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We continue to see false positives from -Warray-bounds even in GCC 10,
which is getting reported in a few places[1] still:
security/security.c:811:2: warning: `memcpy' offset 32 is out of the bounds [0, 0] [-Warray-bounds]
Lower the GCC version check from 11 to 10.
Link: https://lkml.kernel.org/r/20240223170824.work.768-kees@kernel.org
Reported-by: Lu Yao <yaolu@kylinos.cn>
Closes: https://lore.kernel.org/lkml/20240117014541.8887-1-yaolu@kylinos.cn/
Link: https://lore.kernel.org/linux-next/65d84438.620a0220.7d171.81a7@mx.google.com [1]
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Paul Moore <paul@paul-moore.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Marc Aurèle La France <tsi@tuyoix.net>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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In commit 4356e9f841f7 ("work around gcc bugs with 'asm goto' with
outputs") I did the gcc workaround unconditionally, because the cause of
the bad code generation wasn't entirely clear.
In the meantime, Jakub Jelinek debugged the issue, and has come up with
a fix in gcc [2], which also got backported to the still maintained
branches of gcc-11, gcc-12 and gcc-13.
Note that while the fix technically wasn't in the original gcc-14
branch, Jakub says:
"while it is true that no GCC 14 snapshots until today (or whenever the
fix will be committed) have the fix, for GCC trunk it is up to the
distros to use the latest snapshot if they use it at all and would
allow better testing of the kernel code without the workaround, so
that if there are other issues they won't be discovered years later.
Most userland code doesn't actually use asm goto with outputs..."
so we will consider gcc-14 to be fixed - if somebody is using gcc
snapshots of the gcc-14 before the fix, they should upgrade.
Note that while the bug goes back to gcc-11, in practice other gcc
changes seem to have effectively hidden it since gcc-12.1 as per a
bisect by Jakub. So even a gcc-14 snapshot without the fix likely
doesn't show actual problems.
Also, make the default 'asm_goto_output()' macro mark the asm as
volatile by hand, because of an unrelated gcc issue [1] where it doesn't
match the documented behavior ("asm goto is always volatile").
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103979 [1]
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113921 [2]
Link: https://lore.kernel.org/all/20240208220604.140859-1-seanjc@google.com/
Requested-by: Jakub Jelinek <jakub@redhat.com>
Cc: Uros Bizjak <ubizjak@gmail.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Andrew Pinski <quic_apinski@quicinc.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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It turns out it was never just gcc-11 that was broken. Apparently it
just happens to work on x86-64 with other gcc versions.
On arm64, I see warnings with gcc version 13.2.1, and the kernel test
robot reports the same problem on s390 with gcc 13.2.0.
Admittedly it seems to be just the new Xe drm driver, but this is
keeping me from doing my normal arm64 build testing. So it gets
reverted until somebody figures out what causes the problem (and why it
doesn't show on x86-64, which is what makes me suspect it was never just
about gcc-11, and more about just random happenstance).
This also changes the Kconfig naming a bit - just make the "disable this
for GCC" conditional be one simple Kconfig entry, and we can put the gcc
version dependencies in that entry once we figure out what the correct
rules are.
The version dependency _may_ still end up being "gcc version larger than
11" if the issue is purely in the Xe driver, but even if that ends up
the case, let's make that all part of the "GCC_NO_STRINGOP_OVERFLOW"
logic.
For now, we just disable it for all gcc versions while the exact cause
is unknown.
Link: https://lore.kernel.org/all/202401161031.hjGJHMiJ-lkp@intel.com/T/
Cc: Gustavo A. R. Silva <gustavoars@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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-Wstringop-overflow is buggy in GCC-11. Therefore, we should disable
this option specifically for that compiler version. To achieve this,
we introduce a new configuration option: GCC11_NO_STRINGOP_OVERFLOW.
The compiler option related to string operation overflow is now managed
under configuration CC_STRINGOP_OVERFLOW. This option is enabled by
default for all other versions of GCC that support it.
Link: https://lore.kernel.org/lkml/b3c99290-40bc-426f-b3d2-1aa903f95c4e@embeddedor.com/
Link: https://lore.kernel.org/lkml/20231128091351.2bfb38dd@canb.auug.org.au/
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/linux-hardening/ZWj1+jkweEDWbmAR@work/
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core updates from Greg KH:
"Here are the set of driver core and kernfs changes for 6.8-rc1.
Nothing major in here this release cycle, just lots of small cleanups
and some tweaks on kernfs that in the very end, got reverted and will
come back in a safer way next release cycle.
Included in here are:
- more driver core 'const' cleanups and fixes
- fw_devlink=rpm is now the default behavior
- kernfs tiny changes to remove some string functions
- cpu handling in the driver core is updated to work better on many
systems that add topologies and cpus after booting
- other minor changes and cleanups
All of the cpu handling patches have been acked by the respective
maintainers and are coming in here in one series. Everything has been
in linux-next for a while with no reported issues"
* tag 'driver-core-6.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (51 commits)
Revert "kernfs: convert kernfs_idr_lock to an irq safe raw spinlock"
kernfs: convert kernfs_idr_lock to an irq safe raw spinlock
class: fix use-after-free in class_register()
PM: clk: make pm_clk_add_notifier() take a const pointer
EDAC: constantify the struct bus_type usage
kernfs: fix reference to renamed function
driver core: device.h: fix Excess kernel-doc description warning
driver core: class: fix Excess kernel-doc description warning
driver core: mark remaining local bus_type variables as const
driver core: container: make container_subsys const
driver core: bus: constantify subsys_register() calls
driver core: bus: make bus_sort_breadthfirst() take a const pointer
kernfs: d_obtain_alias(NULL) will do the right thing...
driver core: Better advertise dev_err_probe()
kernfs: Convert kernfs_path_from_node_locked() from strlcpy() to strscpy()
kernfs: Convert kernfs_name_locked() from strlcpy() to strscpy()
kernfs: Convert kernfs_walk_ns() from strlcpy() to strscpy()
initramfs: Expose retained initrd as sysfs file
fs/kernfs/dir: obey S_ISGID
kernel/cgroup: use kernfs_create_dir_ns()
...
