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.
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.
Pull Kbuild fixes from Masahiro Yamada:
- Fix the module compression with xz so the in-kernel decompressor
works
- Document a kconfig idiom to express an optional dependency between
modules
- Make modpost, when W=1 is given, detect broken drivers that reference
.exit.* sections
- Remove unused code
* tag 'kbuild-fixes-v6.6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
kbuild: remove stale code for 'source' symlink in packaging scripts
modpost: Don't let "driver"s reference .exit.*
vmlinux.lds.h: remove unused CPU_KEEP and CPU_DISCARD macros
modpost: add missing else to the "of" check
Documentation: kbuild: explain handling optional dependencies
kbuild: Use CRC32 and a 1MiB dictionary for XZ compressed modules
Pull misc fixes from Andrew Morton:
"Fourteen hotfixes, eleven of which are cc:stable. The remainder
pertain to issues which were introduced after 6.5"
* tag 'mm-hotfixes-stable-2023-10-01-08-34' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
Crash: add lock to serialize crash hotplug handling
selftests/mm: fix awk usage in charge_reserved_hugetlb.sh and hugetlb_reparenting_test.sh that may cause error
mm: mempolicy: keep VMA walk if both MPOL_MF_STRICT and MPOL_MF_MOVE are specified
mm/damon/vaddr-test: fix memory leak in damon_do_test_apply_three_regions()
mm, memcg: reconsider kmem.limit_in_bytes deprecation
mm: zswap: fix potential memory corruption on duplicate store
arm64: hugetlb: fix set_huge_pte_at() to work with all swap entries
mm: hugetlb: add huge page size param to set_huge_pte_at()
maple_tree: add MAS_UNDERFLOW and MAS_OVERFLOW states
maple_tree: add mas_is_active() to detect in-tree walks
nilfs2: fix potential use after free in nilfs_gccache_submit_read_data()
mm: abstract moving to the next PFN
mm: report success more often from filemap_map_folio_range()
fs: binfmt_elf_efpic: fix personality for ELF-FDPIC
Since commit d8131c2965d5 ("kbuild: remove $(MODLIB)/source symlink"),
modules_install does not create the 'source' symlink.
Remove the stale code from builddeb and kernel.spec.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Pull misc driver fix from Greg KH:
"Here is a single, much requested, fix for a set of misc drivers to
resolve a much reported regression in the -rc series that has also
propagated back to the stable releases. Sorry for the delay, lots of
conference travel for a few weeks put me very far behind in patch
wrangling.
It has been reported by many to resolve the reported problem, and has
been in linux-next with no reported issues"
* tag 'char-misc-6.6-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
misc: rtsx: Fix some platforms can not boot and move the l1ss judgment to probe
Eric reported that handling corresponding crash hotplug event can be
failed easily when many memory hotplug event are notified in a short
period. They failed because failing to take __kexec_lock.
=======
[ 78.714569] Fallback order for Node 0: 0
[ 78.714575] Built 1 zonelists, mobility grouping on. Total pages: 1817886
[ 78.717133] Policy zone: Normal
[ 78.724423] crash hp: kexec_trylock() failed, elfcorehdr may be inaccurate
[ 78.727207] crash hp: kexec_trylock() failed, elfcorehdr may be inaccurate
[ 80.056643] PEFILE: Unsigned PE binary
=======
The memory hotplug events are notified very quickly and very many, while
the handling of crash hotplug is much slower relatively. So the atomic
variable __kexec_lock and kexec_trylock() can't guarantee the
serialization of crash hotplug handling.
Here, add a new mutex lock __crash_hotplug_lock to serialize crash hotplug
handling specifically. This doesn't impact the usage of __kexec_lock.
Link: https://lkml.kernel.org/r/20230926120905.392903-1-bhe@redhat.com
Fixes: 247262756121 ("crash: add generic infrastructure for crash hotplug support")
Signed-off-by: Baoquan He <bhe@redhat.com>
Tested-by: Eric DeVolder <eric.devolder@oracle.com>
Reviewed-by: Eric DeVolder <eric.devolder@oracle.com>
Reviewed-by: Valentin Schneider <vschneid@redhat.com>
Cc: Sourabh Jain <sourabhjain@linux.ibm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Drivers must not reference functions marked with __exit as these likely
are not available when the code is built-in.
There are few creative offenders uncovered for example in ARCH=amd64
allmodconfig builds. So only trigger the section mismatch warning for
W=1 builds.
The dual rule that drivers must not reference .init.* is implemented
since commit 0db252452378 ("modpost: don't allow *driver to reference
.init.*") which however missed that .exit.* should be handled in the
same way.
Thanks to Masahiro Yamada and Arnd Bergmann who gave valuable hints to
find this improvement.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Pull tty / serial driver fixes from Greg KH:
"Here are two tty/serial driver fixes for 6.6-rc4 that resolve some
reported regressions:
- revert a n_gsm change that ended up causing problems
- 8250_port fix for irq data
both have been in linux-next for over a week with no reported
problems"
* tag 'tty-6.6-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
Revert "tty: n_gsm: fix UAF in gsm_cleanup_mux"
serial: 8250_port: Check IRQ data before use
commit 101bd907b424 ("misc: rtsx: judge ASPM Mode to set PETXCFG Reg")
some readers no longer force #CLKREQ to low
when the system need to enter ASPM.
But some platform maybe not implement complete ASPM?
it causes some platforms can not boot
Like in the past only the platform support L1ss we release the #CLKREQ.
