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2019-03-01bpf: fix sanitation rewrite in case of non-pointersDaniel Borkmann1-1/+2
Marek reported that he saw an issue with the below snippet in that timing measurements where off when loaded as unpriv while results were reasonable when loaded as privileged: [...] uint64_t a = bpf_ktime_get_ns(); uint64_t b = bpf_ktime_get_ns(); uint64_t delta = b - a; if ((int64_t)delta > 0) { [...] Turns out there is a bug where a corner case is missing in the fix d3bd7413e0ca ("bpf: fix sanitation of alu op with pointer / scalar type from different paths"), namely fixup_bpf_calls() only checks whether aux has a non-zero alu_state, but it also needs to test for the case of BPF_ALU_NON_POINTER since in both occasions we need to skip the masking rewrite (as there is nothing to mask). Fixes: d3bd7413e0ca ("bpf: fix sanitation of alu op with pointer / scalar type from different paths") Reported-by: Marek Majkowski <marek@cloudflare.com> Reported-by: Arthur Fabre <afabre@cloudflare.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/netdev/CAJPywTJqP34cK20iLM5YmUMz9KXQOdu1-+BZrGMAGgLuBWz7fg@mail.gmail.com/T/ Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-03-01bpf: drop refcount if bpf_map_new_fd() fails in map_create()Peng Sun1-2/+2
In bpf/syscall.c, map_create() first set map->usercnt to 1, a file descriptor is supposed to return to userspace. When bpf_map_new_fd() fails, drop the refcount. Fixes: bd5f5f4ecb78 ("bpf: Add BPF_MAP_GET_FD_BY_ID") Signed-off-by: Peng Sun <sironhide0null@gmail.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-02-26bpf: decrease usercnt if bpf_map_new_fd() fails in bpf_map_get_fd_by_id()Peng Sun1-1/+1
In bpf/syscall.c, bpf_map_get_fd_by_id() use bpf_map_inc_not_zero() to increase the refcount, both map->refcnt and map->usercnt. Then, if bpf_map_new_fd() fails, should handle map->usercnt too. Fixes: bd5f5f4ecb78 ("bpf: Add BPF_MAP_GET_FD_BY_ID") Signed-off-by: Peng Sun <sironhide0null@gmail.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-02-24Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds1-0/+1
Pull networking fixes from David Miller: "Hopefully the last pull request for this release. Fingers crossed: 1) Only refcount ESP stats on full sockets, from Martin Willi. 2) Missing barriers in AF_UNIX, from Al Viro. 3) RCU protection fixes in ipv6 route code, from Paolo Abeni. 4) Avoid false positives in untrusted GSO validation, from Willem de Bruijn. 5) Forwarded mesh packets in mac80211 need more tailroom allocated, from Felix Fietkau. 6) Use operstate consistently for linkup in team driver, from George Wilkie. 7) ThunderX bug fixes from Vadim Lomovtsev. Mostly races between VF and PF code paths. 8) Purge ipv6 exceptions during netdevice removal, from Paolo Abeni. 9) nfp eBPF code gen fixes from Jiong Wang. 10) bnxt_en firmware timeout fix from Michael Chan. 11) Use after free in udp/udpv6 error handlers, from Paolo Abeni. 12) Fix a race in x25_bind triggerable by syzbot, from Eric Dumazet" * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (65 commits) net: phy: realtek: Dummy IRQ calls for RTL8366RB tcp: repaired skbs must init their tso_segs net/x25: fix a race in x25_bind() net: dsa: Remove documentation for port_fdb_prepare Revert "bridge: do not add port to router list when receives query with source 0.0.0.0" selftests: fib_tests: sleep after changing carrier. again. net: set static variable an initial value in atl2_probe() net: phy: marvell10g: Fix Multi-G advertisement to only advertise 10G bpf, doc: add bpf list as secondary entry to maintainers file udp: fix possible user after free in error handler udpv6: fix possible user after free in error handler fou6: fix proto error handler argument type udpv6: add the required annotation to mib type mdio_bus: Fix use-after-free on device_register fails net: Set rtm_table to RT_TABLE_COMPAT for ipv6 for tables > 255 bnxt_en: Wait longer for the firmware message response to complete. bnxt_en: Fix typo in firmware message timeout logic. nfp: bpf: fix ALU32 high bits clearance bug nfp: bpf: fix code-gen bug on BPF_ALU | BPF_XOR | BPF_K Documentation: networking: switchdev: Update port parent ID section ...
2019-02-22Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpfDavid S. Miller1-0/+1
Daniel Borkmann says: ==================== pull-request: bpf 2019-02-23 The following pull-request contains BPF updates for your *net* tree. The main changes are: 1) Fix a bug in BPF's LPM deletion logic to match correct prefix length, from Alban. 2) Fix AF_XDP teardown by not destroying umem prematurely as it is still needed till all outstanding skbs are freed, from Björn. 3) Fix unkillable BPF_PROG_TEST_RUN under preempt kernel by checking signal_pending() outside need_resched() condition which is never triggered there, from Stanislav. 4) Fix two nfp JIT bugs, one in code emission for K-based xor, and another one to explicitly clear upper bits in alu32, from Jiong. 5) Add bpf list address to maintainers file, from Daniel. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2019-02-22bpf, lpm: fix lookup bug in map_delete_elemAlban Crequy1-0/+1
trie_delete_elem() was deleting an entry even though it was not matching if the prefixlen was correct. This patch adds a check on matchlen. Reproducer: $ sudo bpftool map create /sys/fs/bpf/mylpm type lpm_trie key 8 value 1 entries 128 name mylpm flags 1 $ sudo bpftool map update pinned /sys/fs/bpf/mylpm key hex 10 00 00 00 aa bb cc dd value hex 01 $ sudo bpftool map dump pinned /sys/fs/bpf/mylpm key: 10 00 00 00 aa bb cc dd value: 01 Found 1 element $ sudo bpftool map delete pinned /sys/fs/bpf/mylpm key hex 10 00 00 00 ff ff ff ff $ echo $? 0 $ sudo bpftool map dump pinned /sys/fs/bpf/mylpm Found 0 elements A similar reproducer is added in the selftests. Without the patch: $ sudo ./tools/testing/selftests/bpf/test_lpm_map test_lpm_map: test_lpm_map.c:485: test_lpm_delete: Assertion `bpf_map_delete_elem(map_fd, key) == -1 && errno == ENOENT' failed. Aborted With the patch: test_lpm_map runs without errors. Fixes: e454cf595853 ("bpf: Implement map_delete_elem for BPF_MAP_TYPE_LPM_TRIE") Cc: Craig Gallek <kraig@google.com> Signed-off-by: Alban Crequy <alban@kinvolk.io> Acked-by: Craig Gallek <kraig@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-02-21psi: avoid divide-by-zero crash inside virtual machinesJohannes Weiner1-1/+1
We've been seeing hard-to-trigger psi crashes when running inside VM instances: divide error: 0000 [#1] SMP PTI Modules linked in: [...] CPU: 0 PID: 212 Comm: kworker/0:2 Not tainted 4.16.18-119_fbk9_3817_gfe944c98d695 #119 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 0.0.0 02/06/2015 Workqueue: events psi_clock RIP: 0010:psi_update_stats+0x270/0x490 RSP: 0018:ffffc90001117e10 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff8800a35a13f8 RDX: 0000000000000000 RSI: ffff8800a35a1340 RDI: 0000000000000000 RBP: 0000000000000658 R08: ffff8800a35a1470 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 00000000000f8502 FS: 0000000000000000(0000) GS:ffff88023fc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fbe370fa000 CR3: 00000000b1e3a000 CR4: 00000000000006f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: psi_clock+0x12/0x50 process_one_work+0x1e0/0x390 worker_thread+0x2b/0x3c0 ? rescuer_thread+0x330/0x330 kthread+0x113/0x130 ? kthread_create_worker_on_cpu+0x40/0x40 ? SyS_exit_group+0x10/0x10 ret_from_fork+0x35/0x40 Code: 48 0f 47 c7 48 01 c2 45 85 e4 48 89 16 0f 85 e6 00 00 00 4c 8b 49 10 4c 8b 51 08 49 69 d9 f2 07 00 00 48 6b c0 64 4c 8b 29 31 d2 <48> f7 f7 49 69 d5 8d 06 00 00 48 89 c5 4c 69 f0 00 98 0b 00 48 The Code-line points to `period` being 0 inside update_stats(), and we divide by that when calculating that period's pressure percentage. The elapsed period should never be 0. The reason this can happen is due to an off-by-one in the idle time / missing period calculation combined with a coarse sched_clock() in the virtual machine. The target time for aggregation is advanced into the future on a fixed grid to prevent clock drift. So when an aggregation runs after some idle period, we can not just set it to "now + psi_period", but have to calculate the downtime and advance the target time relative to itself. However, if the aggregator was disabled exactly one psi_period (ns), we drop one idle period in the calculation due to a > when we should do >=. In that case, next_update will be advanced from 'now - psi_period' to 'now' when it should be moved to 'now + psi_period'. The run finishes with last_update == next_update == sched_clock(). With hardware clocks, this exact nanosecond match isn't likely in the first place; but if it does happen, the clock will still have moved on and the period non-zero by the time the worker runs. A pointlessly short period, but besides the extra work, no harm no foul. However, a slow sched_clock() like we have on VMs might not have advanced either by the time the worker runs again. And when we calculate the elapsed period, the result, our pressure divisor, will be 0. Ouch. Fix this by correctly handling the situation when the elapsed time between aggregation runs is precisely two periods, and advance the expiration timestamp correctly to period into the future. Link: http://lkml.kernel.org/r/20190214193157.15788-1-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reported-by: Łukasz Siudut <lsiudut@fb.com Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-02-19Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds2-5/+14
Pull networking fixes from David Miller: 1) Fix suspend and resume in mt76x0u USB driver, from Stanislaw Gruszka. 2) Missing memory barriers in xsk, from Magnus Karlsson. 3) rhashtable fixes in mac80211 from Herbert Xu. 4) 32-bit MIPS eBPF JIT fixes from Paul Burton. 5) Fix for_each_netdev_feature() on big endian, from Hauke Mehrtens. 6) GSO validation fixes from Willem de Bruijn. 7) Endianness fix for dwmac4 timestamp handling, from Alexandre Torgue. 8) More strict checks in tcp_v4_err(), from Eric Dumazet. 9) af_alg_release should NULL out the sk after the sock_put(), from Mao Wenan. 10) Missing unlock in mac80211 mesh error path, from Wei Yongjun. 11) Missing device put in hns driver, from Salil Mehta. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (44 commits) sky2: Increase D3 delay again vhost: correctly check the return value of translate_desc() in log_used() net: netcp: Fix ethss driver probe issue net: hns: Fixes the missing put_device in positive leg for roce reset net: stmmac: Fix a race in EEE enable callback qed: Fix iWARP syn packet mac address validation. qed: Fix iWARP buffer size provided for syn packet processing. r8152: Add support for MAC address pass through on RTL8153-BD mac80211: mesh: fix missing unlock on error in table_path_del() net/mlx4_en: fix spelling mistake: "quiting" -> "quitting" net: crypto set sk to NULL when af_alg_release. net: Do not allocate page fragments that are not skb aligned mm: Use fixed constant in page_frag_alloc instead of size + 1 tcp: tcp_v4_err() should be more careful tcp: clear icsk_backoff in tcp_write_queue_purge() net: mv643xx_eth: disable clk on error path in mv643xx_eth_shared_probe() qmi_wwan: apply SET_DTR quirk to Sierra WP7607 net: stmmac: handle endianness in dwmac4_get_timestamp doc: Mention MSG_ZEROCOPY implementation for UDP mlxsw: __mlxsw_sp_port_headroom_set(): Fix a use of local variable ...
