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Odroidxu4 v4.14 #3
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Thomas reported that 'perf buildid-list' gets a SEGFAULT due to NULL pointer deref when he ran it on a data with namespace events. It was because the buildid_id__mark_dso_hit_ops lacks the namespace event handler and perf_too__fill_default() didn't set it. Program received signal SIGSEGV, Segmentation fault. 0x0000000000000000 in ?? () Missing separate debuginfos, use: dnf debuginfo-install audit-libs-2.7.7-1.fc25.s390x bzip2-libs-1.0.6-21.fc25.s390x elfutils-libelf-0.169-1.fc25.s390x +elfutils-libs-0.169-1.fc25.s390x libcap-ng-0.7.8-1.fc25.s390x numactl-libs-2.0.11-2.ibm.fc25.s390x openssl-libs-1.1.0e-1.1.ibm.fc25.s390x perl-libs-5.24.1-386.fc25.s390x +python-libs-2.7.13-2.fc25.s390x slang-2.3.0-7.fc25.s390x xz-libs-5.2.3-2.fc25.s390x zlib-1.2.8-10.fc25.s390x (gdb) where #0 0x0000000000000000 in ?? () #1 0x00000000010fad6a in machines__deliver_event (machines=<optimized out>, machines@entry=0x2c6fd18, evlist=<optimized out>, event=event@entry=0x3fffdf00470, sample=0x3ffffffe880, sample@entry=0x3ffffffe888, tool=tool@entry=0x1312968 <build_id.mark_dso_hit_ops>, file_offset=1136) at util/session.c:1287 #2 0x00000000010fbf4e in perf_session__deliver_event (file_offset=1136, tool=0x1312968 <build_id.mark_dso_hit_ops>, sample=0x3ffffffe888, event=0x3fffdf00470, session=0x2c6fc30) at util/session.c:1340 #3 perf_session__process_event (session=0x2c6fc30, session@entry=0x0, event=event@entry=0x3fffdf00470, file_offset=file_offset@entry=1136) at util/session.c:1522 #4 0x00000000010fddde in __perf_session__process_events (file_size=11880, data_size=<optimized out>, data_offset=<optimized out>, session=0x0) at util/session.c:1899 #5 perf_session__process_events (session=0x0, session@entry=0x2c6fc30) at util/session.c:1953 #6 0x000000000103b2ac in perf_session__list_build_ids (with_hits=<optimized out>, force=<optimized out>) at builtin-buildid-list.c:83 #7 cmd_buildid_list (argc=<optimized out>, argv=<optimized out>) at builtin-buildid-list.c:115 #8 0x00000000010a026c in run_builtin (p=0x1311f78 <commands+24>, argc=argc@entry=2, argv=argv@entry=0x3fffffff3c0) at perf.c:296 #9 0x000000000102bc00 in handle_internal_command (argv=<optimized out>, argc=2) at perf.c:348 hardkernel#10 run_argv (argcp=<synthetic pointer>, argv=<synthetic pointer>) at perf.c:392 hardkernel#11 main (argc=<optimized out>, argv=0x3fffffff3c0) at perf.c:536 (gdb) Fix it by adding a stub event handler for namespace event. Committer testing: Further clarifying, plain using 'perf buildid-list' will not end up in a SEGFAULT when processing a perf.data file with namespace info: # perf record -a --namespaces sleep 1 [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 2.024 MB perf.data (1058 samples) ] # perf buildid-list | wc -l 38 # perf buildid-list | head -5 e2a171c7b905826fc8494f0711ba76ab6abbd604 /lib/modules/4.14.0-rc3+/build/vmlinux 874840a02d8f8a31cedd605d0b8653145472ced3 /lib/modules/4.14.0-rc3+/kernel/arch/x86/kvm/kvm-intel.ko ea7223776730cd8a22f320040aae4d54312984bc /lib/modules/4.14.0-rc3+/kernel/drivers/gpu/drm/i915/i915.ko 5961535e6732a8edb7f22b3f148bb2fa2e0be4b9 /lib/modules/4.14.0-rc3+/kernel/drivers/gpu/drm/drm.ko f045f54aa78cf1931cc893f78b6cbc52c72a8cb1 /usr/lib64/libc-2.25.so # It is only when one asks for checking what of those entries actually had samples, i.e. when we use either -H or --with-hits, that we will process all the PERF_RECORD_ events, and since tools/perf/builtin-buildid-list.c neither explicitely set a perf_tool.namespaces() callback nor the default stub was set that we end up, when processing a PERF_RECORD_NAMESPACE record, causing a SEGFAULT: # perf buildid-list -H Segmentation fault (core dumped) ^C # Reported-and-Tested-by: Thomas-Mich Richter <tmricht@linux.vnet.ibm.com> Signed-off-by: Namhyung Kim <namhyung@kernel.org> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Hari Bathini <hbathini@linux.vnet.ibm.com> Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas-Mich Richter <tmricht@linux.vnet.ibm.com> Fixes: f3b3614 ("perf tools: Add PERF_RECORD_NAMESPACES to include namespaces related info") Link: http://lkml.kernel.org/r/20171017132900.11043-1-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Oct 31, 2017
