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 PCI fix from Bjorn Helgaas:
"Move alpha PCI IRQ map/swizzle functions out of initdata to fix
regression from PCI core IRQ mapping changes (Lorenzo Pieralisi)"
* tag 'pci-v4.14-fixes-6' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci:
alpha/PCI: Move pci_map_irq()/pci_swizzle() out of initdata
Pull drm fixes from Dave Airlie:
"Two amd fixes, one i915 core and a few i915 GVT fixes, things seem
fairly quiet"
* tag 'drm-fixes-for-v4.14-rc7' of git://people.freedesktop.org/~airlied/linux:
drm/i915/gvt: Adding ACTHD mmio read handler
drm/i915/gvt: Extract mmio_read_from_hw() common function
drm/i915/gvt: Refine MMIO_RING_F()
drm/i915/gvt: properly check per_ctx bb valid state
drm/i915/perf: fix perf enable/disable ioctls with 32bits userspace
drm/amd/amdgpu: Remove workaround check for UVD6 on APUs
drm/amd/powerplay: fix uninitialized variable
The introduction of {map/swizzle}_irq() hooks in the struct pci_host_bridge
allowed to replace the pci_fixup_irqs() PCI IRQ allocation in alpha arch
PCI code with per-bridge map/swizzle functions with commit 0e4c2eeb758a
("alpha/PCI: Replace pci_fixup_irqs() call with host bridge IRQ mapping
hooks").
As a side effect of converting PCI IRQ allocation to the struct
pci_host_bridge {map/swizzle}_irq() hooks mechanism, the actual PCI IRQ
allocation function (ie pci_assign_irq()) is carried out per-device in
pci_device_probe() that is called when a PCI device driver is about to be
probed.
This means that, for drivers compiled as loadable modules, the actual PCI
device IRQ allocation can now happen after the system has booted so the
struct pci_host_bridge {map/swizzle}_irq() hooks pci_assign_irq() relies on
must stay valid after the system has booted so that PCI core can carry out
PCI IRQ allocation correctly.
Most of the alpha board structures pci_map_irq() and pci_swizzle() hooks
(that are used to initialize their struct pci_host_bridge equivalent
through the alpha_mv global variable - that represents the struct
alpha_machine_vector of the running kernel) are marked as
__init/__initdata; this causes freed memory dereferences when PCI IRQ
allocation is carried out after the kernel has booted (ie when loading PCI
drivers as loadable module) because when the kernel tries to bind the PCI
device to its (module) driver, the function pci_assign_irq() is called,
that in turn retrieves the struct pci_host_bridge {map/swizzle}_irq() hooks
to carry out PCI IRQ allocation; if those hooks are marked as __init
code/__initdata they point at freed/invalid memory.
Fix the issue by removing the __init/__initdata markers from all subarch
struct alpha_machine_vector.pci_map_irq()/pci_swizzle() functions (and
data).
Fixes: 0e4c2eeb758a ("alpha/PCI: Replace pci_fixup_irqs() call with host bridge IRQ mapping hooks")
Link: http://lkml.kernel.org/r/alpine.LRH.2.21.1710251043170.7098@math.ut.ee
Reported-by: Meelis Roos <mroos@linux.ee>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Meelis Roos <mroos@linux.ee>
Cc: Matt Turner <mattst88@gmail.com>
Pull SCSI fixes from James Bottomley:
"Six fixes for mostly minor issues, most of which have small race
windows for occurring"
* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
scsi: Suppress a kernel warning in case the prep function returns BLKPREP_DEFER
scsi: sg: Re-fix off by one in sg_fill_request_table()
scsi: aacraid: Fix controller initialization failure
scsi: hpsa: Fix configured_logical_drive_count·check
scsi: qla2xxx: Initialize Work element before requesting IRQs
scsi: zfcp: fix erp_action use-before-initialize in REC action trace
One fix for stable:
- fix perf enable/disable ioctls for 32bits (Lionel)
Plus GVT fixes:
- Fix per_ctx_bb check (Zhenyu)
- Fix GPU hang of Linux guest (Xion)
- Refine MMIO_RING_F to check for presence of VCS2 ring (Zhi)
* tag 'drm-intel-fixes-2017-10-26' of git://anongit.freedesktop.org/drm/drm-intel:
drm/i915/gvt: Adding ACTHD mmio read handler
drm/i915/gvt: Extract mmio_read_from_hw() common function
drm/i915/gvt: Refine MMIO_RING_F()
drm/i915/gvt: properly check per_ctx bb valid state
struct pci_host_bridge gained hooks to map/swizzle IRQs, so that the IRQ
mapping can be done automatically by PCI core code through the
pci_assign_irq() function instead of resorting to arch-specific
implementation callbacks to carry out the same task which force PCI host
bridge drivers implementation to implement per-arch kludges to carry out a
task that is inherently architecture agnostic.
