1. 30 Aug, 2017 40 commits
    • Zhang Bo's avatar
      Revert "leds: handle suspend/resume in heartbeat trigger" · 090911a2
      Zhang Bo authored
      commit 436c4c45 upstream.
      
      This reverts commit 5ab92a7c.
      
      System cannot enter suspend mode because of heartbeat led trigger.
      In autosleep_wq, try_to_suspend function will try to enter suspend
      mode in specific period. it will get wakeup_count then call pm_notifier
      chain callback function and freeze processes.
      Heartbeat_pm_notifier is called and it call led_trigger_unregister to
      change the trigger of led device to none. It will send uevent message
      and the wakeup source count changed. As wakeup_count changed, suspend
      will abort.
      
      Fixes: 5ab92a7c ("leds: handle suspend/resume in heartbeat trigger")
      Signed-off-by: default avatarZhang Bo <bo.zhang@nxp.com>
      Acked-by: default avatarPavel Machek <pavel@ucw.cz>
      Reviewed-by: default avatarLinus Walleij <linus.walleij@linaro.org>
      Signed-off-by: default avatarJacek Anaszewski <jacek.anaszewski@gmail.com>
      Cc: Geert Uytterhoeven <geert@linux-m68k.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      090911a2
    • Vadim Lomovtsev's avatar
      net: sunrpc: svcsock: fix NULL-pointer exception · d4c5c26c
      Vadim Lomovtsev authored
      commit eebe53e8 upstream.
      
      While running nfs/connectathon tests kernel NULL-pointer exception
      has been observed due to races in svcsock.c.
      
      Race is appear when kernel accepts connection by kernel_accept
      (which creates new socket) and start queuing ingress packets
      to new socket. This happens in ksoftirq context which could run
      concurrently on a different core while new socket setup is not done yet.
      
      The fix is to re-order socket user data init sequence and add
      write/read barrier calls to be sure that we got proper values
      for callback pointers before actually calling them.
      
      Test results: nfs/connectathon reports '0' failed tests for about 200+ iterations.
      
      Crash log:
      ---<-snip->---
      [ 6708.638984] Unable to handle kernel NULL pointer dereference at virtual address 00000000
      [ 6708.647093] pgd = ffff0000094e0000
      [ 6708.650497] [00000000] *pgd=0000010ffff90003, *pud=0000010ffff90003, *pmd=0000010ffff80003, *pte=0000000000000000
      [ 6708.660761] Internal error: Oops: 86000005 [#1] SMP
      [ 6708.665630] Modules linked in: nfsv3 nfnetlink_queue nfnetlink_log nfnetlink rpcsec_gss_krb5 nfsv4 dns_resolver nfs fscache overlay xt_CONNSECMARK xt_SECMARK xt_conntrack iptable_security ip_tables ah4 xfrm4_mode_transport sctp tun binfmt_misc ext4 jbd2 mbcache loop tcp_diag udp_diag inet_diag rpcrdma ib_isert iscsi_target_mod ib_iser rdma_cm iw_cm libiscsi scsi_transport_iscsi ib_srpt target_core_mod ib_srp scsi_transport_srp ib_ipoib ib_ucm ib_uverbs ib_umad ib_cm ib_core nls_koi8_u nls_cp932 ts_kmp nf_conntrack_ipv4 nf_defrag_ipv4 nf_conntrack vfat fat ghash_ce sha2_ce sha1_ce cavium_rng_vf i2c_thunderx sg thunderx_edac i2c_smbus edac_core cavium_rng nfsd auth_rpcgss nfs_acl lockd grace sunrpc xfs libcrc32c nicvf nicpf ast i2c_algo_bit drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops
      [ 6708.736446]  ttm drm i2c_core thunder_bgx thunder_xcv mdio_thunder mdio_cavium dm_mirror dm_region_hash dm_log dm_mod [last unloaded: stap_3c300909c5b3f46dcacd49aab3334af_87021]
      [ 6708.752275] CPU: 84 PID: 0 Comm: swapper/84 Tainted: G        W  OE   4.11.0-4.el7.aarch64 #1
      [ 6708.760787] Hardware name: www.cavium.com CRB-2S/CRB-2S, BIOS 0.3 Mar 13 2017
      [ 6708.767910] task: ffff810006842e80 task.stack: ffff81000689c000
      [ 6708.773822] PC is at 0x0
      [ 6708.776739] LR is at svc_data_ready+0x38/0x88 [sunrpc]
      [ 6708.781866] pc : [<0000000000000000>] lr : [<ffff0000029d7378>] pstate: 60000145
      [ 6708.789248] sp : ffff810ffbad3900
      [ 6708.792551] x29: ffff810ffbad3900 x28: ffff000008c73d58
      [ 6708.797853] x27: 0000000000000000 x26: ffff81000bbe1e00
      [ 6708.803156] x25: 0000000000000020 x24: ffff800f7410bf28
      [ 6708.808458] x23: ffff000008c63000 x22: ffff000008c63000
      [ 6708.813760] x21: ffff800f7410bf28 x20: ffff81000bbe1e00
      [ 6708.819063] x19: ffff810012412400 x18: 00000000d82a9df2
      [ 6708.824365] x17: 0000000000000000 x16: 0000000000000000
      [ 6708.829667] x15: 0000000000000000 x14: 0000000000000001
      [ 6708.834969] x13: 0000000000000000 x12: 722e736f622e676e
      [ 6708.840271] x11: 00000000f814dd99 x10: 0000000000000000
      [ 6708.845573] x9 : 7374687225000000 x8 : 0000000000000000
      [ 6708.850875] x7 : 0000000000000000 x6 : 0000000000000000
      [ 6708.856177] x5 : 0000000000000028 x4 : 0000000000000000
      [ 6708.861479] x3 : 0000000000000000 x2 : 00000000e5000000
      [ 6708.866781] x1 : 0000000000000000 x0 : ffff81000bbe1e00
      [ 6708.872084]
      [ 6708.873565] Process swapper/84 (pid: 0, stack limit = 0xffff81000689c000)
      [ 6708.880341] Stack: (0xffff810ffbad3900 to 0xffff8100068a0000)
      [ 6708.886075] Call trace:
      [ 6708.888513] Exception stack(0xffff810ffbad3710 to 0xffff810ffbad3840)
      [ 6708.894942] 3700:                                   ffff810012412400 0001000000000000
      [ 6708.902759] 3720: ffff810ffbad3900 0000000000000000 0000000060000145 ffff800f79300000
      [ 6708.910577] 3740: ffff000009274d00 00000000000003ea 0000000000000015 ffff000008c63000
      [ 6708.918395] 3760: ffff810ffbad3830 ffff800f79300000 000000000000004d 0000000000000000
      [ 6708.926212] 3780: ffff810ffbad3890 ffff0000080f88dc ffff800f79300000 000000000000004d
      [ 6708.934030] 37a0: ffff800f7930093c ffff000008c63000 0000000000000000 0000000000000140
      [ 6708.941848] 37c0: ffff000008c2c000 0000000000040b00 ffff81000bbe1e00 0000000000000000
      [ 6708.949665] 37e0: 00000000e5000000 0000000000000000 0000000000000000 0000000000000028
      [ 6708.957483] 3800: 0000000000000000 0000000000000000 0000000000000000 7374687225000000
      [ 6708.965300] 3820: 0000000000000000 00000000f814dd99 722e736f622e676e 0000000000000000
      [ 6708.973117] [<          (null)>]           (null)
      [ 6708.977824] [<ffff0000086f9fa4>] tcp_data_queue+0x754/0xc5c
      [ 6708.983386] [<ffff0000086fa64c>] tcp_rcv_established+0x1a0/0x67c
      [ 6708.989384] [<ffff000008704120>] tcp_v4_do_rcv+0x15c/0x22c
      [ 6708.994858] [<ffff000008707418>] tcp_v4_rcv+0xaf0/0xb58
      [ 6709.000077] [<ffff0000086df784>] ip_local_deliver_finish+0x10c/0x254
      [ 6709.006419] [<ffff0000086dfea4>] ip_local_deliver+0xf0/0xfc
      [ 6709.011980] [<ffff0000086dfad4>] ip_rcv_finish+0x208/0x3a4
      [ 6709.017454] [<ffff0000086e018c>] ip_rcv+0x2dc/0x3c8
      [ 6709.022328] [<ffff000008692fc8>] __netif_receive_skb_core+0x2f8/0xa0c
      [ 6709.028758] [<ffff000008696068>] __netif_receive_skb+0x38/0x84
      [ 6709.034580] [<ffff00000869611c>] netif_receive_skb_internal+0x68/0xdc
      [ 6709.041010] [<ffff000008696bc0>] napi_gro_receive+0xcc/0x1a8
      [ 6709.046690] [<ffff0000014b0fc4>] nicvf_cq_intr_handler+0x59c/0x730 [nicvf]
      [ 6709.053559] [<ffff0000014b1380>] nicvf_poll+0x38/0xb8 [nicvf]
      [ 6709.059295] [<ffff000008697a6c>] net_rx_action+0x2f8/0x464
      [ 6709.064771] [<ffff000008081824>] __do_softirq+0x11c/0x308
      [ 6709.070164] [<ffff0000080d14e4>] irq_exit+0x12c/0x174
      [ 6709.075206] [<ffff00000813101c>] __handle_domain_irq+0x78/0xc4
      [ 6709.081027] [<ffff000008081608>] gic_handle_irq+0x94/0x190
      [ 6709.086501] Exception stack(0xffff81000689fdf0 to 0xffff81000689ff20)
      [ 6709.092929] fde0:                                   0000810ff2ec0000 ffff000008c10000
      [ 6709.100747] fe00: ffff000008c70ef4 0000000000000001 0000000000000000 ffff810ffbad9b18
      [ 6709.108565] fe20: ffff810ffbad9c70 ffff8100169d3800 ffff810006843ab0 ffff81000689fe80
      [ 6709.116382] fe40: 0000000000000bd0 0000ffffdf979cd0 183f5913da192500 0000ffff8a254ce4
      [ 6709.124200] fe60: 0000ffff8a254b78 0000aaab10339808 0000000000000000 0000ffff8a0c2a50
      [ 6709.132018] fe80: 0000ffffdf979b10 ffff000008d6d450 ffff000008c10000 ffff000008d6d000
      [ 6709.139836] fea0: 0000000000000054 ffff000008cd3dbc 0000000000000000 0000000000000000
      [ 6709.147653] fec0: 0000000000000000 0000000000000000 0000000000000000 ffff81000689ff20
      [ 6709.155471] fee0: ffff000008085240 ffff81000689ff20 ffff000008085244 0000000060000145
      [ 6709.163289] ff00: ffff81000689ff10 ffff00000813f1e4 ffffffffffffffff ffff00000813f238
      [ 6709.171107] [<ffff000008082eb4>] el1_irq+0xb4/0x140
      [ 6709.175976] [<ffff000008085244>] arch_cpu_idle+0x44/0x11c
      [ 6709.181368] [<ffff0000087bf3b8>] default_idle_call+0x20/0x30
      [ 6709.187020] [<ffff000008116d50>] do_idle+0x158/0x1e4
      [ 6709.191973] [<ffff000008116ff4>] cpu_startup_entry+0x2c/0x30
      [ 6709.197624] [<ffff00000808e7cc>] secondary_start_kernel+0x13c/0x160
      [ 6709.203878] [<0000000001bc71c4>] 0x1bc71c4
      [ 6709.207967] Code: bad PC value
      [ 6709.211061] SMP: stopping secondary CPUs
      [ 6709.218830] Starting crashdump kernel...
      [ 6709.222749] Bye!
      ---<-snip>---
      Signed-off-by: default avatarVadim Lomovtsev <vlomovts@redhat.com>
      Reviewed-by: default avatarJeff Layton <jlayton@redhat.com>
      Signed-off-by: default avatarJ. Bruce Fields <bfields@redhat.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      d4c5c26c
    • Eric Biggers's avatar
      x86/mm: Fix use-after-free of ldt_struct · 3559de45
      Eric Biggers authored
      commit ccd5b323 upstream.
      