2019-02-18Merge tag 'trace-v5.0-rc4-3' of ↵Linus Torvalds2-9/+3
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing fixes from Steven Rostedt: "Two more tracing fixes - Have kprobes not use copy_from_user() to access kernel addresses, because kprobes can legitimately poke at bad kernel memory, which will fault. Copy from user code should never fault in kernel space. Using probe_mem_read() can handle kernel address space faulting. - Put back the entries counter in the tracing output that was accidentally removed" * tag 'trace-v5.0-rc4-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing: Fix number of entries in trace header kprobe: Do not use uaccess functions to access kernel memory that can fault
2019-02-17Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds2-1/+17
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Ingo Molnar: "Two fixes on the kernel side: fix an over-eager condition that failed larger perf ring-buffer sizes, plus fix crashes in the Intel BTS code for a corner case, found by fuzzing" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/core: Fix impossible ring-buffer sizes warning perf/x86: Add check_period PMU callback
2019-02-16Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpfDavid S. Miller2-5/+14
Alexei Starovoitov says: ==================== pull-request: bpf 2019-02-16 The following pull-request contains BPF updates for your *net* tree. The main changes are: 1) fix lockdep false positive in bpf_get_stackid(), from Alexei. 2) several AF_XDP fixes, from Bjorn, Magnus, Davidlohr. 3) fix narrow load from struct bpf_sock, from Martin. 4) mips JIT fixes, from Paul. 5) gso handling fix in bpf helpers, from Willem. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2019-02-15tracing: Fix number of entries in trace headerQuentin Perret1-0/+2
The following commit 441dae8f2f29 ("tracing: Add support for display of tgid in trace output") removed the call to print_event_info() from print_func_help_header_irq() which results in the ftrace header not reporting the number of entries written in the buffer. As this wasn't the original intent of the patch, re-introduce the call to print_event_info() to restore the orginal behaviour. Link: http://lkml.kernel.org/r/20190214152950.4179-1-quentin.perret@arm.com Acked-by: Joel Fernandes <joelaf@google.com> Cc: stable@vger.kernel.org Fixes: 441dae8f2f29 ("tracing: Add support for display of tgid in trace output") Signed-off-by: Quentin Perret <quentin.perret@arm.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-15kprobe: Do not use uaccess functions to access kernel memory that can faultChangbin Du1-9/+1
The userspace can ask kprobe to intercept strings at any memory address, including invalid kernel address. In this case, fetch_store_strlen() would crash since it uses general usercopy function, and user access functions are no longer allowed to access kernel memory. For example, we can crash the kernel by doing something as below: $ sudo kprobe 'p:do_sys_open +0(+0(%si)):string' [ 103.620391] BUG: GPF in non-whitelisted uaccess (non-canonical address?) [ 103.622104] general protection fault: 0000 [#1] SMP PTI [ 103.623424] CPU: 10 PID: 1046 Comm: cat Not tainted 5.0.0-rc3-00130-gd73aba1-dirty #96 [ 103.625321] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.12.0-2-g628b2e6-dirty-20190104_103505-linux 04/01/2014 [ 103.628284] RIP: 0010:process_fetch_insn+0x1ab/0x4b0 [ 103.629518] Code: 10 83 80 28 2e 00 00 01 31 d2 31 ff 48 8b 74 24 28 eb 0c 81 fa ff 0f 00 00 7f 1c 85 c0 75 18 66 66 90 0f ae e8 48 63 ca 89 f8 <8a> 0c 31 66 66 90 83 c2 01 84 c9 75 dc 89 54 24 34 89 44 24 28 48 [ 103.634032] RSP: 0018:ffff88845eb37ce0 EFLAGS: 00010246 [ 103.635312] RAX: 0000000000000000 RBX: ffff888456c4e5a8 RCX: 0000000000000000 [ 103.637057] RDX: 0000000000000000 RSI: 2e646c2f6374652f RDI: 0000000000000000 [ 103.638795] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 [ 103.640556] R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000 [ 103.642297] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 103.644040] FS: 0000000000000000(0000) GS:ffff88846f000000(0000) knlGS:0000000000000000 [ 103.646019] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 103.647436] CR2: 00007ffc79758038 CR3: 0000000463360006 CR4: 0000000000020ee0 [ 103.649147] Call Trace: [ 103.649781] ? sched_clock_cpu+0xc/0xa0 [ 103.650747] ? do_sys_open+0x5/0x220 [ 103.651635] kprobe_trace_func+0x303/0x380 [ 103.652645] ? do_sys_open+0x5/0x220 [ 103.653528] kprobe_dispatcher+0x45/0x50 [ 103.654682] ? do_sys_open+0x1/0x220 [ 103.655875] kprobe_ftrace_handler+0x90/0xf0 [ 103.657282] ftrace_ops_assist_func+0x54/0xf0 [ 103.658564] ? __call_rcu+0x1dc/0x280 [ 103.659482] 0xffffffffc00000bf [ 103.660384] ? __ia32_sys_open+0x20/0x20 [ 103.661682] ? do_sys_open+0x1/0x220 [ 103.662863] do_sys_open+0x5/0x220 [ 103.663988] do_syscall_64+0x60/0x210 [ 103.665201] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 103.666862] RIP: 0033:0x7fc22fadccdd [ 103.668034] Code: 48 89 54 24 e0 41 83 e2 40 75 32 89 f0 25 00 00 41 00 3d 00 00 41 00 74 24 89 f2 b8 01 01 00 00 48 89 fe bf 9c ff ff ff 0f 05 <48> 3d 00 f0 ff ff 77 33 f3 c3 66 0f 1f 84 00 00 00 00 00 48 8d 44 [ 103.674029] RSP: 002b:00007ffc7972c3a8 EFLAGS: 00000287 ORIG_RAX: 0000000000000101 [ 103.676512] RAX: ffffffffffffffda RBX: 0000562f86147a21 RCX: 00007fc22fadccdd [ 103.678853] RDX: 0000000000080000 RSI: 00007fc22fae1428 RDI: 00000000ffffff9c [ 103.681151] RBP: ffffffffffffffff R08: 0000000000000000 R09: 0000000000000000 [ 103.683489] R10: 0000000000000000 R11: 0000000000000287 R12: 00007fc22fce90a8 [ 103.685774] R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000000 [ 103.688056] Modules linked in: [ 103.689131] ---[ end trace 43792035c28984a1 ]--- This can be fixed by using probe_mem_read() instead, as it can handle faulting kernel memory addresses, which kprobes can legitimately do. Link: http://lkml.kernel.org/r/20190125151051.7381-1-changbin.du@gmail.com Cc: stable@vger.kernel.org Fixes: 9da3f2b7405 ("x86/fault: BUG() when uaccess helpers fault on kernel addresses") Signed-off-by: Changbin Du <changbin.du@gmail.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-15Merge branch 'for-linus' of ↵Linus Torvalds1-2/+5
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull signal fix from Eric Biederman: "Just a single patch that restores PTRACE_EVENT_EXIT functionality that was accidentally broken by last weeks fixes" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: signal: Restore the stop PTRACE_EVENT_EXIT
2019-02-13Merge tag 'trace-v5.0-rc4' of ↵Linus Torvalds1-2/+4
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing fix from Steven Rostedt: "This fixes kprobes/uprobes dynamic processing of strings, where it processes the args but does not update the remaining length of the buffer that the string arguments will be placed in. It constantly passes in the total size of buffer used instead of passing in the remaining size of the buffer used. This could cause issues if the strings are larger than the max size of an event which could cause the strings to be written beyond what was reserved on the buffer" * tag 'trace-v5.0-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing: probeevent: Correctly update remaining space in dynamic area
