kernel/linux.git, branch v5.7.18

Linux 5.7.18

2020-08-26T09:42:25+00:00

Tested-by: Jon Hunter Tested-by: Guenter Roeck Signed-off-by: Greg Kroah-Hartman

Revert "drm/amd/display: Improve DisplayPort monitor interop"

2020-08-26T09:42:25+00:00

This reverts commit 1adb2ff1f6b170cdbc3925a359c8f39d2215dc20. This breaks display wake up in stable kernels (5.7.x and 5.8.x). Note that there is no upstream equivalent to this revert. This patch was targeted for stable by Sasha's stable patch process. Presumably there are some other changes necessary for this patch to work properly on stable kernels. Bug: https://gitlab.freedesktop.org/drm/amd/-/issues/1266 Signed-off-by: Alex Deucher Cc: stable@vger.kernel.org # 5.7.x, 5.8.x Cc: Sasha Levin Signed-off-by: Greg Kroah-Hartman

KVM: arm64: Only reschedule if MMU_NOTIFIER_RANGE_BLOCKABLE is not set

2020-08-26T09:42:25+00:00

commit b5331379bc62611d1026173a09c73573384201d9 upstream. When an MMU notifier call results in unmapping a range that spans multiple PGDs, we end up calling into cond_resched_lock() when crossing a PGD boundary, since this avoids running into RCU stalls during VM teardown. Unfortunately, if the VM is destroyed as a result of OOM, then blocking is not permitted and the call to the scheduler triggers the following BUG(): | BUG: sleeping function called from invalid context at arch/arm64/kvm/mmu.c:394 | in_atomic(): 1, irqs_disabled(): 0, non_block: 1, pid: 36, name: oom_reaper | INFO: lockdep is turned off. | CPU: 3 PID: 36 Comm: oom_reaper Not tainted 5.8.0 #1 | Hardware name: QEMU QEMU Virtual Machine, BIOS 0.0.0 02/06/2015 | Call trace: | dump_backtrace+0x0/0x284 | show_stack+0x1c/0x28 | dump_stack+0xf0/0x1a4 | ___might_sleep+0x2bc/0x2cc | unmap_stage2_range+0x160/0x1ac | kvm_unmap_hva_range+0x1a0/0x1c8 | kvm_mmu_notifier_invalidate_range_start+0x8c/0xf8 | __mmu_notifier_invalidate_range_start+0x218/0x31c | mmu_notifier_invalidate_range_start_nonblock+0x78/0xb0 | __oom_reap_task_mm+0x128/0x268 | oom_reap_task+0xac/0x298 | oom_reaper+0x178/0x17c | kthread+0x1e4/0x1fc | ret_from_fork+0x10/0x30 Use the new 'flags' argument to kvm_unmap_hva_range() to ensure that we only reschedule if MMU_NOTIFIER_RANGE_BLOCKABLE is set in the notifier flags. Cc: Fixes: 8b3405e345b5 ("kvm: arm/arm64: Fix locking for kvm_free_stage2_pgd") Cc: Marc Zyngier Cc: Suzuki K Poulose Cc: James Morse Signed-off-by: Will Deacon Message-Id: <20200811102725.7121-3-will@kernel.org> Signed-off-by: Paolo Bonzini Signed-off-by: Will Deacon Signed-off-by: Greg Kroah-Hartman

KVM: Pass MMU notifier range flags to kvm_unmap_hva_range()

2020-08-26T09:42:24+00:00

commit fdfe7cbd58806522e799e2a50a15aee7f2cbb7b6 upstream. The 'flags' field of 'struct mmu_notifier_range' is used to indicate whether invalidate_range_{start,end}() are permitted to block. In the case of kvm_mmu_notifier_invalidate_range_start(), this field is not forwarded on to the architecture-specific implementation of kvm_unmap_hva_range() and therefore the backend cannot sensibly decide whether or not to block. Add an extra 'flags' parameter to kvm_unmap_hva_range() so that architectures are aware as to whether or not they are permitted to block. Cc: Cc: Marc Zyngier Cc: Suzuki K Poulose Cc: James Morse Signed-off-by: Will Deacon Message-Id: <20200811102725.7121-2-will@kernel.org> Signed-off-by: Paolo Bonzini Signed-off-by: Will Deacon Signed-off-by: Greg Kroah-Hartman