      The following commit:
      
        39a0526f ("x86/mm: Factor out LDT init from context init")
      
      renamed init_new_context() to init_new_context_ldt() and added a new
      init_new_context() which calls init_new_context_ldt().  However, the
      error code of init_new_context_ldt() was ignored.  Consequently, if a
      memory allocation in alloc_ldt_struct() failed during a fork(), the
      ->context.ldt of the new task remained the same as that of the old task
      (due to the memcpy() in dup_mm()).  ldt_struct's are not intended to be
      shared, so a use-after-free occurred after one task exited.
      
      Fix the bug by making init_new_context() pass through the error code of
      init_new_context_ldt().
      
      This bug was found by syzkaller, which encountered the following splat:
      
          BUG: KASAN: use-after-free in free_ldt_struct.part.2+0x10a/0x150 arch/x86/kernel/ldt.c:116
          Read of size 4 at addr ffff88006d2cb7c8 by task kworker/u9:0/3710
      
          CPU: 1 PID: 3710 Comm: kworker/u9:0 Not tainted 4.13.0-rc4-next-20170811 #2
          Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
          Call Trace:
           __dump_stack lib/dump_stack.c:16 [inline]
           dump_stack+0x194/0x257 lib/dump_stack.c:52
           print_address_description+0x73/0x250 mm/kasan/report.c:252
           kasan_report_error mm/kasan/report.c:351 [inline]
           kasan_report+0x24e/0x340 mm/kasan/report.c:409
           __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:429
           free_ldt_struct.part.2+0x10a/0x150 arch/x86/kernel/ldt.c:116
           free_ldt_struct arch/x86/kernel/ldt.c:173 [inline]
           destroy_context_ldt+0x60/0x80 arch/x86/kernel/ldt.c:171
           destroy_context arch/x86/include/asm/mmu_context.h:157 [inline]
           __mmdrop+0xe9/0x530 kernel/fork.c:889
           mmdrop include/linux/sched/mm.h:42 [inline]
           exec_mmap fs/exec.c:1061 [inline]
           flush_old_exec+0x173c/0x1ff0 fs/exec.c:1291
           load_elf_binary+0x81f/0x4ba0 fs/binfmt_elf.c:855
           search_binary_handler+0x142/0x6b0 fs/exec.c:1652
           exec_binprm fs/exec.c:1694 [inline]
           do_execveat_common.isra.33+0x1746/0x22e0 fs/exec.c:1816
           do_execve+0x31/0x40 fs/exec.c:1860
           call_usermodehelper_exec_async+0x457/0x8f0 kernel/umh.c:100
           ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:431
      
          Allocated by task 3700:
           save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
           save_stack+0x43/0xd0 mm/kasan/kasan.c:447
           set_track mm/kasan/kasan.c:459 [inline]
           kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:551
           kmem_cache_alloc_trace+0x136/0x750 mm/slab.c:3627
           kmalloc include/linux/slab.h:493 [inline]
           alloc_ldt_struct+0x52/0x140 arch/x86/kernel/ldt.c:67
           write_ldt+0x7b7/0xab0 arch/x86/kernel/ldt.c:277
           sys_modify_ldt+0x1ef/0x240 arch/x86/kernel/ldt.c:307
           entry_SYSCALL_64_fastpath+0x1f/0xbe
      
          Freed by task 3700:
           save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
           save_stack+0x43/0xd0 mm/kasan/kasan.c:447
           set_track mm/kasan/kasan.c:459 [inline]
           kasan_slab_free+0x71/0xc0 mm/kasan/kasan.c:524
           __cache_free mm/slab.c:3503 [inline]
           kfree+0xca/0x250 mm/slab.c:3820
           free_ldt_struct.part.2+0xdd/0x150 arch/x86/kernel/ldt.c:121
           free_ldt_struct arch/x86/kernel/ldt.c:173 [inline]
           destroy_context_ldt+0x60/0x80 arch/x86/kernel/ldt.c:171
           destroy_context arch/x86/include/asm/mmu_context.h:157 [inline]
           __mmdrop+0xe9/0x530 kernel/fork.c:889
           mmdrop include/linux/sched/mm.h:42 [inline]
           __mmput kernel/fork.c:916 [inline]
           mmput+0x541/0x6e0 kernel/fork.c:927
           copy_process.part.36+0x22e1/0x4af0 kernel/fork.c:1931
           copy_process kernel/fork.c:1546 [inline]
           _do_fork+0x1ef/0xfb0 kernel/fork.c:2025
           SYSC_clone kernel/fork.c:2135 [inline]
           SyS_clone+0x37/0x50 kernel/fork.c:2129
           do_syscall_64+0x26c/0x8c0 arch/x86/entry/common.c:287
           return_from_SYSCALL_64+0x0/0x7a
      
      Here is a C reproducer:
      
          #include <asm/ldt.h>
          #include <pthread.h>
          #include <signal.h>
          #include <stdlib.h>
          #include <sys/syscall.h>
          #include <sys/wait.h>
          #include <unistd.h>
      
          static void *fork_thread(void *_arg)
          {
              fork();
          }
      
          int main(void)
          {
              struct user_desc desc = { .entry_number = 8191 };
      
              syscall(__NR_modify_ldt, 1, &desc, sizeof(desc));
      
              for (;;) {
                  if (fork() == 0) {
                      pthread_t t;
      
                      srand(getpid());
                      pthread_create(&t, NULL, fork_thread, NULL);
                      usleep(rand() % 10000);
                      syscall(__NR_exit_group, 0);
                  }
                  wait(NULL);
              }
          }
      
      Note: the reproducer takes advantage of the fact that alloc_ldt_struct()
      may use vmalloc() to allocate a large ->entries array, and after
      commit:
      
        5d17a73a ("vmalloc: back off when the current task is killed")
      
      it is possible for userspace to fail a task's vmalloc() by
      sending a fatal signal, e.g. via exit_group().  It would be more
      difficult to reproduce this bug on kernels without that commit.
      
      This bug only affected kernels with CONFIG_MODIFY_LDT_SYSCALL=y.
      Signed-off-by: default avatarEric Biggers <ebiggers@google.com>
      Acked-by: default avatarDave Hansen <dave.hansen@linux.intel.com>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: Christoph Hellwig <hch@lst.de>
      Cc: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: Dmitry Vyukov <dvyukov@google.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Michal Hocko <mhocko@suse.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: linux-mm@kvack.org
      Fixes: 39a0526f ("x86/mm: Factor out LDT init from context init")
      Link: http://lkml.kernel.org/r/20170824175029.76040-1-ebiggers3@gmail.comSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      3559de45
    • Nicholas Piggin's avatar
      timers: Fix excessive granularity of new timers after a nohz idle · 70b3fd5c
      Nicholas Piggin authored
      commit 2fe59f50 upstream.
      
      When a timer base is idle, it is forwarded when a new timer is added
      to ensure that granularity does not become excessive. When not idle,
      the timer tick is expected to increment the base.
      
      However there are several problems:
      
      - If an existing timer is modified, the base is forwarded only after
        the index is calculated.
      
      - The base is not forwarded by add_timer_on.
      
      - There is a window after a timer is restarted from a nohz idle, after
        it is marked not-idle and before the timer tick on this CPU, where a
        timer may be added but the ancient base does not get forwarded.
      
      These result in excessive granularity (a 1 jiffy timeout can blow out
      to 100s of jiffies), which cause the rcu lockup detector to trigger,
      among other things.
      
      Fix this by keeping track of whether the timer base has been idle
      since it was last run or forwarded, and if so then forward it before
      adding a new timer.
      
      There is still a case where mod_timer optimises the case of a pending
      timer mod with the same expiry time, where the timer can see excessive
      granularity relative to the new, shorter interval. A comment is added,
      but it's not changed because it is an important fastpath for
      networking.
      
      This has been tested and found to fix the RCU softlockup messages.
      
      Testing was also done with tracing to measure requested versus
      achieved wakeup latencies for all non-deferrable timers in an idle
      system (with no lockup watchdogs running). Wakeup latency relative to
      absolute latency is calculated (note this suffers from round-up skew
      at low absolute times) and analysed:
      
                   max     avg      std
      upstream   506.0    1.20     4.68
      patched      2.0    1.08     0.15
      
      The bug was noticed due to the lockup detector Kconfig changes
      dropping it out of people's .configs and resulting in larger base
      clk skew When the lockup detectors are enabled, no CPU can go idle for
      longer than 4 seconds, which limits the granularity errors.
      Sub-optimal timer behaviour is observable on a smaller scale in that
      case:
      
      	     max     avg      std
      upstream     9.0    1.05     0.19
      patched      2.0    1.04     0.11
      
      Fixes: Fixes: a683f390 ("timers: Forward the wheel clock whenever possible")
      Signed-off-by: default avatarNicholas Piggin <npiggin@gmail.com>
      Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Tested-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
      Tested-by: default avatarDavid Miller <davem@davemloft.net>
      Cc: dzickus@redhat.com
      Cc: sfr@canb.auug.org.au
      Cc: mpe@ellerman.id.au
      Cc: Stephen Boyd <sboyd@codeaurora.org>
      Cc: linuxarm@huawei.com
      Cc: abdhalee@linux.vnet.ibm.com
      Cc: John Stultz <john.stultz@linaro.org>
      Cc: akpm@linux-foundation.org
      Cc: paulmck@linux.vnet.ibm.com
      Cc: torvalds@linux-foundation.org
      Link: http://lkml.kernel.org/r/20170822084348.21436-1-npiggin@gmail.comSigned-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      70b3fd5c
    • Thomas Gleixner's avatar
      perf/x86/intel/rapl: Make package handling more robust · 3df3b2ef
      Thomas Gleixner authored
      commit dd86e373 upstream.
      
      The package management code in RAPL relies on package mapping being
      available before a CPU is started. This changed with:
      
        9d85eb91 ("x86/smpboot: Make logical package management more robust")
      
      because the ACPI/BIOS information turned out to be unreliable, but that
      left RAPL in broken state. This was not noticed because on a regular boot
      all CPUs are online before RAPL is initialized.
      
      A possible fix would be to reintroduce the mess which allocates a package
      data structure in CPU prepare and when it turns out to already exist in
      starting throw it away later in the CPU online callback. But that's a
      horrible hack and not required at all because RAPL becomes functional for
      perf only in the CPU online callback. That's correct because user space is
      not yet informed about the CPU being onlined, so nothing caan rely on RAPL
      being available on that particular CPU.
      