2019-02-13signal: Restore the stop PTRACE_EVENT_EXITEric W. Biederman1-2/+5
In the middle of do_exit() there is there is a call "ptrace_event(PTRACE_EVENT_EXIT, code);" That call places the process in TACKED_TRACED aka "(TASK_WAKEKILL | __TASK_TRACED)" and waits for for the debugger to release the task or SIGKILL to be delivered. Skipping past dequeue_signal when we know a fatal signal has already been delivered resulted in SIGKILL remaining pending and TIF_SIGPENDING remaining set. This in turn caused the scheduler to not sleep in PTACE_EVENT_EXIT as it figured a fatal signal was pending. This also caused ptrace_freeze_traced in ptrace_check_attach to fail because it left a per thread SIGKILL pending which is what fatal_signal_pending tests for. This difference in signal state caused strace to report strace: Exit of unknown pid NNNNN ignored Therefore update the signal handling state like dequeue_signal would when removing a per thread SIGKILL, by removing SIGKILL from the per thread signal mask and clearing TIF_SIGPENDING. Acked-by: Oleg Nesterov <oleg@redhat.com> Reported-by: Oleg Nesterov <oleg@redhat.com> Reported-by: Ivan Delalande <colona@arista.com> Cc: stable@vger.kernel.org Fixes: 35634ffa1751 ("signal: Always notice exiting tasks") Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2019-02-13perf/core: Fix impossible ring-buffer sizes warningIngo Molnar1-1/+1
The following commit: 9dff0aa95a32 ("perf/core: Don't WARN() for impossible ring-buffer sizes") results in perf recording failures with larger mmap areas: root@skl:/tmp# perf record -g -a failed to mmap with 12 (Cannot allocate memory) The root cause is that the following condition is buggy: if (order_base_2(size) >= MAX_ORDER) goto fail; The problem is that @size is in bytes and MAX_ORDER is in pages, so the right test is: if (order_base_2(size) >= PAGE_SHIFT+MAX_ORDER) goto fail; Fix it. Reported-by: "Jin, Yao" <yao.jin@linux.intel.com> Bisected-by: Borislav Petkov <bp@alien8.de> Analyzed-by: Peter Zijlstra <peterz@infradead.org> Cc: Julien Thierry <julien.thierry@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: <stable@vger.kernel.org> Fixes: 9dff0aa95a32 ("perf/core: Don't WARN() for impossible ring-buffer sizes") Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-11tracing: probeevent: Correctly update remaining space in dynamic areaAndreas Ziegler1-2/+4
Commit 9178412ddf5a ("tracing: probeevent: Return consumed bytes of dynamic area") improved the string fetching mechanism by returning the number of required bytes after copying the argument to the dynamic area. However, this return value is now only used to increment the pointer inside the dynamic area but misses updating the 'maxlen' variable which indicates the remaining space in the dynamic area. This means that fetch_store_string() always reads the *total* size of the dynamic area from the data_loc pointer instead of the *remaining* size (and passes it along to strncpy_from_{user,unsafe}) even if we're already about to copy data into the middle of the dynamic area. Link: http://lkml.kernel.org/r/20190206190013.16405-1-andreas.ziegler@fau.de Cc: Ingo Molnar <mingo@redhat.com> Cc: stable@vger.kernel.org Fixes: 9178412ddf5a ("tracing: probeevent: Return consumed bytes of dynamic area") Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Andreas Ziegler <andreas.ziegler@fau.de> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-11bpf: fix lockdep false positive in stackmapAlexei Starovoitov1-1/+7
Lockdep warns about false positive: [ 11.211460] ------------[ cut here ]------------ [ 11.211936] DEBUG_LOCKS_WARN_ON(depth <= 0) [ 11.211985] WARNING: CPU: 0 PID: 141 at ../kernel/locking/lockdep.c:3592 lock_release+0x1ad/0x280 [ 11.213134] Modules linked in: [ 11.214954] RIP: 0010:lock_release+0x1ad/0x280 [ 11.223508] Call Trace: [ 11.223705] <IRQ> [ 11.223874] ? __local_bh_enable+0x7a/0x80 [ 11.224199] up_read+0x1c/0xa0 [ 11.224446] do_up_read+0x12/0x20 [ 11.224713] irq_work_run_list+0x43/0x70 [ 11.225030] irq_work_run+0x26/0x50 [ 11.225310] smp_irq_work_interrupt+0x57/0x1f0 [ 11.225662] irq_work_interrupt+0xf/0x20 since rw_semaphore is released in a different task vs task that locked the sema. It is expected behavior. Fix the warning with up_read_non_owner() and rwsem_release() annotation. Fixes: bae77c5eb5b2 ("bpf: enable stackmap with build_id in nmi context") Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-02-11perf/x86: Add check_period PMU callbackJiri Olsa1-0/+16
Vince (and later on Ravi) reported crashes in the BTS code during fuzzing with the following backtrace: general protection fault: 0000 [#1] SMP PTI ... RIP: 0010:perf_prepare_sample+0x8f/0x510 ... Call Trace: <IRQ> ? intel_pmu_drain_bts_buffer+0x194/0x230 intel_pmu_drain_bts_buffer+0x160/0x230 ? tick_nohz_irq_exit+0x31/0x40 ? smp_call_function_single_interrupt+0x48/0xe0 ? call_function_single_interrupt+0xf/0x20 ? call_function_single_interrupt+0xa/0x20 ? x86_schedule_events+0x1a0/0x2f0 ? x86_pmu_commit_txn+0xb4/0x100 ? find_busiest_group+0x47/0x5d0 ? perf_event_set_state.part.42+0x12/0x50 ? perf_mux_hrtimer_restart+0x40/0xb0 intel_pmu_disable_event+0xae/0x100 ? intel_pmu_disable_event+0xae/0x100 x86_pmu_stop+0x7a/0xb0 x86_pmu_del+0x57/0x120 event_sched_out.isra.101+0x83/0x180 group_sched_out.part.103+0x57/0xe0 ctx_sched_out+0x188/0x240 ctx_resched+0xa8/0xd0 __perf_event_enable+0x193/0x1e0 event_function+0x8e/0xc0 remote_function+0x41/0x50 flush_smp_call_function_queue+0x68/0x100 generic_smp_call_function_single_interrupt+0x13/0x30 smp_call_function_single_interrupt+0x3e/0xe0 call_function_single_interrupt+0xf/0x20 </IRQ> The reason is that while event init code does several checks for BTS events and prevents several unwanted config bits for BTS event (like precise_ip), the PERF_EVENT_IOC_PERIOD allows to create BTS event without those checks being done. Following sequence will cause the crash: If we create an 'almost' BTS event with precise_ip and callchains, and it into a BTS event it will crash the perf_prepare_sample() function because precise_ip events are expected to come in with callchain data initialized, but that's not the case for intel_pmu_drain_bts_buffer() caller. Adding a check_period callback to be called before the period is changed via PERF_EVENT_IOC_PERIOD. It will deny the change if the event would become BTS. Plus adding also the limit_period check as well. Reported-by: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: <stable@vger.kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20190204123532.GA4794@krava Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-10Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds1-0/+3
