kernel/linux.git, branch v4.14.186

Linux 4.14.186

2020-06-25T13:42:02+00:00

KVM: x86/mmu: Set mmio_value to '0' if reserved #PF can't be generated

2020-06-25T13:42:02+00:00

[ Upstream commit 6129ed877d409037b79866327102c9dc59a302fe ] Set the mmio_value to '0' instead of simply clearing the present bit to squash a benign warning in kvm_mmu_set_mmio_spte_mask() that complains about the mmio_value overlapping the lower GFN mask on systems with 52 bits of PA space. Opportunistically clean up the code and comments. Cc: stable@vger.kernel.org Fixes: d43e2675e96fc ("KVM: x86: only do L1TF workaround on affected processors") Signed-off-by: Sean Christopherson Message-Id: <20200527084909.23492-1-sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini Signed-off-by: Sasha Levin

kvm: x86: Fix reserved bits related calculation errors caused by MKTME

2020-06-25T13:42:02+00:00

[ Upstream commit f3ecb59dd49f1742b97df6ba071aaa3d031154ac ] Intel MKTME repurposes several high bits of physical address as 'keyID' for memory encryption thus effectively reduces platform's maximum physical address bits. Exactly how many bits are reduced is configured by BIOS. To honor such HW behavior, the repurposed bits are reduced from cpuinfo_x86->x86_phys_bits when MKTME is detected in CPU detection. Similarly, AMD SME/SEV also reduces physical address bits for memory encryption, and cpuinfo->x86_phys_bits is reduced too when SME/SEV is detected, so for both MKTME and SME/SEV, boot_cpu_data.x86_phys_bits doesn't hold physical address bits reported by CPUID anymore. Currently KVM treats bits from boot_cpu_data.x86_phys_bits to 51 as reserved bits, but it's not true anymore for MKTME, since MKTME treats those reduced bits as 'keyID', but not reserved bits. Therefore boot_cpu_data.x86_phys_bits cannot be used to calculate reserved bits anymore, although we can still use it for AMD SME/SEV since SME/SEV treats the reduced bits differently -- they are treated as reserved bits, the same as other reserved bits in page table entity [1]. Fix by introducing a new 'shadow_phys_bits' variable in KVM x86 MMU code to store the effective physical bits w/o reserved bits -- for MKTME, it equals to physical address reported by CPUID, and for SME/SEV, it is boot_cpu_data.x86_phys_bits. Note that for the physical address bits reported to guest should remain unchanged -- KVM should report physical address reported by CPUID to guest, but not boot_cpu_data.x86_phys_bits. Because for Intel MKTME, there's no harm if guest sets up 'keyID' bits in guest page table (since MKTME only works at physical address level), and KVM doesn't even expose MKTME to guest. Arguably, for AMD SME/SEV, guest is aware of SEV thus it should adjust boot_cpu_data.x86_phys_bits when it detects SEV, therefore KVM should still reports physcial address reported by CPUID to guest. Reviewed-by: Sean Christopherson Signed-off-by: Kai Huang Signed-off-by: Paolo Bonzini Signed-off-by: Sasha Levin

kvm: x86: Move kvm_set_mmio_spte_mask() from x86.c to mmu.c

2020-06-25T13:42:02+00:00

[ Upstream commit 7b6f8a06e482960ba6ab06faba51c8f3727a5c7b ] As a prerequisite to fix several SPTE reserved bits related calculation errors caused by MKTME, which requires kvm_set_mmio_spte_mask() to use local static variable defined in mmu.c. Also move call site of kvm_set_mmio_spte_mask() from kvm_arch_init() to kvm_mmu_module_init() so that kvm_set_mmio_spte_mask() can be static. Reviewed-by: Sean Christopherson Signed-off-by: Kai Huang Signed-off-by: Paolo Bonzini Signed-off-by: Sasha Levin

md: add feature flag MD_FEATURE_RAID0_LAYOUT

2020-06-25T13:42:02+00:00

[ Upstream commit 33f2c35a54dfd75ad0e7e86918dcbe4de799a56c ] Due to a bug introduced in Linux 3.14 we cannot determine the correctly layout for a multi-zone RAID0 array - there are two possibilities. It is possible to tell the kernel which to chose using a module parameter, but this can be clumsy to use. It would be best if the choice were recorded in the metadata. So add a feature flag for this purpose. If it is set, then the 'layout' field of the superblock is used to determine which layout to use. If this flag is not set, then mddev->layout gets set to -1, which causes the module parameter to be required. Acked-by: Guoqing Jiang Signed-off-by: NeilBrown Signed-off-by: Song Liu Signed-off-by: Sasha Levin