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git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char/misc and other driver updates from Greg KH:
"Here is the big set of char/misc and other driver subsystem changes
for 6.8-rc1.
Other than lots of binder driver changes (as you can see by the merge
conflicts) included in here are:
- lots of iio driver updates and additions
- spmi driver updates
- eeprom driver updates
- firmware driver updates
- ocxl driver updates
- mhi driver updates
- w1 driver updates
- nvmem driver updates
- coresight driver updates
- platform driver remove callback api changes
- tags.sh script updates
- bus_type constant marking cleanups
- lots of other small driver updates
All of these have been in linux-next for a while with no reported
issues"
* tag 'char-misc-6.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (341 commits)
android: removed duplicate linux/errno
uio: Fix use-after-free in uio_open
drivers: soc: xilinx: add check for platform
firmware: xilinx: Export function to use in other module
scripts/tags.sh: remove find_sources
scripts/tags.sh: use -n to test archinclude
scripts/tags.sh: add local annotation
scripts/tags.sh: use more portable -path instead of -wholename
scripts/tags.sh: Update comment (addition of gtags)
firmware: zynqmp: Convert to platform remove callback returning void
firmware: turris-mox-rwtm: Convert to platform remove callback returning void
firmware: stratix10-svc: Convert to platform remove callback returning void
firmware: stratix10-rsu: Convert to platform remove callback returning void
firmware: raspberrypi: Convert to platform remove callback returning void
firmware: qemu_fw_cfg: Convert to platform remove callback returning void
firmware: mtk-adsp-ipc: Convert to platform remove callback returning void
firmware: imx-dsp: Convert to platform remove callback returning void
firmware: coreboot_table: Convert to platform remove callback returning void
firmware: arm_scpi: Convert to platform remove callback returning void
firmware: arm_scmi: Convert to platform remove callback returning void
...
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Pull header cleanups from Kent Overstreet:
"The goal is to get sched.h down to a type only header, so the main
thing happening in this patchset is splitting out various _types.h
headers and dependency fixups, as well as moving some things out of
sched.h to better locations.
This is prep work for the memory allocation profiling patchset which
adds new sched.h interdepencencies"
* tag 'header_cleanup-2024-01-10' of https://evilpiepirate.org/git/bcachefs: (51 commits)
Kill sched.h dependency on rcupdate.h
kill unnecessary thread_info.h include
Kill unnecessary kernel.h include
preempt.h: Kill dependency on list.h
rseq: Split out rseq.h from sched.h
LoongArch: signal.c: add header file to fix build error
restart_block: Trim includes
lockdep: move held_lock to lockdep_types.h
sem: Split out sem_types.h
uidgid: Split out uidgid_types.h
seccomp: Split out seccomp_types.h
refcount: Split out refcount_types.h
uapi/linux/resource.h: fix include
x86/signal: kill dependency on time.h
syscall_user_dispatch.h: split out *_types.h
mm_types_task.h: Trim dependencies
Split out irqflags_types.h
ipc: Kill bogus dependency on spinlock.h
shm: Slim down dependencies
workqueue: Split out workqueue_types.h
...
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Trimming down sched.h dependencies: we don't want to include more than
the base types.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
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KCMP, RSEQ, CACHESTAT_SYSCALL, and PC104 depend on EXPERT but not shown in
the EXPERT menu. Move some lines around so that they are displayed in the
EXPERT menu.
Drop one useless comment.
Change "enabled" to "enable" for DEBUG_RSEQ.
Link: https://lkml.kernel.org/r/20231208045819.2922-1-rdunlap@infradead.org
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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When the kernel command line option "retain_initrd" is set, we do not
free the initrd memory. However, we also don't expose it to anyone for
consumption. That leaves us in a weird situation where the only user of
this feature is ppc64 and arm64 specific kexec tooling.
To make it more generally useful, this patch adds a kobject to the
firmware object that contains the initrd context when "retain_initrd"
is set. That way, we can access the initrd any time after boot from
user space and for example hand it into kexec as --initrd parameter
if we want to reboot the same initrd. Or inspect it directly locally.
With this patch applied, there is a new /sys/firmware/initrd file when
the kernel was booted with an initrd and "retain_initrd" command line
option is set.
Signed-off-by: Alexander Graf <graf@amazon.com>
Tested-by: Bagas Sanjaya <bagasdotme@gmail.com>
Link: https://lore.kernel.org/r/20231207235654.16622-1-graf@amazon.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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IA-64 was the only architecture which selected ARCH_TASK_STRUCT_ON_STACK.
IA-64 was removed with commit cf8e8658100d ("arch: Remove Itanium (IA-64)
architecture"). Therefore remove support for ARCH_TASK_STRUCT_ON_STACK
as well.
Note: this also reveals a potential bug in powerpc code, which makes use of
__init_task_data without selecting ARCH_TASK_STRUCT_ON_STACK which makes
__init_task_data a no-op. This is broken since commit d11ed3ab3166 ("Expand
INIT_TASK() in init/init_task.c and remove") from 2018 and needs to be
addressed separately.
Link: https://lkml.kernel.org/r/20231116133638.1636277-4-hca@linux.ibm.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Documentation/filesystems/ramfs-rootfs-initramfs.rst states:
If CONFIG_TMPFS is enabled, rootfs will use tmpfs instead of ramfs by
default. To force ramfs, add "rootfstype=ramfs" to the kernel command
line.
This currently does not work when root= is provided since then
saved_root_name contains a string and rootfstype= is ignored. Therefore,
ramfs is currently always chosen when root= is provided.