Commit 769b461fc0c0 ("arm64: PCI: Drop DT IRQ allocation from
pcibios_alloc_irq()") was assuming all PCI host controller drivers had been
converted to use ->map_irq(), but that wasn't the case: pci-aardvark had
not been converted. Due to this, it broke the support for legacy PCI
interrupts when using the pci-aardvark driver (used on Marvell Armada 3720
platforms).
In order to fix this, we make sure the ->map_irq and ->swizzle_irq fields
of pci_host_bridge are properly filled in.
Fixes: 769b461fc0c0 ("arm64: PCI: Drop DT IRQ allocation from pcibios_alloc_irq()")
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: stable@vger.kernel.org # v4.13+
This fixes CVE-2017-12193.
Fix a case in the assoc_array implementation in which a new leaf is
added that needs to go into a node that happens to be full, where the
existing leaves in that node cluster together at that level to the
exclusion of new leaf.
What needs to happen is that the existing leaves get moved out to a new
node, N1, at level + 1 and the existing node needs replacing with one,
N0, that has pointers to the new leaf and to N1.
The code that tries to do this gets this wrong in two ways:
(1) The pointer that should've pointed from N0 to N1 is set to point
recursively to N0 instead.
(2) The backpointer from N0 needs to be set correctly in the case N0 is
either the root node or reached through a shortcut.
Fix this by removing this path and using the split_node path instead,
which achieves the same end, but in a more general way (thanks to Eric
Biggers for spotting the redundancy).
The problem manifests itself as:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000010
IP: assoc_array_apply_edit+0x59/0xe5
Fixes: 3cb989501c26 ("Add a generic associative array implementation.")
Reported-and-tested-by: WU Fan <u3536072@connect.hku.hk>
Signed-off-by: David Howells <dhowells@redhat.com>
Cc: stable@vger.kernel.org [v3.13-rc1+]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The legacy block layer handles requests as follows:
- If the prep function returns BLKPREP_OK, let blk_peek_request()
return the pointer to that request.
- If the prep function returns BLKPREP_DEFER, keep the RQF_STARTED
flag and retry calling the prep function later.
- If the prep function returns BLKPREP_KILL or BLKPREP_INVALID, end
the request.
In none of these cases it is correct to clear the SCMD_INITIALIZED
flag from inside scsi_prep_fn(). Since scsi_prep_fn() already
guarantees that scsi_init_command() will be called once even if
scsi_prep_fn() is called multiple times, remove the code that clears
SCMD_INITIALIZED from scsi_prep_fn().
The scsi-mq code handles requests as follows:
- If scsi_mq_prep_fn() returns BLKPREP_OK, set the RQF_DONTPREP flag
and submit the request to the SCSI LLD.
- If scsi_mq_prep_fn() returns BLKPREP_DEFER, call
blk_mq_delay_run_hw_queue() and return BLK_STS_RESOURCE.
- If the prep function returns BLKPREP_KILL or BLKPREP_INVALID, call
scsi_mq_uninit_cmd() and let the blk-mq core end the request.
In none of these cases scsi_mq_prep_fn() should clear the
SCMD_INITIALIZED flag. Hence remove the code from scsi_mq_prep_fn()
function that clears that flag.
