Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.
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Pull EFI fix from Thomas Gleixner:
"A single fix to prevent partially initialized pointers in mixed mode
(64bit kernel on 32bit UEFI)"
* 'efi-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
efi/libstub/tpm: Initialize pointer variables to zero for mixed mode
Pull KVM fixes from Paolo Bonzini:
"PPC:
- fix bug leading to lost IPIs and smp_call_function_many() lockups
on POWER9
ARM:
- locking fix
- reset fix
- GICv2 multi-source SGI injection fix
- GICv2-on-v3 MMIO synchronization fix
- make the console less verbose.
x86:
- fix device passthrough on AMD SME"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: x86: Fix device passthrough when SME is active
kvm: arm/arm64: vgic-v3: Tighten synchronization for guests using v2 on v3
KVM: arm/arm64: vgic: Don't populate multiple LRs with the same vintid
KVM: arm/arm64: Reduce verbosity of KVM init log
KVM: arm/arm64: Reset mapped IRQs on VM reset
KVM: arm/arm64: Avoid vcpu_load for other vcpu ioctls than KVM_RUN
KVM: arm/arm64: vgic: Add missing irq_lock to vgic_mmio_read_pending
KVM: PPC: Book3S HV: Fix trap number return from __kvmppc_vcore_entry
As reported by Jeremy Cline, running the new TPM libstub code in mixed
mode (i.e., 64-bit kernel on 32-bit UEFI) results in hangs when invoking
the TCG2 protocol, or when accessing the log_tbl pool allocation.
The reason turns out to be that in both cases, the 64-bit pointer
variables are not fully initialized by the 32-bit EFI code, and so
we should take care to zero initialize these variables beforehand,
or we'll end up dereferencing bogus pointers.
Reported-by: Jeremy Cline <jeremy@jcline.org>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: hdegoede@redhat.com
Cc: jarkko.sakkinen@linux.intel.com
Cc: javierm@redhat.com
Cc: linux-efi@vger.kernel.org
Cc: tweek@google.com
Link: http://lkml.kernel.org/r/20180313140922.17266-2-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Just when I had decided that flush_cache_range() was always called with
a valid context, Helge reported two cases where the
"BUG_ON(!vma->vm_mm->context);" was hit on the phantom buildd:
kernel BUG at /mnt/sdb6/linux/linux-4.15.4/arch/parisc/kernel/cache.c:587!
CPU: 1 PID: 3254 Comm: kworker/1:2 Tainted: G D 4.15.0-1-parisc64-smp #1 Debian 4.15.4-1+b1
Workqueue: events free_ioctx
IAOQ[0]: flush_cache_range+0x164/0x168
IAOQ[1]: flush_cache_page+0x0/0x1c8
RP(r2): unmap_page_range+0xae8/0xb88
Backtrace:
[<00000000404a6980>] unmap_page_range+0xae8/0xb88
[<00000000404a6ae0>] unmap_single_vma+0xc0/0x188
[<00000000404a6cdc>] zap_page_range_single+0x134/0x1f8
[<00000000404a702c>] unmap_mapping_range+0x1cc/0x208
[<0000000040461518>] truncate_pagecache+0x98/0x108
[<0000000040461624>] truncate_setsize+0x9c/0xb8
[<00000000405d7f30>] put_aio_ring_file+0x80/0x100
[<00000000405d803c>] aio_free_ring+0x8c/0x290
[<00000000405d82c0>] free_ioctx+0x80/0x180
[<0000000040284e6c>] process_one_work+0x21c/0x668
[<00000000402854c4>] worker_thread+0x20c/0x778
[<0000000040291d44>] kthread+0x2d4/0x2e0
[<0000000040204020>] end_fault_vector+0x20/0xc0
This indicates that we need to handle the no context case in
flush_cache_range() as we do in flush_cache_mm().
In thinking about this, I realized that we don't need to flush the TLB
when there is no context. So, I added context checks to the large flush
cases in flush_cache_mm() and flush_cache_range(). The large flush case
occurs frequently in flush_cache_mm() and the change should improve fork
performance.
The v2 version of this change removes the BUG_ON from flush_cache_page()
by skipping the TLB flush when there is no context. I also added code
to flush the TLB in flush_cache_mm() and flush_cache_range() when we
have a context that's not current. Now all three routines handle TLB
flushes in a similar manner.
