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2017-12-27tracing: Remove extra zeroing out of the ring buffer pageSteven Rostedt (VMware)
The ring_buffer_read_page() takes care of zeroing out any extra data in the page that it returns. There's no need to zero it out again from the consumer. It was removed from one consumer of this function, but read_buffers_splice_read() did not remove it, and worse, it contained a nasty bug because of it. Cc: stable@vger.kernel.org Fixes: 2711ca237a084 ("ring-buffer: Move zeroing out excess in page to ring buffer code") Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-12-27ring-buffer: Mask out the info bits when returning buffer page lengthSteven Rostedt (VMware)
Two info bits were added to the "commit" part of the ring buffer data page when returned to be consumed. This was to inform the user space readers that events have been missed, and that the count may be stored at the end of the page. What wasn't handled, was the splice code that actually called a function to return the length of the data in order to zero out the rest of the page before sending it up to user space. These data bits were returned with the length making the value negative, and that negative value was not checked. It was compared to PAGE_SIZE, and only used if the size was less than PAGE_SIZE. Luckily PAGE_SIZE is unsigned long which made the compare an unsigned compare, meaning the negative size value did not end up causing a large portion of memory to be randomly zeroed out. Cc: stable@vger.kernel.org Fixes: 66a8cb95ed040 ("ring-buffer: Add place holder recording of dropped events") Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-12-27cpu/hotplug: Move inline keyword at the beginning of declarationMathieu Malaterre
Fix non-fatal warnings such as: kernel/cpu.c:95:1: warning: ‘inline’ is not at beginning of declaration [-Wold-style-declaration] static void inline cpuhp_lock_release(bool bringup) { } ^~~~~~ Signed-off-by: Mathieu Malaterre <malat@debian.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Link: https://lkml.kernel.org/r/20171226140855.16583-1-malat@debian.org
2017-12-23pid: Handle failure to allocate the first pid in a pid namespaceEric W. Biederman
With the replacement of the pid bitmap and hashtable with an idr in alloc_pid started occassionally failing when allocating the first pid in a pid namespace. Things were not completely reset resulting in the first allocated pid getting the number 2 (not 1). Which further resulted in ns->proc_mnt not getting set and eventually causing an oops in proc_flush_task. Oops: 0000 [#1] SMP CPU: 2 PID: 6743 Comm: trinity-c117 Not tainted 4.15.0-rc4-think+ #2 RIP: 0010:proc_flush_task+0x8e/0x1b0 RSP: 0018:ffffc9000bbffc40 EFLAGS: 00010286 RAX: 0000000000000001 RBX: 0000000000000001 RCX: 00000000fffffffb RDX: 0000000000000000 RSI: ffffc9000bbffc50 RDI: 0000000000000000 RBP: ffffc9000bbffc63 R08: 0000000000000000 R09: 0000000000000002 R10: ffffc9000bbffb70 R11: ffffc9000bbffc64 R12: 0000000000000003 R13: 0000000000000000 R14: 0000000000000003 R15: ffff8804c10d7840 FS: 00007f7cb8965700(0000) GS:ffff88050a200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 00000003e21ae003 CR4: 00000000001606e0 DR0: 00007fb1d6c22000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: ? release_task+0xaf/0x680 release_task+0xd2/0x680 ? wait_consider_task+0xb82/0xce0 wait_consider_task+0xbe9/0xce0 ? do_wait+0xe1/0x330 do_wait+0x151/0x330 kernel_wait4+0x8d/0x150 ? task_stopped_code+0x50/0x50 SYSC_wait4+0x95/0xa0 ? rcu_read_lock_sched_held+0x6c/0x80 ? syscall_trace_enter+0x2d7/0x340 ? do_syscall_64+0x60/0x210 do_syscall_64+0x60/0x210 entry_SYSCALL64_slow_path+0x25/0x25 RIP: 0033:0x7f7cb82603aa RSP: 002b:00007ffd60770bc8 EFLAGS: 00000246 ORIG_RAX: 000000000000003d RAX: ffffffffffffffda RBX: 00007f7cb6cd4000 RCX: 00007f7cb82603aa RDX: 000000000000000b RSI: 00007ffd60770bd0 RDI: 0000000000007cca RBP: 0000000000007cca R08: 00007f7cb8965700 R09: 00007ffd607c7080 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd60770bd0 R14: 00007f7cb6cd4058 R15: 00000000cccccccd Code: c1 e2 04 44 8b 60 30 48 8b 40 38 44 8b 34 11 48 c7 c2 60 3a f5 81 44 89 e1 4c 8b 68 58 e8 4b b4 77 00 89 44 24 14 48 8d 74 24 10 <49> 8b 7d 00 e8 b9 6a f9 ff 48 85 c0 74 1a 48 89 c7 48 89 44 24 RIP: proc_flush_task+0x8e/0x1b0 RSP: ffffc9000bbffc40 CR2: 0000000000000000 ---[ end trace 53d67a6481059862 ]--- Improve the quality of the implementation by resetting the place to start allocating pids on failure to allocate the first pid. As improving the quality of the implementation is the goal remove the now unnecesarry disable_pid_allocations call when we fail to mount proc. Fixes: 95846ecf9dac ("pid: replace pid bitmap implementation with IDR API") Fixes: 8ef047aaaeb8 ("pid namespaces: make alloc_pid(), free_pid() and put_pid() work with struct upid") Reported-by: Dave Jones <davej@codemonkey.org.uk> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2017-12-23Merge branch 'x86-pti-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 PTI preparatory patches from Thomas Gleixner: "Todays Advent calendar window contains twentyfour easy to digest patches. The original plan was to have twenty three matching the date, but a late fixup made that moot. - Move the cpu_entry_area mapping out of the fixmap into a separate address space. That's necessary because the fixmap becomes too big with NRCPUS=8192 and this caused already subtle and hard to diagnose failures. The top most patch is fresh from today and cures a brain slip of that tall grumpy german greybeard, who ignored the intricacies of 32bit wraparounds. - Limit the number of CPUs on 32bit to 64. That's insane big already, but at least it's small enough to prevent address space issues with the cpu_entry_area map, which have been observed and debugged with the fixmap code - A few TLB flush fixes in various places plus documentation which of the TLB functions should be used for what. - Rename the SYSENTER stack to CPU_ENTRY_AREA stack as it is used for more than sysenter now and keeping the name makes backtraces confusing. - Prevent LDT inheritance on exec() by moving it to arch_dup_mmap(), which is only invoked on fork(). - Make vysycall more robust. - A few fixes and cleanups of the debug_pagetables code. Check PAGE_PRESENT instead of checking the PTE for 0 and a cleanup of the C89 initialization of the address hint array which already was out of sync with the index enums. - Move the ESPFIX init to a different place to prepare for PTI. - Several code moves with no functional change to make PTI integration simpler and header files less convoluted. - Documentation fixes and clarifications" * 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits) x86/cpu_entry_area: Prevent wraparound in setup_cpu_entry_area_ptes() on 32bit init: Invoke init_espfix_bsp() from mm_init() x86/cpu_entry_area: Move it out of the fixmap x86/cpu_entry_area: Move it to a separate unit x86/mm: Create asm/invpcid.h x86/mm: Put MMU to hardware ASID translation in one place x86/mm: Remove hard-coded ASID limit checks x86/mm: Move the CR3 construction functions to tlbflush.h x86/mm: Add comments to clarify which TLB-flush functions are supposed to flush what x86/mm: Remove superfluous barriers x86/mm: Use __flush_tlb_one() for kernel memory x86/microcode: Dont abuse the TLB-flush interface x86/uv: Use the right TLB-flush API x86/entry: Rename SYSENTER_stack to CPU_ENTRY_AREA_entry_stack x86/doc: Remove obvious weirdnesses from the x86 MM layout documentation x86/mm/64: Improve the memory map documentation x86/ldt: Prevent LDT inheritance on exec x86/ldt: Rework locking arch, mm: Allow arch_dup_mmap() to fail x86/vsyscall/64: Warn and fail vsyscall emulation in NATIVE mode ...
2017-12-22arch, mm: Allow arch_dup_mmap() to failThomas Gleixner
In order to sanitize the LDT initialization on x86 arch_dup_mmap() must be allowed to fail. Fix up all instances. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Andy Lutomirsky <luto@kernel.org> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bpetkov@suse.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Laight <David.Laight@aculab.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Eduardo Valentin <eduval@amazon.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Will Deacon <will.deacon@arm.com> Cc: aliguori@amazon.com Cc: dan.j.williams@intel.com Cc: hughd@google.com Cc: keescook@google.com Cc: kirill.shutemov@linux.intel.com Cc: linux-mm@kvack.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-21Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds
Pull networking fixes from David Miller" "What's a holiday weekend without some networking bug fixes? [1] 1) Fix some eBPF JIT bugs wrt. SKB pointers across helper function calls, from Daniel Borkmann. 2) Fix regression from errata limiting change to marvell PHY driver, from Zhao Qiang. 3) Fix u16 overflow in SCTP, from Xin Long. 4) Fix potential memory leak during bridge newlink, from Nikolay Aleksandrov. 5) Fix BPF selftest build on s390, from Hendrik Brueckner. 6) Don't append to cfg80211 automatically generated certs file, always write new ones from scratch. From Thierry Reding. 7) Fix sleep in atomic in mac80211 hwsim, from Jia-Ju Bai. 8) Fix hang on tg3 MTU change with certain chips, from Brian King. 9) Add stall detection to arc emac driver and reset chip when this happens, from Alexander Kochetkov. 10) Fix MTU limitng in GRE tunnel drivers, from Xin Long. 11) Fix stmmac timestamping bug due to mis-shifting of field. From Fredrik Hallenberg. 12) Fix metrics match when deleting an ipv4 route. The kernel sets some internal metrics bits which the user isn't going to set when it makes the delete request. From Phil Sutter. 13) mvneta driver loop over RX queues limits on "txq_number" :-) Fix from Yelena Krivosheev. 14) Fix double free and memory corruption in get_net_ns_by_id, from Eric W. Biederman. 15) Flush ipv4 FIB tables in the reverse order. Some tables can share their actual backing data, in particular this happens for the MAIN and LOCAL tables. We have to kill the LOCAL table first, because it uses MAIN's backing memory. Fix from Ido Schimmel. 16) Several eBPF verifier value tracking fixes, from Edward Cree, Jann Horn, and Alexei Starovoitov. 17) Make changes to ipv6 autoflowlabel sysctl really propagate to sockets, unless the socket has set the per-socket value explicitly. From Shaohua Li. 18) Fix leaks and double callback invocations of zerocopy SKBs, from Willem de Bruijn" [1] Is this a trick question? "Relaxing"? "Quiet"? "Fine"? - Linus. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (77 commits) skbuff: skb_copy_ubufs must release uarg even without user frags skbuff: orphan frags before zerocopy clone net: reevalulate autoflowlabel setting after sysctl setting openvswitch: Fix pop_vlan action for double tagged frames ipv6: Honor specified parameters in fibmatch lookup bpf: do not allow root to mangle valid pointers selftests/bpf: add tests for recent bugfixes bpf: fix integer overflows bpf: don't prune branches when a scalar is replaced with a pointer bpf: force strict alignment checks for stack pointers bpf: fix missing error return in check_stack_boundary() bpf: fix 32-bit ALU op verification bpf: fix incorrect tracking of register size truncation bpf: fix incorrect sign extension in check_alu_op() bpf/verifier: fix bounds calculation on BPF_RSH ipv4: Fix use-after-free when flushing FIB tables s390/qeth: fix error handling in checksum cmd callback tipc: remove joining group member from congested list selftests: net: Adding config fragment CONFIG_NUMA=y nfp: bpf: keep track of the offloaded program ...