This patch avoids that the following warning is triggered when using
the legacy block layer:
------------[ cut here ]------------
WARNING: CPU: 1 PID: 4198 at drivers/scsi/scsi_lib.c:654 scsi_end_request+0x1de/0x220
CPU: 1 PID: 4198 Comm: mkfs.f2fs Not tainted 4.14.0-rc5+ #1
task: ffff91c147a4b800 task.stack: ffffb282c37b8000
RIP: 0010:scsi_end_request+0x1de/0x220
Call Trace:
<IRQ>
scsi_io_completion+0x204/0x5e0
scsi_finish_command+0xce/0xe0
scsi_softirq_done+0x126/0x130
blk_done_softirq+0x6e/0x80
__do_softirq+0xcf/0x2a8
irq_exit+0xab/0xb0
do_IRQ+0x7b/0xc0
common_interrupt+0x90/0x90
</IRQ>
RIP: 0010:_raw_spin_unlock_irqrestore+0x9/0x10
__test_set_page_writeback+0xc7/0x2c0
__block_write_full_page+0x158/0x3b0
block_write_full_page+0xc4/0xd0
blkdev_writepage+0x13/0x20
__writepage+0x12/0x40
write_cache_pages+0x204/0x500
generic_writepages+0x48/0x70
blkdev_writepages+0x9/0x10
do_writepages+0x34/0xc0
__filemap_fdatawrite_range+0x6c/0x90
file_write_and_wait_range+0x31/0x90
blkdev_fsync+0x16/0x40
vfs_fsync_range+0x44/0xa0
do_fsync+0x38/0x60
SyS_fsync+0xb/0x10
entry_SYSCALL_64_fastpath+0x13/0x94
---[ end trace 86e8ef85a4a6c1d1 ]---
Fixes: commit 64104f703212 ("scsi: Call scsi_initialize_rq() for filesystem requests")
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Damien Le Moal <damien.lemoal@wdc.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
drm-intel-fixes-2017-10-25:
only 1 fix for stable:
- fix perf enable/disable ioctls for 32bits (lionel)
* tag 'drm-intel-fixes-2017-10-25' of git://anongit.freedesktop.org/drm/drm-intel:
drm/i915/perf: fix perf enable/disable ioctls with 32bits userspace
When a workload is too heavy to finish it in gpu hang check timer
intervals(1.5), gpu hang check function will check ACTHD register
value to decide whether gpu is real dead or not. On real hw,
ACTHD is updated by HW when workload is running, then host kernel
won't think it is gpu hang. while guest kernel always read a constant
ACTHD value as GVT doesn't supply ACTHD emulate handler, then
guest kernel detects a fake gpu hang.
To remove such guest fake gpu hang, this patch supply ACTHD
mmio read handler which read real HW ACTHD register directly.
Signed-off-by: Xiong Zhang <xiong.y.zhang@intel.com>
Signed-off-by: Zhi Wang <zhi.a.wang@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/b4c9a097-3e62-124e-6856-b0c37764df7b@intel.com
This reverts commit d7bd554f27c942e6b8b54100b4044f9be1038edf.
It turns out that Tegra20 has a bug in the implementation of the MSI
target address register (which is worked around by the existence of the
struct tegra_pcie_soc.msi_base_shift parameter) that restricts the MSI
target memory to the lower 32 bits of physical memory on that particular
generation. The offending patch causes a regression on TrimSlice, which
is a Tegra20-based device and has a PCI network interface card.
An initial, simpler fix was to change the MSI target address for Tegra20
only, but it was pointed out that the offending commit also prevents the
use of 32-bit only MSI capable devices, even on later chips. Technically
this was never guaranteed to work with the prior code in the first place
because the allocated page could have resided beyond the 4 GiB boundary,
but it is still possible that this could've introduced a regression.
The proper fix that was settled on is to select a fixed address within
the lowest 32 bits of physical address space that is otherwise unused,
but testing of that patch has provided mixed results that are not fully
understood yet.
Given all of the above and the relative urgency to get this fixed in
v4.13, revert the offending commit until a universal fix is found.
Fixes: d7bd554f27c9 ("PCI: tegra: Do not allocate MSI target memory")
Reported-by: Tomasz Maciej Nowak <tmn505@gmail.com>
Reported-by: Erik Faye-Lund <kusmabite@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: stable@vger.kernel.org # 4.13.x
Pull cifs fixes from Steve French:
"Various SMB3 fixes for 4.14 and stable"
* tag '4.14-smb3-fixes-for-stable' of git://git.samba.org/sfrench/cifs-2.6:
SMB3: Validate negotiate request must always be signed
SMB: fix validate negotiate info uninitialised memory use
SMB: fix leak of validate negotiate info response buffer
CIFS: Fix NULL pointer deref on SMB2_tcon() failure
CIFS: do not send invalid input buffer on QUERY_INFO requests
cifs: Select all required crypto modules
CIFS: SMBD: Fix the definition for SMB2_CHANNEL_RDMA_V1_INVALIDATE
cifs: handle large EA requests more gracefully in smb2+
Fix encryption labels and lengths for SMB3.1.1
Commit 109bade9c625 ("scsi: sg: use standard lists for sg_requests")
introduced an off-by-one error in sg_ioctl(), which was fixed by commit
bd46fc406b30 ("scsi: sg: off by one in sg_ioctl()").
Unfortunately commit 4759df905a47 ("scsi: sg: factor out
sg_fill_request_table()") moved that code, and reintroduced the
bug (perhaps due to a botched rebase). Fix it again.
Fixes: 4759df905a47 ("scsi: sg: factor out sg_fill_request_table()")
Cc: stable@vger.kernel.org
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>