The current behavior for rootfs's filesystem is:
root= | rootfstype= | chosen rootfs filesystem
------------+-------------+--------------------------
unspecified | unspecified | tmpfs
unspecified | tmpfs | tmpfs
unspecified | ramfs | ramfs
provided | ignored | ramfs
rootfstype= should be respected regardless whether root= is given,
as shown below:
root= | rootfstype= | chosen rootfs filesystem
------------+-------------+--------------------------
unspecified | unspecified | tmpfs (as before)
unspecified | tmpfs | tmpfs (as before)
unspecified | ramfs | ramfs (as before)
provided | unspecified | ramfs (compatibility with before)
provided | tmpfs | tmpfs (new)
provided | ramfs | ramfs (new)
This table represents the new behavior.
Fixes: 6e19eded3684 ("initmpfs: use initramfs if rootfstype= or root= specified")
Cc: <stable@vger.kernel.org>
Signed-off-by: Rob Landley <rob@landley.net>
Link: https://lore.kernel.org/lkml/8244c75f-445e-b15b-9dbf-266e7ca666e2@landley.net/
Reviewed-and-Tested-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Link: https://lore.kernel.org/r/20231120011248.396012-1-stefanb@linux.ibm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull non-MM updates from Andrew Morton:
"As usual, lots of singleton and doubleton patches all over the tree
and there's little I can say which isn't in the individual changelogs.
The lengthier patch series are
- 'kdump: use generic functions to simplify crashkernel reservation
in arch', from Baoquan He. This is mainly cleanups and
consolidation of the 'crashkernel=' kernel parameter handling
- After much discussion, David Laight's 'minmax: Relax type checks in
min() and max()' is here. Hopefully reduces some typecasting and
the use of min_t() and max_t()
- A group of patches from Oleg Nesterov which clean up and slightly
fix our handling of reads from /proc/PID/task/... and which remove
task_struct.thread_group"
* tag 'mm-nonmm-stable-2023-11-02-14-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (64 commits)
scripts/gdb/vmalloc: disable on no-MMU
scripts/gdb: fix usage of MOD_TEXT not defined when CONFIG_MODULES=n
.mailmap: add address mapping for Tomeu Vizoso
mailmap: update email address for Claudiu Beznea
tools/testing/selftests/mm/run_vmtests.sh: lower the ptrace permissions
.mailmap: map Benjamin Poirier's address
scripts/gdb: add lx_current support for riscv
ocfs2: fix a spelling typo in comment
proc: test ProtectionKey in proc-empty-vm test
proc: fix proc-empty-vm test with vsyscall
fs/proc/base.c: remove unneeded semicolon
do_io_accounting: use sig->stats_lock
do_io_accounting: use __for_each_thread()
ocfs2: replace BUG_ON() at ocfs2_num_free_extents() with ocfs2_error()
ocfs2: fix a typo in a comment
scripts/show_delta: add __main__ judgement before main code
treewide: mark stuff as __ro_after_init
fs: ocfs2: check status values
proc: test /proc/${pid}/statm
compiler.h: move __is_constexpr() to compiler.h
...
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git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux
Pull sysctl updates from Luis Chamberlain:
"To help make the move of sysctls out of kernel/sysctl.c not incur a
size penalty sysctl has been changed to allow us to not require the
sentinel, the final empty element on the sysctl array. Joel Granados
has been doing all this work. On the v6.6 kernel we got the major
infrastructure changes required to support this. For v6.7-rc1 we have
all arch/ and drivers/ modified to remove the sentinel. Both arch and
driver changes have been on linux-next for a bit less than a month. It
is worth re-iterating the value:
- this helps reduce the overall build time size of the kernel and run
time memory consumed by the kernel by about ~64 bytes per array
- the extra 64-byte penalty is no longer inncurred now when we move
sysctls out from kernel/sysctl.c to their own files
For v6.8-rc1 expect removal of all the sentinels and also then the
unneeded check for procname == NULL.
The last two patches are fixes recently merged by Krister Johansen
which allow us again to use softlockup_panic early on boot. This used
to work but the alias work broke it. This is useful for folks who want
to detect softlockups super early rather than wait and spend money on
cloud solutions with nothing but an eventual hung kernel. Although
this hadn't gone through linux-next it's also a stable fix, so we
might as well roll through the fixes now"
* tag 'sysctl-6.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux: (23 commits)
watchdog: move softlockup_panic back to early_param
proc: sysctl: prevent aliased sysctls from getting passed to init
intel drm: Remove now superfluous sentinel element from ctl_table array
Drivers: hv: Remove now superfluous sentinel element from ctl_table array
raid: Remove now superfluous sentinel element from ctl_table array
fw loader: Remove the now superfluous sentinel element from ctl_table array
sgi-xp: Remove the now superfluous sentinel element from ctl_table array
vrf: Remove the now superfluous sentinel element from ctl_table array
char-misc: Remove the now superfluous sentinel element from ctl_table array
infiniband: Remove the now superfluous sentinel element from ctl_table array
macintosh: Remove the now superfluous sentinel element from ctl_table array
parport: Remove the now superfluous sentinel element from ctl_table array
scsi: Remove now superfluous sentinel element from ctl_table array
tty: Remove now superfluous sentinel element from ctl_table array
xen: Remove now superfluous sentinel element from ctl_table array
hpet: Remove now superfluous sentinel element from ctl_table array
c-sky: Remove now superfluous sentinel element from ctl_talbe array
powerpc: Remove now superfluous sentinel element from ctl_table arrays
riscv: Remove now superfluous sentinel element from ctl_table array
x86/vdso: Remove now superfluous sentinel element from ctl_table array
...
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git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic
Pull ia64 removal and asm-generic updates from Arnd Bergmann:
- The ia64 architecture gets its well-earned retirement as planned,
now that there is one last (mostly) working release that will be
maintained as an LTS kernel.
- The architecture specific system call tables are updated for the
added map_shadow_stack() syscall and to remove references to the
long-gone sys_lookup_dcookie() syscall.