net: core: device_rename: Use rwsem instead of a seqcount

2020-06-25T13:42:02+00:00

[ Upstream commit 11d6011c2cf29f7c8181ebde6c8bc0c4d83adcd7 ] Sequence counters write paths are critical sections that must never be preempted, and blocking, even for CONFIG_PREEMPTION=n, is not allowed. Commit 5dbe7c178d3f ("net: fix kernel deadlock with interface rename and netdev name retrieval.") handled a deadlock, observed with CONFIG_PREEMPTION=n, where the devnet_rename seqcount read side was infinitely spinning: it got scheduled after the seqcount write side blocked inside its own critical section. To fix that deadlock, among other issues, the commit added a cond_resched() inside the read side section. While this will get the non-preemptible kernel eventually unstuck, the seqcount reader is fully exhausting its slice just spinning -- until TIF_NEED_RESCHED is set. The fix is also still broken: if the seqcount reader belongs to a real-time scheduling policy, it can spin forever and the kernel will livelock. Disabling preemption over the seqcount write side critical section will not work: inside it are a number of GFP_KERNEL allocations and mutex locking through the drivers/base/ :: device_rename() call chain. >From all the above, replace the seqcount with a rwsem. Fixes: 5dbe7c178d3f (net: fix kernel deadlock with interface rename and netdev name retrieval.) Fixes: 30e6c9fa93cf (net: devnet_rename_seq should be a seqcount) Fixes: c91f6df2db49 (sockopt: Change getsockopt() of SO_BINDTODEVICE to return an interface name) Cc: Reported-by: kbuild test robot [ v1 missing up_read() on error exit ] Reported-by: Dan Carpenter [ v1 missing up_read() on error exit ] Signed-off-by: Ahmed S. Darwish Reviewed-by: Sebastian Andrzej Siewior Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

sched/rt, net: Use CONFIG_PREEMPTION.patch

2020-06-25T13:42:02+00:00

[ Upstream commit 2da2b32fd9346009e9acdb68c570ca8d3966aba7 ] CONFIG_PREEMPTION is selected by CONFIG_PREEMPT and by CONFIG_PREEMPT_RT. Both PREEMPT and PREEMPT_RT require the same functionality which today depends on CONFIG_PREEMPT. Update the comment to use CONFIG_PREEMPTION. Signed-off-by: Thomas Gleixner Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Thomas Gleixner Acked-by: David S. Miller Cc: Linus Torvalds Cc: Peter Zijlstra Cc: netdev@vger.kernel.org Link: https://lore.kernel.org/r/20191015191821.11479-22-bigeasy@linutronix.de Signed-off-by: Ingo Molnar Signed-off-by: Sasha Levin