Move the judgment (L1ss) to probe,
we think read config space one time when the driver start is enough
Fixes: 101bd907b424 ("misc: rtsx: judge ASPM Mode to set PETXCFG Reg")
Cc: stable <stable@kernel.org>
Reported-by: Paul Grandperrin <paul.grandperrin@gmail.com>
Signed-off-by: Ricky Wu <ricky_wu@realtek.com>
Tested-By: Jade Lovelace <lists@jade.fyi>
Link: https://lore.kernel.org/r/37b1afb997f14946a8784c73d1f9a4f5@realtek.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
According to the awk manual, the -e option does not need to be specified
in front of 'program' (unless you need to mix program-file).
The redundant -e option can cause error when users use awk tools other
than gawk (for example, mawk does not support the -e option).
Error Example:
awk: not an option: -e
Link: https://lkml.kernel.org/r/VI1P193MB075228810591AF2FDD7D42C599C3A@VI1P193MB0752.EURP193.PROD.OUTLOOK.COM
Signed-off-by: Juntong Deng <juntong.deng@outlook.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Remove the left-over of commit e24f6628811e ("modpost: remove all
traces of cpuinit/cpuexit sections").
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Pull x86 fixes from Ingo Molnar:
"Misc fixes: a kerneldoc build warning fix, add SRSO mitigation for
AMD-derived Hygon processors, and fix a SGX kernel crash in the page
fault handler that can trigger when ksgxd races to reclaim the SECS
special page, by making the SECS page unswappable"
* tag 'x86-urgent-2023-10-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/sgx: Resolves SECS reclaim vs. page fault for EAUG race
x86/srso: Add SRSO mitigation for Hygon processors
x86/kgdb: Fix a kerneldoc warning when build with W=1
This reverts commit 9b9c8195f3f0d74a826077fc1c01b9ee74907239.
The commit above is reverted as it did not solve the original issue.
gsm_cleanup_mux() tries to free up the virtual ttys by calling
gsm_dlci_release() for each available DLCI. There, dlci_put() is called to
decrease the reference counter for the DLCI via tty_port_put() which
finally calls gsm_dlci_free(). This already clears the pointer which is
being checked in gsm_cleanup_mux() before calling gsm_dlci_release().
Therefore, it is not necessary to clear this pointer in gsm_cleanup_mux()
as done in the reverted commit. The commit introduces a null pointer
dereference:
<TASK>
? __die+0x1f/0x70
? page_fault_oops+0x156/0x420
? search_exception_tables+0x37/0x50
? fixup_exception+0x21/0x310
? exc_page_fault+0x69/0x150
? asm_exc_page_fault+0x26/0x30
? tty_port_put+0x19/0xa0
gsmtty_cleanup+0x29/0x80 [n_gsm]
release_one_tty+0x37/0xe0
process_one_work+0x1e6/0x3e0
worker_thread+0x4c/0x3d0
? __pfx_worker_thread+0x10/0x10
kthread+0xe1/0x110
? __pfx_kthread+0x10/0x10
ret_from_fork+0x2f/0x50
? __pfx_kthread+0x10/0x10
ret_from_fork_asm+0x1b/0x30
</TASK>
The actual issue is that nothing guards dlci_put() from being called
multiple times while the tty driver was triggered but did not yet finished
calling gsm_dlci_free().
Fixes: 9b9c8195f3f0 ("tty: n_gsm: fix UAF in gsm_cleanup_mux")
Cc: stable <stable@kernel.org>
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
Link: https://lore.kernel.org/r/20230914051507.3240-1-daniel.starke@siemens.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When calling mbind() with MPOL_MF_{MOVE|MOVEALL} | MPOL_MF_STRICT, kernel
should attempt to migrate all existing pages, and return -EIO if there is
misplaced or unmovable page. Then commit 6f4576e3687b ("mempolicy: apply
page table walker on queue_pages_range()") messed up the return value and
didn't break VMA scan early ianymore when MPOL_MF_STRICT alone. The
return value problem was fixed by commit a7f40cfe3b7a ("mm: mempolicy:
make mbind() return -EIO when MPOL_MF_STRICT is specified"), but it broke
the VMA walk early if unmovable page is met, it may cause some pages are
not migrated as expected.
The code should conceptually do:
if (MPOL_MF_MOVE|MOVEALL)
scan all vmas
try to migrate the existing pages
return success
else if (MPOL_MF_MOVE* | MPOL_MF_STRICT)
scan all vmas
try to migrate the existing pages
return -EIO if unmovable or migration failed
else /* MPOL_MF_STRICT alone */
break early if meets unmovable and don't call mbind_range() at all
else /* none of those flags */
check the ranges in test_walk, EFAULT without mbind_range() if discontig.
Fixed the behavior.
Link: https://lkml.kernel.org/r/20230920223242.3425775-1-yang@os.amperecomputing.com
Fixes: a7f40cfe3b7a ("mm: mempolicy: make mbind() return -EIO when MPOL_MF_STRICT is specified")
Signed-off-by: Yang Shi <yang@os.amperecomputing.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Rafael Aquini <aquini@redhat.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: David Rientjes <rientjes@google.com>
Cc: <stable@vger.kernel.org> [4.9+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Without this 'else' statement, an "usb" name goes into two handlers:
the first/previous 'if' statement _AND_ the for-loop over 'devtable',
but the latter is useless as it has no 'usb' device_id entry anyway.
Tested with allmodconfig before/after patch; no changes to *.mod.c:
git checkout v6.6-rc3
make -j$(nproc) allmodconfig
make -j$(nproc) olddefconfig
make -j$(nproc)
find . -name '*.mod.c' | cpio -pd /tmp/before
# apply patch
make -j$(nproc)
find . -name '*.mod.c' | cpio -pd /tmp/after
diff -r /tmp/before/ /tmp/after/
# no difference
Fixes: acbef7b76629 ("modpost: fix module autoloading for OF devices with generic compatible property")
Signed-off-by: Mauricio Faria de Oliveira <mfo@canonical.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>