* tag 'asm-generic-6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic:
hexagon: Remove unusable symbols from the ptrace.h uapi
asm-generic: Fix spelling of architecture
arch: Reserve map_shadow_stack() syscall number for all architectures
syscalls: Cleanup references to sys_lookup_dcookie()
Documentation: Drop or replace remaining mentions of IA64
lib/raid6: Drop IA64 support
Documentation: Drop IA64 from feature descriptions
kernel: Drop IA64 support from sig_fault handlers
arch: Remove Itanium (IA-64) architecture
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The code that checks for unknown boot options is unaware of the sysctl
alias facility, which maps bootparams to sysctl values. If a user sets
an old value that has a valid alias, a message about an invalid
parameter will be printed during boot, and the parameter will get passed
to init. Fix by checking for the existence of aliased parameters in the
unknown boot parameter code. If an alias exists, don't return an error
or pass the value to init.
Signed-off-by: Krister Johansen <kjlx@templeofstupid.com>
Cc: stable@vger.kernel.org
Fixes: 0a477e1ae21b ("kernel/sysctl: support handling command line aliases")
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull hardening updates from Kees Cook:
"One of the more voluminous set of changes is for adding the new
__counted_by annotation[1] to gain run-time bounds checking of
dynamically sized arrays with UBSan.
- Add LKDTM test for stuck CPUs (Mark Rutland)
- Improve LKDTM selftest behavior under UBSan (Ricardo Cañuelo)
- Refactor more 1-element arrays into flexible arrays (Gustavo A. R.
Silva)
- Analyze and replace strlcpy and strncpy uses (Justin Stitt, Azeem
Shaikh)
- Convert group_info.usage to refcount_t (Elena Reshetova)
- Add __counted_by annotations (Kees Cook, Gustavo A. R. Silva)
- Add Kconfig fragment for basic hardening options (Kees Cook, Lukas
Bulwahn)
- Fix randstruct GCC plugin performance mode to stay in groups (Kees
Cook)
- Fix strtomem() compile-time check for small sources (Kees Cook)"
* tag 'hardening-v6.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (56 commits)
hwmon: (acpi_power_meter) replace open-coded kmemdup_nul
reset: Annotate struct reset_control_array with __counted_by
kexec: Annotate struct crash_mem with __counted_by
virtio_console: Annotate struct port_buffer with __counted_by
ima: Add __counted_by for struct modsig and use struct_size()
MAINTAINERS: Include stackleak paths in hardening entry
string: Adjust strtomem() logic to allow for smaller sources
hardening: x86: drop reference to removed config AMD_IOMMU_V2
randstruct: Fix gcc-plugin performance mode to stay in group
mailbox: zynqmp: Annotate struct zynqmp_ipi_pdata with __counted_by
drivers: thermal: tsens: Annotate struct tsens_priv with __counted_by
irqchip/imx-intmux: Annotate struct intmux_data with __counted_by
KVM: Annotate struct kvm_irq_routing_table with __counted_by
virt: acrn: Annotate struct vm_memory_region_batch with __counted_by
hwmon: Annotate struct gsc_hwmon_platform_data with __counted_by
sparc: Annotate struct cpuinfo_tree with __counted_by
isdn: kcapi: replace deprecated strncpy with strscpy_pad
isdn: replace deprecated strncpy with strscpy
NFS/flexfiles: Annotate struct nfs4_ff_layout_segment with __counted_by
nfs41: Annotate struct nfs4_file_layout_dsaddr with __counted_by
...
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 hw mitigation updates from Borislav Petkov:
- A bunch of improvements, cleanups and fixlets to the SRSO mitigation
machinery and other, general cleanups to the hw mitigations code, by
Josh Poimboeuf
- Improve the return thunk detection by objtool as it is absolutely
important that the default return thunk is not used after returns
have been patched. Future work to detect and report this better is
pending
- Other misc cleanups and fixes
* tag 'x86_bugs_for_6.7_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (21 commits)
x86/retpoline: Document some thunk handling aspects
x86/retpoline: Make sure there are no unconverted return thunks due to KCSAN
x86/callthunks: Delete unused "struct thunk_desc"
x86/vdso: Run objtool on vdso32-setup.o
objtool: Fix return thunk patching in retpolines
x86/srso: Remove unnecessary semicolon
x86/pti: Fix kernel warnings for pti= and nopti cmdline options
x86/calldepth: Rename __x86_return_skl() to call_depth_return_thunk()
x86/nospec: Refactor UNTRAIN_RET[_*]
x86/rethunk: Use SYM_CODE_START[_LOCAL]_NOALIGN macros
x86/srso: Disentangle rethunk-dependent options
x86/srso: Move retbleed IBPB check into existing 'has_microcode' code block
x86/bugs: Remove default case for fully switched enums
x86/srso: Remove 'pred_cmd' label
x86/srso: Unexport untraining functions
x86/srso: Improve i-cache locality for alias mitigation
x86/srso: Fix unret validation dependencies
x86/srso: Fix vulnerability reporting for missing microcode
x86/srso: Print mitigation for retbleed IBPB case
x86/srso: Print actual mitigation if requested mitigation isn't possible
...
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Pull initial bcachefs updates from Kent Overstreet:
"Here's the bcachefs filesystem pull request.
One new patch since last week: the exportfs constants ended up
conflicting with other filesystems that are also getting added to the
global enum, so switched to new constants picked by Amir.