2017-12-21bpf: do not allow root to mangle valid pointersAlexei Starovoitov
Do not allow root to convert valid pointers into unknown scalars. In particular disallow: ptr &= reg ptr <<= reg ptr += ptr and explicitly allow: ptr -= ptr since pkt_end - pkt == length 1. This minimizes amount of address leaks root can do. In the future may need to further tighten the leaks with kptr_restrict. 2. If program has such pointer math it's likely a user mistake and when verifier complains about it right away instead of many instructions later on invalid memory access it's easier for users to fix their progs. 3. when register holding a pointer cannot change to scalar it allows JITs to optimize better. Like 32-bit archs could use single register for pointers instead of a pair required to hold 64-bit scalars. 4. reduces architecture dependent behavior. Since code: r1 = r10; r1 &= 0xff; if (r1 ...) will behave differently arm64 vs x64 and offloaded vs native. A significant chunk of ptr mangling was allowed by commit f1174f77b50c ("bpf/verifier: rework value tracking") yet some of it was allowed even earlier. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2017-12-21bpf: fix integer overflowsAlexei Starovoitov
There were various issues related to the limited size of integers used in the verifier: - `off + size` overflow in __check_map_access() - `off + reg->off` overflow in check_mem_access() - `off + reg->var_off.value` overflow or 32-bit truncation of `reg->var_off.value` in check_mem_access() - 32-bit truncation in check_stack_boundary() Make sure that any integer math cannot overflow by not allowing pointer math with large values. Also reduce the scope of "scalar op scalar" tracking. Fixes: f1174f77b50c ("bpf/verifier: rework value tracking") Reported-by: Jann Horn <jannh@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2017-12-21bpf: don't prune branches when a scalar is replaced with a pointerJann Horn
This could be made safe by passing through a reference to env and checking for env->allow_ptr_leaks, but it would only work one way and is probably not worth the hassle - not doing it will not directly lead to program rejection. Fixes: f1174f77b50c ("bpf/verifier: rework value tracking") Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2017-12-21bpf: force strict alignment checks for stack pointersJann Horn
Force strict alignment checks for stack pointers because the tracking of stack spills relies on it; unaligned stack accesses can lead to corruption of spilled registers, which is exploitable. Fixes: f1174f77b50c ("bpf/verifier: rework value tracking") Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2017-12-21bpf: fix missing error return in check_stack_boundary()Jann Horn
Prevent indirect stack accesses at non-constant addresses, which would permit reading and corrupting spilled pointers. Fixes: f1174f77b50c ("bpf/verifier: rework value tracking") Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2017-12-21bpf: fix 32-bit ALU op verificationJann Horn
32-bit ALU ops operate on 32-bit values and have 32-bit outputs. Adjust the verifier accordingly. Fixes: f1174f77b50c ("bpf/verifier: rework value tracking") Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2017-12-21bpf: fix incorrect tracking of register size truncationJann Horn
Properly handle register truncation to a smaller size. The old code first mirrors the clearing of the high 32 bits in the bitwise tristate representation, which is correct. But then, it computes the new arithmetic bounds as the intersection between the old arithmetic bounds and the bounds resulting from the bitwise tristate representation. Therefore, when coerce_reg_to_32() is called on a number with bounds [0xffff'fff8, 0x1'0000'0007], the verifier computes [0xffff'fff8, 0xffff'ffff] as bounds of the truncated number. This is incorrect: The truncated number could also be in the range [0, 7], and no meaningful arithmetic bounds can be computed in that case apart from the obvious [0, 0xffff'ffff]. Starting with v4.14, this is exploitable by unprivileged users as long as the unprivileged_bpf_disabled sysctl isn't set. Debian assigned CVE-2017-16996 for this issue. v2: - flip the mask during arithmetic bounds calculation (Ben Hutchings) v3: - add CVE number (Ben Hutchings) Fixes: b03c9f9fdc37 ("bpf/verifier: track signed and unsigned min/max values") Signed-off-by: Jann Horn <jannh@google.com> Acked-by: Edward Cree <ecree@solarflare.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2017-12-21bpf: fix incorrect sign extension in check_alu_op()Jann Horn
Distinguish between BPF_ALU64|BPF_MOV|BPF_K (load 32-bit immediate, sign-extended to 64-bit) and BPF_ALU|BPF_MOV|BPF_K (load 32-bit immediate, zero-padded to 64-bit); only perform sign extension in the first case. Starting with v4.14, this is exploitable by unprivileged users as long as the unprivileged_bpf_disabled sysctl isn't set. Debian assigned CVE-2017-16995 for this issue. v3: - add CVE number (Ben Hutchings) Fixes: 484611357c19 ("bpf: allow access into map value arrays") Signed-off-by: Jann Horn <jannh@google.com> Acked-by: Edward Cree <ecree@solarflare.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2017-12-21bpf/verifier: fix bounds calculation on BPF_RSHEdward Cree
Incorrect signed bounds were being computed. If the old upper signed bound was positive and the old lower signed bound was negative, this could cause the new upper signed bound to be too low, leading to security issues. Fixes: b03c9f9fdc37 ("bpf/verifier: track signed and unsigned min/max values") Reported-by: Jann Horn <jannh@google.com> Signed-off-by: Edward Cree <ecree@solarflare.com> Acked-by: Alexei Starovoitov <ast@kernel.org> [jannh@google.com: changed description to reflect bug impact] Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2017-12-20cgroup: fix css_task_iter crash on CSS_TASK_ITER_PROCTejun Heo