v4.10 commit 6f2ce1c ("scsi: zfcp: fix rport unblock race with LUN recovery") extended accessing parent pointer fields of struct zfcp_erp_action for tracing. If an erp_action has never been enqueued before, these parent pointer fields are uninitialized and NULL. Examples are zfcp objects freshly added to the parent object's children list, before enqueueing their first recovery subsequently. In zfcp_erp_try_rport_unblock(), we iterate such list. Accessing erp_action fields can cause a NULL pointer dereference. Since the kernel can read from lowcore on s390, it does not immediately cause a kernel page fault. Instead it can cause hangs on trying to acquire the wrong erp_action->adapter->dbf->rec_lock in zfcp_dbf_rec_action_lvl() ^bogus^ while holding already other locks with IRQs disabled. Real life example from attaching lots of LUNs in parallel on many CPUs: crash> bt 17723 PID: 17723 TASK: ... CPU: 25 COMMAND: "zfcperp0.0.1800" LOWCORE INFO: -psw : 0x0404300180000000 0x000000000038e424 -function : _raw_spin_lock_wait_flags at 38e424 ... #0 [fdde8fc90] zfcp_dbf_rec_action_lvl at 3e0004e9862 [zfcp] #1 [fdde8fce8] zfcp_erp_try_rport_unblock at 3e0004dfddc [zfcp] #2 [fdde8fd38] zfcp_erp_strategy at 3e0004e0234 [zfcp] #3 [fdde8fda8] zfcp_erp_thread at 3e0004e0a12 [zfcp] #4 [fdde8fe60] kthread at 173550 #5 [fdde8feb8] kernel_thread_starter at 10add2 zfcp_adapter zfcp_port zfcp_unit <address>, 0x404040d600000000 scsi_device NULL, returning early! zfcp_scsi_dev.status = 0x40000000 0x40000000 ZFCP_STATUS_COMMON_RUNNING crash> zfcp_unit <address> struct zfcp_unit { erp_action = { adapter = 0x0, port = 0x0, unit = 0x0, }, } zfcp_erp_action is always fully embedded into its container object. Such container object is never moved in its object tree (only add or delete). Hence, erp_action parent pointers can never change. To fix the issue, initialize the erp_action parent pointers before adding the erp_action container to any list and thus before it becomes accessible from outside of its initializing function. In order to also close the time window between zfcp_erp_setup_act() memsetting the entire erp_action to zero and setting the parent pointers again, drop the memset and instead explicitly initialize individually all erp_action fields except for parent pointers. To be extra careful not to introduce any other unintended side effect, even keep zeroing the erp_action fields for list and timer. Also double-check with WARN_ON_ONCE that erp_action parent pointers never change, so we get to know when we would deviate from previous behavior. Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com> Fixes: 6f2ce1c ("scsi: zfcp: fix rport unblock race with LUN recovery") Cc: <stable@vger.kernel.org> #2.6.32+ Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
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Jan 21, 2019
Yonghong Song says: ==================== The previous BTF kind_flag support patch set introduced a bug for kernel bpffs pretty printing and another bug for bpftool map pretty printing. If a bitfield struct member offset is greater than 256 bits, printed value for that struct member will be incorrect. - Patch #1 fixed the bug in kernel bpffs pretty printing. - Patch #2 enhanced the test_btf test case to cover the issue exposed by patch #1. - Patch #3 fixed the bug in bpftool map pretty printing. ==================== Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
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Jan 21, 2019
Taehee Yoo says: ==================== net: bpfilter: fix two bugs in bpfilter This patches fix two bugs in the bpfilter_umh which are related in iptables command. The first patch adds an exit code for UMH process. This provides an opportunity to cleanup members of the umh_info to modules which use the UMH. In order to identify UMH processes, a new flag PF_UMH is added. The second patch makes the bpfilter_umh use UMH cleanup callback. The third patch adds re-start routine for the bpfilter_umh. The bpfilter_umh does not re-start after error occurred. because there is no re-start routine in the module. The fourth patch ensures that the bpfilter.ko module will not removed while it's being used. The bpfilter.ko is not protected by locks or module reference counter. Therefore that can be removed while module is being used. In order to protect that, mutex is used. The first and second patch are preparation patches for the third and fourth patch. TEST #1 while : do modprobe bpfilter kill -9 <pid of the bpfilter_umh> iptables -vnL done TEST #2 while : do iptables -I FORWARD -m string --string ap --algo kmp & iptables -F & modprobe -rv bpfilter & done TEST #3 while : do modprobe bpfilter & modprobe -rv bpfilter & done The TEST1 makes a failure of iptables command. This is fixed by the third patch. The TEST2 makes a panic because of a race condition in the bpfilter_umh module. This is fixed by the fourth patch. The TEST3 makes a double-create UMH process. This is fixed by the third and fourth patch. v4 : - declare the exit_umh() as static inline - check stop flag in the load_umh() to avoid a double-create UMH v3 : - Avoid unnecessary list lookup for non-UMH processes - Add a new PF_UMH flag v2 : add the first and second patch v1 : Initial patch ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