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Ingo Molnar: "A couple of kernel side fixes: - Fix the Intel uncore driver on certain hardware configurations - Fix a CPU hotplug related memory allocation bug - Remove a spurious WARN() ... plus also a handful of perf tooling fixes" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf script python: Add Python3 support to tests/attr.py perf trace: Support multiple "vfs_getname" probes perf symbols: Filter out hidden symbols from labels perf symbols: Add fallback definitions for GELF_ST_VISIBILITY() tools headers uapi: Sync linux/in.h copy from the kernel sources perf clang: Do not use 'return std::move(something)' perf mem/c2c: Fix perf_mem_events to support powerpc perf tests evsel-tp-sched: Fix bitwise operator perf/core: Don't WARN() for impossible ring-buffer sizes perf/x86/intel: Delay memory deallocation until x86_pmu_dead_cpu() perf/x86/intel/uncore: Add Node ID mask
2019-02-10Merge branch 'locking-urgent-for-linus' of ↵Linus Torvalds2-17/+52
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking fixes from Ingo Molnar: "An rtmutex (PI-futex) deadlock scenario fix, plus a locking documentation fix" * 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: futex: Handle early deadlock return correctly futex: Fix barrier comment
2019-02-09bpf: Fix narrow load on a bpf_sock returned from sk_lookup()Martin KaFai Lau1-4/+7
By adding this test to test_verifier: { "reference tracking: access sk->src_ip4 (narrow load)", .insns = { BPF_SK_LOOKUP, BPF_MOV64_REG(BPF_REG_6, BPF_REG_0), BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 3), BPF_LDX_MEM(BPF_H, BPF_REG_2, BPF_REG_0, offsetof(struct bpf_sock, src_ip4) + 2), BPF_MOV64_REG(BPF_REG_1, BPF_REG_6), BPF_EMIT_CALL(BPF_FUNC_sk_release), BPF_EXIT_INSN(), }, .prog_type = BPF_PROG_TYPE_SCHED_CLS, .result = ACCEPT, }, The above test loads 2 bytes from sk->src_ip4 where sk is obtained by bpf_sk_lookup_tcp(). It hits an internal verifier error from convert_ctx_accesses(): [root@arch-fb-vm1 bpf]# ./test_verifier 665 665 Failed to load prog 'Invalid argument'! 0: (b7) r2 = 0 1: (63) *(u32 *)(r10 -8) = r2 2: (7b) *(u64 *)(r10 -16) = r2 3: (7b) *(u64 *)(r10 -24) = r2 4: (7b) *(u64 *)(r10 -32) = r2 5: (7b) *(u64 *)(r10 -40) = r2 6: (7b) *(u64 *)(r10 -48) = r2 7: (bf) r2 = r10 8: (07) r2 += -48 9: (b7) r3 = 36 10: (b7) r4 = 0 11: (b7) r5 = 0 12: (85) call bpf_sk_lookup_tcp#84 13: (bf) r6 = r0 14: (15) if r0 == 0x0 goto pc+3 R0=sock(id=1,off=0,imm=0) R6=sock(id=1,off=0,imm=0) R10=fp0,call_-1 fp-8=????0000 fp-16=0000mmmm fp-24=mmmmmmmm fp-32=mmmmmmmm fp-40=mmmmmmmm fp-48=mmmmmmmm refs=1 15: (69) r2 = *(u16 *)(r0 +26) 16: (bf) r1 = r6 17: (85) call bpf_sk_release#86 18: (95) exit from 14 to 18: safe processed 20 insns (limit 131072), stack depth 48 bpf verifier is misconfigured Summary: 0 PASSED, 0 SKIPPED, 1 FAILED The bpf_sock_is_valid_access() is expecting src_ip4 can be narrowly loaded (meaning load any 1 or 2 bytes of the src_ip4) by marking info->ctx_field_size. However, this marked ctx_field_size is not used. This patch fixes it. Due to the recent refactoring in test_verifier, this new test will be added to the bpf-next branch (together with the bpf_tcp_sock patchset) to avoid merge conflict. Fixes: c64b7983288e ("bpf: Add PTR_TO_SOCKET verifier type") Cc: Joe Stringer <joe@wand.net.nz> Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Joe Stringer <joe@wand.net.nz> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-02-08Merge branch 'for-linus' of ↵Linus Torvalds1-4/+59
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull signal fixes from Eric Biederman: "This contains four small fixes for signal handling. A missing range check, a regression fix, prioritizing signals we have already started a signal group exit for, and better detection of synchronous signals. The confused decision of which signals to handle failed spectacularly when a timer was pointed at SIGBUS and the stack overflowed. Resulting in an unkillable process in an infinite loop instead of a SIGSEGV and core dump" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: signal: Better detection of synchronous signals signal: Always notice exiting tasks signal: Always attempt to allocate siginfo for SIGSTOP signal: Make siginmask safe when passed a signal of 0
2019-02-08Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds7-30/+50
Pull networking fixes from David Miller: "This pull request is dedicated to the upcoming snowpocalypse parts 2 and 3 in the Pacific Northwest: 1) Drop profiles are broken because some drivers use dev_kfree_skb* instead of dev_consume_skb*, from Yang Wei. 2) Fix IWLWIFI kconfig deps, from Luca Coelho. 3) Fix percpu maps updating in bpftool, from Paolo Abeni. 4) Missing station release in batman-adv, from Felix Fietkau. 5) Fix some networking compat ioctl bugs, from Johannes Berg. 6) ucc_geth must reset the BQL queue state when stopping the device, from Mathias Thore. 7) Several XDP bug fixes in virtio_net from Toshiaki Makita. 8) TSO packets must be sent always on queue 0 in stmmac, from Jose Abreu. 9) Fix socket refcounting bug in RDS, from Eric Dumazet. 10) Handle sparse cpu allocations in bpf selftests, from Martynas Pumputis. 11) Make sure mgmt frames have enough tailroom in mac80211, from Felix Feitkau. 12) Use safe list walking in sctp_sendmsg() asoc list traversal, from Greg Kroah-Hartman. 13) Make DCCP's ccid_hc_[rt]x_parse_options always check for NULL ccid, from Eric Dumazet. 14) Need to reload WoL password into bcmsysport device after deep sleeps, from Florian Fainelli. 15) Remove filter from mask before freeing in cls_flower, from Petr Machata. 16) Missing release and use after free in error paths of s390 qeth code, from Julian Wiedmann. 17) Fix lockdep false positive in dsa code, from Marc Zyngier. 18) Fix counting of ATU violations in mv88e6xxx, from Andrew Lunn. 19) Fix EQ firmware assert in qed driver, from Manish Chopra. 20) Don't default Caivum PTP to Y in kconfig, from Bjorn Helgaas" * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (116 commits) net: dsa: b53: Fix for failure when irq is not defined in dt sit: check if IPv6 enabled before calling ip6_err_gen_icmpv6_unreach() geneve: should not call rt6_lookup() when ipv6 was disabled net: Don't default Cavium PTP driver to 'y' net: broadcom: replace dev_kfree_skb_irq by dev_consume_skb_irq for drop profiles net: via-velocity: replace dev_kfree_skb_irq by dev_consume_skb_irq for drop profiles net: tehuti: replace dev_kfree_skb_irq by dev_consume_skb_irq for drop profiles net: sun: replace dev_kfree_skb_irq by dev_consume_skb_irq for drop profiles net: fsl_ucc_hdlc: replace dev_kfree_skb_irq by dev_consume_skb_irq for drop profiles net: fec_mpc52xx: replace dev_kfree_skb_irq by dev_consume_skb_irq for drop profiles net: smsc: epic100: replace dev_kfree_skb_irq by dev_consume_skb_irq for drop profiles net: dscc4: replace dev_kfree_skb_irq by dev_consume_skb_irq for drop profiles net: tulip: de2104x: replace dev_kfree_skb_irq by dev_consume_skb_irq for drop profiles net: defxx: replace dev_kfree_skb_irq by dev_consume_skb_irq for drop profiles net/mlx5e: Don't overwrite pedit action when multiple pedit used net/mlx5e: Update hw flows when encap source mac changed qed*: Advance drivers version to 8.37.0.20 qed: Change verbosity for coalescing message. qede: Fix system crash on configuring channels. qed: Consider TX tcs while deriving the max num_queues for PF. ...