The only new non fs/bcachefs/ patch is the objtool patch that adds
bcachefs functions to the list of noreturns. The patch that exports
osq_lock() has been dropped for now, per Ingo"
* tag 'bcachefs-2023-10-30' of https://evilpiepirate.org/git/bcachefs: (2781 commits)
exportfs: Change bcachefs fid_type enum to avoid conflicts
bcachefs: Refactor memcpy into direct assignment
bcachefs: Fix drop_alloc_keys()
bcachefs: snapshot_create_lock
bcachefs: Fix snapshot skiplists during snapshot deletion
bcachefs: bch2_sb_field_get() refactoring
bcachefs: KEY_TYPE_error now counts towards i_sectors
bcachefs: Fix handling of unknown bkey types
bcachefs: Switch to unsafe_memcpy() in a few places
bcachefs: Use struct_size()
bcachefs: Correctly initialize new buckets on device resize
bcachefs: Fix another smatch complaint
bcachefs: Use strsep() in split_devs()
bcachefs: Add iops fields to bch_member
bcachefs: Rename bch_sb_field_members -> bch_sb_field_members_v1
bcachefs: New superblock section members_v2
bcachefs: Add new helper to retrieve bch_member from sb
bcachefs: bucket_lock() is now a sleepable lock
bcachefs: fix crc32c checksum merge byte order problem
bcachefs: Fix bch2_inode_delete_keys()
...
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Enabling CONFIG_KCSAN leads to unconverted, default return thunks to
remain after patching.
As David Kaplan describes in his debugging of the issue, it is caused by
a couple of KCSAN-generated constructors which aren't processed by
objtool:
"When KCSAN is enabled, GCC generates lots of constructor functions
named _sub_I_00099_0 which call __tsan_init and then return. The
returns in these are generally annotated normally by objtool and fixed
up at runtime. But objtool runs on vmlinux.o and vmlinux.o does not
include a couple of object files that are in vmlinux, like
init/version-timestamp.o and .vmlinux.export.o, both of which contain
_sub_I_00099_0 functions. As a result, the returns in these functions
are not annotated, and the panic occurs when we call one of them in
do_ctors and it uses the default return thunk.
This difference can be seen by counting the number of these functions in the object files:
$ objdump -d vmlinux.o|grep -c "<_sub_I_00099_0>:"
2601
$ objdump -d vmlinux|grep -c "<_sub_I_00099_0>:"
2603
If these functions are only run during kernel boot, there is no
speculation concern."
Fix it by disabling KCSAN on version-timestamp.o and .vmlinux.export.o
so the extra functions don't get generated. KASAN and GCOV are already
disabled for those files.
[ bp: Massage commit message. ]
Closes: https://lore.kernel.org/lkml/20231016214810.GA3942238@dev-arch.thelio-3990X/
Reported-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Acked-by: Marco Elver <elver@google.com>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/20231017165946.v4i2d4exyqwqq3bx@treble
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Given a wrong root device, current log may not give the pretty name
which is useful to locate root cause.
For example, there are 2 blk devs in a VM, /dev/vda which has 2 partitials
/dev/vda1 and /dev/vda2 and /dev/vdb which is blank. /dev/vda2 is the
right root dev. When set "root=/dev/vdb", we get error log:
[ 0.635575] Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(254,16)
It's not straightforward to find out the root cause as there is lack of
the root devive name therefore hard for people to get those info from the
device number, in the example, (254,16).
It is more comprehensive way to hint the root cause if pretty name is
given here, like:
[ 0.559887] Kernel panic - not syncing: VFS: Unable to mount root fs on "/dev/vdb" or unknown-block(254,16)
Signed-off-by: Jianyong Wu <jianyong.wu@arm.com>
Message-Id: <20230907091025.3436878-1-jianyong.wu@arm.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
|
The last user was removed by the previous patch.
Link: https://lkml.kernel.org/r/20230826111409.GA23243@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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|
strlcpy() reads the entire source buffer first.
This read may exceed the destination size limit.
This is both inefficient and can lead to linear read
overflows if a source string is not NUL-terminated [1].
In an effort to remove strlcpy() completely [2], replace
strlcpy() here with strscpy().
Direct replacement is safe here since return value of -errno
is used to check for truncation instead of sizeof(dest).
[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy
[2] https://github.com/KSPP/linux/issues/89
Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com>
Reviewed-by: Justin Stitt <justinstitt@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20230830160806.3821893-1-azeemshaikh38@gmail.com
Signed-off-by: Kees Cook <keescook@chromium.org>
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There has been a long standing page cache coherence bug with direct IO.
This provides part of a mechanism to fix it, currently just used by
bcachefs but potentially worth promoting to the VFS.
Direct IO evicts the range of the pagecache being read or written to.
For reads, we need dirty pages to be written to disk, so that the read
doesn't return stale data. For writes, we need to evict that range of
the pagecache so that it's not stale after the write completes.
However, without a locking mechanism to prevent those pages from being
re-added to the pagecache - by a buffered read or page fault - page
cache inconsistency is still possible.
This isn't necessarily just an issue for userspace when they're playing
games; filesystems may hang arbitrary state off the pagecache, and so
page cache inconsistency may cause real filesystem bugs, depending on
the filesystem. This is less of an issue for iomap based filesystems,
but e.g. buffer heads caches disk block mappings (!) and attaches them
to the pagecache, and bcachefs attaches disk reservations to pagecache
pages.
This issue has been hard to fix, because
- we need to add a lock (henceforth called pagecache_add_lock), which
would be held for the duration of the direct IO
- page faults add pages to the page cache, thus need to take the same
lock
- dio -> gup -> page fault thus can deadlock
And we cannot enforce a lock ordering with this lock, since userspace
will be controlling the lock ordering (via the fd and buffer arguments
to direct IOs), so we need a different method of deadlock avoidance.
We need to tell the page fault handler that we're already holding a
pagecache_add_lock, and since plumbing it through the entire gup() path
would be highly impractical this adds a field to task_struct.
Then the full method is:
- in the dio path, when we first take the pagecache_add_lock, note the
mapping in the current task_struct
- in the page fault handler, if faults_disabled_mapping is set, we
check if it's the same mapping as the one we're taking a page fault
for, and if so return an error.
Then we check lock ordering: if there's a lock ordering violation and
trylock fails, we'll have to cycle the locks and return an error that
tells the DIO path to retry: faults_disabled_mapping is also used for
signalling "locks were dropped, please retry".