      Move the allocation to the CPU online callback and simplify the hotplug
      handling. At this point the package mapping is established and correct.
      
      This also adds a missing check for available package data in the
      event_init() function.
      Reported-by: default avatarYasuaki Ishimatsu <yasu.isimatu@gmail.com>
      Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      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: Peter Zijlstra <peterz@infradead.org>
      Cc: Sebastian Siewior <bigeasy@linutronix.de>
      Cc: Stephane Eranian <eranian@google.com>
      Cc: Vince Weaver <vincent.weaver@maine.edu>
      Fixes: 9d85eb91 ("x86/smpboot: Make logical package management more robust")
      Link: http://lkml.kernel.org/r/20170131230141.212593966@linutronix.deSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
      [ jwang: backport to 4.9 fix Null pointer deref during hotplug cpu.]
      Signed-off-by: default avatarJack Wang <jinpu.wang@profitbricks.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      3df3b2ef
    • Masami Hiramatsu's avatar
      perf probe: Fix --funcs to show correct symbols for offline module · bac83e5c
      Masami Hiramatsu authored
      commit eebc509b upstream.
      
      Fix --funcs (-F) option to show correct symbols for offline module.
      Since previous perf-probe uses machine__findnew_module_map() for offline
      module, even if user passes a module file (with full path) which is for
      other architecture, perf-probe always tries to load symbol map for
      current kernel module.
      
      This fix uses dso__new_map() to load the map from given binary as same
      as a map for user applications.
      Signed-off-by: default avatarMasami Hiramatsu <mhiramat@kernel.org>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Link: http://lkml.kernel.org/r/148350053478.19001.15435255244512631545.stgit@devboxSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Krister Johansen <kjlx@templeofstupid.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      bac83e5c
    • Mark Rutland's avatar
      perf/core: Fix group {cpu,task} validation · bde6608d
      Mark Rutland authored
      commit 64aee2a9 upstream.
      
      Regardless of which events form a group, it does not make sense for the
      events to target different tasks and/or CPUs, as this leaves the group
      inconsistent and impossible to schedule. The core perf code assumes that
      these are consistent across (successfully intialised) groups.
      
      Core perf code only verifies this when moving SW events into a HW
      context. Thus, we can violate this requirement for pure SW groups and
      pure HW groups, unless the relevant PMU driver happens to perform this
      verification itself. These mismatched groups subsequently wreak havoc
      elsewhere.
      
      For example, we handle watchpoints as SW events, and reserve watchpoint
      HW on a per-CPU basis at pmu::event_init() time to ensure that any event
      that is initialised is guaranteed to have a slot at pmu::add() time.
      However, the core code only checks the group leader's cpu filter (via
      event_filter_match()), and can thus install follower events onto CPUs
      violating thier (mismatched) CPU filters, potentially installing them
      into a CPU without sufficient reserved slots.
      
      This can be triggered with the below test case, resulting in warnings
      from arch backends.
      
        #define _GNU_SOURCE
        #include <linux/hw_breakpoint.h>
        #include <linux/perf_event.h>
        #include <sched.h>
        #include <stdio.h>
        #include <sys/prctl.h>
        #include <sys/syscall.h>
        #include <unistd.h>
      
        static int perf_event_open(struct perf_event_attr *attr, pid_t pid, int cpu,
      			   int group_fd, unsigned long flags)
        {
      	return syscall(__NR_perf_event_open, attr, pid, cpu, group_fd, flags);
        }
      
        char watched_char;
      
        struct perf_event_attr wp_attr = {
      	.type = PERF_TYPE_BREAKPOINT,
      	.bp_type = HW_BREAKPOINT_RW,
      	.bp_addr = (unsigned long)&watched_char,
      	.bp_len = 1,
      	.size = sizeof(wp_attr),
        };
      
        int main(int argc, char *argv[])
        {
      	int leader, ret;
      	cpu_set_t cpus;
      
      	/*
      	 * Force use of CPU0 to ensure our CPU0-bound events get scheduled.
      	 */
      	CPU_ZERO(&cpus);
      	CPU_SET(0, &cpus);
      	ret = sched_setaffinity(0, sizeof(cpus), &cpus);
      	if (ret) {
      		printf("Unable to set cpu affinity\n");
      		return 1;
      	}
      
      	/* open leader event, bound to this task, CPU0 only */
      	leader = perf_event_open(&wp_attr, 0, 0, -1, 0);
      	if (leader < 0) {
      		printf("Couldn't open leader: %d\n", leader);
      		return 1;
      	}
      
      	/*
      	 * Open a follower event that is bound to the same task, but a
      	 * different CPU. This means that the group should never be possible to
      	 * schedule.
      	 */
      	ret = perf_event_open(&wp_attr, 0, 1, leader, 0);
      	if (ret < 0) {
      		printf("Couldn't open mismatched follower: %d\n", ret);
      		return 1;
      	} else {
      		printf("Opened leader/follower with mismastched CPUs\n");
      	}
      
      	/*
      	 * Open as many independent events as we can, all bound to the same
      	 * task, CPU0 only.
      	 */
      	do {
      		ret = perf_event_open(&wp_attr, 0, 0, -1, 0);
      	} while (ret >= 0);
      
      	/*
      	 * Force enable/disble all events to trigger the erronoeous
      	 * installation of the follower event.
      	 */
      	printf("Opened all events. Toggling..\n");
      	for (;;) {
      		prctl(PR_TASK_PERF_EVENTS_DISABLE, 0, 0, 0, 0);
      		prctl(PR_TASK_PERF_EVENTS_ENABLE, 0, 0, 0, 0);
      	}
      
      	return 0;
        }
      
      Fix this by validating this requirement regardless of whether we're
      moving events.
      Signed-off-by: default avatarMark Rutland <mark.rutland@arm.com>
      Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
      Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
      Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Zhou Chengming <zhouchengming1@huawei.com>
      Link: http://lkml.kernel.org/r/1498142498-15758-1-git-send-email-mark.rutland@arm.comSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      bde6608d
    • Steven Rostedt (VMware)'s avatar
      ftrace: Check for null ret_stack on profile function graph entry function · 741397d1
      Steven Rostedt (VMware) authored
      commit a8f0f9e4 upstream.
      
      There's a small race when function graph shutsdown and the calling of the
      registered function graph entry callback. The callback must not reference
      the task's ret_stack without first checking that it is not NULL. Note, when
      a ret_stack is allocated for a task, it stays allocated until the task exits.
      The problem here, is that function_graph is shutdown, and a new task was
      created, which doesn't have its ret_stack allocated. But since some of the
      functions are still being traced, the callbacks can still be called.
      
      The normal function_graph code handles this, but starting with commit
      8861dd30 ("ftrace: Access ret_stack->subtime only in the function
      profiler") the profiler code references the ret_stack on function entry, but
      doesn't check if it is NULL first.
      
      Link: https://bugzilla.kernel.org/show_bug.cgi?id=196611
      
      Fixes: 8861dd30 ("ftrace: Access ret_stack->subtime only in the function profiler")
      Reported-by: lilydjwg@gmail.com
      Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      741397d1
    • Chuck Lever's avatar
      nfsd: Limit end of page list when decoding NFSv4 WRITE · fd8235e7
      Chuck Lever authored
      commit fc788f64 upstream.
      
      When processing an NFSv4 WRITE operation, argp->end should never
      point past the end of the data in the final page of the page list.
      Otherwise, nfsd4_decode_compound can walk into uninitialized memory.
      
      More critical, nfsd4_decode_write is failing to increment argp->pagelen
      when it increments argp->pagelist.  This can cause later xdr decoders
      to assume more data is available than really is, which can cause server
      crashes on malformed requests.
      Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
      Signed-off-by: default avatarJ. Bruce Fields <bfields@redhat.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      fd8235e7
    • Ronnie Sahlberg's avatar
      cifs: return ENAMETOOLONG for overlong names in cifs_open()/cifs_lookup() · 5ed70f7d
      Ronnie Sahlberg authored
      commit d3edede2 upstream.
      
      Add checking for the path component length and verify it is <= the maximum
      that the server advertizes via FileFsAttributeInformation.
      
      With this patch cifs.ko will now return ENAMETOOLONG instead of ENOENT
      when users to access an overlong path.
      
      To test this, try to cd into a (non-existing) directory on a CIFS share
      that has a too long name:
      cd /mnt/aaaaaaaaaaaaaaa...
      
      and it now should show a good error message from the shell:
      bash: cd: /mnt/aaaaaaaaaaaaaaaa...aaaaaa: File name too long
      
      rh bz 1153996
      Signed-off-by: default avatarRonnie Sahlberg <lsahlber@redhat.com>
      Signed-off-by: default avatarSteve French <smfrench@gmail.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      5ed70f7d
    • Sachin Prabhu's avatar
      cifs: Fix df output for users with quota limits · 8b053290
      Sachin Prabhu authored
      commit 42bec214 upstream.
      
      The df for a SMB2 share triggers a GetInfo call for
      FS_FULL_SIZE_INFORMATION. The values returned are used to populate
      struct statfs.
      
      The problem is that none of the information returned by the call
      contains the total blocks available on the filesystem. Instead we use
      the blocks available to the user ie. quota limitation when filling out
      statfs.f_blocks. The information returned does contain Actual free units
      on the filesystem and is used to populate statfs.f_bfree. For users with
      quota enabled, it can lead to situations where the total free space
      reported is more than the total blocks on the system ending up with df
      reports like the following
      
       # df -h /mnt/a
      Filesystem         Size  Used Avail Use% Mounted on
      //192.168.22.10/a  2.5G -2.3G  2.5G    - /mnt/a
      
      To fix this problem, we instead populate both statfs.f_bfree with the
      same value as statfs.f_bavail ie. CallerAvailableAllocationUnits. This
      is similar to what is done already in the code for cifs and df now
      reports the quota information for the user used to mount the share.
      
       # df --si /mnt/a
      Filesystem         Size  Used Avail Use% Mounted on
      //192.168.22.10/a  2.7G  101M  2.6G   4% /mnt/a
      Signed-off-by: default avatarSachin Prabhu <sprabhu@redhat.com>
      Signed-off-by: default avatarPierguido Lambri <plambri@redhat.com>
      Signed-off-by: default avatarSteve French <smfrench@gmail.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      8b053290
    • Nicholas Piggin's avatar
      kbuild: linker script do not match C names unless LD_DEAD_CODE_DATA_ELIMINATION is configured · 1fdee091
      Nicholas Piggin authored
      commit cb87481e upstream.
      
      The .data and .bss sections were modified in the generic linker script to
      pull in sections named .data.<C identifier>, which are generated by gcc with
      -ffunction-sections and -fdata-sections options.
      
      The problem with this pattern is it can also match section names that Linux
      defines explicitly, e.g., .data.unlikely. This can cause Linux sections to
      get moved into the wrong place.
      
      The way to avoid this is to use ".." separators for explicit section names
      (the dot character is valid in a section name but not a C identifier).
      However currently there are sections which don't follow this rule, so for
      now just disable the wild card by default.
      