2019-02-08Merge tag 'driver-core-5.0-rc6' of ↵Linus Torvalds1-1/+3
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core fixes from Greg KH: "Here are some driver core fixes for 5.0-rc6. Well, not so much "driver core" as "debugfs". There's a lot of outstanding debugfs cleanup patches coming in through different subsystem trees, and in that process the debugfs core was found that it really should return errors when something bad happens, to prevent random files from showing up in the root of debugfs afterward. So debugfs was fixed up to handle this properly, and then two fixes for the relay and blk-mq code was needed as it was making invalid assumptions about debugfs return values. There's also a cacheinfo fix in here that resolves a tiny issue. All of these have been in linux-next for over a week with no reported problems" * tag 'driver-core-5.0-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: blk-mq: protect debugfs_create_files() from failures relay: check return of create_buf_file() properly debugfs: debugfs_lookup() should return NULL if not found debugfs: return error values, not NULL debugfs: fix debugfs_rename parameter checking cacheinfo: Keep the old value if of_property_read_u32 fails
2019-02-08futex: Handle early deadlock return correctlyThomas Gleixner2-15/+50
commit 56222b212e8e ("futex: Drop hb->lock before enqueueing on the rtmutex") changed the locking rules in the futex code so that the hash bucket lock is not longer held while the waiter is enqueued into the rtmutex wait list. This made the lock and the unlock path symmetric, but unfortunately the possible early exit from __rt_mutex_proxy_start() due to a detected deadlock was not updated accordingly. That allows a concurrent unlocker to observe inconsitent state which triggers the warning in the unlock path. futex_lock_pi() futex_unlock_pi() lock(hb->lock) queue(hb_waiter) lock(hb->lock) lock(rtmutex->wait_lock) unlock(hb->lock) // acquired hb->lock hb_waiter = futex_top_waiter() lock(rtmutex->wait_lock) __rt_mutex_proxy_start() ---> fail remove(rtmutex_waiter); ---> returns -EDEADLOCK unlock(rtmutex->wait_lock) // acquired wait_lock wake_futex_pi() rt_mutex_next_owner() --> returns NULL --> WARN lock(hb->lock) unqueue(hb_waiter) The problem is caused by the remove(rtmutex_waiter) in the failure case of __rt_mutex_proxy_start() as this lets the unlocker observe a waiter in the hash bucket but no waiter on the rtmutex, i.e. inconsistent state. The original commit handles this correctly for the other early return cases (timeout, signal) by delaying the removal of the rtmutex waiter until the returning task reacquired the hash bucket lock. Treat the failure case of __rt_mutex_proxy_start() in the same way and let the existing cleanup code handle the eventual handover of the rtmutex gracefully. The regular rt_mutex_proxy_start() gains the rtmutex waiter removal for the failure case, so that the other callsites are still operating correctly. Add proper comments to the code so all these details are fully documented. Thanks to Peter for helping with the analysis and writing the really valuable code comments. Fixes: 56222b212e8e ("futex: Drop hb->lock before enqueueing on the rtmutex") Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com> Co-developed-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: linux-s390@vger.kernel.org Cc: Stefan Liebler <stli@linux.ibm.com> Cc: Sebastian Sewior <bigeasy@linutronix.de> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1901292311410.1950@nanos.tec.linutronix.de
2019-02-08futex: Fix barrier commentDavidlohr Bueso1-2/+2
The current comment for the barrier that guarantees that waiter increment is always before taking the hb spinlock (barrier (A)) needs to be fixed as it is misplaced. This is obviously referring to hb_waiters_inc, which is a full barrier. Reported-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190206185602.949-1-dave@stgolabs.net
2019-02-07signal: Better detection of synchronous signalsEric W. Biederman1-1/+51
Recently syzkaller was able to create unkillablle processes by creating a timer that is delivered as a thread local signal on SIGHUP, and receiving SIGHUP SA_NODEFERER. Ultimately causing a loop failing to deliver SIGHUP but always trying. When the stack overflows delivery of SIGHUP fails and force_sigsegv is called. Unfortunately because SIGSEGV is numerically higher than SIGHUP next_signal tries again to deliver a SIGHUP. From a quality of implementation standpoint attempting to deliver the timer SIGHUP signal is wrong. We should attempt to deliver the synchronous SIGSEGV signal we just forced. We can make that happening in a fairly straight forward manner by instead of just looking at the signal number we also look at the si_code. In particular for exceptions (aka synchronous signals) the si_code is always greater than 0. That still has the potential to pick up a number of asynchronous signals as in a few cases the same si_codes that are used for synchronous signals are also used for asynchronous signals, and SI_KERNEL is also included in the list of possible si_codes. Still the heuristic is much better and timer signals are definitely excluded. Which is enough to prevent all known ways for someone sending a process signals fast enough to cause unexpected and arguably incorrect behavior. Cc: stable@vger.kernel.org Fixes: a27341cd5fcb ("Prioritize synchronous signals over 'normal' signals") Tested-by: Dmitry Vyukov <dvyukov@google.com> Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2019-02-07signal: Always notice exiting tasksEric W. Biederman1-0/+6
Recently syzkaller was able to create unkillablle processes by creating a timer that is delivered as a thread local signal on SIGHUP, and receiving SIGHUP SA_NODEFERER. Ultimately causing a loop failing to deliver SIGHUP but always trying. Upon examination it turns out part of the problem is actually most of the solution. Since 2.5 signal delivery has found all fatal signals, marked the signal group for death, and queued SIGKILL in every threads thread queue relying on signal->group_exit_code to preserve the information of which was the actual fatal signal. The conversion of all fatal signals to SIGKILL results in the synchronous signal heuristic in next_signal kicking in and preferring SIGHUP to SIGKILL. Which is especially problematic as all fatal signals have already been transformed into SIGKILL. Instead of dequeueing signals and depending upon SIGKILL to be the first signal dequeued, first test if the signal group has already been marked for death. This guarantees that nothing in the signal queue can prevent a process that needs to exit from exiting. Cc: stable@vger.kernel.org Tested-by: Dmitry Vyukov <dvyukov@google.com> Reported-by: Dmitry Vyukov <dvyukov@google.com> Ref: ebf5ebe31d2c ("[PATCH] signal-fixes-2.5.59-A4") History Tree: https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2019-02-07Merge tag 'trace-v5.0-rc3' of ↵Linus Torvalds1-1/+8
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing fixes from Steven Rostedt: "This has two fixes for uprobe code. - Cut and paste fix to have uprobe printks say "uprobe" and not "kprobe" - Add terminating '\0' byte when copying function arguments" * tag 'trace-v5.0-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing/uprobes: Fix output for multiple string arguments tracing: uprobes: Fix typo in pr_fmt string
2019-02-05signal: Always attempt to allocate siginfo for SIGSTOPEric W. Biederman1-3/+2
Since 2.5.34 the code has had the potential to not allocate siginfo for SIGSTOP signals. Except for ptrace this is perfectly fine as only ptrace can use PTRACE_PEEK_SIGINFO and see what the contents of the delivered siginfo are. Users of PTRACE_PEEK_SIGINFO that care about the contents siginfo for SIGSTOP are rare, but they do exist. A seccomp self test has cared and lldb cares. Jack Andersen <jackoalan@gmail.com> writes: > The patch titled > `signal: Never allocate siginfo for SIGKILL or SIGSTOP` > created a regression for users of PTRACE_GETSIGINFO needing to > discern signals that were raised via the tgkill syscall. > > A notable user of this tgkill+ptrace combination is lldb while > debugging a multithreaded program. Without the ability to detect a > SIGSTOP originating from tgkill, lldb does not have a way to > synchronize on a per-thread basis and falls back to SIGSTOP-ing the > entire process. Everyone affected by this please note. The kernel can still fail to allocate a siginfo structure. The allocation is with GFP_KERNEL and is best effort only. If memory is tight when the signal allocation comes in this will fail to allocate a siginfo. So I strongly recommend looking at more robust solutions for synchronizing with a single thread such as PTRACE_INTERRUPT. Or if that does not work persuading your friendly local kernel developer to build the interface you need. Reported-by: Tycho Andersen <tycho@tycho.ws> Reported-by: Kees Cook <keescook@chromium.org> Reported-by: Jack Andersen <jackoalan@gmail.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Reviewed-by: Christian Brauner <christian@brauner.io> Cc: stable@vger.kernel.org Fixes: f149b3155744 ("signal: Never allocate siginfo for SIGKILL or SIGSTOP") Fixes: 6dfc88977e42 ("[PATCH] shared thread signals") History Tree: https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2019-02-04perf/core: Don't WARN() for impossible ring-buffer sizesMark Rutland1-0/+3