Also relevant to this patch: mapping->invalidate_lock.
mapping->invalidate_lock provides most of the required semantics - it's
used by truncate/fallocate to block pages being added to the pagecache.
However, since it's a rwsem, direct IOs would need to take the write
side in order to block page cache adds, and would then be exclusive with
each other - we'll need a new type of lock to pair with this approach.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Jan Kara <jack@suse.cz>
Cc: Darrick J. Wong <djwong@kernel.org>
Cc: linux-fsdevel@vger.kernel.org
Cc: Andreas Grünbacher <andreas.gruenbacher@gmail.com>
|
|
The Itanium architecture is obsolete, and an informal survey [0] reveals
that any residual use of Itanium hardware in production is mostly HP-UX
or OpenVMS based. The use of Linux on Itanium appears to be limited to
enthusiasts that occasionally boot a fresh Linux kernel to see whether
things are still working as intended, and perhaps to churn out some
distro packages that are rarely used in practice.
None of the original companies behind Itanium still produce or support
any hardware or software for the architecture, and it is listed as
'Orphaned' in the MAINTAINERS file, as apparently, none of the engineers
that contributed on behalf of those companies (nor anyone else, for that
matter) have been willing to support or maintain the architecture
upstream or even be responsible for applying the odd fix. The Intel
firmware team removed all IA-64 support from the Tianocore/EDK2
reference implementation of EFI in 2018. (Itanium is the original
architecture for which EFI was developed, and the way Linux supports it
deviates significantly from other architectures.) Some distros, such as
Debian and Gentoo, still maintain [unofficial] ia64 ports, but many have
dropped support years ago.
While the argument is being made [1] that there is a 'for the common
good' angle to being able to build and run existing projects such as the
Grid Community Toolkit [2] on Itanium for interoperability testing, the
fact remains that none of those projects are known to be deployed on
Linux/ia64, and very few people actually have access to such a system in
the first place. Even if there were ways imaginable in which Linux/ia64
could be put to good use today, what matters is whether anyone is
actually doing that, and this does not appear to be the case.
There are no emulators widely available, and so boot testing Itanium is
generally infeasible for ordinary contributors. GCC still supports IA-64
but its compile farm [3] no longer has any IA-64 machines. GLIBC would
like to get rid of IA-64 [4] too because it would permit some overdue
code cleanups. In summary, the benefits to the ecosystem of having IA-64
be part of it are mostly theoretical, whereas the maintenance overhead
of keeping it supported is real.
So let's rip off the band aid, and remove the IA-64 arch code entirely.
This follows the timeline proposed by the Debian/ia64 maintainer [5],
which removes support in a controlled manner, leaving IA-64 in a known
good state in the most recent LTS release. Other projects will follow
once the kernel support is removed.
[0] https://lore.kernel.org/all/CAMj1kXFCMh_578jniKpUtx_j8ByHnt=s7S+yQ+vGbKt9ud7+kQ@mail.gmail.com/
[1] https://lore.kernel.org/all/0075883c-7c51-00f5-2c2d-5119c1820410@web.de/
[2] https://gridcf.org/gct-docs/latest/index.html
[3] https://cfarm.tetaneutral.net/machines/list/
[4] https://lore.kernel.org/all/87bkiilpc4.fsf@mid.deneb.enyo.de/
[5] https://lore.kernel.org/all/ff58a3e76e5102c94bb5946d99187b358def688a.camel@physik.fu-berlin.de/
Acked-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
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|
Pull workqueue updates from Tejun Heo:
- Unbound workqueues now support more flexible affinity scopes.
The default behavior is to soft-affine according to last level cache
boundaries. A work item queued from a given LLC is executed by a
worker running on the same LLC but the worker may be moved across
cache boundaries as the scheduler sees fit. On machines which
multiple L3 caches, which are becoming more popular along with
chiplet designs, this improves cache locality while not harming work
conservation too much.
Unbound workqueues are now also a lot more flexible in terms of
execution affinity. Differeing levels of affinity scopes are
supported and both the default and per-workqueue affinity settings
can be modified dynamically. This should help working around amny of
sub-optimal behaviors observed recently with asymmetric ARM CPUs.
This involved signficant restructuring of workqueue code. Nothing was
reported yet but there's some risk of subtle regressions. Should keep
an eye out.
- Rescuer workers now has more identifiable comms.
- workqueue.unbound_cpus added so that CPUs which can be used by
workqueue can be constrained early during boot.
- Now that all the in-tree users have been flushed out, trigger warning
if system-wide workqueues are flushed.
* tag 'wq-for-6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: (31 commits)
workqueue: fix data race with the pwq->stats[] increment
workqueue: Rename rescuer kworker
workqueue: Make default affinity_scope dynamically updatable
workqueue: Add "Affinity Scopes and Performance" section to documentation
workqueue: Implement non-strict affinity scope for unbound workqueues
workqueue: Add workqueue_attrs->__pod_cpumask
workqueue: Factor out need_more_worker() check and worker wake-up
workqueue: Factor out work to worker assignment and collision handling
workqueue: Add multiple affinity scopes and interface to select them
workqueue: Modularize wq_pod_type initialization
workqueue: Add tools/workqueue/wq_dump.py which prints out workqueue configuration
workqueue: Generalize unbound CPU pods
workqueue: Factor out clearing of workqueue-only attrs fields
workqueue: Factor out actual cpumask calculation to reduce subtlety in wq_update_pod()
workqueue: Initialize unbound CPU pods later in the boot
workqueue: Move wq_pod_init() below workqueue_init()
workqueue: Rename NUMA related names to use pod instead
workqueue: Rename workqueue_attrs->no_numa to ->ordered
workqueue: Make unbound workqueues to use per-cpu pool_workqueues
workqueue: Call wq_update_unbound_numa() on all CPUs in NUMA node on CPU hotplug
...