kretprobe: Prevent triggering kretprobe from within kprobe_flush_task

2020-06-25T13:42:02+00:00

[ Upstream commit 9b38cc704e844e41d9cf74e647bff1d249512cb3 ] Ziqian reported lockup when adding retprobe on _raw_spin_lock_irqsave. My test was also able to trigger lockdep output: ============================================ WARNING: possible recursive locking detected 5.6.0-rc6+ #6 Not tainted -------------------------------------------- sched-messaging/2767 is trying to acquire lock: ffffffff9a492798 (&(kretprobe_table_locks[i].lock)){-.-.}, at: kretprobe_hash_lock+0x52/0xa0 but task is already holding lock: ffffffff9a491a18 (&(kretprobe_table_locks[i].lock)){-.-.}, at: kretprobe_trampoline+0x0/0x50 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&(kretprobe_table_locks[i].lock)); lock(&(kretprobe_table_locks[i].lock)); *** DEADLOCK *** May be due to missing lock nesting notation 1 lock held by sched-messaging/2767: #0: ffffffff9a491a18 (&(kretprobe_table_locks[i].lock)){-.-.}, at: kretprobe_trampoline+0x0/0x50 stack backtrace: CPU: 3 PID: 2767 Comm: sched-messaging Not tainted 5.6.0-rc6+ #6 Call Trace: dump_stack+0x96/0xe0 __lock_acquire.cold.57+0x173/0x2b7 ? native_queued_spin_lock_slowpath+0x42b/0x9e0 ? lockdep_hardirqs_on+0x590/0x590 ? __lock_acquire+0xf63/0x4030 lock_acquire+0x15a/0x3d0 ? kretprobe_hash_lock+0x52/0xa0 _raw_spin_lock_irqsave+0x36/0x70 ? kretprobe_hash_lock+0x52/0xa0 kretprobe_hash_lock+0x52/0xa0 trampoline_handler+0xf8/0x940 ? kprobe_fault_handler+0x380/0x380 ? find_held_lock+0x3a/0x1c0 kretprobe_trampoline+0x25/0x50 ? lock_acquired+0x392/0xbc0 ? _raw_spin_lock_irqsave+0x50/0x70 ? __get_valid_kprobe+0x1f0/0x1f0 ? _raw_spin_unlock_irqrestore+0x3b/0x40 ? finish_task_switch+0x4b9/0x6d0 ? __switch_to_asm+0x34/0x70 ? __switch_to_asm+0x40/0x70 The code within the kretprobe handler checks for probe reentrancy, so we won't trigger any _raw_spin_lock_irqsave probe in there. The problem is in outside kprobe_flush_task, where we call: kprobe_flush_task kretprobe_table_lock raw_spin_lock_irqsave _raw_spin_lock_irqsave where _raw_spin_lock_irqsave triggers the kretprobe and installs kretprobe_trampoline handler on _raw_spin_lock_irqsave return. The kretprobe_trampoline handler is then executed with already locked kretprobe_table_locks, and first thing it does is to lock kretprobe_table_locks ;-) the whole lockup path like: kprobe_flush_task kretprobe_table_lock raw_spin_lock_irqsave _raw_spin_lock_irqsave ---> probe triggered, kretprobe_trampoline installed ---> kretprobe_table_locks locked kretprobe_trampoline trampoline_handler kretprobe_hash_lock(current, &head, &flags); <--- deadlock Adding kprobe_busy_begin/end helpers that mark code with fake probe installed to prevent triggering of another kprobe within this code. Using these helpers in kprobe_flush_task, so the probe recursion protection check is hit and the probe is never set to prevent above lockup. Link: http://lkml.kernel.org/r/158927059835.27680.7011202830041561604.stgit@devnote2 Fixes: ef53d9c5e4da ("kprobes: improve kretprobe scalability with hashed locking") Cc: Ingo Molnar Cc: "Gustavo A . R . Silva" Cc: Anders Roxell Cc: "Naveen N . Rao" Cc: Anil S Keshavamurthy Cc: David Miller Cc: Ingo Molnar Cc: Peter Zijlstra Cc: stable@vger.kernel.org Reported-by: "Ziqian SUN (Zamir)" Acked-by: Masami Hiramatsu Signed-off-by: Jiri Olsa Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Sasha Levin

e1000e: Do not wake up the system via WOL if device wakeup is disabled

2020-06-25T13:42:01+00:00

commit 6bf6be1127f7e6d4bf39f84d56854e944d045d74 upstream. Currently the system will be woken up via WOL(Wake On LAN) even if the device wakeup ability has been disabled via sysfs: cat /sys/devices/pci0000:00/0000:00:1f.6/power/wakeup disabled The system should not be woken up if the user has explicitly disabled the wake up ability for this device. This patch clears the WOL ability of this network device if the user has disabled the wake up ability in sysfs. Fixes: bc7f75fa9788 ("[E1000E]: New pci-express e1000 driver") Reported-by: "Rafael J. Wysocki" Reviewed-by: Andy Shevchenko Cc: Signed-off-by: Chen Yu Tested-by: Aaron Brown Signed-off-by: Jeff Kirsher Signed-off-by: Greg Kroah-Hartman

kprobes: Fix to protect kick_kprobe_optimizer() by kprobe_mutex

2020-06-25T13:42:01+00:00

commit 1a0aa991a6274161c95a844c58cfb801d681eb59 upstream. In kprobe_optimizer() kick_kprobe_optimizer() is called without kprobe_mutex, but this can race with other caller which is protected by kprobe_mutex. To fix that, expand kprobe_mutex protected area to protect kick_kprobe_optimizer() call. Link: http://lkml.kernel.org/r/158927057586.27680.5036330063955940456.stgit@devnote2 Fixes: cd7ebe2298ff ("kprobes: Use text_poke_smp_batch for optimizing") Cc: Ingo Molnar Cc: "Gustavo A . R . Silva" Cc: Anders Roxell Cc: "Naveen N . Rao" Cc: Anil S Keshavamurthy Cc: David Miller Cc: Ingo Molnar Cc: Peter Zijlstra Cc: Ziqian SUN Cc: stable@vger.kernel.org Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Greg Kroah-Hartman