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
1427336
2
921
Clone this repository
https://tangled.org/tjh.dev/kernel
https://tangled.org/did:plc:65gha4t3avpfpzmvpbwovss7/kernel
git@gordian.tjh.dev:tjh.dev/kernel
git@gordian.tjh.dev:did:plc:65gha4t3avpfpzmvpbwovss7/kernel
For self-hosted knots, clone URLs may differ based on your setup.
Download tar.gz
It's better to use HEADER_PREAMBLE_SIZE because the unfolded expression
too long. No actual functional changes, minor readability improvement.
Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
Since commit:
cifs: alloc_path_with_tree_prefix: do not append sep. if the path is empty
alloc_path_with_tree_prefix() function was no longer including the
trailing separator when @path is empty, although @out_len was still
assuming a path separator thus adding an extra byte to the final
filename.
This has caused mount issues in some Synology servers due to the extra
NULL byte in filenames when sending SMB2_CREATE requests with
SMB2_FLAGS_DFS_OPERATIONS set.
Fix this by checking if @path is not empty and then add extra byte for
separator. Also, do not include any trailing NULL bytes in filename
as MS-SMB2 requires it to be 8-byte aligned and not NULL terminated.
Cc: stable@vger.kernel.org
Fixes: 7eacba3b00a3 ("cifs: alloc_path_with_tree_prefix: do not append sep. if the path is empty")
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
smb3 fallocate punch hole was not grabbing the inode or filemap_invalidate
locks so could have race with pagemap reinstantiating the page.
Cc: stable@vger.kernel.org
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
smb3 fallocate zero range was not grabbing the inode or filemap_invalidate
locks so could have race with pagemap reinstantiating the page.
Cc: stable@vger.kernel.org
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Pull irq fixes from Ingo Molnar:
"Misc irqchip fixes: LoongArch driver fixes and a Hyper-V IOMMU fix"
* tag 'irq-urgent-2022-08-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
irqchip/loongson-liointc: Fix an error handling path in liointc_init()
irqchip/loongarch: Fix irq_domain_alloc_fwnode() abuse
irqchip/loongson-pch-pic: Move find_pch_pic() into CONFIG_ACPI
irqchip/loongson-eiointc: Fix a build warning
irqchip/loongson-eiointc: Fix irq affinity setting
iommu/hyper-v: Use helper instead of directly accessing affinity
Pull x86 kprobes fix from Ingo Molnar:
"Fix a kprobes bug in JNG/JNLE emulation when a kprobe is installed at
such instructions, possibly resulting in incorrect execution (the
wrong branch taken)"
* tag 'perf-urgent-2022-08-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/kprobes: Fix JNG/JNLE emulation
Pull irqchip fixes from Marc Zyngier:
- A bunch of small fixes for the recently merged LoongArch drivers
- A leftover from the non-SMP IRQ affinity rework affecting
the Hyper-V IOMMU code
Link: https://lore.kernel.org/r/20220812125910.2227338-1-maz@kernel.org
Pull tracing fixes from Steven Rostedt:
"Various fixes for tracing:
- Fix a return value of traceprobe_parse_event_name()
- Fix NULL pointer dereference from failed ftrace enabling
- Fix NULL pointer dereference when asking for registers from eprobes
- Make eprobes consistent with kprobes/uprobes, filters and
histograms"
* tag 'trace-v6.0-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing: Have filter accept "common_cpu" to be consistent
tracing/probes: Have kprobes and uprobes use $COMM too
tracing/eprobes: Have event probes be consistent with kprobes and uprobes
tracing/eprobes: Fix reading of string fields
tracing/eprobes: Do not hardcode $comm as a string
tracing/eprobes: Do not allow eprobes to use $stack, or % for regs
ftrace: Fix NULL pointer dereference in is_ftrace_trampoline when ftrace is dead
tracing/perf: Fix double put of trace event when init fails
tracing: React to error return from traceprobe_parse_event_name()
When kprobes emulates JNG/JNLE instructions on x86 it uses the wrong
condition. For JNG (opcode: 0F 8E), according to Intel SDM, the jump is
performed if (ZF == 1 or SF != OF). However the kernel emulation
currently uses 'and' instead of 'or'.
As a result, setting a kprobe on JNG/JNLE might cause the kernel to
behave incorrectly whenever the kprobe is hit.
Fix by changing the 'and' to 'or'.
Fixes: 6256e668b7af ("x86/kprobes: Use int3 instead of debug trap for single-step")
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20220813225943.143767-1-namit@vmware.com
All errors lead to the error handling path, except the one dealing
with "reg-names" in DT.
Fix it and release some resources before returning if this test fails.
Fixes: 0858ed035a85 ("irqchip/loongson-liointc: Add ACPI init support")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
[maz: fix commit message]
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/1a6d74ab70712279023aa7bdbd31bd3aec103bc0.1659382063.git.christophe.jaillet@wanadoo.fr
Pull i2c fixes from Wolfram Sang:
"A revert to fix a regression introduced this merge window and a fix
for proper error handling in the remove path of the iMX driver"
* tag 'i2c-for-6.0-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
i2c: imx: Make sure to unregister adapter on remove()
Revert "i2c: scmi: Replace open coded device_get_match_data()"
Make filtering consistent with histograms. As "cpu" can be a field of an
event, allow for "common_cpu" to keep it from being confused with the
"cpu" field of the event.
Link: https://lkml.kernel.org/r/20220820134401.513062765@goodmis.org
Link: https://lore.kernel.org/all/20220820220920.e42fa32b70505b1904f0a0ad@kernel.org/
Cc: stable@vger.kernel.org
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tzvetomir Stoyanov <tz.stoyanov@gmail.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Fixes: 1e3bac71c5053 ("tracing/histogram: Rename "cpu" to "common_cpu"")
Suggested-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Users of GNU ld (BFD) from binutils 2.39+ will observe multiple
instances of a new warning when linking kernels in the form:
ld: warning: arch/x86/boot/pmjump.o: missing .note.GNU-stack section implies executable stack
ld: NOTE: This behaviour is deprecated and will be removed in a future version of the linker
ld: warning: arch/x86/boot/compressed/vmlinux has a LOAD segment with RWX permissions
Generally, we would like to avoid the stack being executable. Because
there could be a need for the stack to be executable, assembler sources
have to opt-in to this security feature via explicit creation of the
.note.GNU-stack feature (which compilers create by default) or command
line flag --noexecstack. Or we can simply tell the linker the
production of such sections is irrelevant and to link the stack as
--noexecstack.
LLVM's LLD linker defaults to -z noexecstack, so this flag isn't
strictly necessary when linking with LLD, only BFD, but it doesn't hurt
to be explicit here for all linkers IMO. --no-warn-rwx-segments is
currently BFD specific and only available in the current latest release,
so it's wrapped in an ld-option check.
While the kernel makes extensive usage of ELF sections, it doesn't use
permissions from ELF segments.
Link: https://lore.kernel.org/linux-block/3af4127a-f453-4cf7-f133-a181cce06f73@kernel.dk/
Link: https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=ba951afb99912da01a6e8434126b8fac7aa75107
Link: https://github.com/llvm/llvm-project/issues/57009
Reported-and-tested-by: Jens Axboe <axboe@kernel.dk>
Suggested-by: Fangrui Song <maskray@google.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
README