While teaching css_task_iter to handle skipping over tasks which aren't group leaders, bc2fb7ed089f ("cgroup: add @flags to css_task_iter_start() and implement CSS_TASK_ITER_PROCS") introduced a silly bug. CSS_TASK_ITER_PROCS is implemented by repeating css_task_iter_advance() while the advanced cursor is pointing to a non-leader thread. However, the cursor variable, @l, wasn't updated when the iteration has to advance to the next css_set and the following repetition would operate on the terminal @l from the previous iteration which isn't pointing to a valid task leading to oopses like the following or infinite looping. BUG: unable to handle kernel NULL pointer dereference at 0000000000000254 IP: __task_pid_nr_ns+0xc7/0xf0 PGD 0 P4D 0 Oops: 0000 [#1] SMP ... CPU: 2 PID: 1 Comm: systemd Not tainted 4.14.4-200.fc26.x86_64 #1 Hardware name: System manufacturer System Product Name/PRIME B350M-A, BIOS 3203 11/09/2017 task: ffff88c4baee8000 task.stack: ffff96d5c3158000 RIP: 0010:__task_pid_nr_ns+0xc7/0xf0 RSP: 0018:ffff96d5c315bd50 EFLAGS: 00010206 RAX: 0000000000000000 RBX: ffff88c4b68c6000 RCX: 0000000000000250 RDX: ffffffffa5e47960 RSI: 0000000000000000 RDI: ffff88c490f6ab00 RBP: ffff96d5c315bd50 R08: 0000000000001000 R09: 0000000000000005 R10: ffff88c4be006b80 R11: ffff88c42f1b8004 R12: ffff96d5c315bf18 R13: ffff88c42d7dd200 R14: ffff88c490f6a510 R15: ffff88c4b68c6000 FS: 00007f9446f8ea00(0000) GS:ffff88c4be680000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000254 CR3: 00000007f956f000 CR4: 00000000003406e0 Call Trace: cgroup_procs_show+0x19/0x30 cgroup_seqfile_show+0x4c/0xb0 kernfs_seq_show+0x21/0x30 seq_read+0x2ec/0x3f0 kernfs_fop_read+0x134/0x180 __vfs_read+0x37/0x160 ? security_file_permission+0x9b/0xc0 vfs_read+0x8e/0x130 SyS_read+0x55/0xc0 entry_SYSCALL_64_fastpath+0x1a/0xa5 RIP: 0033:0x7f94455f942d RSP: 002b:00007ffe81ba2d00 EFLAGS: 00000293 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00005574e2233f00 RCX: 00007f94455f942d RDX: 0000000000001000 RSI: 00005574e2321a90 RDI: 000000000000002b RBP: 0000000000000000 R08: 00005574e2321a90 R09: 00005574e231de60 R10: 00007f94458c8b38 R11: 0000000000000293 R12: 00007f94458c8ae0 R13: 00007ffe81ba3800 R14: 0000000000000000 R15: 00005574e2116560 Code: 04 74 0e 89 f6 48 8d 04 76 48 8d 04 c5 f0 05 00 00 48 8b bf b8 05 00 00 48 01 c7 31 c0 48 8b 0f 48 85 c9 74 18 8b b2 30 08 00 00 <3b> 71 04 77 0d 48 c1 e6 05 48 01 f1 48 3b 51 38 74 09 5d c3 8b RIP: __task_pid_nr_ns+0xc7/0xf0 RSP: ffff96d5c315bd50 Fix it by moving the initialization of the cursor below the repeat label. While at it, rename it to @next for readability. Signed-off-by: Tejun Heo <tj@kernel.org> Fixes: bc2fb7ed089f ("cgroup: add @flags to css_task_iter_start() and implement CSS_TASK_ITER_PROCS") Cc: stable@vger.kernel.org # v4.14+ Reported-by: Laura Abbott <labbott@redhat.com> Reported-by: Bronek Kozicki <brok@incorrekt.com> Reported-by: George Amanakis <gamanakis@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2017-12-19cgroup: Fix deadlock in cpu hotplug pathPrateek Sood
Deadlock during cgroup migration from cpu hotplug path when a task T is being moved from source to destination cgroup. kworker/0:0 cpuset_hotplug_workfn() cpuset_hotplug_update_tasks() hotplug_update_tasks_legacy() remove_tasks_in_empty_cpuset() cgroup_transfer_tasks() // stuck in iterator loop cgroup_migrate() cgroup_migrate_add_task() In cgroup_migrate_add_task() it checks for PF_EXITING flag of task T. Task T will not migrate to destination cgroup. css_task_iter_start() will keep pointing to task T in loop waiting for task T cg_list node to be removed. Task T do_exit() exit_signals() // sets PF_EXITING exit_task_namespaces() switch_task_namespaces() free_nsproxy() put_mnt_ns() drop_collected_mounts() namespace_unlock() synchronize_rcu() _synchronize_rcu_expedited() schedule_work() // on cpu0 low priority worker pool wait_event() // waiting for work item to execute Task T inserted a work item in the worklist of cpu0 low priority worker pool. It is waiting for expedited grace period work item to execute. This work item will only be executed once kworker/0:0 complete execution of cpuset_hotplug_workfn(). kworker/0:0 ==> Task T ==>kworker/0:0 In case of PF_EXITING task being migrated from source to destination cgroup, migrate next available task in source cgroup. Signed-off-by: Prateek Sood <prsood@codeaurora.org> Signed-off-by: Tejun Heo <tj@kernel.org>
2017-12-18Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpfDavid S. Miller
Daniel Borkmann says: ==================== pull-request: bpf 2017-12-17 The following pull-request contains BPF updates for your *net* tree. The main changes are: 1) Fix a corner case in generic XDP where we have non-linear skbs but enough tailroom in the skb to not miss to linearizing there, from Song. 2) Fix BPF JIT bugs in s390x and ppc64 to not recache skb data when BPF context is not skb, from Daniel. 3) Fix a BPF JIT bug in sparc64 where recaching skb data after helper call would use the wrong register for the skb, from Daniel. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-18sched/isolation: Make CONFIG_NO_HZ_FULL select CONFIG_CPU_ISOLATIONPaul E. McKenney
CONFIG_NO_HZ_FULL doesn't make sense without CONFIG_CPU_ISOLATION. In fact enabling the first without the second is a regression as nohz_full= boot parameter gets silently ignored. Besides this unnatural combination hangs RCU gp kthread when running rcutorture for reasons that are not yet fully understood: rcu_preempt kthread starved for 9974 jiffies! g4294967208 +c4294967207 f0x0 RCU_GP_WAIT_FQS(3) ->state=0x402 ->cpu=0 rcu_preempt I 7464 8 2 0x80000000 Call Trace: __schedule+0x493/0x620 schedule+0x24/0x40 schedule_timeout+0x330/0x3b0 ? preempt_count_sub+0xea/0x140 ? collect_expired_timers+0xb0/0xb0 rcu_gp_kthread+0x6bf/0xef0 This commit therefore makes NO_HZ_FULL select CPU_ISOLATION, which prevents all these bad behaviours. Reported-by: kernel test robot <xiaolong.ye@intel.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Christoph Lameter <cl@linux.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luiz Capitulino <lcapitulino@redhat.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wanpeng Li <kernellwp@gmail.com> Fixes: 5c4991e24c69 ("sched/isolation: Split out new CONFIG_CPU_ISOLATION=y config from CONFIG_NO_HZ_FULL") Link: http://lkml.kernel.org/r/1513275507-29200-2-git-send-email-frederic@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-17Merge branch 'timers-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer fix from Thomas Gleixner: "A single bugfix which prevents arbitrary sigev_notify values in posix-timers" * 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: posix-timer: Properly check sigevent->sigev_notify
2017-12-17locking/barriers: Convert users of lockless_dereference() to READ_ONCE()Will Deacon