The perf tool uses /proc/sys/kernel/perf_event_mlock_kb to determine how large its ringbuffer mmap should be. This can be configured to arbitrary values, which can be larger than the maximum possible allocation from kmalloc. When this is configured to a suitably large value (e.g. thanks to the perf fuzzer), attempting to use perf record triggers a WARN_ON_ONCE() in __alloc_pages_nodemask(): WARNING: CPU: 2 PID: 5666 at mm/page_alloc.c:4511 __alloc_pages_nodemask+0x3f8/0xbc8 Let's avoid this by checking that the requested allocation is possible before calling kzalloc. Reported-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Julien Thierry <julien.thierry@arm.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: <stable@vger.kernel.org> Link: https://lkml.kernel.org/r/20190110142745.25495-1-mark.rutland@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-03Merge branch 'smp-urgent-for-linus' of ↵Linus Torvalds3-35/+6
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull cpu hotplug fixes from Thomas Gleixner: "Two fixes for the cpu hotplug machinery: - Replace the overly clever 'SMT disabled by BIOS' detection logic as it breaks KVM scenarios and prevents speculation control updates when the Hyperthreads are brought online late after boot. - Remove a redundant invocation of the speculation control update function" * 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: cpu/hotplug: Fix "SMT disabled by BIOS" detection for KVM x86/speculation: Remove redundant arch_smt_update() invocation
2019-02-03Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds1-7/+7
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Thomas Gleixner: "A pile of perf updates: - Fix broken sanity check in the /proc/sys/kernel/perf_cpu_time_max_percent write handler - Cure a perf script crash which caused by an unitinialized data structure - Highlight the hottest instruction in perf top and not a random one - Cure yet another clang issue when building perf python - Handle topology entries with no CPU correctly in the tools - Handle perf data which contains both tracepoints and performance counter entries correctly. - Add a missing NULL pointer check in perf ordered_events_free()" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf script: Fix crash when processing recorded stat data perf top: Fix wrong hottest instruction highlighted perf tools: Handle TOPOLOGY headers with no CPU perf python: Remove -fstack-clash-protection when building with some clang versions perf core: Fix perf_proc_update_handler() bug perf script: Fix crash with printing mixed trace point and other events perf ordered_events: Fix crash in ordered_events__free
2019-02-01psi: fix aggregation idle shut-offJohannes Weiner3-5/+45
psi has provisions to shut off the periodic aggregation worker when there is a period of no task activity - and thus no data that needs aggregating. However, while developing psi monitoring, Suren noticed that the aggregation clock currently won't stay shut off for good. Debugging this revealed a flaw in the idle design: an aggregation run will see no task activity and decide to go to sleep; shortly thereafter, the kworker thread that executed the aggregation will go idle and cause a scheduling change, during which the psi callback will kick the !pending worker again. This will ping-pong forever, and is equivalent to having no shut-off logic at all (but with more code!) Fix this by exempting aggregation workers from psi's clock waking logic when the state change is them going to sleep. To do this, tag workers with the last work function they executed, and if in psi we see a worker going to sleep after aggregating psi data, we will not reschedule the aggregation work item. What if the worker is also executing other items before or after? Any psi state times that were incurred by work items preceding the aggregation work will have been collected from the per-cpu buckets during the aggregation itself. If there are work items following the aggregation work, the worker's last_func tag will be overwritten and the aggregator will be kept alive to process this genuine new activity. If the aggregation work is the last thing the worker does, and we decide to go idle, the brief period of non-idle time incurred between the aggregation run and the kworker's dequeue will be stranded in the per-cpu buckets until the clock is woken by later activity. But that should not be a problem. The buckets can hold 4s worth of time, and future activity will wake the clock with a 2s delay, giving us 2s worth of data we can leave behind when disabling aggregation. If it takes a worker more than two seconds to go idle after it finishes its last work item, we likely have bigger problems in the system, and won't notice one sample that was averaged with a bogus per-CPU weight. Link: http://lkml.kernel.org/r/20190116193501.1910-1-hannes@cmpxchg.org Fixes: eb414681d5a0 ("psi: pressure stall information for CPU, memory, and IO") Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reported-by: Suren Baghdasaryan <surenb@google.com> Acked-by: Tejun Heo <tj@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-02-01kernel/exit.c: release ptraced tasks before zap_pid_ns_processesAndrei Vagin1-2/+10
Currently, exit_ptrace() adds all ptraced tasks in a dead list, then zap_pid_ns_processes() waits on all tasks in a current pidns, and only then are tasks from the dead list released. zap_pid_ns_processes() can get stuck on waiting tasks from the dead list. In this case, we will have one unkillable process with one or more dead children. Thanks to Oleg for the advice to release tasks in find_child_reaper(). Link: http://lkml.kernel.org/r/20190110175200.12442-1-avagin@gmail.com Fixes: 7c8bd2322c7f ("exit: ptrace: shift "reap dead" code from exit_ptrace() to forget_original_parent()") Signed-off-by: Andrei Vagin <avagin@gmail.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-02-01Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpfDavid S. Miller7-30/+50
Alexei Starovoitov says: ==================== pull-request: bpf 2019-01-31 The following pull-request contains BPF updates for your *net* tree. The main changes are: 1) disable preemption in sender side of socket filters, from Alexei. 2) fix two potential deadlocks in syscall bpf lookup and prog_register, from Martin and Alexei. 3) fix BTF to allow typedef on func_proto, from Yonghong. 4) two bpftool fixes, from Jiri and Paolo. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2019-01-31bpf: Fix syscall's stackmap lookup potential deadlockMartin KaFai Lau1-2/+10
The map_lookup_elem used to not acquiring spinlock in order to optimize the reader. It was true until commit 557c0c6e7df8 ("bpf: convert stackmap to pre-allocation") The syscall's map_lookup_elem(stackmap) calls bpf_stackmap_copy(). bpf_stackmap_copy() may find the elem no longer needed after the copy is done. If that is the case, pcpu_freelist_push() saves this elem for reuse later. This push requires a spinlock. If a tracing bpf_prog got run in the middle of the syscall's map_lookup_elem(stackmap) and this tracing bpf_prog is calling bpf_get_stackid(stackmap) which also requires the same pcpu_freelist's spinlock, it may end up with a dead lock situation as reported by Eric Dumazet in https://patchwork.ozlabs.org/patch/1030266/ The situation is the same as the syscall's map_update_elem() which needs to acquire the pcpu_freelist's spinlock and could race with tracing bpf_prog. Hence, this patch fixes it by protecting bpf_stackmap_copy() with this_cpu_inc(bpf_prog_active) to prevent tracing bpf_prog from running. A later syscall's map_lookup_elem commit f1a2e44a3aec ("bpf: add queue and stack maps") also acquires a spinlock and races with tracing bpf_prog similarly. Hence, this patch is forward looking and protects the majority of the map lookups. bpf_map_offload_lookup_elem() is the exception since it is for network bpf_prog only (i.e. never called by tracing bpf_prog). Fixes: 557c0c6e7df8 ("bpf: convert stackmap to pre-allocation") Reported-by: Eric Dumazet <eric.dumazet@gmail.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-01-31bpf: fix potential deadlock in bpf_prog_registerAlexei Starovoitov1-12/+2