Signed-off-by: John David Anglin <dave.anglin@bell.net>
Cc: stable@vger.kernel.org # 4.9+
Signed-off-by: Helge Deller <deller@gmx.de>
When using device passthrough with SME active, the MMIO range that is
mapped for the device should not be mapped encrypted. Add a check in
set_spte() to insure that a page is not mapped encrypted if that page
is a device MMIO page as indicated by kvm_is_mmio_pfn().
Cc: <stable@vger.kernel.org> # 4.14.x-
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Pull NFS client bugfixes from Trond Myklebust:
"Hightlights include the following stable fixes:
- NFS: Fix an incorrect type in struct nfs_direct_req
- pNFS: Prevent the layout header refcount going to zero in
pnfs_roc()
- NFS: Fix unstable write completion"
* tag 'nfs-for-4.16-4' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
NFS: Fix unstable write completion
pNFS: Prevent the layout header refcount going to zero in pnfs_roc()
NFS: Fix an incorrect type in struct nfs_direct_req
Pull btrfs fixes from David Sterba:
"There's an important revert in this pull request that needs to go to
stable as it causes a corruption on big endian machines.
The other fix is for FIEMAP incorrectly reporting shared extents
before a sync and one fix for a crash in raid56.
So far we got only one report about the BE corruption, the stable
kernels were out for like a week, so hopefully the scope of the damage
is low"
* tag 'for-4.16-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
Revert "btrfs: use proper endianness accessors for super_copy"
btrfs: add missing initialization in btrfs_check_shared
btrfs: Fix NULL pointer exception in find_bio_stripe
Fix for PPC KVM for 4.16
- Fix bug leading to lost IPIs on POWER9 and hence to other CPUs reporting
lockups in smp_call_function_many().
We do want to respect the FLUSH_SYNC argument to nfs_commit_inode() to
ensure that all outstanding COMMIT requests to the inode in question are
complete. Currently we may exit early from both nfs_commit_inode() and
nfs_write_inode() even if there are COMMIT requests in flight, or unstable
writes on the commit list.
In order to get the right semantics w.r.t. sync_inode(), we don't need
to have nfs_commit_inode() reset the inode dirty flags when called from
nfs_wb_page() and/or nfs_wb_all(). We just need to ensure that
nfs_write_inode() leaves them in the right state if there are outstanding
commits, or stable pages.
Reported-by: Scott Mayhew <smayhew@redhat.com>
Fixes: dc4fd9ab01ab ("nfs: don't wait on commit in nfs_commit_inode()...")
Cc: stable@vger.kernel.org # v4.14+
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Pull microblaze fixes from Michal Simek:
- Use NO_BOOTMEM to fix boot issue
- Fix opt lib endian dependencies
* tag 'microblaze-4.16-rc6' of git://git.monstr.eu/linux-2.6-microblaze:
microblaze: switch to NO_BOOTMEM
microblaze: remove unused alloc_maybe_bootmem
microblaze: Setup dependencies for ASM optimized lib functions
This reverts commit 3c181c12c431fe33b669410d663beb9cceefcd1b.
The offending patch was merged in 4.16-rc4 and was promptly applied to
stable kernels 4.14.25 and 4.15.8.
The patch causes a corruption in several superblock items on big-endian
machines because of messed up endianity conversions. The damage is
manually repairable. A filesystem cannot be mounted again after it has
been unmounted once.
We do a full revert and not a fixup so stable can pick that patch ASAP.
Fixes: 3c181c12c431 ("btrfs: use proper endianness accessors for super_copy")
Link: https://lkml.kernel.org/r/1521139304@msgid.manchmal.in-ulm.de
CC: stable@vger.kernel.org # 4.14+
Reported-by: Christoph Biedl <linux-kernel.bfrz@manchmal.in-ulm.de>
Signed-off-by: David Sterba <dsterba@suse.com>
kvm/arm fixes for 4.16, take 2
- Peace of mind locking fix in vgic_mmio_read_pending
- Allow hw-mapped interrupts to be reset when the VM resets
- Fix GICv2 multi-source SGI injection
- Fix MMIO synchronization for GICv2 on v3 emulation
- Remove excess verbosity on the console