Added needed_headroom and a skb->len check net/tls: Fix kmap usage ...
2020-08-13futex: Convert to use the preferred 'fallthrough' macroMiaohe Lin
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20200813122117.51173-1-linmiaohe@huawei.com
2020-08-13task_work: only grab task signal lock when neededJens Axboe
If JOBCTL_TASK_WORK is already set on the targeted task, then we need not go through {lock,unlock}_task_sighand() to set it again and queue a signal wakeup. This is safe as we're checking it _after_ adding the new task_work with cmpxchg(). The ordering is as follows: task_work_add() get_signal() -------------------------------------------------------------- STORE(task->task_works, new_work); STORE(task->jobctl); mb(); mb(); LOAD(task->jobctl); LOAD(task->task_works); This speeds up TWA_SIGNAL handling quite a bit, which is important now that io_uring is relying on it for all task_work deliveries. Cc: Peter Zijlstra <peterz@infradead.org> Cc: Jann Horn <jannh@google.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-08-13genirq: Unlock irq descriptor after errorsGuenter Roeck
In irq_set_irqchip_state(), the irq descriptor is not unlocked after an error is encountered. While that should never happen in practice, a buggy driver may trigger it. This would result in a lockup, so fix it. Fixes: 1d0326f352bb ("genirq: Check irq_data_get_irq_chip() return value before use") Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20200811180012.80269-1-linux@roeck-us.net
2020-08-12bpf: Iterate through all PT_NOTE sections when looking for build idJiri Olsa
Currently when we look for build id within bpf_get_stackid helper call, we check the first NOTE section and we fail if build id is not there. However on some system (Fedora) there can be multiple NOTE sections in binaries and build id data is not always the first one, like: $ readelf -a /usr/bin/ls ... [ 2] .note.gnu.propert NOTE 0000000000000338 00000338 0000000000000020 0000000000000000 A 0 0 8358 [ 3] .note.gnu.build-i NOTE 0000000000000358 00000358 0000000000000024 0000000000000000 A 0 0 437c [ 4] .note.ABI-tag NOTE 000000000000037c 0000037c ... So the stack_map_get_build_id function will fail on build id retrieval and fallback to BPF_STACK_BUILD_ID_IP. This patch is changing the stack_map_get_build_id code to iterate through all the NOTE sections and try to get build id data from each of them. When tracing on sched_switch tracepoint that does bpf_get_stackid helper call kernel build, I can see about 60% increase of successful build id retrieval. The rest seems fails on -EFAULT. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Song Liu <songliubraving@fb.com> Link: https://lore.kernel.org/bpf/20200812123102.20032-1-jolsa@kernel.org
2020-08-12Merge branch 'akpm' (patches from Andrew)Linus Torvalds
Merge more updates from Andrew Morton: - most of the rest of MM (memcg, hugetlb, vmscan, proc, compaction, mempolicy, oom-kill, hugetlbfs, migration, thp, cma, util, memory-hotplug, cleanups, uaccess, migration, gup, pagemap), - various other subsystems (alpha, misc, sparse, bitmap, lib, bitops, checkpatch, autofs, minix, nilfs, ufs, fat, signals, kmod, coredump, exec, kdump, rapidio, panic, kcov, kgdb, ipc). * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (164 commits) mm/gup: remove task_struct pointer for all gup code mm: clean up the last pieces of page fault accountings mm/xtensa: use general page fault accounting mm/x86: use general page fault accounting mm/sparc64: use general page fault accounting mm/sparc32: use general page fault accounting mm/sh: use general page fault accounting mm/s390: use general page fault accounting mm/riscv: use general page fault accounting mm/powerpc: use general page fault accounting mm/parisc: use general page fault accounting mm/openrisc: use general page fault accounting mm/nios2: use general page fault accounting mm/nds32: use general page fault accounting mm/mips: use general page fault accounting mm/microblaze: use general page fault accounting mm/m68k: use general page fault accounting mm/ia64: use general page fault accounting mm/hexagon: use general page fault accounting mm/csky: use general page fault accounting ...
2020-08-12mm/gup: remove task_struct pointer for all gup codePeter Xu
After the cleanup of page fault accounting, gup does not need to pass task_struct around any more. Remove that parameter in the whole gup stack. Signed-off-by: Peter Xu <peterx@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Link: http://lkml.kernel.org/r/20200707225021.200906-26-peterx@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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