Lockdep found a potential deadlock between cpu_hotplug_lock, bpf_event_mutex, and cpuctx_mutex: [ 13.007000] WARNING: possible circular locking dependency detected [ 13.007587] 5.0.0-rc3-00018-g2fa53f892422-dirty #477 Not tainted [ 13.008124] ------------------------------------------------------ [ 13.008624] test_progs/246 is trying to acquire lock: [ 13.009030] 0000000094160d1d (tracepoints_mutex){+.+.}, at: tracepoint_probe_register_prio+0x2d/0x300 [ 13.009770] [ 13.009770] but task is already holding lock: [ 13.010239] 00000000d663ef86 (bpf_event_mutex){+.+.}, at: bpf_probe_register+0x1d/0x60 [ 13.010877] [ 13.010877] which lock already depends on the new lock. [ 13.010877] [ 13.011532] [ 13.011532] the existing dependency chain (in reverse order) is: [ 13.012129] [ 13.012129] -> #4 (bpf_event_mutex){+.+.}: [ 13.012582] perf_event_query_prog_array+0x9b/0x130 [ 13.013016] _perf_ioctl+0x3aa/0x830 [ 13.013354] perf_ioctl+0x2e/0x50 [ 13.013668] do_vfs_ioctl+0x8f/0x6a0 [ 13.014003] ksys_ioctl+0x70/0x80 [ 13.014320] __x64_sys_ioctl+0x16/0x20 [ 13.014668] do_syscall_64+0x4a/0x180 [ 13.015007] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 13.015469] [ 13.015469] -> #3 (&cpuctx_mutex){+.+.}: [ 13.015910] perf_event_init_cpu+0x5a/0x90 [ 13.016291] perf_event_init+0x1b2/0x1de [ 13.016654] start_kernel+0x2b8/0x42a [ 13.016995] secondary_startup_64+0xa4/0xb0 [ 13.017382] [ 13.017382] -> #2 (pmus_lock){+.+.}: [ 13.017794] perf_event_init_cpu+0x21/0x90 [ 13.018172] cpuhp_invoke_callback+0xb3/0x960 [ 13.018573] _cpu_up+0xa7/0x140 [ 13.018871] do_cpu_up+0xa4/0xc0 [ 13.019178] smp_init+0xcd/0xd2 [ 13.019483] kernel_init_freeable+0x123/0x24f [ 13.019878] kernel_init+0xa/0x110 [ 13.020201] ret_from_fork+0x24/0x30 [ 13.020541] [ 13.020541] -> #1 (cpu_hotplug_lock.rw_sem){++++}: [ 13.021051] static_key_slow_inc+0xe/0x20 [ 13.021424] tracepoint_probe_register_prio+0x28c/0x300 [ 13.021891] perf_trace_event_init+0x11f/0x250 [ 13.022297] perf_trace_init+0x6b/0xa0 [ 13.022644] perf_tp_event_init+0x25/0x40 [ 13.023011] perf_try_init_event+0x6b/0x90 [ 13.023386] perf_event_alloc+0x9a8/0xc40 [ 13.023754] __do_sys_perf_event_open+0x1dd/0xd30 [ 13.024173] do_syscall_64+0x4a/0x180 [ 13.024519] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 13.024968] [ 13.024968] -> #0 (tracepoints_mutex){+.+.}: [ 13.025434] __mutex_lock+0x86/0x970 [ 13.025764] tracepoint_probe_register_prio+0x2d/0x300 [ 13.026215] bpf_probe_register+0x40/0x60 [ 13.026584] bpf_raw_tracepoint_open.isra.34+0xa4/0x130 [ 13.027042] __do_sys_bpf+0x94f/0x1a90 [ 13.027389] do_syscall_64+0x4a/0x180 [ 13.027727] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 13.028171] [ 13.028171] other info that might help us debug this: [ 13.028171] [ 13.028807] Chain exists of: [ 13.028807] tracepoints_mutex --> &cpuctx_mutex --> bpf_event_mutex [ 13.028807] [ 13.029666] Possible unsafe locking scenario: [ 13.029666] [ 13.030140] CPU0 CPU1 [ 13.030510] ---- ---- [ 13.030875] lock(bpf_event_mutex); [ 13.031166] lock(&cpuctx_mutex); [ 13.031645] lock(bpf_event_mutex); [ 13.032135] lock(tracepoints_mutex); [ 13.032441] [ 13.032441] *** DEADLOCK *** [ 13.032441] [ 13.032911] 1 lock held by test_progs/246: [ 13.033239] #0: 00000000d663ef86 (bpf_event_mutex){+.+.}, at: bpf_probe_register+0x1d/0x60 [ 13.033909] [ 13.033909] stack backtrace: [ 13.034258] CPU: 1 PID: 246 Comm: test_progs Not tainted 5.0.0-rc3-00018-g2fa53f892422-dirty #477 [ 13.034964] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2.el7 04/01/2014 [ 13.035657] Call Trace: [ 13.035859] dump_stack+0x5f/0x8b [ 13.036130] print_circular_bug.isra.37+0x1ce/0x1db [ 13.036526] __lock_acquire+0x1158/0x1350 [ 13.036852] ? lock_acquire+0x98/0x190 [ 13.037154] lock_acquire+0x98/0x190 [ 13.037447] ? tracepoint_probe_register_prio+0x2d/0x300 [ 13.037876] __mutex_lock+0x86/0x970 [ 13.038167] ? tracepoint_probe_register_prio+0x2d/0x300 [ 13.038600] ? tracepoint_probe_register_prio+0x2d/0x300 [ 13.039028] ? __mutex_lock+0x86/0x970 [ 13.039337] ? __mutex_lock+0x24a/0x970 [ 13.039649] ? bpf_probe_register+0x1d/0x60 [ 13.039992] ? __bpf_trace_sched_wake_idle_without_ipi+0x10/0x10 [ 13.040478] ? tracepoint_probe_register_prio+0x2d/0x300 [ 13.040906] tracepoint_probe_register_prio+0x2d/0x300 [ 13.041325] bpf_probe_register+0x40/0x60 [ 13.041649] bpf_raw_tracepoint_open.isra.34+0xa4/0x130 [ 13.042068] ? __might_fault+0x3e/0x90 [ 13.042374] __do_sys_bpf+0x94f/0x1a90 [ 13.042678] do_syscall_64+0x4a/0x180 [ 13.042975] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 13.043382] RIP: 0033:0x7f23b10a07f9 [ 13.045155] RSP: 002b:00007ffdef42fdd8 EFLAGS: 00000202 ORIG_RAX: 0000000000000141 [ 13.045759] RAX: ffffffffffffffda RBX: 00007ffdef42ff70 RCX: 00007f23b10a07f9 [ 13.046326] RDX: 0000000000000070 RSI: 00007ffdef42fe10 RDI: 0000000000000011 [ 13.046893] RBP: 00007ffdef42fdf0 R08: 0000000000000038 R09: 00007ffdef42fe10 [ 13.047462] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000 [ 13.048029] R13: 0000000000000016 R14: 00007f23b1db4690 R15: 0000000000000000 Since tracepoints_mutex will be taken in tracepoint_probe_register/unregister() there is no need to take bpf_event_mutex too. bpf_event_mutex is protecting modifications to prog array used in kprobe/perf bpf progs. bpf_raw_tracepoints don't need to take this mutex. Fixes: c4f6699dfcb8 ("bpf: introduce BPF_RAW_TRACEPOINT") Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-01-31bpf: fix lockdep false positive in percpu_freelistAlexei Starovoitov3-14/+35
Lockdep warns about false positive: [ 12.492084] 00000000e6b28347 (&head->lock){+...}, at: pcpu_freelist_push+0x2a/0x40 [ 12.492696] but this lock was taken by another, HARDIRQ-safe lock in the past: [ 12.493275] (&rq->lock){-.-.} [ 12.493276] [ 12.493276] [ 12.493276] and interrupts could create inverse lock ordering between them. [ 12.493276] [ 12.494435] [ 12.494435] other info that might help us debug this: [ 12.494979] Possible interrupt unsafe locking scenario: [ 12.494979] [ 12.495518] CPU0 CPU1 [ 12.495879] ---- ---- [ 12.496243] lock(&head->lock); [ 12.496502] local_irq_disable(); [ 12.496969] lock(&rq->lock); [ 12.497431] lock(&head->lock); [ 12.497890] <Interrupt> [ 12.498104] lock(&rq->lock); [ 12.498368] [ 12.498368] *** DEADLOCK *** [ 12.498368] [ 12.498837] 1 lock held by dd/276: [ 12.499110] #0: 00000000c58cb2ee (rcu_read_lock){....}, at: trace_call_bpf+0x5e/0x240 [ 12.499747] [ 12.499747] the shortest dependencies between 2nd lock and 1st lock: [ 12.500389] -> (&rq->lock){-.-.} { [ 12.500669] IN-HARDIRQ-W at: [ 12.500934] _raw_spin_lock+0x2f/0x40 [ 12.501373] scheduler_tick+0x4c/0xf0 [ 12.501812] update_process_times+0x40/0x50 [ 12.502294] tick_periodic+0x27/0xb0 [ 12.502723] tick_handle_periodic+0x1f/0x60 [ 12.503203] timer_interrupt+0x11/0x20 [ 12.503651] __handle_irq_event_percpu+0x43/0x2c0 [ 12.504167] handle_irq_event_percpu+0x20/0x50 [ 12.504674] handle_irq_event+0x37/0x60 [ 12.505139] handle_level_irq+0xa7/0x120 [ 12.505601] handle_irq+0xa1/0x150 [ 12.506018] do_IRQ+0x77/0x140 [ 12.506411] ret_from_intr+0x0/0x1d [ 12.506834] _raw_spin_unlock_irqrestore+0x53/0x60 [ 12.507362] __setup_irq+0x481/0x730 [ 12.507789] setup_irq+0x49/0x80 [ 12.508195] hpet_time_init+0x21/0x32 [ 12.508644] x86_late_time_init+0xb/0x16 [ 12.509106] start_kernel+0x390/0x42a [ 12.509554] secondary_startup_64+0xa4/0xb0 [ 12.510034] IN-SOFTIRQ-W at: [ 12.510305] _raw_spin_lock+0x2f/0x40 [ 12.510772] try_to_wake_up+0x1c7/0x4e0 [ 12.511220] swake_up_locked+0x20/0x40 [ 12.511657] swake_up_one+0x1a/0x30 [ 12.512070] rcu_process_callbacks+0xc5/0x650 [ 12.512553] __do_softirq+0xe6/0x47b [ 12.512978] irq_exit+0xc3/0xd0 [ 12.513372] smp_apic_timer_interrupt+0xa9/0x250 [ 12.513876] apic_timer_interrupt+0xf/0x20 [ 12.514343] default_idle+0x1c/0x170 [ 12.514765] do_idle+0x199/0x240 [ 12.515159] cpu_startup_entry+0x19/0x20 [ 12.515614] start_kernel+0x422/0x42a [ 12.516045] secondary_startup_64+0xa4/0xb0 [ 12.516521] INITIAL USE at: [ 12.516774] _raw_spin_lock_irqsave+0x38/0x50 [ 12.517258] rq_attach_root+0x16/0xd0 [ 12.517685] sched_init+0x2f2/0x3eb [ 12.518096] start_kernel+0x1fb/0x42a [ 12.518525] secondary_startup_64+0xa4/0xb0 [ 12.518986] } [ 12.519132] ... key at: [<ffffffff82b7bc28>] __key.71384+0x0/0x8 [ 12.519649] ... acquired at: [ 12.519892] pcpu_freelist_pop+0x7b/0xd0 [ 12.520221] bpf_get_stackid+0x1d2/0x4d0 [ 12.520563] ___bpf_prog_run+0x8b4/0x11a0 [ 12.520887] [ 12.521008] -> (&head->lock){+...} { [ 12.521292] HARDIRQ-ON-W at: [ 12.521539] _raw_spin_lock+0x2f/0x40 [ 12.521950] pcpu_freelist_push+0x2a/0x40 [ 12.522396] bpf_get_stackid+0x494/0x4d0 [ 12.522828] ___bpf_prog_run+0x8b4/0x11a0 [ 12.523296] INITIAL USE at: [ 12.523537] _raw_spin_lock+0x2f/0x40 [ 12.523944] pcpu_freelist_populate+0xc0/0x120 [ 12.524417] htab_map_alloc+0x405/0x500 [ 12.524835] __do_sys_bpf+0x1a3/0x1a90 [ 12.525253] do_syscall_64+0x4a/0x180 [ 12.525659] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 12.526167] } [ 12.526311] ... key at: [<ffffffff838f7668>] __key.13130+0x0/0x8 [ 12.526812] ... acquired at: [ 12.527047] __lock_acquire+0x521/0x1350 [ 12.527371] lock_acquire+0x98/0x190 [ 12.527680] _raw_spin_lock+0x2f/0x40 [ 12.527994] pcpu_freelist_push+0x2a/0x40 [ 12.528325] bpf_get_stackid+0x494/0x4d0 [ 12.528645] ___bpf_prog_run+0x8b4/0x11a0 [ 12.528970] [ 12.529092] [ 12.529092] stack backtrace: [ 12.529444] CPU: 0 PID: 276 Comm: dd Not tainted 5.0.0-rc3-00018-g2fa53f892422 #475 [ 12.530043] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2.el7 04/01/2014 [ 12.530750] Call Trace: [ 12.530948] dump_stack+0x5f/0x8b [ 12.531248] check_usage_backwards+0x10c/0x120 [ 12.531598] ? ___bpf_prog_run+0x8b4/0x11a0 [ 12.531935] ? mark_lock+0x382/0x560 [ 12.532229] mark_lock+0x382/0x560 [ 12.532496] ? print_shortest_lock_dependencies+0x180/0x180 [ 12.532928] __lock_acquire+0x521/0x1350 [ 12.533271] ? find_get_entry+0x17f/0x2e0 [ 12.533586] ? find_get_entry+0x19c/0x2e0 [ 12.533902] ? lock_acquire+0x98/0x190 [ 12.534196] lock_acquire+0x98/0x190 [ 12.534482] ? pcpu_freelist_push+0x2a/0x40 [ 12.534810] _raw_spin_lock+0x2f/0x40 [ 12.535099] ? pcpu_freelist_push+0x2a/0x40 [ 12.535432] pcpu_freelist_push+0x2a/0x40 [ 12.535750] bpf_get_stackid+0x494/0x4d0 [ 12.536062] ___bpf_prog_run+0x8b4/0x11a0 It has been explained that is a false positive here: https://lkml.org/lkml/2018/7/25/756 Recap: - stackmap uses pcpu_freelist - The lock in pcpu_freelist is a percpu lock - stackmap is only used by tracing bpf_prog - A tracing bpf_prog cannot be run if another bpf_prog has already been running (ensured by the percpu bpf_prog_active counter). Eric pointed out that this lockdep splats stops other legit lockdep splats in selftests/bpf/test_progs.c. Fix this by calling local_irq_save/restore for stackmap. Another false positive had also been worked around by calling local_irq_save in commit 89ad2fa3f043 ("bpf: fix lockdep splat"). That commit added unnecessary irq_save/restore to fast path of bpf hash map. irqs are already disabled at that point, since htab is holding per bucket spin_lock with irqsave. Let's reduce overhead for htab by introducing __pcpu_freelist_push/pop function w/o irqsave and convert pcpu_freelist_push/pop to irqsave to be used elsewhere (right now only in stackmap). It stops lockdep false positive in stackmap with a bit of acceptable overhead. Fixes: 557c0c6e7df8 ("bpf: convert stackmap to pre-allocation") Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org> Reported-by: Eric Dumazet <eric.dumazet@gmail.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-01-31bpf: run bpf programs with preemption disabledAlexei Starovoitov1-1/+1