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Jan 28, 2019
We were experiencing a crash similar to the one reported as part of commit:a5ba1d95e46e ("uart: fix race between uart_put_char() and uart_shutdown()") in our testbed as well. We continue to observe the same crash after integrating the commit a5ba1d9 ("uart: fix race between uart_put_char() and uart_shutdown()") On reviewing the change, the port lock should be taken prior to checking for if (!circ->buf) in fn. __uart_put_char and other fns. that update the buffer uart_state->xmit. Traceback: [11/27/2018 06:24:32.4870] Unable to handle kernel NULL pointer dereference at virtual address 0000003b [11/27/2018 06:24:32.4950] PC is at memcpy+0x48/0x180 [11/27/2018 06:24:32.4950] LR is at uart_write+0x74/0x120 [11/27/2018 06:24:32.4950] pc : [<ffffffc0002e6808>] lr : [<ffffffc0003747cc>] pstate: 000001c5 [11/27/2018 06:24:32.4950] sp : ffffffc076433d30 [11/27/2018 06:24:32.4950] x29: ffffffc076433d30 x28: 0000000000000140 [11/27/2018 06:24:32.4950] x27: ffffffc0009b9d5e x26: ffffffc07ce36580 [11/27/2018 06:24:32.4950] x25: 0000000000000000 x24: 0000000000000140 [11/27/2018 06:24:32.4950] x23: ffffffc000891200 x22: ffffffc01fc34000 [11/27/2018 06:24:32.4950] x21: 0000000000000fff x20: 0000000000000076 [11/27/2018 06:24:32.4950] x19: 0000000000000076 x18: 0000000000000000 [11/27/2018 06:24:32.4950] x17: 000000000047cf08 x16: ffffffc000099e68 [11/27/2018 06:24:32.4950] x15: 0000000000000018 x14: 776d726966205948 [11/27/2018 06:24:32.4950] x13: 50203a6c6974755f x12: 74647075205d3333 [11/27/2018 06:24:32.4950] x11: 3a35323a36203831 x10: 30322f37322f3131 [11/27/2018 06:24:32.4950] x9 : 5b205d303638342e x8 : 746164206f742070 [11/27/2018 06:24:32.4950] x7 : 7520736920657261 x6 : 000000000000003b [11/27/2018 06:24:32.4950] x5 : 000000000000817a x4 : 0000000000000008 [11/27/2018 06:24:32.4950] x3 : 2f37322f31312a5b x2 : 000000000000006e [11/27/2018 06:24:32.4950] x1 : ffffffc0009b9cf0 x0 : 000000000000003b [11/27/2018 06:24:32.4950] CPU2: stopping [11/27/2018 06:24:32.4950] CPU: 2 PID: 0 Comm: swapper/2 Tainted: P D O 4.1.51 #3 [11/27/2018 06:24:32.4950] Hardware name: Broadcom-v8A (DT) [11/27/2018 06:24:32.4950] Call trace: [11/27/2018 06:24:32.4950] [<ffffffc0000883b8>] dump_backtrace+0x0/0x150 [11/27/2018 06:24:32.4950] [<ffffffc00008851c>] show_stack+0x14/0x20 [11/27/2018 06:24:32.4950] [<ffffffc0005ee810>] dump_stack+0x90/0xb0 [11/27/2018 06:24:32.4950] [<ffffffc00008e844>] handle_IPI+0x18c/0x1a0 [11/27/2018 06:24:32.4950] [<ffffffc000080c68>] gic_handle_irq+0x88/0x90 Fixes: a5ba1d9 ("uart: fix race between uart_put_char() and uart_shutdown()") Cc: stable <stable@vger.kernel.org> Signed-off-by: Samir Virmani <samir@embedur.com> Acked-by: Tycho Andersen <tycho@tycho.ws> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
mihailescu2m
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Feb 4, 2019
Song Liu reported crash in 'perf record': > #0 0x0000000000500055 in ordered_events(float, long double,...)(...) () > #1 0x0000000000500196 in ordered_events.reinit () > #2 0x00000000004fe413 in perf_session.process_events () > #3 0x0000000000440431 in cmd_record () > #4 0x00000000004a439f in run_builtin () > #5 0x000000000042b3e5 in main ()" This can happen when we get out of buffers during event processing. The subsequent ordered_events__free() call assumes oe->buffer != NULL and crashes. Add a check to prevent that. Reported-by: Song Liu <liu.song.a23@gmail.com> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Reviewed-by: Song Liu <liu.song.a23@gmail.com> Tested-by: Song Liu <liu.song.a23@gmail.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/r/20190117113017.12977-1-jolsa@kernel.org Fixes: d5ceb62 ("perf ordered_events: Add 'struct ordered_events_buffer' layer") Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Feb 4, 2019