[ Note, this is a Git cherry-pick of the following commit: 506458efaf15 ("locking/barriers: Convert users of lockless_dereference() to READ_ONCE()") ... for easier x86 PTI code testing and back-porting. ] READ_ONCE() now has an implicit smp_read_barrier_depends() call, so it can be used instead of lockless_dereference() without any change in semantics. Signed-off-by: Will Deacon <will.deacon@arm.com> 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> Link: http://lkml.kernel.org/r/1508840570-22169-4-git-send-email-will.deacon@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-15Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds
Pull networking fixes from David Miller: 1) Clamp timeouts to INT_MAX in conntrack, from Jay Elliot. 2) Fix broken UAPI for BPF_PROG_TYPE_PERF_EVENT, from Hendrik Brueckner. 3) Fix locking in ieee80211_sta_tear_down_BA_sessions, from Johannes Berg. 4) Add missing barriers to ptr_ring, from Michael S. Tsirkin. 5) Don't advertise gigabit in sh_eth when not available, from Thomas Petazzoni. 6) Check network namespace when delivering to netlink taps, from Kevin Cernekee. 7) Kill a race in raw_sendmsg(), from Mohamed Ghannam. 8) Use correct address in TCP md5 lookups when replying to an incoming segment, from Christoph Paasch. 9) Add schedule points to BPF map alloc/free, from Eric Dumazet. 10) Don't allow silly mtu values to be used in ipv4/ipv6 multicast, also from Eric Dumazet. 11) Fix SKB leak in tipc, from Jon Maloy. 12) Disable MAC learning on OVS ports of mlxsw, from Yuval Mintz. 13) SKB leak fix in skB_complete_tx_timestamp(), from Willem de Bruijn. 14) Add some new qmi_wwan device IDs, from Daniele Palmas. 15) Fix static key imbalance in ingress qdisc, from Jiri Pirko. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (76 commits) net: qcom/emac: Reduce timeout for mdio read/write net: sched: fix static key imbalance in case of ingress/clsact_init error net: sched: fix clsact init error path ip_gre: fix wrong return value of erspan_rcv net: usb: qmi_wwan: add Telit ME910 PID 0x1101 support pkt_sched: Remove TC_RED_OFFLOADED from uapi net: sched: Move to new offload indication in RED net: sched: Add TCA_HW_OFFLOAD net: aquantia: Increment driver version net: aquantia: Fix typo in ethtool statistics names net: aquantia: Update hw counters on hw init net: aquantia: Improve link state and statistics check interval callback net: aquantia: Fill in multicast counter in ndev stats from hardware net: aquantia: Fill ndev stat couters from hardware net: aquantia: Extend stat counters to 64bit values net: aquantia: Fix hardware DMA stream overload on large MRRS net: aquantia: Fix actual speed capabilities reporting sock: free skb in skb_complete_tx_timestamp on error s390/qeth: update takeover IPs after configuration change s390/qeth: lock IP table while applying takeover changes ...
2017-12-15Merge branch 'locking-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking fixes from Ingo Molnar: "Misc fixes: - Fix a S390 boot hang that was caused by the lock-break logic. Remove lock-break to begin with, as review suggested it was unreasonably fragile and our confidence in its continued good health is lower than our confidence in its removal. - Remove the lockdep cross-release checking code for now, because of unresolved false positive warnings. This should make lockdep work well everywhere again. - Get rid of the final (and single) ACCESS_ONCE() straggler and remove the API from v4.15. - Fix a liblockdep build warning" * 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: tools/lib/lockdep: Add missing declaration of 'pr_cont()' checkpatch: Remove ACCESS_ONCE() warning compiler.h: Remove ACCESS_ONCE() tools/include: Remove ACCESS_ONCE() tools/perf: Convert ACCESS_ONCE() to READ_ONCE() locking/lockdep: Remove the cross-release locking checks locking/core: Remove break_lock field when CONFIG_GENERIC_LOCKBREAK=y locking/core: Fix deadlock during boot on systems with GENERIC_LOCKBREAK
2017-12-15Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fixes from Ingo Molnar: "Two fixes: a crash fix for an ARM SoC platform, and kernel-doc warnings fixes" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/rt: Do not pull from current CPU if only one CPU to pull sched/core: Fix kernel-doc warnings after code movement
2017-12-15bpf: guarantee r1 to be ctx in case of bpf_helper_changes_pkt_dataDaniel Borkmann
Some JITs don't cache skb context on stack in prologue, so when LD_ABS/IND is used and helper calls yield bpf_helper_changes_pkt_data() as true, then they temporarily save/restore skb pointer. However, the assumption that skb always has to be in r1 is a bit of a gamble. Right now it turned out to be true for all helpers listed in bpf_helper_changes_pkt_data(), but lets enforce that from verifier side, so that we make this a guarantee and bail out if the func proto is misconfigured in future helpers. In case of BPF helper calls from cBPF, bpf_helper_changes_pkt_data() is completely unrelevant here (since cBPF is context read-only) and therefore always false. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2017-12-15sched/rt: Do not pull from current CPU if only one CPU to pullSteven Rostedt
Daniel Wagner reported a crash on the BeagleBone Black SoC. This is a single CPU architecture, and does not have a functional arch_send_call_function_single_ipi() implementation which can crash the kernel if that is called. As it only has one CPU, it shouldn't be called, but if the kernel is compiled for SMP, the push/pull RT scheduling logic now calls it for irq_work if the one CPU is overloaded, it can use that function to call itself and crash the kernel. Ideally, we should disable the SCHED_FEAT(RT_PUSH_IPI) if the system only has a single CPU. But SCHED_FEAT is a constant if sched debugging is turned off. Another fix can also be used, and this should also help with normal SMP machines. That is, do not initiate the pull code if there's only one RT overloaded CPU, and that CPU happens to be the current CPU that is scheduling in a lower priority task. Even on a system with many CPUs, if there's many RT tasks waiting to run on a single CPU, and that CPU schedules in another RT task of lower priority, it will initiate the PULL logic in case there's a higher priority RT task on another CPU that is waiting to run. But if there is no other CPU with waiting RT tasks, it will initiate the RT pull logic on itself (as it still has RT tasks waiting to run). This is a wasted effort. Not only does this help with SMP code where the current CPU is the only one with RT overloaded tasks, it should also solve the issue that Daniel encountered, because it will prevent the PULL logic from executing, as there's only one CPU on the system, and the check added here will cause it to exit the RT pull code. Reported-by: Daniel Wagner <wagi@monom.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-rt-users <linux-rt-users@vger.kernel.org> Cc: stable@vger.kernel.org Fixes: 4bdced5c9 ("sched/rt: Simplify the IPI based RT balancing logic") Link: http://lkml.kernel.org/r/20171202130454.4cbbfe8d@vmware.local.home Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-15cgroup: use strlcpy() instead of strscpy() to avoid spurious warningArnd Bergmann
