Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
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.
Clone this repository
For self-hosted knots, clone URLs may differ based on your setup.
Download tar.gz
Pull rdma fixes from Jason Gunthorpe:
"One core bug fix and a few driver ones
- FRWR memory registration for hfi1/qib didn't work with with some
iovas causing a NFSoRDMA failure regression due to a fix in the NFS
side
- A command flow error in mlx5 allowed user space to send a corrupt
command (and also smash the kernel stack we've since learned)
- Fix a regression and some bugs with device hot unplug that was
discovered while reviewing Andrea's patches
- hns has a failure if the user asks for certain QP configurations"
* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma:
RDMA/hns: Bugfix for mapping user db
RDMA/ucontext: Fix regression with disassociate
RDMA/mlx5: Use rdma_user_map_io for mapping BAR pages
RDMA/mlx5: Do not allow the user to write to the clock page
IB/mlx5: Fix scatter to CQE in DCT QP creation
IB/rdmavt: Fix frwr memory registration
Pull dmaengine fixes from Vinod Koul:
- fix for wrong register use in mediatek driver
- fix in sh driver for glitch is tx_status and treating 0 a valid
residue for cyclic
- fix in bcm driver for using right memory allocation flag
* tag 'dmaengine-fix-5.1-rc7' of git://git.infradead.org/users/vkoul/slave-dma:
dmaengine: mediatek-cqdma: fix wrong register usage in mtk_cqdma_start
dmaengine: sh: rcar-dmac: Fix glitch in dmaengine_tx_status
dmaengine: sh: rcar-dmac: With cyclic DMA residue 0 is valid
dmaengine: bcm2835: Avoid GFP_KERNEL in device_prep_slave_sg
When the maximum send wr delivered by the user is zero, the qp does not
have a sq.
When allocating the sq db buffer to store the user sq pi pointer and map
it to the kernel mode, max_send_wr is used as the trigger condition, while
the kernel does not consider the max_send_wr trigger condition when
mapmping db. It will cause sq record doorbell map fail and create qp fail.
The failed print information as follows:
hns3 0000:7d:00.1: Send cmd: tail - 418, opcode - 0x8504, flag - 0x0011, retval - 0x0000
hns3 0000:7d:00.1: Send cmd: 0xe59dc000 0x00000000 0x00000000 0x00000000 0x00000116 0x0000ffff
hns3 0000:7d:00.1: sq record doorbell map failed!
hns3 0000:7d:00.1: Create RC QP failed
Fixes: 0425e3e6e0c7 ("RDMA/hns: Support flush cqe for hip08 in kernel space")
Signed-off-by: Lijun Ou <oulijun@huawei.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Pull input fixes from Dmitry Torokhov:
"Just a couple of fixups for Synaptics RMI4 driver and allowing
snvs_pwrkey to be selected on more boards"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
Input: synaptics-rmi4 - write config register values to the right offset
Input: synaptics-rmi4 - fix possible double free
Input: snvs_pwrkey - make it depend on ARCH_MXC
This patch fixes wrong register usage in the mtk_cqdma_start. The
destination register should be MTK_CQDMA_DST2 instead.
Fixes: b1f01e48df5a ("dmaengine: mediatek: Add MediaTek Command-Queue DMA controller for MT6765 SoC")
Signed-off-by: Shun-Chih Yu <shun-chih.yu@mediatek.com>
Cc: stable@vger.kernel.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>
When this code was consolidated the intention was that the VMA would
become backed by anonymous zero pages after the zap_vma_pte - however this
very subtly relied on setting the vm_ops = NULL and clearing the VM_SHARED
bits to transform the VMA into an anonymous VMA. Since the vm_ops was
removed this broke.
Now userspace gets a SIGBUS if it touches the vma after disassociation.
Instead of converting the VMA to anonymous provide a fault handler that
puts a zero'd page into the VMA when user-space touches it after
disassociation.
Cc: stable@vger.kernel.org
Suggested-by: Andrea Arcangeli <aarcange@redhat.com>
Fixes: 5f9794dc94f5 ("RDMA/ucontext: Add a core API for mmaping driver IO memory")
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Pull x86 fixes from Ingo Molnar:
- Fix an early boot crash in the RSDP parsing code by effectively
turning off the parsing call - we ran out of time but want to fix the
regression. The more involved fix is being worked on.
- Fix a crash that can trigger in the kmemlek code.
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mm: Fix a crash with kmemleak_scan()
x86/boot: Disable RSDP parsing temporarily
Currently any changed config register values don't take effect, as the
function to write them back is called with the wrong register offset.
Fixes: ff8f83708b3e (Input: synaptics-rmi4 - add support for 2D
sensors and F11)
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Cc: stable@vger.kernel.org
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
The tx_status poll in the rcar_dmac driver reads the status register
which indicates which chunk is busy (DMACHCRB). Afterwards the point
inside the chunk is read from DMATCRB. It is possible that the chunk
has changed between the two reads. The result is a non-monotonous
increase of the residue. Fix this by introducing a 'safe read' logic.
Fixes: 73a47bd0da66 ("dmaengine: rcar-dmac: use TCRB instead of TCR for residue")
Signed-off-by: Achim Dahlhoff <Achim.Dahlhoff@de.bosch.com>
Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com>
Reviewed-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Cc: <stable@vger.kernel.org> # v4.16+
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Since mlx5 supports device disassociate it must use this API for all
BAR page mmaps, otherwise the pages can remain mapped after the device
is unplugged causing a system crash.
Cc: stable@vger.kernel.org
Fixes: 5f9794dc94f5 ("RDMA/ucontext: Add a core API for mmaping driver IO memory")
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Reviewed-by: Haggai Eran <haggaie@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Pull scheduler fix from Ingo Molnar:
"Fix a division by zero bug that can trigger in the NUMA placement
code"
* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/numa: Fix a possible divide-by-zero
The first kmemleak_scan() call after boot would trigger the crash below
because this callpath:
kernel_init
free_initmem
mem_encrypt_free_decrypted_mem
free_init_pages
unmaps memory inside the .bss when DEBUG_PAGEALLOC=y.
kmemleak_init() will register the .data/.bss sections and then
kmemleak_scan() will scan those addresses and dereference them looking
for pointer references. If free_init_pages() frees and unmaps pages in
those sections, kmemleak_scan() will crash if referencing one of those
addresses:
BUG: unable to handle kernel paging request at ffffffffbd402000
CPU: 12 PID: 325 Comm: kmemleak Not tainted 5.1.0-rc4+ #4
RIP: 0010:scan_block
Call Trace:
scan_gray_list
kmemleak_scan
kmemleak_scan_thread
kthread
ret_from_fork
Since kmemleak_free_part() is tolerant to unknown objects (not tracked
by kmemleak), it is fine to call it from free_init_pages() even if not
all address ranges passed to this function are known to kmemleak.
[ bp: Massage. ]
Fixes: b3f0907c71e0 ("x86/mm: Add .bss..decrypted section to hold shared variables")
Signed-off-by: Qian Cai <cai@lca.pw>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190423165811.36699-1-cai@lca.pw
The RMI4 function structure has been released in rmi_register_function
if error occurs. However, it will be released again in the function
rmi_create_function, which may result in a double-free bug.
Signed-off-by: Pan Bian <bianpan2016@163.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>