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git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull non-MM updates from Andrew Morton:
- An extensive rework of kexec and crash Kconfig from Eric DeVolder
("refactor Kconfig to consolidate KEXEC and CRASH options")
- kernel.h slimming work from Andy Shevchenko ("kernel.h: Split out a
couple of macros to args.h")
- gdb feature work from Kuan-Ying Lee ("Add GDB memory helper
commands")
- vsprintf inclusion rationalization from Andy Shevchenko
("lib/vsprintf: Rework header inclusions")
- Switch the handling of kdump from a udev scheme to in-kernel
handling, by Eric DeVolder ("crash: Kernel handling of CPU and memory
hot un/plug")
- Many singleton patches to various parts of the tree
* tag 'mm-nonmm-stable-2023-08-28-22-48' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (81 commits)
document while_each_thread(), change first_tid() to use for_each_thread()
drivers/char/mem.c: shrink character device's devlist[] array
x86/crash: optimize CPU changes
crash: change crash_prepare_elf64_headers() to for_each_possible_cpu()
crash: hotplug support for kexec_load()
x86/crash: add x86 crash hotplug support
crash: memory and CPU hotplug sysfs attributes
kexec: exclude elfcorehdr from the segment digest
crash: add generic infrastructure for crash hotplug support
crash: move a few code bits to setup support of crash hotplug
kstrtox: consistently use _tolower()
kill do_each_thread()
nilfs2: fix WARNING in mark_buffer_dirty due to discarded buffer reuse
scripts/bloat-o-meter: count weak symbol sizes
treewide: drop CONFIG_EMBEDDED
lockdep: fix static memory detection even more
lib/vsprintf: declare no_hash_pointers in sprintf.h
lib/vsprintf: split out sprintf() and friends
kernel/fork: stop playing lockless games for exe_file replacement
adfs: delete unused "union adfs_dirtail" definition
...
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git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
- Some swap cleanups from Ma Wupeng ("fix WARN_ON in
add_to_avail_list")
- Peter Xu has a series (mm/gup: Unify hugetlb, speed up thp") which
reduces the special-case code for handling hugetlb pages in GUP. It
also speeds up GUP handling of transparent hugepages.
- Peng Zhang provides some maple tree speedups ("Optimize the fast path
of mas_store()").
- Sergey Senozhatsky has improved te performance of zsmalloc during
compaction (zsmalloc: small compaction improvements").
- Domenico Cerasuolo has developed additional selftest code for zswap
("selftests: cgroup: add zswap test program").
- xu xin has doe some work on KSM's handling of zero pages. These
changes are mainly to enable the user to better understand the
effectiveness of KSM's treatment of zero pages ("ksm: support
tracking KSM-placed zero-pages").
- Jeff Xu has fixes the behaviour of memfd's
MEMFD_NOEXEC_SCOPE_NOEXEC_ENFORCED sysctl ("mm/memfd: fix sysctl
MEMFD_NOEXEC_SCOPE_NOEXEC_ENFORCED").
- David Howells has fixed an fscache optimization ("mm, netfs, fscache:
Stop read optimisation when folio removed from pagecache").
- Axel Rasmussen has given userfaultfd the ability to simulate memory
poisoning ("add UFFDIO_POISON to simulate memory poisoning with
UFFD").
- Miaohe Lin has contributed some routine maintenance work on the
memory-failure code ("mm: memory-failure: remove unneeded PageHuge()
check").
- Peng Zhang has contributed some maintenance work on the maple tree
code ("Improve the validation for maple tree and some cleanup").
- Hugh Dickins has optimized the collapsing of shmem or file pages into
THPs ("mm: free retracted page table by RCU").
- Jiaqi Yan has a patch series which permits us to use the healthy
subpages within a hardware poisoned huge page for general purposes
("Improve hugetlbfs read on HWPOISON hugepages").
- Kemeng Shi has done some maintenance work on the pagetable-check code
("Remove unused parameters in page_table_check").
- More folioification work from Matthew Wilcox ("More filesystem folio
conversions for 6.6"), ("Followup folio conversions for zswap"). And
from ZhangPeng ("Convert several functions in page_io.c to use a
folio").
- page_ext cleanups from Kemeng Shi ("minor cleanups for page_ext").
- Baoquan He has converted some architectures to use the
GENERIC_IOREMAP ioremap()/iounmap() code ("mm: ioremap: Convert
architectures to take GENERIC_IOREMAP way").
- Anshuman Khandual has optimized arm64 tlb shootdown ("arm64: support
batched/deferred tlb shootdown during page reclamation/migration").
- Better maple tree lockdep checking from Liam Howlett ("More strict
maple tree lockdep"). Liam also developed some efficiency
improvements ("Reduce preallocations for maple tree").
- Cleanup and optimization to the secondary IOMMU TLB invalidation,
from Alistair Popple ("Invalidate secondary IOMMU TLB on permission
upgrade").
- Ryan Roberts fixes some arm64 MM selftest issues ("selftests/mm fixes
for arm64").
- Kemeng Shi provides some maintenance work on the compaction code
("Two minor cleanups for compaction").
- Some reduction in mmap_lock pressure from Matthew Wilcox ("Handle
most file-backed faults under the VMA lock").
- Aneesh Kumar contributes code to use the vmemmap optimization for DAX
on ppc64, under some circumstances ("Add support for DAX vmemmap
optimization for ppc64").
- page-ext cleanups from Kemeng Shi ("add page_ext_data to get client
data in page_ext"), ("minor cleanups to page_ext header").
- Some zswap cleanups from Johannes Weiner ("mm: zswap: three
cleanups").
- kmsan cleanups from ZhangPeng ("minor cleanups for kmsan").
- VMA handling cleanups from Kefeng Wang ("mm: convert to
vma_is_initial_heap/stack()").
- DAMON feature work from SeongJae Park ("mm/damon/sysfs-schemes:
implement DAMOS tried total bytes file"), ("Extend DAMOS filters for
address ranges and DAMON monitoring targets").
- Compaction work from Kemeng Shi ("Fixes and cleanups to compaction").