As long as cft->name is guaranteed to be NUL-terminated, using strlcpy() would work just as well and avoid that warning, so the change below could be folded into that commit. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Tejun Heo <tj@kernel.org>
2017-12-15posix-timer: Properly check sigevent->sigev_notifyThomas Gleixner
timer_create() specifies via sigevent->sigev_notify the signal delivery for the new timer. The valid modes are SIGEV_NONE, SIGEV_SIGNAL, SIGEV_THREAD and (SIGEV_SIGNAL | SIGEV_THREAD_ID). The sanity check in good_sigevent() is only checking the valid combination for the SIGEV_THREAD_ID bit, i.e. SIGEV_SIGNAL, but if SIGEV_THREAD_ID is not set it accepts any random value. This has no real effects on the posix timer and signal delivery code, but it affects show_timer() which handles the output of /proc/$PID/timers. That function uses a string array to pretty print sigev_notify. The access to that array has no bound checks, so random sigev_notify cause access beyond the array bounds. Add proper checks for the valid notify modes and remove the SIGEV_THREAD_ID masking from various code pathes as SIGEV_NONE can never be set in combination with SIGEV_THREAD_ID. Reported-by: Eric Biggers <ebiggers3@gmail.com> Reported-by: Dmitry Vyukov <dvyukov@google.com> Reported-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: John Stultz <john.stultz@linaro.org> Cc: stable@vger.kernel.org
2017-12-14Merge tag 'trace-v4.15-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing fixes from Steven Rostedt: "Various fix-ups: - comment fixes - build fix - better memory alloction (don't use NR_CPUS) - configuration fix - build warning fix - enhanced callback parameter (to simplify users of trace hooks) - give up on stack tracing when RCU isn't watching (it's a lost cause)" * tag 'trace-v4.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing: Have stack trace not record if RCU is not watching tracing: Pass export pointer as argument to ->write() ring-buffer: Remove unused function __rb_data_page_index() tracing: make PREEMPTIRQ_EVENTS depend on TRACING tracing: Allocate mask_str buffer dynamically tracing: always define trace_{irq,preempt}_{enable_disable} tracing: Fix code comments in trace.c
2017-12-14tracing: Have stack trace not record if RCU is not watchingSteven Rostedt (VMware)
The stack tracer records a stack dump whenever it sees a stack usage that is more than what it ever saw before. This can happen at any function that is being traced. If it happens when the CPU is going idle (or other strange locations), RCU may not be watching, and in this case, the recording of the stack trace will trigger a warning. There's been lots of efforts to make hacks to allow stack tracing to proceed even if RCU is not watching, but this only causes more issues to appear. Simply do not trace a stack if RCU is not watching. It probably isn't a bad stack anyway. Acked-by: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-12-14arch: define weak abort()Sudip Mukherjee
gcc toggle -fisolate-erroneous-paths-dereference (default at -O2 onwards) isolates faulty code paths such as null pointer access, divide by zero etc. If gcc port doesnt implement __builtin_trap, an abort() is generated which causes kernel link error. In this case, gcc is generating abort due to 'divide by zero' in lib/mpi/mpih-div.c. Currently 'frv' and 'arc' are failing. Previously other arch was also broken like m32r was fixed by commit d22e3d69ee1a ("m32r: fix build failure"). Let's define this weak function which is common for all arch and fix the problem permanently. We can even remove the arch specific 'abort' after this is done. Link: http://lkml.kernel.org/r/1513118956-8718-1-git-send-email-sudipm.mukherjee@gmail.com Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com> Cc: Alexey Brodkin <Alexey.Brodkin@synopsys.com> Cc: Vineet Gupta <Vineet.Gupta1@synopsys.com> Cc: Sudip Mukherjee <sudipm.mukherjee@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-12-14kernel: make groups_sort calling a responsibility group_info allocatorsThiago Rafael Becker
In testing, we found that nfsd threads may call set_groups in parallel for the same entry cached in auth.unix.gid, racing in the call of groups_sort, corrupting the groups for that entry and leading to permission denials for the client. This patch: - Make groups_sort globally visible. - Move the call to groups_sort to the modifiers of group_info - Remove the call to groups_sort from set_groups Link: http://lkml.kernel.org/r/20171211151420.18655-1-thiago.becker@gmail.com Signed-off-by: Thiago Rafael Becker <thiago.becker@gmail.com> Reviewed-by: Matthew Wilcox <mawilcox@microsoft.com> Reviewed-by: NeilBrown <neilb@suse.com> Acked-by: "J. Bruce Fields" <bfields@fieldses.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-12-14kcov: fix comparison callback signatureDmitry Vyukov
Fix a silly copy-paste bug. We truncated u32 args to u16. Link: http://lkml.kernel.org/r/20171207101134.107168-1-dvyukov@google.com Fixes: ded97d2c2b2c ("kcov: support comparison operands collection") Signed-off-by: Dmitry Vyukov <dvyukov@google.com> Cc: syzkaller@googlegroups.com Cc: Alexander Potapenko <glider@google.com> Cc: Vegard Nossum <vegard.nossum@oracle.com> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-12-12bpf: add schedule points to map alloc/freeEric Dumazet
While using large percpu maps, htab_map_alloc() can hold cpu for hundreds of ms. This patch adds cond_resched() calls to percpu alloc/free call sites, all running in process context. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2017-12-12bpf: fix corruption on concurrent perf_event_output callsDaniel Borkmann