This patch adds quirk VID/PID IDs for the Opus #3 DAP (made by 'The Bit') in order to enable Native DSD support. [ NOTE: this could be handled in the generic way with fp->dvd_raw if we add 0x10cb to the vendor whitelist, but since 0x10cb shows a different vendor name (Erantech), put to the individual entry at this time -- tiwai ] Signed-off-by: Olek Poplavsky <woodenbits@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
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Feb 4, 2019
The async_file might be freed before the disassociation has been ended, causing qp shutdown to use after free on it. Since uverbs_destroy_ufile_hw is not a fence, it returns if a disassociation is ongoing in another thread. It has to be written this way to avoid deadlock. However this means that the ufile FD close cannot destroy anything that may still be used by an active kref, such as the the async_file. To fix that move the kref_put() to be in ib_uverbs_release_file(). BUG: unable to handle kernel paging request at ffffffffba682787 PGD bc80e067 P4D bc80e067 PUD bc80f063 PMD 1313df163 PTE 80000000bc682061 Oops: 0003 [#1] SMP PTI CPU: 1 PID: 32410 Comm: bash Tainted: G OE 4.20.0-rc6+ #3 Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011 RIP: 0010:__pv_queued_spin_lock_slowpath+0x1b3/0x2a0 Code: 98 83 e2 60 49 89 df 48 8b 04 c5 80 18 72 ba 48 8d ba 80 32 02 00 ba 00 80 00 00 4c 8d 65 14 41 bd 01 00 00 00 48 01 c7 85 d2 <48> 89 2f 48 89 fb 74 14 8b 45 08 85 c0 75 42 84 d2 74 6b f3 90 83 RSP: 0018:ffffc1bbc064fb58 EFLAGS: 00010006 RAX: ffffffffba65f4e7 RBX: ffff9f209c656c00 RCX: 0000000000000001 RDX: 0000000000008000 RSI: 0000000000000000 RDI: ffffffffba682787 RBP: ffff9f217bb23280 R08: 0000000000000001 R09: 0000000000000000 R10: ffff9f209d2c7800 R11: ffffffffffffffe8 R12: ffff9f217bb23294 R13: 0000000000000001 R14: 0000000000000000 R15: ffff9f209c656c00 FS: 00007fac55aad740(0000) GS:ffff9f217bb00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffba682787 CR3: 000000012f8e0000 CR4: 00000000000006e0 Call Trace: _raw_spin_lock_irq+0x27/0x30 ib_uverbs_release_uevent+0x1e/0xa0 [ib_uverbs] uverbs_free_qp+0x7e/0x90 [ib_uverbs] destroy_hw_idr_uobject+0x1c/0x50 [ib_uverbs] uverbs_destroy_uobject+0x2e/0x180 [ib_uverbs] __uverbs_cleanup_ufile+0x73/0x90 [ib_uverbs] uverbs_destroy_ufile_hw+0x5d/0x120 [ib_uverbs] ib_uverbs_remove_one+0xea/0x240 [ib_uverbs] ib_unregister_device+0xfb/0x200 [ib_core] mlx5_ib_remove+0x51/0xe0 [mlx5_ib] mlx5_remove_device+0xc1/0xd0 [mlx5_core] mlx5_unregister_device+0x3d/0xb0 [mlx5_core] remove_one+0x2a/0x90 [mlx5_core] pci_device_remove+0x3b/0xc0 device_release_driver_internal+0x16d/0x240 unbind_store+0xb2/0x100 kernfs_fop_write+0x102/0x180 __vfs_write+0x36/0x1a0 ? __alloc_fd+0xa9/0x170 ? set_close_on_exec+0x49/0x70 vfs_write+0xad/0x1a0 ksys_write+0x52/0xc0 do_syscall_64+0x5b/0x180 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7fac551aac60 Cc: <stable@vger.kernel.org> # 4.2 Fixes: 036b106 ("IB/uverbs: Enable device removal when there are active user space applications") Signed-off-by: Yishai Hadas <yishaih@mellanox.com> Signed-off-by: Leon Romanovsky <leonro@mellanox.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
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Methods cannot peak into the ufile, the only way to get a ucontext and hence a device is via the ib_uverbs_get_ucontext() call or inspecing a locked uobject. Otherwise during/after disassociation the pointers may be null or free'd. BUG: unable to handle kernel NULL pointer dereference at 0000000000000078 PGD 800000005ece6067 P4D 800000005ece6067 PUD 5ece7067 PMD 0 Oops: 0000 [#1] SMP PTI CPU: 0 PID: 10631 Comm: ibv_ud_pingpong Tainted: GW OE 4.20.0-rc6+ #3 Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011 RIP: 0010:ib_uverbs_handler_UVERBS_METHOD_QUERY_PORT+0x53/0x191 [ib_uverbs] Code: 80 00 00 00 31 c0 48 8b 47 40 48 8d 5c 24 38 48 8d 6c 24 08 48 89 df 48 8b 40 08 4c 8b a0 18 03 00 00 31 c0 f3 48 ab 48 89 ef <49> 83 7c 24 78 00 b1 06 f3 48 ab 0f 84 89 00 00 00 45 31 c9 31 d2 RSP: 0018:ffffb54802ccfb10 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffffb54802ccfb48 RCX:0000000000000000 RDX: fffffffffffffffa RSI: ffffb54802ccfcf8 RDI:ffffb54802ccfb18 RBP: ffffb54802ccfb18 R08: ffffb54802ccfd18 R09:0000000000000000 R10: 0000000000000000 R11: 00000000000000d0 R12:0000000000000000 R13: ffffb54802ccfcb0 R14: ffffb54802ccfc48 R15:ffff9f736e0059a0 FS: 00007f55a6bd7740(0000) GS:ffff9f737ba00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000078 CR3: 0000000064214000 CR4:00000000000006f0 Call Trace: ib_uverbs_cmd_verbs.isra.5+0x94d/0xa60 [ib_uverbs] ? copy_port_attr_to_resp+0x120/0x120 [ib_uverbs] ? arch_tlb_finish_mmu+0x16/0xc0 ? tlb_finish_mmu+0x1f/0x30 ? unmap_region+0xd9/0x120 ib_uverbs_ioctl+0xbc/0x120 [ib_uverbs] do_vfs_ioctl+0xa9/0x620 ? __do_munmap+0x29f/0x3a0 ksys_ioctl+0x60/0x90 __x64_sys_ioctl+0x16/0x20 do_syscall_64+0x5b/0x180 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f55a62cb567 Fixes: 641d120 ("IB/core: Move query port to ioctl") Signed-off-by: Yishai Hadas <yishaih@mellanox.com> Signed-off-by: Leon Romanovsky <leonro@mellanox.