xen: don't reschedule in preemption off sections

2020-08-26T09:42:24+00:00

For support of long running hypercalls xen_maybe_preempt_hcall() is calling cond_resched() in case a hypercall marked as preemptible has been interrupted. Normally this is no problem, as only hypercalls done via some ioctl()s are marked to be preemptible. In rare cases when during such a preemptible hypercall an interrupt occurs and any softirq action is started from irq_exit(), a further hypercall issued by the softirq handler will be regarded to be preemptible, too. This might lead to rescheduling in spite of the softirq handler potentially having set preempt_disable(), leading to splats like: BUG: sleeping function called from invalid context at drivers/xen/preempt.c:37 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 20775, name: xl INFO: lockdep is turned off. CPU: 1 PID: 20775 Comm: xl Tainted: G D W 5.4.46-1_prgmr_debug.el7.x86_64 #1 Call Trace: dump_stack+0x8f/0xd0 ___might_sleep.cold.76+0xb2/0x103 xen_maybe_preempt_hcall+0x48/0x70 xen_do_hypervisor_callback+0x37/0x40 RIP: e030:xen_hypercall_xen_version+0xa/0x20 Code: ... RSP: e02b:ffffc900400dcc30 EFLAGS: 00000246 RAX: 000000000004000d RBX: 0000000000000200 RCX: ffffffff8100122a RDX: ffff88812e788000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffffff83ee3ad0 R08: 0000000000000001 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000246 R12: ffff8881824aa0b0 R13: 0000000865496000 R14: 0000000865496000 R15: ffff88815d040000 ? xen_hypercall_xen_version+0xa/0x20 ? xen_force_evtchn_callback+0x9/0x10 ? check_events+0x12/0x20 ? xen_restore_fl_direct+0x1f/0x20 ? _raw_spin_unlock_irqrestore+0x53/0x60 ? debug_dma_sync_single_for_cpu+0x91/0xc0 ? _raw_spin_unlock_irqrestore+0x53/0x60 ? xen_swiotlb_sync_single_for_cpu+0x3d/0x140 ? mlx4_en_process_rx_cq+0x6b6/0x1110 [mlx4_en] ? mlx4_en_poll_rx_cq+0x64/0x100 [mlx4_en] ? net_rx_action+0x151/0x4a0 ? __do_softirq+0xed/0x55b ? irq_exit+0xea/0x100 ? xen_evtchn_do_upcall+0x2c/0x40 ? xen_do_hypervisor_callback+0x29/0x40 ? xen_hypercall_domctl+0xa/0x20 ? xen_hypercall_domctl+0x8/0x20 ? privcmd_ioctl+0x221/0x990 [xen_privcmd] ? do_vfs_ioctl+0xa5/0x6f0 ? ksys_ioctl+0x60/0x90 ? trace_hardirqs_off_thunk+0x1a/0x20 ? __x64_sys_ioctl+0x16/0x20 ? do_syscall_64+0x62/0x250 ? entry_SYSCALL_64_after_hwframe+0x49/0xbe Fix that by testing preempt_count() before calling cond_resched(). In kernel 5.8 this can't happen any more due to the entry code rework (more than 100 patches, so not a candidate for backporting). The issue was introduced in kernel 4.3, so this patch should go into all stable kernels in [4.3 ... 5.7]. Reported-by: Sarah Newman Fixes: 0fa2f5cb2b0ecd8 ("sched/preempt, xen: Use need_resched() instead of should_resched()") Cc: Sarah Newman Cc: stable@vger.kernel.org Signed-off-by: Juergen Gross Tested-by: Chris Brannon Signed-off-by: Greg Kroah-Hartman

do_epoll_ctl(): clean the failure exits up a bit

2020-08-26T09:42:24+00:00

commit 52c479697c9b73f628140dcdfcd39ea302d05482 upstream. Signed-off-by: Al Viro Signed-off-by: Greg Kroah-Hartman

efi/libstub: Handle NULL cmdline

2020-08-26T09:42:24+00:00

commit a37ca6a2af9df2972372b918f09390c9303acfbd upstream. Treat a NULL cmdline the same as empty. Although this is unlikely to happen in practice, the x86 kernel entry does check for NULL cmdline and handles it, so do it here as well. Cc: Signed-off-by: Arvind Sankar Link: https://lore.kernel.org/r/20200729193300.598448-1-nivedita@alum.mit.edu Signed-off-by: Ard Biesheuvel Signed-off-by: Greg Kroah-Hartman

efi/libstub: Stop parsing arguments at "--"

2020-08-26T09:42:24+00:00

commit 1fd9717d75df68e3c3509b8e7b1138ca63472f88 upstream. Arguments after "--" are arguments for init, not for the kernel. Cc: Signed-off-by: Arvind Sankar Link: https://lore.kernel.org/r/20200725155916.1376773-1-nivedita@alum.mit.edu Signed-off-by: Ard Biesheuvel Signed-off-by: Greg Kroah-Hartman

efi: add missed destroy_workqueue when efisubsys_init fails

2020-08-26T09:42:24+00:00

commit 98086df8b70c06234a8f4290c46064e44dafa0ed upstream. destroy_workqueue() should be called to destroy efi_rts_wq when efisubsys_init() init resources fails. Cc: Reported-by: Hulk Robot Signed-off-by: Li Heng Link: https://lore.kernel.org/r/1595229738-10087-1-git-send-email-liheng40@huawei.com Signed-off-by: Ard Biesheuvel Signed-off-by: Greg Kroah-Hartman

efi/x86: Mark kernel rodata non-executable for mixed mode

2020-08-26T09:42:23+00:00

commit c8502eb2d43b6b9b1dc382299a4d37031be63876 upstream. When remapping the kernel rodata section RO in the EFI pagetables, the protection flags that were used for the text section are being reused, but the rodata section should not be marked executable. Cc: Signed-off-by: Arvind Sankar Link: https://lore.kernel.org/r/20200717194526.3452089-1-nivedita@alum.mit.edu Signed-off-by: Ard Biesheuvel Signed-off-by: Greg Kroah-Hartman