      Example: http://marc.info/?l=linux-arm-kernel&m=150106824024221&w=2
      
      Fixes: b67067f1 ("kbuild: allow archs to select link dead code/data elimination")
      Signed-off-by: default avatarNicholas Piggin <npiggin@gmail.com>
      Signed-off-by: default avatarMasahiro Yamada <yamada.masahiro@socionext.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      1fdee091
    • Steven Rostedt (VMware)'s avatar
      tracing: Fix freeing of filter in create_filter() when set_str is false · 8838cd5c
      Steven Rostedt (VMware) authored
      commit 8b0db1a5 upstream.
      
      Performing the following task with kmemleak enabled:
      
       # cd /sys/kernel/tracing/events/irq/irq_handler_entry/
       # echo 'enable_event:kmem:kmalloc:3 if irq >' > trigger
       # echo 'enable_event:kmem:kmalloc:3 if irq > 31' > trigger
       # echo scan > /sys/kernel/debug/kmemleak
       # cat /sys/kernel/debug/kmemleak
      unreferenced object 0xffff8800b9290308 (size 32):
        comm "bash", pid 1114, jiffies 4294848451 (age 141.139s)
        hex dump (first 32 bytes):
          00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
          00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
        backtrace:
          [<ffffffff81cef5aa>] kmemleak_alloc+0x4a/0xa0
          [<ffffffff81357938>] kmem_cache_alloc_trace+0x158/0x290
          [<ffffffff81261c09>] create_filter_start.constprop.28+0x99/0x940
          [<ffffffff812639c9>] create_filter+0xa9/0x160
          [<ffffffff81263bdc>] create_event_filter+0xc/0x10
          [<ffffffff812655e5>] set_trigger_filter+0xe5/0x210
          [<ffffffff812660c4>] event_enable_trigger_func+0x324/0x490
          [<ffffffff812652e2>] event_trigger_write+0x1a2/0x260
          [<ffffffff8138cf87>] __vfs_write+0xd7/0x380
          [<ffffffff8138f421>] vfs_write+0x101/0x260
          [<ffffffff8139187b>] SyS_write+0xab/0x130
          [<ffffffff81cfd501>] entry_SYSCALL_64_fastpath+0x1f/0xbe
          [<ffffffffffffffff>] 0xffffffffffffffff
      
      The function create_filter() is passed a 'filterp' pointer that gets
      allocated, and if "set_str" is true, it is up to the caller to free it, even
      on error. The problem is that the pointer is not freed by create_filter()
      when set_str is false. This is a bug, and it is not up to the caller to free
      the filter on error if it doesn't care about the string.
      
      Link: http://lkml.kernel.org/r/1502705898-27571-2-git-send-email-chuhu@redhat.com
      
      Fixes: 38b78eb8 ("tracing: Factorize filter creation")
      Reported-by: default avatarChunyu Hu <chuhu@redhat.com>
      Tested-by: default avatarChunyu Hu <chuhu@redhat.com>
      Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      8838cd5c
    • Chunyu Hu's avatar
      tracing: Fix kmemleak in tracing_map_array_free() · 2818a765
      Chunyu Hu authored
      commit 475bb3c6 upstream.
      
      kmemleak reported the below leak when I was doing clear of the hist
      trigger. With this patch, the kmeamleak is gone.
      
      unreferenced object 0xffff94322b63d760 (size 32):
        comm "bash", pid 1522, jiffies 4403687962 (age 2442.311s)
        hex dump (first 32 bytes):
          00 01 00 00 04 00 00 00 08 00 00 00 ff 00 00 00  ................
          10 00 00 00 00 00 00 00 80 a8 7a f2 31 94 ff ff  ..........z.1...
        backtrace:
          [<ffffffff9e96c27a>] kmemleak_alloc+0x4a/0xa0
          [<ffffffff9e424cba>] kmem_cache_alloc_trace+0xca/0x1d0
          [<ffffffff9e377736>] tracing_map_array_alloc+0x26/0x140
          [<ffffffff9e261be0>] kretprobe_trampoline+0x0/0x50
          [<ffffffff9e38b935>] create_hist_data+0x535/0x750
          [<ffffffff9e38bd47>] event_hist_trigger_func+0x1f7/0x420
          [<ffffffff9e38893d>] event_trigger_write+0xfd/0x1a0
          [<ffffffff9e44dfc7>] __vfs_write+0x37/0x170
          [<ffffffff9e44f552>] vfs_write+0xb2/0x1b0
          [<ffffffff9e450b85>] SyS_write+0x55/0xc0
          [<ffffffff9e203857>] do_syscall_64+0x67/0x150
          [<ffffffff9e977ce7>] return_from_SYSCALL_64+0x0/0x6a
          [<ffffffffffffffff>] 0xffffffffffffffff
      unreferenced object 0xffff9431f27aa880 (size 128):
        comm "bash", pid 1522, jiffies 4403687962 (age 2442.311s)
        hex dump (first 32 bytes):
          00 00 8c 2a 32 94 ff ff 00 f0 8b 2a 32 94 ff ff  ...*2......*2...
          00 e0 8b 2a 32 94 ff ff 00 d0 8b 2a 32 94 ff ff  ...*2......*2...
        backtrace:
          [<ffffffff9e96c27a>] kmemleak_alloc+0x4a/0xa0
          [<ffffffff9e425348>] __kmalloc+0xe8/0x220
          [<ffffffff9e3777c1>] tracing_map_array_alloc+0xb1/0x140
          [<ffffffff9e261be0>] kretprobe_trampoline+0x0/0x50
          [<ffffffff9e38b935>] create_hist_data+0x535/0x750
          [<ffffffff9e38bd47>] event_hist_trigger_func+0x1f7/0x420
          [<ffffffff9e38893d>] event_trigger_write+0xfd/0x1a0
          [<ffffffff9e44dfc7>] __vfs_write+0x37/0x170
          [<ffffffff9e44f552>] vfs_write+0xb2/0x1b0
          [<ffffffff9e450b85>] SyS_write+0x55/0xc0
          [<ffffffff9e203857>] do_syscall_64+0x67/0x150
          [<ffffffff9e977ce7>] return_from_SYSCALL_64+0x0/0x6a
          [<ffffffffffffffff>] 0xffffffffffffffff
      
      Link: http://lkml.kernel.org/r/1502705898-27571-1-git-send-email-chuhu@redhat.com
      
      Fixes: 08d43a5f ("tracing: Add lock-free tracing_map")
      Signed-off-by: default avatarChunyu Hu <chuhu@redhat.com>
      Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      2818a765
    • Steven Rostedt (VMware)'s avatar
      tracing: Call clear_boot_tracer() at lateinit_sync · 3170d9ab
      Steven Rostedt (VMware) authored
      commit 4bb0f0e7 upstream.
      
      The clear_boot_tracer function is used to reset the default_bootup_tracer
      string to prevent it from being accessed after boot, as it originally points
      to init data. But since clear_boot_tracer() is called via the
      init_lateinit() call, it races with the initcall for registering the hwlat
      tracer. If someone adds "ftrace=hwlat" to the kernel command line, depending
      on how the linker sets up the text, the saved command line may be cleared,
      and the hwlat tracer never is initialized.
      
      Simply have the clear_boot_tracer() be called by initcall_lateinit_sync() as
      that's for tasks to be called after lateinit.
      
      Link: https://bugzilla.kernel.org/show_bug.cgi?id=196551
      
      Fixes: e7c15cd8 ("tracing: Added hardware latency tracer")
      Reported-by: default avatarZamir SUN <sztsian@gmail.com>
      Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      3170d9ab
    • Koji Matsuoka's avatar
      drm: rcar-du: Fix H/V sync signal polarity configuration · 46cd0a3b
      Koji Matsuoka authored
      commit fd1adef3 upstream.
      
      The VSL and HSL bits in the DSMR register set the corresponding
      horizontal and vertical sync signal polarity to active high. The code
      got it the wrong way around, fix it.
      Signed-off-by: default avatarKoji Matsuoka <koji.matsuoka.xm@renesas.com>
      Signed-off-by: default avatarLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
      Signed-off-by: default avatarThong Ho <thong.ho.px@rvc.renesas.com>
      Signed-off-by: default avatarNhan Nguyen <nhan.nguyen.yb@renesas.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      46cd0a3b
    • Koji Matsuoka's avatar
      drm: rcar-du: Fix display timing controller parameter · 1fb8ff8b
      Koji Matsuoka authored
      commit 9cdced8a upstream.
      
      There is a bug in the setting of the DES (Display Enable Signal)
      register. This current setting occurs 1 dot left shift. The DES
      register should be set minus one value about the specifying value
      with H/W specification. This patch corrects it.
      Signed-off-by: default avatarKoji Matsuoka <koji.matsuoka.xm@renesas.com>
      Signed-off-by: default avatarLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
      Signed-off-by: default avatarThong Ho <thong.ho.px@rvc.renesas.com>
      Signed-off-by: default avatarNhan Nguyen <nhan.nguyen.yb@renesas.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      1fb8ff8b
    • Laurent Pinchart's avatar
      drm: rcar-du: Fix crash in encoder failure error path · 35fd2b84
      Laurent Pinchart authored
      commit 05ee29e9 upstream.
      
      When an encoder fails to initialize the driver prints an error message
      to the kernel log. The message contains the name of the encoder's DT
      node, which is NULL for internal encoders. Use the of_node_full_name()
      macro to avoid dereferencing a NULL pointer, print the output number to
      add more context to the error, and make sure we still own a reference to
      the encoder's DT node by delaying the of_node_put() call.
      Signed-off-by: default avatarLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
      Reviewed-by: default avatarGustavo Padovan <gustavo.padovan@collabora.co.uk>
      Signed-off-by: default avatarThong Ho <thong.ho.px@rvc.renesas.com>
      Signed-off-by: default avatarNhan Nguyen <nhan.nguyen.yb@renesas.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      35fd2b84
    • Maarten Lankhorst's avatar
      drm/atomic: If the atomic check fails, return its value first · eed96e75
      Maarten Lankhorst authored
      commit a0ffc51e upstream.
      
      The last part of drm_atomic_check_only is testing whether we need to
      fail with -EINVAL when modeset is not allowed, but forgets to return
      the value when atomic_check() fails first.
      