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
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Feb 4, 2019
The vma->vm_mm can become impossible to get before rdma_umap_close() is called, in this case we must not try to get an mm that is already undergoing process exit. In this case there is no need to wait for anything as the VMA will be destroyed by another thread soon and is already effectively 'unreachable' by userspace. BUG: unable to handle kernel NULL pointer dereference at 0000000000000000 PGD 800000012bc50067 P4D 800000012bc50067 PUD 129db5067 PMD 0 Oops: 0000 [#1] SMP PTI CPU: 1 PID: 2050 Comm: bash Tainted: G W OE 4.20.0-rc6+ #3 Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011 RIP: 0010:__rb_erase_color+0xb9/0x280 Code: 84 17 01 00 00 48 3b 68 10 0f 84 15 01 00 00 48 89 58 08 48 89 de 48 89 ef 4c 89 e3 e8 90 84 22 00 e9 60 ff ff ff 48 8b 5d 10 <f6> 03 01 0f 84 9c 00 00 00 48 8b 43 10 48 85 c0 74 09 f6 00 01 0f RSP: 0018:ffffbecfc090bab8 EFLAGS: 00010246 RAX: ffff97616346cf30 RBX: 0000000000000000 RCX: 0000000000000101 RDX: 0000000000000000 RSI: ffff97623b6ca828 RDI: ffff97621ef10828 RBP: ffff97621ef10828 R08: ffff97621ef10828 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff97623b6ca838 R13: ffffffffbb3fef50 R14: ffff97623b6ca828 R15: 0000000000000000 FS: 00007f7a5c31d740(0000) GS:ffff97623bb00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000011255a000 CR4: 00000000000006e0 Call Trace: unlink_file_vma+0x3b/0x50 free_pgtables+0xa1/0x110 exit_mmap+0xca/0x1a0 ? mlx5_ib_dealloc_pd+0x28/0x30 [mlx5_ib] mmput+0x54/0x140 uverbs_user_mmap_disassociate+0xcc/0x160 [ib_uverbs] uverbs_destroy_ufile_hw+0xf7/0x120 [ib_uverbs] ib_uverbs_remove_one+0xea/0x240 [ib_uverbs] ib_unregister_device+0xfb/0x200 [ib_core] mlx5_ib_remove+0x51/0xe0 [mlx5_ib] mlx5_remove_device+0xc1/0xd0 [mlx5_core] mlx5_unregister_device+0x3d/0xb0 [mlx5_core] remove_one+0x2a/0x90 [mlx5_core] pci_device_remove+0x3b/0xc0 device_release_driver_internal+0x16d/0x240 unbind_store+0xb2/0x100 kernfs_fop_write+0x102/0x180 __vfs_write+0x36/0x1a0 ? __alloc_fd+0xa9/0x170 ? set_close_on_exec+0x49/0x70 vfs_write+0xad/0x1a0 ksys_write+0x52/0xc0 do_syscall_64+0x5b/0x180 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Cc: <stable@vger.kernel.org> # 4.19 Fixes: 5f9794d ("RDMA/ucontext: Add a core API for mmaping driver IO memory") Signed-off-by: Yishai Hadas <yishaih@mellanox.com> Signed-off-by: Leon Romanovsky <leonro@mellanox.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
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…l/git/tiwai/sound Pull sound fixes from Takashi Iwai: "Only three fixes. The fix for Realtek HD-audio looks lengthy, but it's just a code shuffling, and the actual changes are fairly small. The rest are a PCM core fix for a long-standing bug that was recently scratched by syzkaller, and a trivial USB-audio quirk for DSD support" * tag 'sound-5.0-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound: ALSA: hda/realtek - Fixed hp_pin no value ALSA: pcm: Fix tight loop of OSS capture stream ALSA: usb-audio: Add Opus #3 to quirks for native DSD support
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When option CONFIG_KASAN is enabled toghether with ftrace, function ftrace_graph_caller() gets in to a recursion, via functions kasan_check_read() and kasan_check_write(). Breakpoint 2, ftrace_graph_caller () at ../arch/arm64/kernel/entry-ftrace.S:179 179 mcount_get_pc x0 // function's pc (gdb) bt #0 ftrace_graph_caller () at ../arch/arm64/kernel/entry-ftrace.S:179 #1 0xffffff90101406c8 in ftrace_caller () at ../arch/arm64/kernel/entry-ftrace.S:151 #2 0xffffff90106fd084 in kasan_check_write (p=0xffffffc06c170878, size=4) at ../mm/kasan/common.c:105 #3 0xffffff90104a2464 in atomic_add_return (v=<optimized out>, i=<optimized out>) at ./include/generated/atomic-instrumented.h:71 #4 atomic_inc_return (v=<optimized out>) at ./include/generated/atomic-fallback.h:284 #5 trace_graph_entry (trace=0xffffffc03f5ff380) at ../kernel/trace/trace_functions_graph.c:441 #6 0xffffff9010481774 in trace_graph_entry_watchdog (trace=<optimized out>) at ../kernel/trace/trace_selftest.c:741 #7 0xffffff90104a185c in function_graph_enter (ret=<optimized out>, func=<optimized out>, frame_pointer=18446743799894897728, retp=<optimized out>) at ../kernel/trace/trace_functions_graph.c:196 #8 0xffffff9010140628 in prepare_ftrace_return (self_addr=18446743592948977792, parent=0xffffffc03f5ff418, frame_pointer=18446743799894897728) at ../arch/arm64/kernel/ftrace.c:231 #9 0xffffff90101406f4 in ftrace_graph_caller () at ../arch/arm64/kernel/entry-ftrace.S:182 Backtrace stopped: previous frame identical to this frame (corrupt stack?) (gdb) Rework so that the kasan implementation isn't traced. Link: http://lkml.kernel.org/r/20181212183447.15890-1-anders.roxell@linaro.org Signed-off-by: Anders Roxell <anders.roxell@linaro.org> Acked-by: Dmitry Vyukov <dvyukov@google.com> Tested-by: Dmitry Vyukov <dvyukov@google.com> Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Feb 14, 2019
The H6 main pin controller has four banks of interrupt-triggering pins. The driver as originally submitted only specified three, but had pin descriptions referencing a fourth bank. This results in a out-of-bounds access into .irq_array of struct sunxi_pinctrl. This however did not result in a crash until v4.20, with commit a66d972 ("devres: Align data[] to ARCH_KMALLOC_MINALIGN"), which changed the alignment of memory region returned by devm_kcalloc(). The increase likely moved the out-of-bounds access into the next, unmapped page. With KASAN on, the bug is quite clear: BUG: KASAN: slab-out-of-bounds in sunxi_pinctrl_init_with_variant+0x49c/0x12b8 Write of size 4 at addr ffff80002c680280 by task swapper/0/1 CPU: 2 PID: 1 Comm: swapper/0 Not tainted 5.0.0-rc1-00016-gc480a5e6a077 #3 Hardware name: OrangePi Lite2 (DT) Call trace: dump_backtrace+0x0/0x220 show_stack+0x14/0x20 dump_stack+0xac/0xd4 print_address_description+0x60/0x25c kasan_report+0x14c/0x1ac __asan_store4+0x80/0xa0 sunxi_pinctrl_init_with_variant+0x49c/0x12b8 h6_pinctrl_probe+0x18/0x20 platform_drv_probe+0x6c/0xc8 really_probe+0x244/0x4b0 driver_probe_device.part.4+0x11c/0x164 __driver_attach+0x120/0x190 bus_for_each_dev+0xe8/0x158 driver_attach+0x30/0x40 bus_add_driver+0x308/0x318 driver_register+0xbc/0x1d0 __platform_driver_register+0x7c/0x88 h6_pinctrl_driver_init+0x18/0x20 do_one_initcall+0xd4/0x208 kernel_init_freeable+0x230/0x2c8 kernel_init+0x10/0x108 ret_from_fork+0x10/0x1c Allocated by task 1: kasan_kmalloc.part.0+0x4c/0x100 kasan_kmalloc+0xc4/0xe8 kasan_slab_alloc+0x14/0x20 __kmalloc_track_caller+0x130/0x238 devm_kmalloc+0x34/0xd0 sunxi_pinctrl_init_with_variant+0x1d8/0x12b8 h6_pinctrl_probe+0x18/0x20 platform_drv_probe+0x6c/0xc8 really_probe+0x244/0x4b0 driver_probe_device.part.4+0x11c/0x164 __driver_attach+0x120/0x190 bus_for_each_dev+0xe8/0x158 driver_attach+0x30/0x40 bus_add_driver+0x308/0x318 driver_register+0xbc/0x1d0 __platform_driver_register+0x7c/0x88 h6_pinctrl_driver_init+0x18/0x20 do_one_initcall+0xd4/0x208 kernel_init_freeable+0x230/0x2c8 kernel_init+0x10/0x108 ret_from_fork+0x10/0x1c Freed by task 0: (stack is not available) The buggy address belongs to the object at ffff80002c680080 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 0 bytes to the right of 512-byte region [ffff80002c680080, ffff80002c680280) The buggy address belongs to the page: page:ffff7e0000b1a000 count:1 mapcount:0 mapping:ffff80002e00c780 index:0xffff80002c683c80 compound_mapcount: 0 flags: 0x10200(slab|head) raw: 0000000000010200 ffff80002e003a10 ffff80002e003a10 ffff80002e00c780 raw: ffff80002c683c80 0000000000100001 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff80002c680180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff80002c680200: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff80002c680280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff80002c680300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff80002c680380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc Correct the number of IRQ banks so there are no more mismatches. Fixes: c8a8309 ("pinctrl: sunxi: add support for the Allwinner H6 main pin controller") Cc: <stable@vger.kernel.org> Signed-off-by: Chen-Yu Tsai <wens@csie.org> Tested-by: Neil Armstrong <narmstrong@baylibre.com> Acked-by: Maxime Ripard <maxime.ripard@bootlin.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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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 torvalds#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 torvalds#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: c4f6699 ("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>