When tracing and networking programs are both attached in the system and both use event-output helpers that eventually call into perf_event_output(), then we could end up in a situation where the tracing attached program runs in user context while a cls_bpf program is triggered on that same CPU out of softirq context. Since both rely on the same per-cpu perf_sample_data, we could potentially corrupt it. This can only ever happen in a combination of the two types; all tracing programs use a bpf_prog_active counter to bail out in case a program is already running on that CPU out of a different context. XDP and cls_bpf programs by themselves don't have this issue as they run in the same context only. Therefore, split both perf_sample_data so they cannot be accessed from each other. Fixes: 20b9d7ac4852 ("bpf: avoid excessive stack usage for perf_sample_data") Reported-by: Alexei Starovoitov <ast@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Tested-by: Song Liu <songliubraving@fb.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2017-12-12cgroup: avoid copying strings longer than the buffersMa Shimiao
cgroup root name and file name have max length limit, we should avoid copying longer name than that to the name. tj: minor update to $SUBJ. Signed-off-by: Ma Shimiao <mashimiao.fnst@cn.fujitsu.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2017-12-12locking/lockdep: Remove the cross-release locking checksIngo Molnar
This code (CONFIG_LOCKDEP_CROSSRELEASE=y and CONFIG_LOCKDEP_COMPLETIONS=y), while it found a number of old bugs initially, was also causing too many false positives that caused people to disable lockdep - which is arguably a worse overall outcome. If we disable cross-release by default but keep the code upstream then in practice the most likely outcome is that we'll allow the situation to degrade gradually, by allowing entropy to introduce more and more false positives, until it overwhelms maintenance capacity. Another bad side effect was that people were trying to work around the false positives by uglifying/complicating unrelated code. There's a marked difference between annotating locking operations and uglifying good code just due to bad lock debugging code ... This gradual decrease in quality happened to a number of debugging facilities in the kernel, and lockdep is pretty complex already, so we cannot risk this outcome. Either cross-release checking can be done right with no false positives, or it should not be included in the upstream kernel. ( Note that it might make sense to maintain it out of tree and go through the false positives every now and then and see whether new bugs were introduced. ) Cc: Byungchul Park <byungchul.park@lge.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-12locking/core: Remove break_lock field when CONFIG_GENERIC_LOCKBREAK=yWill Deacon
When CONFIG_GENERIC_LOCKBEAK=y, locking structures grow an extra int ->break_lock field which is used to implement raw_spin_is_contended() by setting the field to 1 when waiting on a lock and clearing it to zero when holding a lock. However, there are a few problems with this approach: - There is a write-write race between a CPU successfully taking the lock (and subsequently writing break_lock = 0) and a waiter waiting on the lock (and subsequently writing break_lock = 1). This could result in a contended lock being reported as uncontended and vice-versa. - On machines with store buffers, nothing guarantees that the writes to break_lock are visible to other CPUs at any particular time. - READ_ONCE/WRITE_ONCE are not used, so the field is potentially susceptible to harmful compiler optimisations, Consequently, the usefulness of this field is unclear and we'd be better off removing it and allowing architectures to implement raw_spin_is_contended() by providing a definition of arch_spin_is_contended(), as they can when CONFIG_GENERIC_LOCKBREAK=n. Signed-off-by: Will Deacon <will.deacon@arm.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Sebastian Ott <sebott@linux.vnet.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1511894539-7988-3-git-send-email-will.deacon@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-12locking/core: Fix deadlock during boot on systems with GENERIC_LOCKBREAKWill Deacon
Commit: a8a217c22116 ("locking/core: Remove {read,spin,write}_can_lock()") removed the definition of raw_spin_can_lock(), causing the GENERIC_LOCKBREAK spin_lock() routines to poll the ->break_lock field when waiting on a lock. This has been reported to cause a deadlock during boot on s390, because the ->break_lock field is also set by the waiters, and can potentially remain set indefinitely if no other CPUs come in to take the lock after it has been released. This patch removes the explicit spinning on ->break_lock from the waiters, instead relying on the outer trylock() operation to determine when the lock is available. Reported-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Tested-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: a8a217c22116 ("locking/core: Remove {read,spin,write}_can_lock()") Link: http://lkml.kernel.org/r/1511894539-7988-2-git-send-email-will.deacon@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-11Merge branch 'for-4.15-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup fixes from Tejun Heo: - Prateek posted a couple patches to fix a deadlock involving cpuset and workqueue. It unfortunately caused a different deadlock and the recent workqueue hotplug simplification removed the original deadlock, so Prateek's two patches are reverted for now. - The new stat code was missing u64_stats initialization. Fixed. - Doc and other misc changes * 'for-4.15-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cgroup: add warning about RT not being supported on cgroup2 Revert "cgroup/cpuset: remove circular dependency deadlock" Revert "cpuset: Make cpuset hotplug synchronous" cgroup: properly init u64_stats debug cgroup: use task_css_set instead of rcu_dereference cpuset: Make cpuset hotplug synchronous cgroup/cpuset: remove circular dependency deadlock
2017-12-11Merge branch 'for-4.15-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq Pull workqueue fixes from Tejun Heo: - Lai's hotplug simplifications inadvertently fix a possible deadlock involving cpuset and workqueue - CPU isolation fix which was reverted due to the changes in the housekeeping code resurrected - A trivial unused include removal * 'for-4.15-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: workqueue: remove unneeded kallsyms include workqueue/hotplug: remove the workaround in rebind_workers() workqueue/hotplug: simplify workqueue_offline_cpu() workqueue: respect isolated cpus when queueing an unbound work main: kernel_start: move housekeeping_init() before workqueue_init_early()
