tjh.dev
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.
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
code
Clone this repository
https://tangled.org/tjh.dev/kernel
git@gordian.tjh.dev:tjh.dev/kernel
For self-hosted knots, clone URLs may differ based on your setup.
Merge misc fixes from Andrew Morton:
"11 fixes"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
scripts/spdxcheck.py: always open files in binary mode
checkstack.pl: fix for aarch64
userfaultfd: check VM_MAYWRITE was set after verifying the uffd is registered
fs/iomap.c: get/put the page in iomap_page_create/release()
hugetlbfs: call VM_BUG_ON_PAGE earlier in free_huge_page()
memblock: annotate memblock_is_reserved() with __init_memblock
psi: fix reference to kernel commandline enable
arch/sh/include/asm/io.h: provide prototypes for PCI I/O mapping in asm/io.h
mm/sparse: add common helper to mark all memblocks present
mm: introduce common STRUCT_PAGE_MAX_SHIFT define
alpha: fix hang caused by the bootmem removal
Pull block fixes from Jens Axboe:
"Three small fixes for this week. contains:
- spectre indexing fix for aio (Jeff)
- fix for the previous zeroing bio fix, we don't need it for user
mapped pages, and in fact it breaks some applications if we do
(Keith)
- allocation failure fix for null_blk with zoned (Shin'ichiro)"
* tag 'for-linus-20181214' of git://git.kernel.dk/linux-block:
block: Fix null_blk_zoned creation failure with small number of zones
aio: fix spectre gadget in lookup_ioctx
block/bio: Do not zero user pages
The spdxcheck script currently falls over when confronted with a binary
file (such as Documentation/logo.gif). To avoid that, always open files
in binary mode and decode line-by-line, ignoring encoding errors.
One tricky case is when piping data into the script and reading it from
standard input. By default, standard input will be opened in text mode,
so we need to reopen it in binary mode.
The breakage only happens with python3 and results in a
UnicodeDecodeError (according to Uwe).
Link: http://lkml.kernel.org/r/20181212131210.28024-1-thierry.reding@gmail.com
Fixes: 6f4d29df66ac ("scripts/spdxcheck.py: make python3 compliant")
Signed-off-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Jeremy Cline <jcline@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Joe Perches <joe@perches.com>
Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull clk fix from Stephen Boyd:
"One fix for the qcom QCS404 clk driver that was merged for this
release.
It specified the wrong parent for a PLL so a part of the clk tree
wasn't rooted correctly. This fixes it by using the right name"
* tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux:
clk: qcom: qcs404: Fix gpll0_out_main parent
null_blk_zoned creation fails if the number of zones specified is equal to or is
smaller than 64 due to a memory allocation failure in blk_alloc_zones(). With
such a small number of zones, the required memory size for all zones descriptors
fits in a single page, and the page order for alloc_pages_node() is zero. Allow
this value in blk_alloc_zones() for the allocation to succeed.
Fixes: bf5054569653 "block: Introduce blk_revalidate_disk_zones()"
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
There is actually a space after "sp," like this,
ffff2000080813c8: a9bb7bfd stp x29, x30, [sp, #-80]!
Right now, checkstack.pl isn't able to print anything on aarch64,
because it won't be able to match the stating objdump line of a function
due to this missing space. Hence, it displays every stack as zero-size.
After this patch, checkpatch.pl is able to match the start of a
function's objdump, and is then able to calculate each function's stack
correctly.
Link: http://lkml.kernel.org/r/20181207195843.38528-1-cai@lca.pw
Signed-off-by: Qian Cai <cai@lca.pw>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull arm64 fix from Catalin Marinas:
"Invalidate the caches before clearing the DMA buffer via the
non-cacheable alias in the FORCE_CONTIGUOUS case"
* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
arm64: dma-mapping: Fix FORCE_CONTIGUOUS buffer clearing
gpll0_out_main parent is cxo so fix it.