      This results in -EDEADLK being replaced by -EINVAL, and the sanity
      check in drm_modeset_drop_locks kicks in:
      
      [  308.531734] ------------[ cut here ]------------
      [  308.531791] WARNING: CPU: 0 PID: 1886 at drivers/gpu/drm/drm_modeset_lock.c:217 drm_modeset_drop_locks+0x33/0xc0 [drm]
      [  308.531828] Modules linked in:
      [  308.532050] CPU: 0 PID: 1886 Comm: kms_atomic Tainted: G     U  W 4.13.0-rc5-patser+ #5225
      [  308.532082] Hardware name: NUC5i7RYB, BIOS RYBDWi35.86A.0246.2015.0309.1355 03/09/2015
      [  308.532124] task: ffff8800cd9dae00 task.stack: ffff8800ca3b8000
      [  308.532168] RIP: 0010:drm_modeset_drop_locks+0x33/0xc0 [drm]
      [  308.532189] RSP: 0018:ffff8800ca3bf980 EFLAGS: 00010282
      [  308.532211] RAX: dffffc0000000000 RBX: ffff8800ca3bfaf8 RCX: 0000000013a171e6
      [  308.532235] RDX: 1ffff10019477f69 RSI: ffffffffa8ba4fa0 RDI: ffff8800ca3bfb48
      [  308.532258] RBP: ffff8800ca3bf998 R08: 0000000000000000 R09: 0000000000000003
      [  308.532281] R10: 0000000079dbe066 R11: 00000000f760b34b R12: 0000000000000001
      [  308.532304] R13: dffffc0000000000 R14: 00000000ffffffea R15: ffff880096889680
      [  308.532328] FS:  00007ff00959cec0(0000) GS:ffff8800d4e00000(0000) knlGS:0000000000000000
      [  308.532359] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
      [  308.532380] CR2: 0000000000000008 CR3: 00000000ca2e3000 CR4: 00000000003406f0
      [  308.532402] Call Trace:
      [  308.532440]  drm_mode_atomic_ioctl+0x19fa/0x1c00 [drm]
      [  308.532488]  ? drm_atomic_set_property+0x1220/0x1220 [drm]
      [  308.532565]  ? avc_has_extended_perms+0xc39/0xff0
      [  308.532593]  ? lock_downgrade+0x610/0x610
      [  308.532640]  ? drm_atomic_set_property+0x1220/0x1220 [drm]
      [  308.532680]  drm_ioctl_kernel+0x154/0x1a0 [drm]
      [  308.532755]  drm_ioctl+0x624/0x8f0 [drm]
      [  308.532858]  ? drm_atomic_set_property+0x1220/0x1220 [drm]
      [  308.532976]  ? drm_getunique+0x210/0x210 [drm]
      [  308.533061]  do_vfs_ioctl+0xd92/0xe40
      [  308.533121]  ? ioctl_preallocate+0x1b0/0x1b0
      [  308.533160]  ? selinux_capable+0x20/0x20
      [  308.533191]  ? do_fcntl+0x1b1/0xbf0
      [  308.533219]  ? kasan_slab_free+0xa2/0xb0
      [  308.533249]  ? f_getown+0x4b/0xa0
      [  308.533278]  ? putname+0xcf/0xe0
      [  308.533309]  ? security_file_ioctl+0x57/0x90
      [  308.533342]  SyS_ioctl+0x4e/0x80
      [  308.533374]  entry_SYSCALL_64_fastpath+0x18/0xad
      [  308.533405] RIP: 0033:0x7ff00779e4d7
      [  308.533431] RSP: 002b:00007fff66a043d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
      [  308.533481] RAX: ffffffffffffffda RBX: 000000e7c7ca5910 RCX: 00007ff00779e4d7
      [  308.533560] RDX: 00007fff66a04430 RSI: 00000000c03864bc RDI: 0000000000000003
      [  308.533608] RBP: 00007ff007a5fb00 R08: 000000e7c7ca4620 R09: 000000e7c7ca5e60
      [  308.533647] R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000070
      [  308.533685] R13: 0000000000000000 R14: 0000000000000000 R15: 000000e7c7ca5930
      [  308.533770] Code: ff df 55 48 89 e5 41 55 41 54 53 48 89 fb 48 83 c7
      50 48 89 fa 48 c1 ea 03 80 3c 02 00 74 05 e8 94 d4 16 e7 48 83 7b 50 00
      74 02 <0f> ff 4c 8d 6b 58 48 b8 00 00 00 00 00 fc ff df 4c 89 ea 48 c1
      [  308.534086] ---[ end trace 77f11e53b1df44ad ]---
      
      Solve this by adding the missing return.
      
      This is also a bugfix because we could end up rejecting updates with
      -EINVAL because of a early -EDEADLK, while if atomic_check ran to
      completion it might have downgraded the modeset to a fastset.
      Signed-off-by: default avatarMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
      Testcase: kms_atomic
      Link: https://patchwork.freedesktop.org/patch/msgid/20170815095706.23624-1-maarten.lankhorst@linux.intel.com
      Fixes: d34f20d6 ("drm: Atomic modeset ioctl")
      Reviewed-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      eed96e75
    • Chris Wilson's avatar
      drm: Release driver tracking before making the object available again · ce66f629
      Chris Wilson authored
      commit fe4600a5 upstream.
      
      This is the same bug as we fixed in commit f6cd7dae ("drm: Release
      driver references to handle before making it available again"), but now
      the exposure is via the PRIME lookup tables. If we remove the
      object/handle from the PRIME lut, then a new request for the same
      object/fd will generate a new handle, thus for a short window that
      object is known to userspace by two different handles. Fix this by
      releasing the driver tracking before PRIME.
      
      Fixes: 0ff926c7 ("drm/prime: add exported buffers to current fprivs
      imported buffer list (v2)")
      Signed-off-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
      Cc: David Airlie <airlied@linux.ie>
      Cc: Daniel Vetter <daniel.vetter@intel.com>
      Cc: Rob Clark <robdclark@gmail.com>
      Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
      Cc: Thierry Reding <treding@nvidia.com>
      Reviewed-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
      Signed-off-by: default avatarJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
      Link: https://patchwork.freedesktop.org/patch/msgid/20170819120558.6465-1-chris@chris-wilson.co.ukSigned-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      ce66f629
    • Pavel Tatashin's avatar
      mm/memblock.c: reversed logic in memblock_discard() · 9d263321
      Pavel Tatashin authored
      commit 91b540f9 upstream.
      
      In recently introduced memblock_discard() there is a reversed logic bug.
      Memory is freed of static array instead of dynamically allocated one.
      
      Link: http://lkml.kernel.org/r/1503511441-95478-2-git-send-email-pasha.tatashin@oracle.com
      Fixes: 3010f876 ("mm: discard memblock data later")
      Signed-off-by: default avatarPavel Tatashin <pasha.tatashin@oracle.com>
      Reported-by: default avatarWoody Suwalski <terraluna977@gmail.com>
      Tested-by: default avatarWoody Suwalski <terraluna977@gmail.com>
      Acked-by: default avatarMichal Hocko <mhocko@suse.com>
      Cc: Vlastimil Babka <vbabka@suse.cz>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      9d263321
    • Eric Biggers's avatar
      fork: fix incorrect fput of ->exe_file causing use-after-free · b65b6ac5
      Eric Biggers authored
      commit 2b7e8665 upstream.
      
      Commit 7c051267 ("mm, fork: make dup_mmap wait for mmap_sem for
      write killable") made it possible to kill a forking task while it is
      waiting to acquire its ->mmap_sem for write, in dup_mmap().
      
      However, it was overlooked that this introduced an new error path before
      a reference is taken on the mm_struct's ->exe_file.  Since the
      ->exe_file of the new mm_struct was already set to the old ->exe_file by
      the memcpy() in dup_mm(), it was possible for the mmput() in the error
      path of dup_mm() to drop a reference to ->exe_file which was never
      taken.
      
      This caused the struct file to later be freed prematurely.
      
      Fix it by updating mm_init() to NULL out the ->exe_file, in the same
      place it clears other things like the list of mmaps.
      
      This bug was found by syzkaller.  It can be reproduced using the
      following C program:
      
          #define _GNU_SOURCE
          #include <pthread.h>
          #include <stdlib.h>
          #include <sys/mman.h>
          #include <sys/syscall.h>
          #include <sys/wait.h>
          #include <unistd.h>
      
          static void *mmap_thread(void *_arg)
          {
              for (;;) {
                  mmap(NULL, 0x1000000, PROT_READ,
                       MAP_POPULATE|MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
              }
          }
      
          static void *fork_thread(void *_arg)
          {
              usleep(rand() % 10000);
              fork();
          }
      
          int main(void)
          {
              fork();
              fork();
              fork();
              for (;;) {
                  if (fork() == 0) {
                      pthread_t t;
      
                      pthread_create(&t, NULL, mmap_thread, NULL);
                      pthread_create(&t, NULL, fork_thread, NULL);
                      usleep(rand() % 10000);
                      syscall(__NR_exit_group, 0);
                  }
                  wait(NULL);
              }
          }
      
      No special kernel config options are needed.  It usually causes a NULL
      pointer dereference in __remove_shared_vm_struct() during exit, or in
      dup_mmap() (which is usually inlined into copy_process()) during fork.
      Both are due to a vm_area_struct's ->vm_file being used after it's
      already been freed.
      
      Google Bug Id: 64772007
      
      Link: http://lkml.kernel.org/r/20170823211408.31198-1-ebiggers3@gmail.com
      Fixes: 7c051267 ("mm, fork: make dup_mmap wait for mmap_sem for write killable")
      Signed-off-by: default avatarEric Biggers <ebiggers@google.com>
      Tested-by: default avatarMark Rutland <mark.rutland@arm.com>
      Acked-by: default avatarMichal Hocko <mhocko@suse.com>
      Cc: Dmitry Vyukov <dvyukov@google.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Konstantin Khlebnikov <koct9i@gmail.com>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Vlastimil Babka <vbabka@suse.cz>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      b65b6ac5
    • Eric Biggers's avatar
      mm/madvise.c: fix freeing of locked page with MADV_FREE · 0f49b051
      Eric Biggers authored
      commit 263630e8 upstream.
      
      If madvise(..., MADV_FREE) split a transparent hugepage, it called
      put_page() before unlock_page().
      
      This was wrong because put_page() can free the page, e.g. if a
      concurrent madvise(..., MADV_DONTNEED) has removed it from the memory
      mapping. put_page() then rightfully complained about freeing a locked
      page.
      
      Fix this by moving the unlock_page() before put_page().
      
      This bug was found by syzkaller, which encountered the following splat:
      
          BUG: Bad page state in process syzkaller412798  pfn:1bd800
          page:ffffea0006f60000 count:0 mapcount:0 mapping:          (null) index:0x20a00
          flags: 0x200000000040019(locked|uptodate|dirty|swapbacked)
          raw: 0200000000040019 0000000000000000 0000000000020a00 00000000ffffffff
          raw: ffffea0006f60020 ffffea0006f60020 0000000000000000 0000000000000000
          page dumped because: PAGE_FLAGS_CHECK_AT_FREE flag(s) set
          bad because of flags: 0x1(locked)
          Modules linked in:
          CPU: 1 PID: 3037 Comm: syzkaller412798 Not tainted 4.13.0-rc5+ #35
          Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
          Call Trace:
           __dump_stack lib/dump_stack.c:16 [inline]
           dump_stack+0x194/0x257 lib/dump_stack.c:52
           bad_page+0x230/0x2b0 mm/page_alloc.c:565
           free_pages_check_bad+0x1f0/0x2e0 mm/page_alloc.c:943
           free_pages_check mm/page_alloc.c:952 [inline]
           free_pages_prepare mm/page_alloc.c:1043 [inline]
           free_pcp_prepare mm/page_alloc.c:1068 [inline]
           free_hot_cold_page+0x8cf/0x12b0 mm/page_alloc.c:2584
           __put_single_page mm/swap.c:79 [inline]
           __put_page+0xfb/0x160 mm/swap.c:113
           put_page include/linux/mm.h:814 [inline]
           madvise_free_pte_range+0x137a/0x1ec0 mm/madvise.c:371
           walk_pmd_range mm/pagewalk.c:50 [inline]
           walk_pud_range mm/pagewalk.c:108 [inline]
           walk_p4d_range mm/pagewalk.c:134 [inline]
           walk_pgd_range mm/pagewalk.c:160 [inline]
           __walk_page_range+0xc3a/0x1450 mm/pagewalk.c:249
           walk_page_range+0x200/0x470 mm/pagewalk.c:326
           madvise_free_page_range.isra.9+0x17d/0x230 mm/madvise.c:444
           madvise_free_single_vma+0x353/0x580 mm/madvise.c:471
           madvise_dontneed_free mm/madvise.c:555 [inline]
           madvise_vma mm/madvise.c:664 [inline]
           SYSC_madvise mm/madvise.c:832 [inline]
           SyS_madvise+0x7d3/0x13c0 mm/madvise.c:760
           entry_SYSCALL_64_fastpath+0x1f/0xbe
      