2017-12-11workqueue: remove unneeded kallsyms includeSergey Senozhatsky
The filw was converted from print_symbol() to %pf some time ago (044c782ce3a901fb "workqueue: fix checkpatch issues"). kallsyms does not seem to be needed anymore. Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Tejun Heo <tj@kernel.org> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2017-12-11sched/core: Fix kernel-doc warnings after code movementRandy Dunlap
Fix the following kernel-doc warnings after code restructuring: ../kernel/sched/core.c:5113: warning: No description found for parameter 't' ../kernel/sched/core.c:5113: warning: Excess function parameter 'interval' description in 'sched_rr_get_interval' get rid of set_fs()") Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: abca5fc535a3e ("sched_rr_get_interval(): move compat to native, Link: http://lkml.kernel.org/r/995c6ded-b32e-bbe4-d9f5-4d42d121aff1@infradead.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-12-10futex: futex_wake_op, fix sign_extend32 sign bitsJiri Slaby
sign_extend32 counts the sign bit parameter from 0, not from 1. So we have to use "11" for 12th bit, not "12". This mistake means we have not allowed negative op and cmp args since commit 30d6e0a4190d ("futex: Remove duplicated code and fix undefined behaviour") till now. Fixes: 30d6e0a4190d ("futex: Remove duplicated code and fix undefined behaviour") Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Darren Hart <dvhart@infradead.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-12-08Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds
Pull networking fixes from David Miller: 1) CAN fixes from Martin Kelly (cancel URBs properly in all the CAN usb drivers). 2) Revert returning -EEXIST from __dev_alloc_name() as this propagates to userspace and broke some apps. From Johannes Berg. 3) Fix conn memory leaks and crashes in TIPC, from Jon Malloc and Cong Wang. 4) Gianfar MAC can't do EEE so don't advertise it by default, from Claudiu Manoil. 5) Relax strict netlink attribute validation, but emit a warning. From David Ahern. 6) Fix regression in checksum offload of thunderx driver, from Florian Westphal. 7) Fix UAPI bpf issues on s390, from Hendrik Brueckner. 8) New card support in iwlwifi, from Ihab Zhaika. 9) BBR congestion control bug fixes from Neal Cardwell. 10) Fix port stats in nfp driver, from Pieter Jansen van Vuuren. 11) Fix leaks in qualcomm rmnet, from Subash Abhinov Kasiviswanathan. 12) Fix DMA API handling in sh_eth driver, from Thomas Petazzoni. 13) Fix spurious netpoll warnings in bnxt_en, from Calvin Owens. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (67 commits) net: mvpp2: fix the RSS table entry offset tcp: evaluate packet losses upon RTT change tcp: fix off-by-one bug in RACK tcp: always evaluate losses in RACK upon undo tcp: correctly test congestion state in RACK bnxt_en: Fix sources of spurious netpoll warnings tcp_bbr: reset long-term bandwidth sampling on loss recovery undo tcp_bbr: reset full pipe detection on loss recovery undo tcp_bbr: record "full bw reached" decision in new full_bw_reached bit sfc: pass valid pointers from efx_enqueue_unwind gianfar: Disable EEE autoneg by default tcp: invalidate rate samples during SACK reneging can: peak/pcie_fd: fix potential bug in restarting tx queue can: usb_8dev: cancel urb on -EPIPE and -EPROTO can: kvaser_usb: cancel urb on -EPIPE and -EPROTO can: esd_usb2: cancel urb on -EPIPE and -EPROTO can: ems_usb: cancel urb on -EPIPE and -EPROTO can: mcba_usb: cancel urb on -EPROTO usbnet: fix alignment for frames with no ethernet header tcp: use current time in tcp_rcv_space_adjust() ...
2017-12-06Merge tag 'for_linus-4.15-rc2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/kgdb Pull kgdb fixes from Jason Wessel: - Fix long standing problem with kdb kallsyms_symbol_next() return value - Add new co-maintainer Daniel Thompson * tag 'for_linus-4.15-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/kgdb: kgdb/kdb/debug_core: Add co-maintainer Daniel Thompson kdb: Fix handling of kallsyms_symbol_next() return value
2017-12-06Merge branch 'smp-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull CPU hotplug fix from Ingo Molnar: "A single fix moving the smp-call queue flush step to the intended point in the state machine" * 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: smp/hotplug: Move step CPUHP_AP_SMPCFD_DYING to the correct place
2017-12-06Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fixes from Ingo Molnar: "This includes a fix for the add_wait_queue() queue ordering brown paperbag bug, plus PELT accounting fixes for cgroups scheduling artifacts" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/fair: Update and fix the runnable propagation rule sched/wait: Fix add_wait_queue() behavioral change
2017-12-06Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Ingo Molnar: "This includes perf namespace support kernel side fixes, plus an accumulated set of perf tooling fixes - including UAPI header synchronization that should make the perf build less noisy" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (31 commits) tooling/headers: Synchronize updated s390 and x86 UAPI headers tools headers: Syncronize mman.h ABI header tools headers: Synchronize prctl.h ABI header tools headers: Synchronize KVM arch ABI headers tools headers: Synchronize drm/i915_drm.h tools headers uapi: Synchronize drm/drm.h tools headers: Synchronize perf_event.h header tools headers: Synchronize kernel ABI headers wrt SPDX tags tools/headers: Synchronize kernel x86 UAPI headers perf intel-pt: Bring instruction decoder files into line with the kernel perf test: Fix test 21 for s390x perf bench numa: Fixup discontiguous/sparse numa nodes perf top: Use signal interface for SIGWINCH handler perf top: Fix window dimensions change handling perf: Fix header.size for namespace events perf top: Ignore kptr_restrict when not sampling the kernel perf record: Ignore kptr_restrict when not sampling the kernel perf report: Ignore kptr_restrict when not sampling the kernel perf evlist: Add helper to check if attr.exclude_kernel is set in all evsels perf test shell: Fix test case probe libc's inet_pton on s390x ...
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