Disabled preemption is necessary for proper access to per-cpu maps from BPF programs. But the sender side of socket filters didn't have preemption disabled: unix_dgram_sendmsg->sk_filter->sk_filter_trim_cap->bpf_prog_run_save_cb->BPF_PROG_RUN and a combination of af_packet with tun device didn't disable either: tpacket_snd->packet_direct_xmit->packet_pick_tx_queue->ndo_select_queue-> tun_select_queue->tun_ebpf_select_queue->bpf_prog_run_clear_cb->BPF_PROG_RUN Disable preemption before executing BPF programs (both classic and extended). Reported-by: Jann Horn <jannh@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Song Liu <songliubraving@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-01-31relay: check return of create_buf_file() properlyGreg Kroah-Hartman1-1/+3
If create_buf_file() returns an error, don't try to reference it later as a valid dentry pointer. This problem was exposed when debugfs started to return errors instead of just NULL for some calls when they do not succeed properly. Also, the check for WARN_ON(dentry) was just wrong :) Reported-by: Kees Cook <keescook@chromium.org> Reported-and-tested-by: syzbot+16c3a70e1e9b29346c43@syzkaller.appspotmail.com Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: David Rientjes <rientjes@google.com> Fixes: ff9fb72bc077 ("debugfs: return error values, not NULL") Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-30cpu/hotplug: Fix "SMT disabled by BIOS" detection for KVMJosh Poimboeuf3-31/+5
With the following commit: 73d5e2b47264 ("cpu/hotplug: detect SMT disabled by BIOS") ... the hotplug code attempted to detect when SMT was disabled by BIOS, in which case it reported SMT as permanently disabled. However, that code broke a virt hotplug scenario, where the guest is booted with only primary CPU threads, and a sibling is brought online later. The problem is that there doesn't seem to be a way to reliably distinguish between the HW "SMT disabled by BIOS" case and the virt "sibling not yet brought online" case. So the above-mentioned commit was a bit misguided, as it permanently disabled SMT for both cases, preventing future virt sibling hotplugs. Going back and reviewing the original problems which were attempted to be solved by that commit, when SMT was disabled in BIOS: 1) /sys/devices/system/cpu/smt/control showed "on" instead of "notsupported"; and 2) vmx_vm_init() was incorrectly showing the L1TF_MSG_SMT warning. I'd propose that we instead consider #1 above to not actually be a problem. Because, at least in the virt case, it's possible that SMT wasn't disabled by BIOS and a sibling thread could be brought online later. So it makes sense to just always default the smt control to "on" to allow for that possibility (assuming cpuid indicates that the CPU supports SMT). The real problem is #2, which has a simple fix: change vmx_vm_init() to query the actual current SMT state -- i.e., whether any siblings are currently online -- instead of looking at the SMT "control" sysfs value. So fix it by: a) reverting the original "fix" and its followup fix: 73d5e2b47264 ("cpu/hotplug: detect SMT disabled by BIOS") bc2d8d262cba ("cpu/hotplug: Fix SMT supported evaluation") and b) changing vmx_vm_init() to query the actual current SMT state -- instead of the sysfs control value -- to determine whether the L1TF warning is needed. This also requires the 'sched_smt_present' variable to exported, instead of 'cpu_smt_control'. Fixes: 73d5e2b47264 ("cpu/hotplug: detect SMT disabled by BIOS") Reported-by: Igor Mammedov <imammedo@redhat.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Joe Mario <jmario@redhat.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: kvm@vger.kernel.org Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/e3a85d585da28cc333ecbc1e78ee9216e6da9396.1548794349.git.jpoimboe@redhat.com
2019-01-29bpf: btf: allow typedef func_protoYonghong Song1-1/+2
Current implementation does not allow typedef func_proto. But it is actually allowed. -bash-4.4$ cat t.c typedef int (f) (int); f *g; -bash-4.4$ clang -O2 -g -c -target bpf t.c -Xclang -target-feature -Xclang +dwarfris -bash-4.4$ pahole -JV t.o File t.o: [1] PTR (anon) type_id=2 [2] TYPEDEF f type_id=3 [3] FUNC_PROTO (anon) return=4 args=(4 (anon)) [4] INT int size=4 bit_offset=0 nr_bits=32 encoding=SIGNED -bash-4.4$ This patch related btf verifier to allow such (typedef func_proto) patterns. Fixes: 2667a2626f4d ("bpf: btf: Add BTF_KIND_FUNC and BTF_KIND_FUNC_PROTO") Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-01-29x86/speculation: Remove redundant arch_smt_update() invocationZhenzhong Duan1-4/+1
With commit a74cfffb03b7 ("x86/speculation: Rework SMT state change"), arch_smt_update() is invoked from each individual CPU hotplug function. Therefore the extra arch_smt_update() call in the sysfs SMT control is redundant. Fixes: a74cfffb03b7 ("x86/speculation: Rework SMT state change") Signed-off-by: Zhenzhong Duan <zhenzhong.duan@oracle.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: <konrad.wilk@oracle.com> Cc: <dwmw@amazon.co.uk> Cc: <bp@suse.de> Cc: <srinivas.eeda@oracle.com> Cc: <peterz@infradead.org> Cc: <hpa@zytor.com> Link: https://lkml.kernel.org/r/e2e064f2-e8ef-42ca-bf4f-76b612964752@default
2019-01-27Merge branch 'timers-urgent-for-linus' of ↵Linus Torvalds1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer fix from Thomas Glexiner: "A single regression fix to address the unintended breakage of posix cpu timers. This is caused by a new sanity check in the common code, which fails for posix cpu timers under certain conditions because the posix cpu timer code never updates the variable which is checked" * 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: posix-cpu-timers: Unbreak timer rearming
2019-01-27Merge branch 'locking-urgent-for-linus' of ↵Linus Torvalds4-11/+34
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking fixes from Thomas Gleixner: "A small series of fixes which all address possible missed wakeups: - Document and fix the wakeup ordering of wake_q - Add the missing barrier in rcuwait_wake_up(), which was documented in the comment but missing in the code - Fix the possible missed wakeups in the rwsem and futex code" * 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: locking/rwsem: Fix (possible) missed wakeup futex: Fix (possible) missed wakeup sched/wake_q: Fix wakeup ordering for wake_q sched/wake_q: Document wake_q_add() sched/wait: Fix rcuwait_wake_up() ordering
2019-01-27Merge branch 'irq-urgent-for-linus' of ↵Linus Torvalds2-1/+4
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull irq fixes from Thomas Gleixner: "A small set of fixes for the interrupt subsystem: - Fix a double increment in the irq descriptor allocator which resulted in a sanity check only being done for every second affinity mask - Add a missing device tree translation in the stm32-exti driver. Without that the interrupt association is completely wrong. - Initialize the mutex in the GIC-V3 MBI driver - Fix the alignment for aliasing devices in the GIC-V3-ITS driver so multi MSI allocations work correctly - Ensure that the initial affinity of a interrupt is not empty at startup time. - Drop bogus include in the madera irq chip driver - Fix KernelDoc regression" * 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: irqchip/gic-v3-its: Align PCI Multi-MSI allocation on their size genirq/irqdesc: Fix double increment in alloc_descs() genirq: Fix the kerneldoc comment for struct irq_affinity_desc irqchip/madera: Drop GPIO includes irqchip/gic-v3-mbi: Fix uninitialized mbi_lock irqchip/stm32-exti: Add domain translate function genirq: Make sure the initial affinity is not empty
2019-01-22Merge tag 'perf-urgent-for-mingo-5.0-20190121' of ↵Ingo Molnar1-7/+7
git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent Pull perf/urgent fixes from Arnaldo Carvalho de Melo: Kernel: Stephane Eranian: - Fix perf_proc_update_handler() bug. perf script: Andi Kleen: - Fix crash with printing mixed trace point and other events. Tony Jones: - Fix crash when processing recorded stat data. perf top: He Kuang: - Fix wrong hottest instruction highlighted. perf python: Arnaldo Carvalho de Melo: - Remove -fstack-clash-protection when building with some clang versions. perf ordered_events: Jiri Olsa: - Fix out of buffers crash in ordered_events__free(). perf cpu_map: Stephane Eranian: - Handle TOPOLOGY headers with no CPU. Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
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