      Here is a C reproducer:
      
          #define _GNU_SOURCE
          #include <pthread.h>
          #include <sys/mman.h>
          #include <unistd.h>
      
          #define MADV_FREE	8
          #define PAGE_SIZE	4096
      
          static void *mapping;
          static const size_t mapping_size = 0x1000000;
      
          static void *madvise_thrproc(void *arg)
          {
              madvise(mapping, mapping_size, (long)arg);
          }
      
          int main(void)
          {
              pthread_t t[2];
      
              for (;;) {
                  mapping = mmap(NULL, mapping_size, PROT_WRITE,
                                 MAP_POPULATE|MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
      
                  munmap(mapping + mapping_size / 2, PAGE_SIZE);
      
                  pthread_create(&t[0], 0, madvise_thrproc, (void*)MADV_DONTNEED);
                  pthread_create(&t[1], 0, madvise_thrproc, (void*)MADV_FREE);
                  pthread_join(t[0], NULL);
                  pthread_join(t[1], NULL);
                  munmap(mapping, mapping_size);
              }
          }
      
      Note: to see the splat, CONFIG_TRANSPARENT_HUGEPAGE=y and
      CONFIG_DEBUG_VM=y are needed.
      
      Google Bug Id: 64696096
      
      Link: http://lkml.kernel.org/r/20170823205235.132061-1-ebiggers3@gmail.com
      Fixes: 854e9ed0 ("mm: support madvise(MADV_FREE)")
      Signed-off-by: default avatarEric Biggers <ebiggers@google.com>
      Acked-by: default avatarDavid Rientjes <rientjes@google.com>
      Acked-by: default avatarMinchan Kim <minchan@kernel.org>
      Acked-by: default avatarMichal Hocko <mhocko@suse.com>
      Cc: Dmitry Vyukov <dvyukov@google.com>
      Cc: Hugh Dickins <hughd@google.com>
      Cc: Andrea Arcangeli <aarcange@redhat.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      0f49b051
    • Ulf Hansson's avatar
      i2c: designware: Fix system suspend · 036c100b
      Ulf Hansson authored
      commit a23318fe upstream.
      
      The commit 8503ff16 ("i2c: designware: Avoid unnecessary resuming
      during system suspend"), may suggest to the PM core to try out the so
      called direct_complete path for system sleep. In this path, the PM core
      treats a runtime suspended device as it's already in a proper low power
      state for system sleep, which makes it skip calling the system sleep
      callbacks for the device, except for the ->prepare() and the ->complete()
      callbacks.
      
      However, the PM core may unset the direct_complete flag for a parent
      device, in case its child device are being system suspended before. In this
      scenario, the PM core invokes the system sleep callbacks, no matter if the
      device is runtime suspended or not.
      
      Particularly in cases of an existing i2c slave device, the above path is
      triggered, which breaks the assumption that the i2c device is always
      runtime resumed whenever the dw_i2c_plat_suspend() is being called.
      
      More precisely, dw_i2c_plat_suspend() calls clk_core_disable() and
      clk_core_unprepare(), for an already disabled/unprepared clock, leading to
      a splat in the log about clocks calls being wrongly balanced and breaking
      system sleep.
      
      To still allow the direct_complete path in cases when it's possible, but
      also to keep the fix simple, let's runtime resume the i2c device in the
      ->suspend() callback, before continuing to put the device into low power
      state.
      
      Note, in cases when the i2c device is attached to the ACPI PM domain, this
      problem doesn't occur, because ACPI's ->suspend() callback, assigned to
      acpi_subsys_suspend(), already calls pm_runtime_resume() for the device.
      
      It should also be noted that this change does not fix commit 8503ff16
      ("i2c: designware: Avoid unnecessary resuming during system suspend").
      Because for the non-ACPI case, the system sleep support was already broken
      prior that point.
      Signed-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
      Acked-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
      Tested-by: default avatarJohn Stultz <john.stultz@linaro.org>
      Tested-by: default avatarJarkko Nikula <jarkko.nikula@linux.intel.com>
      Acked-by: default avatarJarkko Nikula <jarkko.nikula@linux.intel.com>
      Reviewed-by: default avatarMika Westerberg <mika.westerberg@linux.intel.com>
      Signed-off-by: default avatarWolfram Sang <wsa@the-dreams.de>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      036c100b
    • Kirill A. Shutemov's avatar
      mm, shmem: fix handling /sys/kernel/mm/transparent_hugepage/shmem_enabled · 5d8b3cc2
      Kirill A. Shutemov authored
      commit 435c0b87 upstream.
      
      /sys/kernel/mm/transparent_hugepage/shmem_enabled controls if we want
      to allocate huge pages when allocate pages for private in-kernel shmem
      mount.
      
      Unfortunately, as Dan noticed, I've screwed it up and the only way to
      make kernel allocate huge page for the mount is to use "force" there.
      All other values will be effectively ignored.
      
      Link: http://lkml.kernel.org/r/20170822144254.66431-1-kirill.shutemov@linux.intel.com
      Fixes: 5a6e75f8 ("shmem: prepare huge= mount option and sysfs knob")
      Signed-off-by: default avatarKirill A. Shutemov <kirill.shutemov@linux.intel.com>
      Reported-by: default avatarDan Carpenter <dan.carpenter@oracle.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      5d8b3cc2
    • Alexey Brodkin's avatar
      ARCv2: PAE40: Explicitly set MSB counterpart of SLC region ops addresses · 8d362cb3
      Alexey Brodkin authored
      commit 7d79cee2 upstream.
      
      It is necessary to explicitly set both SLC_AUX_RGN_START1 and SLC_AUX_RGN_END1
      which hold MSB bits of the physical address correspondingly of region start
      and end otherwise SLC region operation is executed in unpredictable manner
      
      Without this patch, SLC flushes on HSDK (IOC disabled) were taking
      seconds.
      Reported-by: default avatarVladimir Kondratiev <vladimir.kondratiev@intel.com>
      Signed-off-by: default avatarAlexey Brodkin <abrodkin@synopsys.com>
      Signed-off-by: default avatarVineet Gupta <vgupta@synopsys.com>
      [vgupta: PAR40 regs only written if PAE40 exist]
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      8d362cb3
    • Takashi Sakamoto's avatar
      ALSA: firewire: fix NULL pointer dereference when releasing uninitialized data of iso-resource · 6cba0746
      Takashi Sakamoto authored
      commit 0c264af7 upstream.
      
      When calling 'iso_resource_free()' for uninitialized data, this function
      causes NULL pointer dereference due to its 'unit' member. This occurs when
      unplugging audio and music units on IEEE 1394 bus at failure of card
      registration.
      
      This commit fixes the bug. The bug exists since kernel v4.5.
      
      Fixes: 324540c4 ('ALSA: fireface: postpone sound card registration') at v4.12
      Fixes: 8865a31e ('ALSA: firewire-motu: postpone sound card registration') at v4.12
      Fixes: b610386c ('ALSA: firewire-tascam: deleyed registration of sound card') at v4.7
      Fixes: 86c8dd7f ('ALSA: firewire-digi00x: delayed registration of sound card') at v4.7
      Fixes: 6c29230e ('ALSA: oxfw: delayed registration of sound card') at v4.7
      Fixes: 7d3c1d59 ('ALSA: fireworks: delayed registration of sound card') at v4.7
      Fixes: 04a2c73c ('ALSA: bebob: delayed registration of sound card') at v4.7
      Fixes: b59fb190 ('ALSA: dice: postpone card registration') at v4.5
      Signed-off-by: default avatarTakashi Sakamoto <o-takashi@sakamocchi.jp>
      Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      6cba0746
    • Takashi Iwai's avatar
      ALSA: hda - Add stereo mic quirk for Lenovo G50-70 (17aa:3978) · b52bce93
      Takashi Iwai authored
      commit bbba6f9d upstream.
      
      Lenovo G50-70 (17aa:3978) with Conexant codec chip requires the
      similar workaround for the inverted stereo dmic like other Lenovo
      models.
      
      Bugzilla: https://bugzilla.suse.com/show_bug.cgi?id=1020657Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      b52bce93
    • Takashi Iwai's avatar
      ALSA: core: Fix unexpected error at replacing user TLV · 8989c70d
      Takashi Iwai authored
      commit 88c54cdf upstream.
      
      When user tries to replace the user-defined control TLV, the kernel
      checks the change of its content via memcmp().  The problem is that
      the kernel passes the return value from memcmp() as is.  memcmp()
      gives a non-zero negative value depending on the comparison result,
      and this shall be recognized as an error code.
      
      The patch covers that corner-case, return 1 properly for the changed
      TLV.
      
      Fixes: 8aa9b586 ("[ALSA] Control API - more robust TLV implementation")
      Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      8989c70d
    • Joakim Tjernlund's avatar
      ALSA: usb-audio: Add delay quirk for H650e/Jabra 550a USB headsets · 9767a456
      Joakim Tjernlund authored
      commit 07b3b5e9 upstream.
      
      These headsets reports a lot of: cannot set freq 44100 to ep 0x81
      and need a small delay between sample rate settings, just like
      Zoom R16/24. Add both headsets to the Zoom R16/24 quirk for
      a 1 ms delay between control msgs.
      Signed-off-by: default avatarJoakim Tjernlund <joakim.tjernlund@infinera.com>
      Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      9767a456
    • Paolo Bonzini's avatar
      KVM: x86: block guest protection keys unless the host has them enabled · 275f3033
      Paolo Bonzini authored
      commit c469268c upstream.
      
      If the host has protection keys disabled, we cannot read and write the
      guest PKRU---RDPKRU and WRPKRU fail with #GP(0) if CR4.PKE=0.  Block
      the PKU cpuid bit in that case.
      
      This ensures that guest_CR4.PKE=1 implies host_CR4.PKE=1.
      
      Fixes: 1be0e61cReviewed-by: default avatarDavid Hildenbrand <david@redhat.com>
      Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      275f3033
    • Heiko Carstens's avatar
      KVM: s390: sthyi: fix specification exception detection · cfb917a1
      Heiko Carstens authored
      commit 857b8de9 upstream.
      
      sthyi should only generate a specification exception if the function
      code is zero and the response buffer is not on a 4k boundary.
      
      The current code would also test for unknown function codes if the
      response buffer, that is currently only defined for function code 0,
      is not on a 4k boundary and incorrectly inject a specification
      exception instead of returning with condition code 3 and return code 4
      (unsupported function code).
      
      Fix this by moving the boundary check.
      