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Feb 27, 2019
Evaluating page_mapping() on a poisoned page ends up dereferencing junk and making PF_POISONED_CHECK() considerably crashier than intended: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000006 Mem abort info: ESR = 0x96000005 Exception class = DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 Data abort info: ISV = 0, ISS = 0x00000005 CM = 0, WnR = 0 user pgtable: 4k pages, 39-bit VAs, pgdp = 00000000c2f6ac38 [0000000000000006] pgd=0000000000000000, pud=0000000000000000 Internal error: Oops: 96000005 [#1] PREEMPT SMP Modules linked in: CPU: 2 PID: 491 Comm: bash Not tainted 5.0.0-rc1+ #1 Hardware name: ARM LTD ARM Juno Development Platform/ARM Juno Development Platform, BIOS EDK II Dec 17 2018 pstate: 00000005 (nzcv daif -PAN -UAO) pc : page_mapping+0x18/0x118 lr : __dump_page+0x1c/0x398 Process bash (pid: 491, stack limit = 0x000000004ebd4ecd) Call trace: page_mapping+0x18/0x118 __dump_page+0x1c/0x398 dump_page+0xc/0x18 remove_store+0xbc/0x120 dev_attr_store+0x18/0x28 sysfs_kf_write+0x40/0x50 kernfs_fop_write+0x130/0x1d8 __vfs_write+0x30/0x180 vfs_write+0xb4/0x1a0 ksys_write+0x60/0xd0 __arm64_sys_write+0x18/0x20 el0_svc_common+0x94/0xf8 el0_svc_handler+0x68/0x70 el0_svc+0x8/0xc Code: f9400401 d1000422 f240003f 9a801040 (f9400402) ---[ end trace cdb5eb5bf435cecb ]--- Fix that by not inspecting the mapping until we've determined that it's likely to be valid. Now the above condition still ends up stopping the kernel, but in the correct manner: page:ffffffbf20000000 is uninitialized and poisoned raw: ffffffffffffffff ffffffffffffffff ffffffffffffffff ffffffffffffffff raw: ffffffffffffffff ffffffffffffffff ffffffffffffffff ffffffffffffffff page dumped because: VM_BUG_ON_PAGE(PagePoisoned(p)) ------------[ cut here ]------------ kernel BUG at ./include/linux/mm.h:1006! Internal error: Oops - BUG: 0 [#1] PREEMPT SMP Modules linked in: CPU: 1 PID: 483 Comm: bash Not tainted 5.0.0-rc1+ #3 Hardware name: ARM LTD ARM Juno Development Platform/ARM Juno Development Platform, BIOS EDK II Dec 17 2018 pstate: 40000005 (nZcv daif -PAN -UAO) pc : remove_store+0xbc/0x120 lr : remove_store+0xbc/0x120 ... Link: http://lkml.kernel.org/r/03b53ee9d7e76cda4b9b5e1e31eea080db033396.1550071778.git.robin.murphy@arm.com Fixes: 1c6fb1d ("mm: print more information about mapping in __dump_page") Signed-off-by: Robin Murphy <robin.murphy@arm.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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8-letter strings representing ARC perf events are stores in two 32-bit registers as ASCII characters like that: "IJMP", "IALL", "IJMPTAK" etc. And the same order of bytes in the word is used regardless CPU endianness. Which means in case of big-endian CPU core we need to swap bytes to get the same order as if it was on little-endian CPU. Otherwise we're seeing the following error message on boot: ------------------------->8---------------------- ARC perf : 8 counters (32 bits), 40 conditions, [overflow IRQ support] sysfs: cannot create duplicate filename '/devices/arc_pct/events/pmji' CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.2.18 #3 Stack Trace: arc_unwind_core+0xd4/0xfc dump_stack+0x64/0x80 sysfs_warn_dup+0x46/0x58 sysfs_add_file_mode_ns+0xb2/0x168 create_files+0x70/0x2a0 ------------[ cut here ]------------ WARNING: CPU: 0 PID: 1 at kernel/events/core.c:12144 perf_event_sysfs_init+0x70/0xa0 Failed to register pmu: arc_pct, reason -17 Modules linked in: CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.2.18 #3 Stack Trace: arc_unwind_core+0xd4/0xfc dump_stack+0x64/0x80 __warn+0x9c/0xd4 warn_slowpath_fmt+0x22/0x2c perf_event_sysfs_init+0x70/0xa0 ---[ end trace a75fb9a9837bd1ec ]--- ------------------------->8---------------------- What happens here we're trying to register more than one raw perf event with the same name "PMJI". Why? Because ARC perf events are 4 to 8 letters and encoded into two 32-bit words. In this particular case we deal with 2 events: * "IJMP____" which counts all jump & branch instructions * "IJMPC___" which counts only conditional jumps & branches Those strings are split in two 32-bit words this way "IJMP" + "____" & "IJMP" + "C___" correspondingly. Now if we read them swapped due to CPU core being big-endian then we read "PMJI" + "____" & "PMJI" + "___C". And since we interpret read array of ASCII letters as a null-terminated string on big-endian CPU we end up with 2 events of the same name "PMJI". Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com> Cc: stable@vger.kernel.org Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