Fixes: 652f1813c113 ("clk: qcom: gcc: Add global clock controller driver for QCS404")
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Matthew pointed out that the ioctx_table is susceptible to spectre v1,
because the index can be controlled by an attacker. The below patch
should mitigate the attack for all of the aio system calls.
Cc: stable@vger.kernel.org
Reported-by: Matthew Wilcox <willy@infradead.org>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Calling UFFDIO_UNREGISTER on virtual ranges not yet registered in uffd
could trigger an harmless false positive WARN_ON. Check the vma is
already registered before checking VM_MAYWRITE to shut off the false
positive warning.
Link: http://lkml.kernel.org/r/20181206212028.18726-2-aarcange@redhat.com
Cc: <stable@vger.kernel.org>
Fixes: 29ec90660d68 ("userfaultfd: shmem/hugetlbfs: only allow to register VM_MAYWRITE vmas")
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Reported-by: syzbot+06c7092e7d71218a2c16@syzkaller.appspotmail.com
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull powerpc fixes from Michael Ellerman:
"One notable fix for our change to split pt_regs between user/kernel,
we forgot to update BPF to use the user-visible type which was an ABI
break for BPF programs.
A slightly ugly but minimal fix to do_syscall_trace_enter() so that we
use tracehook_report_syscall_entry() properly. We'll rework the code
in next to avoid the empty if body.
Seven commits fixing bugs in the new papr_scm (Storage Class Memory)
driver. The driver was finally able to be tested on the other
hypervisor which exposed several bugs. The fixes are all fairly
minimal at least.
Fix a crash in our MSI code if an MSI-capable device is plugged into a
non-MSI capable PHB, only seen on older hardware (MPC8378).
Fix our legacy serial code to look for "stdout-path" since the device
trees were updated to use that instead of "linux,stdout-path".
A change to the COFF zImage code to fix booting old powermacs.
A couple of minor build fixes.
Thanks to: Benjamin Herrenschmidt, Daniel Axtens, Dmitry V. Levin,
Elvira Khabirova, Oliver O'Halloran, Paul Mackerras, Radu Rendec, Rob
Herring, Sandipan Das"
* tag 'powerpc-4.20-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
powerpc/ptrace: replace ptrace_report_syscall() with a tracehook call
powerpc/mm: Fallback to RAM if the altmap is unusable
powerpc/papr_scm: Use ibm,unit-guid as the iset cookie
powerpc/papr_scm: Fix DIMM device registration race
powerpc/papr_scm: Remove endian conversions
powerpc/papr_scm: Update DT properties
powerpc/papr_scm: Fix resource end address
powerpc/papr_scm: Use depend instead of select
powerpc/bpf: Fix broken uapi for BPF_PROG_TYPE_PERF_EVENT
powerpc/boot: Fix build failures with -j 1
powerpc: Look for "stdout-path" when setting up legacy consoles
powerpc/msi: Fix NULL pointer access in teardown code
powerpc/mm: Fix linux page tables build with some configs
powerpc: Fix COFF zImage booting on old powermacs
We need to invalidate the caches *before* clearing the buffer via the
non-cacheable alias, else in the worst case __dma_flush_area() may
write back dirty lines over the top of our nice new zeros.
Fixes: dd65a941f6ba ("arm64: dma-mapping: clear buffers allocated with FORCE_CONTIGUOUS flag")
Cc: <stable@vger.kernel.org> # 4.18.x-
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
The > comparison should be >= to prevent reading beyond the end of the
clock[] array.
(The clock[] array is allocated in zynqmp_clk_setup() and has
clock_max_idx elements.)
Fixes: 3fde0e16d016 ("drivers: clk: Add ZynqMP clock driver")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
We don't need to zero fill the bio if not using kernel allocated pages.
Fixes: f3587d76da05 ("block: Clear kernel memory before copying to user") # v4.20-rc2
Reported-by: Todd Aiken <taiken@mvtech.ca>
Cc: Laurence Oberman <loberman@redhat.com>
Cc: stable@vger.kernel.org
Cc: Bart Van Assche <bvanassche@acm.org>
Tested-by: Laurence Oberman <loberman@redhat.com>
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
README