      Fixes: 95ca2cb5 ("KVM: s390: Add sthyi emulation")
      Reviewed-by: default avatarJanosch Frank <frankja@linux.vnet.ibm.com>
      Signed-off-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
      Reviewed-by: default avatarDavid Hildenbrand <david@redhat.com>
      Reviewed-by: default avatarCornelia Huck <cohuck@redhat.com>
      Signed-off-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      cfb917a1
    • Heiko Carstens's avatar
      KVM: s390: sthyi: fix sthyi inline assembly · a745333f
      Heiko Carstens authored
      commit 4a4eefcd upstream.
      
      The sthyi inline assembly misses register r3 within the clobber
      list. The sthyi instruction will always write a return code to
      register "R2+1", which in this case would be r3. Due to that we may
      have register corruption and see host crashes or data corruption
      depending on how gcc decided to allocate and use registers during
      compile time.
      
      Fixes: 95ca2cb5 ("KVM: s390: Add sthyi emulation")
      Reviewed-by: default avatarJanosch Frank <frankja@linux.vnet.ibm.com>
      Signed-off-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
      Reviewed-by: default avatarDavid Hildenbrand <david@redhat.com>
      Reviewed-by: default avatarCornelia Huck <cohuck@redhat.com>
      Signed-off-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      a745333f
    • Masaki Ota's avatar
      Input: ALPS - fix two-finger scroll breakage in right side on ALPS touchpad · 963068b1
      Masaki Ota authored
      commit 4a646580 upstream.
      
      Fixed the issue that two finger scroll does not work correctly
      on V8 protocol. The cause is that V8 protocol X-coordinate decode
      is wrong at SS4 PLUS device. I added SS4 PLUS X decode definition.
      
      Mote notes:
      the problem manifests itself by the commit e7348396 ("Input: ALPS
      - fix V8+ protocol handling (73 03 28)"), where a fix for the V8+
      protocol was applied.  Although the culprit must have been present
      beforehand, the two-finger scroll worked casually even with the
      wrongly reported values by some reason.  It got broken by the commit
      above just because it changed x_max value, and this made libinput
      correctly figuring the MT events.  Since the X coord is reported as
      falsely doubled, the events on the right-half side go outside the
      boundary, thus they are no longer handled.  This resulted as a broken
      two-finger scroll.
      
      One finger event is decoded differently, and it didn't suffer from
      this problem.  The problem was only about MT events. --tiwai
      
      Fixes: e7348396 ("Input: ALPS - fix V8+ protocol handling (73 03 28)")
      Signed-off-by: default avatarMasaki Ota <masaki.ota@jp.alps.com>
      Tested-by: default avatarTakashi Iwai <tiwai@suse.de>
      Tested-by: default avatarPaul Donohue <linux-kernel@PaulSD.com>
      Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      Signed-off-by: default avatarDmitry Torokhov <dmitry.torokhov@gmail.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      963068b1
    • KT Liao's avatar
      Input: elan_i2c - add ELAN0602 ACPI ID to support Lenovo Yoga310 · 9ab605d2
      KT Liao authored
      commit 1d2226e4 upstream.
      
      Add ELAN0602 to the list of known ACPI IDs to enable support for ELAN
      touchpads found in Lenovo Yoga310.
      Signed-off-by: default avatarKT Liao <kt.liao@emc.com.tw>
      Signed-off-by: default avatarDmitry Torokhov <dmitry.torokhov@gmail.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      9ab605d2
    • Aaron Ma's avatar
      Input: trackpoint - add new trackpoint firmware ID · a00a9cd7
      Aaron Ma authored
      commit ec667683 upstream.
      
      Synaptics add new TP firmware ID: 0x2 and 0x3, for now both lower 2 bits
      are indicated as TP. Change the constant to bitwise values.
      
      This makes trackpoint to be recognized on Lenovo Carbon X1 Gen5 instead
      of it being identified as "PS/2 Generic Mouse".
      Signed-off-by: default avatarAaron Ma <aaron.ma@canonical.com>
      Signed-off-by: default avatarDmitry Torokhov <dmitry.torokhov@gmail.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      a00a9cd7
    • Edward Cree's avatar
      bpf/verifier: fix min/max handling in BPF_SUB · 655da3da
      Edward Cree authored
      
      [ Upstream commit 9305706c ]
      
      We have to subtract the src max from the dst min, and vice-versa, since
       (e.g.) the smallest result comes from the largest subtrahend.
      
      Fixes: 48461135 ("bpf: allow access into map value arrays")
      Signed-off-by: default avatarEdward Cree <ecree@solarflare.com>
      Acked-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      655da3da
    • Daniel Borkmann's avatar
      bpf: fix mixed signed/unsigned derived min/max value bounds · bf5b91b7
      Daniel Borkmann authored
      
      [ Upstream commit 4cabc5b1 ]
      
      Edward reported that there's an issue in min/max value bounds
      tracking when signed and unsigned compares both provide hints
      on limits when having unknown variables. E.g. a program such
      as the following should have been rejected:
      
         0: (7a) *(u64 *)(r10 -8) = 0
         1: (bf) r2 = r10
         2: (07) r2 += -8
         3: (18) r1 = 0xffff8a94cda93400
         5: (85) call bpf_map_lookup_elem#1
         6: (15) if r0 == 0x0 goto pc+7
        R0=map_value(ks=8,vs=8,id=0),min_value=0,max_value=0 R10=fp
         7: (7a) *(u64 *)(r10 -16) = -8
         8: (79) r1 = *(u64 *)(r10 -16)
         9: (b7) r2 = -1
        10: (2d) if r1 > r2 goto pc+3
        R0=map_value(ks=8,vs=8,id=0),min_value=0,max_value=0 R1=inv,min_value=0
        R2=imm-1,max_value=18446744073709551615,min_align=1 R10=fp
        11: (65) if r1 s> 0x1 goto pc+2
        R0=map_value(ks=8,vs=8,id=0),min_value=0,max_value=0 R1=inv,min_value=0,max_value=1
        R2=imm-1,max_value=18446744073709551615,min_align=1 R10=fp
        12: (0f) r0 += r1
        13: (72) *(u8 *)(r0 +0) = 0
        R0=map_value_adj(ks=8,vs=8,id=0),min_value=0,max_value=1 R1=inv,min_value=0,max_value=1
        R2=imm-1,max_value=18446744073709551615,min_align=1 R10=fp
        14: (b7) r0 = 0
        15: (95) exit
      
      What happens is that in the first part ...
      
         8: (79) r1 = *(u64 *)(r10 -16)
         9: (b7) r2 = -1
        10: (2d) if r1 > r2 goto pc+3
      
      ... r1 carries an unsigned value, and is compared as unsigned
      against a register carrying an immediate. Verifier deduces in
      reg_set_min_max() that since the compare is unsigned and operation
      is greater than (>), that in the fall-through/false case, r1's
      minimum bound must be 0 and maximum bound must be r2. Latter is
      larger than the bound and thus max value is reset back to being
      'invalid' aka BPF_REGISTER_MAX_RANGE. Thus, r1 state is now
      'R1=inv,min_value=0'. The subsequent test ...
      
        11: (65) if r1 s> 0x1 goto pc+2
      
      ... is a signed compare of r1 with immediate value 1. Here,
      verifier deduces in reg_set_min_max() that since the compare
      is signed this time and operation is greater than (>), that
      in the fall-through/false case, we can deduce that r1's maximum
      bound must be 1, meaning with prior test, we result in r1 having
      the following state: R1=inv,min_value=0,max_value=1. Given that
      the actual value this holds is -8, the bounds are wrongly deduced.
      When this is being added to r0 which holds the map_value(_adj)
      type, then subsequent store access in above case will go through
      check_mem_access() which invokes check_map_access_adj(), that
      will then probe whether the map memory is in bounds based
      on the min_value and max_value as well as access size since
      the actual unknown value is min_value <= x <= max_value; commit
      fce366a9 ("bpf, verifier: fix alu ops against map_value{,
      _adj} register types") provides some more explanation on the
      semantics.
      
      It's worth to note in this context that in the current code,
      min_value and max_value tracking are used for two things, i)
      dynamic map value access via check_map_access_adj() and since
      commit 06c1c049 ("bpf: allow helpers access to variable memory")
      ii) also enforced at check_helper_mem_access() when passing a
      memory address (pointer to packet, map value, stack) and length
      pair to a helper and the length in this case is an unknown value
      defining an access range through min_value/max_value in that
      case. The min_value/max_value tracking is /not/ used in the
      direct packet access case to track ranges. However, the issue
      also affects case ii), for example, the following crafted program
      based on the same principle must be rejected as well:
      
         0: (b7) r2 = 0
         1: (bf) r3 = r10
         2: (07) r3 += -512
         3: (7a) *(u64 *)(r10 -16) = -8
         4: (79) r4 = *(u64 *)(r10 -16)
         5: (b7) r6 = -1
         6: (2d) if r4 > r6 goto pc+5
        R1=ctx R2=imm0,min_value=0,max_value=0,min_align=2147483648 R3=fp-512
        R4=inv,min_value=0 R6=imm-1,max_value=18446744073709551615,min_align=1 R10=fp
         7: (65) if r4 s> 0x1 goto pc+4
        R1=ctx R2=imm0,min_value=0,max_value=0,min_align=2147483648 R3=fp-512
        R4=inv,min_value=0,max_value=1 R6=imm-1,max_value=18446744073709551615,min_align=1
        R10=fp
         8: (07) r4 += 1
         9: (b7) r5 = 0
        10: (6a) *(u16 *)(r10 -512) = 0
        11: (85) call bpf_skb_load_bytes#26
        12: (b7) r0 = 0
        13: (95) exit
      
      Meaning, while we initialize the max_value stack slot that the
      verifier thinks we access in the [1,2] range, in reality we
      pass -7 as length which is interpreted as u32 in the helper.
      Thus, this issue is relevant also for the case of helper ranges.
      Resetting both bounds in check_reg_overflow() in case only one
      of them exceeds limits is also not enough as similar test can be
      created that uses values which are within range, thus also here
      learned min value in r1 is incorrect when mixed with later signed
      test to create a range:
      
         0: (7a) *(u64 *)(r10 -8) = 0
         1: (bf) r2 = r10
         2: (07) r2 += -8
         3: (18) r1 = 0xffff880ad081fa00
         5: (85) call bpf_map_lookup_elem#1
         6: (15) if r0 == 0x0 goto pc+7
        R0=map_value(ks=8,vs=8,id=0),min_value=0,max_value=0 R10=fp
         7: (7a) *(u64 *)(r10 -16) = -8
         8: (79) r1 = *(u64 *)(r10 -16)
         9: (b7) r2 = 2
        10: (3d) if r2 >= r1 goto pc+3
        R0=map_value(ks=8,vs=8,id=0),min_value=0,max_value=0 R1=inv,min_value=3
        R2=imm2,min_value=2,max_value=2,min_align=2 R10=fp
        11: (65) if r1 s> 0x4 goto pc+2
        R0=map_value(ks=8,vs=8,id=0),min_value=0,max_value=0
        R1=inv,min_value=3,max_value=4 R2=imm2,min_value=2,max_value=2,min_align=2 R10=fp
        12: (0f) r0 += r1
        13: (72) *(u8 *)(r0 +0) = 0
        R0=map_value_adj(ks=8,vs=8,id=0),min_value=3,max_value=4
        R1=inv,min_value=3,max_value=4 R2=imm2,min_value=2,max_value=2,min_align=2 R10=fp
        14: (b7) r0 = 0
        15: (95) exit
      