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Nov 14, 2019
When lockdep is enabled, plugging Thunderbolt dock on Dominik's laptop triggers following splat: ====================================================== WARNING: possible circular locking dependency detected 5.3.0-rc6+ #1 Tainted: G T ------------------------------------------------------ pool-/usr/lib/b/1258 is trying to acquire lock: 000000005ab0ad43 (pci_rescan_remove_lock){+.+.}, at: authorized_store+0xe8/0x210 but task is already holding lock: 00000000bfb796b5 (&tb->lock){+.+.}, at: authorized_store+0x7c/0x210 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&tb->lock){+.+.}: __mutex_lock+0xac/0x9a0 tb_domain_add+0x2d/0x130 nhi_probe+0x1dd/0x330 pci_device_probe+0xd2/0x150 really_probe+0xee/0x280 driver_probe_device+0x50/0xc0 bus_for_each_drv+0x84/0xd0 __device_attach+0xe4/0x150 pci_bus_add_device+0x4e/0x70 pci_bus_add_devices+0x2e/0x66 pci_bus_add_devices+0x59/0x66 pci_bus_add_devices+0x59/0x66 enable_slot+0x344/0x450 acpiphp_check_bridge.part.0+0x119/0x150 acpiphp_hotplug_notify+0xaa/0x140 acpi_device_hotplug+0xa2/0x3f0 acpi_hotplug_work_fn+0x1a/0x30 process_one_work+0x234/0x580 worker_thread+0x50/0x3b0 kthread+0x10a/0x140 ret_from_fork+0x3a/0x50 -> #0 (pci_rescan_remove_lock){+.+.}: __lock_acquire+0xe54/0x1ac0 lock_acquire+0xb8/0x1b0 __mutex_lock+0xac/0x9a0 authorized_store+0xe8/0x210 kernfs_fop_write+0x125/0x1b0 vfs_write+0xc2/0x1d0 ksys_write+0x6c/0xf0 do_syscall_64+0x50/0x180 entry_SYSCALL_64_after_hwframe+0x49/0xbe other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&tb->lock); lock(pci_rescan_remove_lock); lock(&tb->lock); lock(pci_rescan_remove_lock); *** DEADLOCK *** 5 locks held by pool-/usr/lib/b/1258: #0: 000000003df1a1ad (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x4d/0x60 #1: 0000000095a40b02 (sb_writers#6){.+.+}, at: vfs_write+0x185/0x1d0 #2: 0000000017a7d714 (&of->mutex){+.+.}, at: kernfs_fop_write+0xf2/0x1b0 #3: 000000004f262981 (kn->count#208){.+.+}, at: kernfs_fop_write+0xfa/0x1b0 #4: 00000000bfb796b5 (&tb->lock){+.+.}, at: authorized_store+0x7c/0x210 stack backtrace: CPU: 0 PID: 1258 Comm: pool-/usr/lib/b Tainted: G T 5.3.0-rc6+ #1 On an system using ACPI hotplug the host router gets hotplugged first and then the firmware starts sending notifications about connected devices so the above scenario should not happen in reality. However, after taking a second look at commit a03e828 ("thunderbolt: Serialize PCIe tunnel creation with PCI rescan") that introduced the locking, I don't think it is actually correct. It may have cured the symptom but probably the real root cause was somewhere closer to PCI stack and possibly is already fixed with recent kernels. I also tried to reproduce the original issue with the commit reverted but could not. So to keep lockdep happy and the code bit less complex drop calls to pci_lock_rescan_remove()/pci_unlock_rescan_remove() in tb_switch_set_authorized() effectively reverting a03e828. Link: https://lkml.org/lkml/2019/8/30/513 Fixes: a03e828 ("thunderbolt: Serialize PCIe tunnel creation with PCI rescan") Reported-by: Dominik Brodowski <linux@dominikbrodowski.net> Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
mihailescu2m
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Nov 27, 2019
Call napi_disable() twice would cause dead lock. There are three situations may result in the issue. 1. rtl8152_pre_reset() and set_carrier() are run at the same time. 2. Call rtl8152_set_tunable() after rtl8152_close(). 3. Call rtl8152_set_ringparam() after rtl8152_close(). For #1, use the same solution as commit 8481141 ("r8152: Re-order napi_disable in rtl8152_close"). For #2 and #3, add checking the flag of IFF_UP and using napi_disable/napi_enable during mutex. Signed-off-by: Hayes Wang <hayeswang@realtek.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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