      This leaves us with two options for fixing this: i) to invalidate
      all prior learned information once we switch signed context, ii)
      to track min/max signed and unsigned boundaries separately as
      done in [0]. (Given latter introduces major changes throughout
      the whole verifier, it's rather net-next material, thus this
      patch follows option i), meaning we can derive bounds either
      from only signed tests or only unsigned tests.) There is still the
      case of adjust_reg_min_max_vals(), where we adjust bounds on ALU
      operations, meaning programs like the following where boundaries
      on the reg get mixed in context later on when bounds are merged
      on the dst reg must get rejected, too:
      
         0: (7a) *(u64 *)(r10 -8) = 0
         1: (bf) r2 = r10
         2: (07) r2 += -8
         3: (18) r1 = 0xffff89b2bf87ce00
         5: (85) call bpf_map_lookup_elem#1
         6: (15) if r0 == 0x0 goto pc+6
        R0=map_value(ks=8,vs=8,id=0),min_value=0,max_value=0 R10=fp
         7: (7a) *(u64 *)(r10 -16) = -8
         8: (79) r1 = *(u64 *)(r10 -16)
         9: (b7) r2 = 2
        10: (3d) if r2 >= r1 goto pc+2
        R0=map_value(ks=8,vs=8,id=0),min_value=0,max_value=0 R1=inv,min_value=3
        R2=imm2,min_value=2,max_value=2,min_align=2 R10=fp
        11: (b7) r7 = 1
        12: (65) if r7 s> 0x0 goto pc+2
        R0=map_value(ks=8,vs=8,id=0),min_value=0,max_value=0 R1=inv,min_value=3
        R2=imm2,min_value=2,max_value=2,min_align=2 R7=imm1,max_value=0 R10=fp
        13: (b7) r0 = 0
        14: (95) exit
      
        from 12 to 15: R0=map_value(ks=8,vs=8,id=0),min_value=0,max_value=0
        R1=inv,min_value=3 R2=imm2,min_value=2,max_value=2,min_align=2 R7=imm1,min_value=1 R10=fp
        15: (0f) r7 += r1
        16: (65) if r7 s> 0x4 goto pc+2
        R0=map_value(ks=8,vs=8,id=0),min_value=0,max_value=0 R1=inv,min_value=3
        R2=imm2,min_value=2,max_value=2,min_align=2 R7=inv,min_value=4,max_value=4 R10=fp
        17: (0f) r0 += r7
        18: (72) *(u8 *)(r0 +0) = 0
        R0=map_value_adj(ks=8,vs=8,id=0),min_value=4,max_value=4 R1=inv,min_value=3
        R2=imm2,min_value=2,max_value=2,min_align=2 R7=inv,min_value=4,max_value=4 R10=fp
        19: (b7) r0 = 0
        20: (95) exit
      
      Meaning, in adjust_reg_min_max_vals() we must also reset range
      values on the dst when src/dst registers have mixed signed/
      unsigned derived min/max value bounds with one unbounded value
      as otherwise they can be added together deducing false boundaries.
      Once both boundaries are established from either ALU ops or
      compare operations w/o mixing signed/unsigned insns, then they
      can safely be added to other regs also having both boundaries
      established. Adding regs with one unbounded side to a map value
      where the bounded side has been learned w/o mixing ops is
      possible, but the resulting map value won't recover from that,
      meaning such op is considered invalid on the time of actual
      access. Invalid bounds are set on the dst reg in case i) src reg,
      or ii) in case dst reg already had them. The only way to recover
      would be to perform i) ALU ops but only 'add' is allowed on map
      value types or ii) comparisons, but these are disallowed on
      pointers in case they span a range. This is fine as only BPF_JEQ
      and BPF_JNE may be performed on PTR_TO_MAP_VALUE_OR_NULL registers
      which potentially turn them into PTR_TO_MAP_VALUE type depending
      on the branch, so only here min/max value cannot be invalidated
      for them.
      
      In terms of state pruning, value_from_signed is considered
      as well in states_equal() when dealing with adjusted map values.
      With regards to breaking existing programs, there is a small
      risk, but use-cases are rather quite narrow where this could
      occur and mixing compares probably unlikely.
      
      Joint work with Josef and Edward.
      
        [0] https://lists.iovisor.org/pipermail/iovisor-dev/2017-June/000822.html
      
      Fixes: 48461135 ("bpf: allow access into map value arrays")
      Reported-by: default avatarEdward Cree <ecree@solarflare.com>
      Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
      Signed-off-by: default avatarEdward Cree <ecree@solarflare.com>
      Signed-off-by: default avatarJosef Bacik <jbacik@fb.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      bf5b91b7
    • Daniel Borkmann's avatar
      bpf, verifier: fix alu ops against map_value{, _adj} register types · 8d674bee
      Daniel Borkmann authored
      
      [ Upstream commit fce366a9 ]
      
      While looking into map_value_adj, I noticed that alu operations
      directly on the map_value() resp. map_value_adj() register (any
      alu operation on a map_value() register will turn it into a
      map_value_adj() typed register) are not sufficiently protected
      against some of the operations. Two non-exhaustive examples are
      provided that the verifier needs to reject:
      
       i) BPF_AND on r0 (map_value_adj):
      
        0: (bf) r2 = r10
        1: (07) r2 += -8
        2: (7a) *(u64 *)(r2 +0) = 0
        3: (18) r1 = 0xbf842a00
        5: (85) call bpf_map_lookup_elem#1
        6: (15) if r0 == 0x0 goto pc+2
         R0=map_value(ks=8,vs=48,id=0),min_value=0,max_value=0 R10=fp
        7: (57) r0 &= 8
        8: (7a) *(u64 *)(r0 +0) = 22
         R0=map_value_adj(ks=8,vs=48,id=0),min_value=0,max_value=8 R10=fp
        9: (95) exit
      
        from 6 to 9: R0=inv,min_value=0,max_value=0 R10=fp
        9: (95) exit
        processed 10 insns
      
      ii) BPF_ADD in 32 bit mode on r0 (map_value_adj):
      
        0: (bf) r2 = r10
        1: (07) r2 += -8
        2: (7a) *(u64 *)(r2 +0) = 0
        3: (18) r1 = 0xc24eee00
        5: (85) call bpf_map_lookup_elem#1
        6: (15) if r0 == 0x0 goto pc+2
         R0=map_value(ks=8,vs=48,id=0),min_value=0,max_value=0 R10=fp
        7: (04) (u32) r0 += (u32) 0
        8: (7a) *(u64 *)(r0 +0) = 22
         R0=map_value_adj(ks=8,vs=48,id=0),min_value=0,max_value=0 R10=fp
        9: (95) exit
      
        from 6 to 9: R0=inv,min_value=0,max_value=0 R10=fp
        9: (95) exit
        processed 10 insns
      
      Issue is, while min_value / max_value boundaries for the access
      are adjusted appropriately, we change the pointer value in a way
      that cannot be sufficiently tracked anymore from its origin.
      Operations like BPF_{AND,OR,DIV,MUL,etc} on a destination register
      that is PTR_TO_MAP_VALUE{,_ADJ} was probably unintended, in fact,
      all the test cases coming with 48461135 ("bpf: allow access
      into map value arrays") perform BPF_ADD only on the destination
      register that is PTR_TO_MAP_VALUE_ADJ.
      
      Only for UNKNOWN_VALUE register types such operations make sense,
      f.e. with unknown memory content fetched initially from a constant
      offset from the map value memory into a register. That register is
      then later tested against lower / upper bounds, so that the verifier
      can then do the tracking of min_value / max_value, and properly
      check once that UNKNOWN_VALUE register is added to the destination
      register with type PTR_TO_MAP_VALUE{,_ADJ}. This is also what the
      original use-case is solving. Note, tracking on what is being
      added is done through adjust_reg_min_max_vals() and later access
      to the map value enforced with these boundaries and the given offset
      from the insn through check_map_access_adj().
      
      Tests will fail for non-root environment due to prohibited pointer
      arithmetic, in particular in check_alu_op(), we bail out on the
      is_pointer_value() check on the dst_reg (which is false in root
      case as we allow for pointer arithmetic via env->allow_ptr_leaks).
      
      Similarly to PTR_TO_PACKET, one way to fix it is to restrict the
      allowed operations on PTR_TO_MAP_VALUE{,_ADJ} registers to 64 bit
      mode BPF_ADD. The test_verifier suite runs fine after the patch
      and it also rejects mentioned test cases.
      
      Fixes: 48461135 ("bpf: allow access into map value arrays")
      Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
      Reviewed-by: default avatarJosef Bacik <jbacik@fb.com>
      Acked-by: default avatarAlexei Starovoitov <ast@kernel.org>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      8d674bee
    • Daniel Borkmann's avatar
      bpf: adjust verifier heuristics · 577aa83b
      Daniel Borkmann authored
      
      [ Upstream commit 3c2ce60b ]
      
      Current limits with regards to processing program paths do not
      really reflect today's needs anymore due to programs becoming
      more complex and verifier smarter, keeping track of more data
      such as const ALU operations, alignment tracking, spilling of
      PTR_TO_MAP_VALUE_ADJ registers, and other features allowing for
      smarter matching of what LLVM generates.
      
      This also comes with the side-effect that we result in fewer
      opportunities to prune search states and thus often need to do
      more work to prove safety than in the past due to different
      register states and stack layout where we mismatch. Generally,
      it's quite hard to determine what caused a sudden increase in
      complexity, it could be caused by something as trivial as a
      single branch somewhere at the beginning of the program where
      LLVM assigned a stack slot that is marked differently throughout
      other branches and thus causing a mismatch, where verifier
      then needs to prove safety for the whole rest of the program.
      Subsequently, programs with even less than half the insn size
      limit can get rejected. We noticed that while some programs
      load fine under pre 4.11, they get rejected due to hitting
      limits on more recent kernels. We saw that in the vast majority
      of cases (90+%) pruning failed due to register mismatches. In
      case of stack mismatches, majority of cases failed due to
      different stack slot types (invalid, spill, misc) rather than
      differences in spilled registers.
      
      This patch makes pruning more aggressive by also adding markers
      that sit at conditional jumps as well. Currently, we only mark
      jump targets for pruning. For example in direct packet access,
      these are usually error paths where we bail out. We found that
      adding these markers, it can reduce number of processed insns
      by up to 30%. Another option is to ignore reg->id in probing
      PTR_TO_MAP_VALUE_OR_NULL registers, which can help pruning
      slightly as well by up to 7% observed complexity reduction as
      stand-alone. Meaning, if a previous path with register type
      PTR_TO_MAP_VALUE_OR_NULL for map X was found to be safe, then
      in the current state a PTR_TO_MAP_VALUE_OR_NULL register for
      the same map X must be safe as well. Last but not least the
      patch also adds a scheduling point and bumps the current limit
      for instructions to be processed to a more adequate value.
      Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
      Acked-by: default avatarAlexei Starovoitov <ast@kernel.org>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      577aa83b