- Liam Howlett has improved the maple tree node replacement code
("maple_tree: Change replacement strategy").
- ZhangPeng has a general code cleanup - use the K() macro more widely
("cleanup with helper macro K()").
- Aneesh Kumar brings memmap-on-memory to ppc64 ("Add support for
memmap on memory feature on ppc64").
- pagealloc cleanups from Kemeng Shi ("Two minor cleanups for pcp list
in page_alloc"), ("Two minor cleanups for get pageblock
migratetype").
- Vishal Moola introduces a memory descriptor for page table tracking,
"struct ptdesc" ("Split ptdesc from struct page").
- memfd selftest maintenance work from Aleksa Sarai ("memfd: cleanups
for vm.memfd_noexec").
- MM include file rationalization from Hugh Dickins ("arch: include
asm/cacheflush.h in asm/hugetlb.h").
- THP debug output fixes from Hugh Dickins ("mm,thp: fix sloppy text
output").
- kmemleak improvements from Xiaolei Wang ("mm/kmemleak: use
object_cache instead of kmemleak_initialized").
- More folio-related cleanups from Matthew Wilcox ("Remove _folio_dtor
and _folio_order").
- A VMA locking scalability improvement from Suren Baghdasaryan
("Per-VMA lock support for swap and userfaults").
- pagetable handling cleanups from Matthew Wilcox ("New page table
range API").
- A batch of swap/thp cleanups from David Hildenbrand ("mm/swap: stop
using page->private on tail pages for THP_SWAP + cleanups").
- Cleanups and speedups to the hugetlb fault handling from Matthew
Wilcox ("Change calling convention for ->huge_fault").
- Matthew Wilcox has also done some maintenance work on the MM
subsystem documentation ("Improve mm documentation").
* tag 'mm-stable-2023-08-28-18-26' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (489 commits)
maple_tree: shrink struct maple_tree
maple_tree: clean up mas_wr_append()
secretmem: convert page_is_secretmem() to folio_is_secretmem()
nios2: fix flush_dcache_page() for usage from irq context
hugetlb: add documentation for vma_kernel_pagesize()
mm: add orphaned kernel-doc to the rst files.
mm: fix clean_record_shared_mapping_range kernel-doc
mm: fix get_mctgt_type() kernel-doc
mm: fix kernel-doc warning from tlb_flush_rmaps()
mm: remove enum page_entry_size
mm: allow ->huge_fault() to be called without the mmap_lock held
mm: move PMD_ORDER to pgtable.h
mm: remove checks for pte_index
memcg: remove duplication detection for mem_cgroup_uncharge_swap
mm/huge_memory: work on folio->swap instead of page->private when splitting folio
mm/swap: inline folio_set_swap_entry() and folio_swap_entry()
mm/swap: use dedicated entry for swap in folio
mm/swap: stop using page->private on tail pages for THP_SWAP
selftests/mm: fix WARNING comparing pointer to 0
selftests: cgroup: fix test_kmem_memcg_deletion kernel mem check
...
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|
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Ingo Molnar:
- The biggest change is introduction of a new iteration of the
SCHED_FAIR interactivity code: the EEVDF ("Earliest Eligible Virtual
Deadline First") scheduler
EEVDF too is a virtual-time scheduler, with two parameters (weight
and relative deadline), compared to CFS that had weight only. It
completely reworks the base scheduler: placement, preemption, picking
-- everything
LWN.net, as usual, has a terrific writeup about EEVDF:
https://lwn.net/Articles/925371/
Preemption (both tick and wakeup) is driven by testing against a
fresh pick. Because the tree is now effectively an interval tree, and
the selection is no longer the 'leftmost' task, over-scheduling is
less of a problem. A lot of the CFS heuristics are removed or
replaced by more natural latency-space parameters & constructs
In terms of expected performance regressions: we will and can fix
everything where a 'good' workload misbehaves with the new scheduler,
but EEVDF inevitably changes workload scheduling in a binary fashion,
hopefully for the better in the overwhelming majority of cases, but
in some cases it won't, especially in adversarial loads that got
lucky with the previous code, such as some variants of hackbench. We
are trying hard to err on the side of fixing all performance
regressions, but we expect some inevitable post-release iterations of
that process
- Improve load-balancing on hybrid x86 systems: enable cluster
scheduling (again)
- Improve & fix bandwidth-scheduling on nohz systems
- Improve bandwidth-throttling
- Use lock guards to simplify and de-goto-ify control flow
- Misc improvements, cleanups and fixes
* tag 'sched-core-2023-08-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (43 commits)
sched/eevdf/doc: Modify the documented knob to base_slice_ns as well
sched/eevdf: Curb wakeup-preemption
sched: Simplify sched_core_cpu_{starting,deactivate}()
sched: Simplify try_steal_cookie()
sched: Simplify sched_tick_remote()
sched: Simplify sched_exec()
sched: Simplify ttwu()
sched: Simplify wake_up_if_idle()
sched: Simplify: migrate_swap_stop()
sched: Simplify sysctl_sched_uclamp_handler()
sched: Simplify get_nohz_timer_target()
sched/rt: sysctl_sched_rr_timeslice show default timeslice after reset
sched/rt: Fix sysctl_sched_rr_timeslice intial value
sched/fair: Block nohz tick_stop when cfs bandwidth in use
sched, cgroup: Restore meaning to hierarchical_quota
MAINTAINERS: Add Peter explicitly to the psi section
sched/psi: Select KERNFS as needed
sched/topology: Align group flags when removing degenerate domain
sched/fair: remove util_est boosting
sched/fair: Propagate enqueue flags into place_entity()
...
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There is only one Kconfig user of CONFIG_EMBEDDED and it can be switched
to EXPERT or "if !ARCH_MULTIPLATFORM" (suggested by Arnd).
Link: https://lkml.kernel.org/r/20230816055010.31534-1-rdunlap@infradead.org
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Palmer Dabbelt <palmer@rivosinc.com> [RISC-V]
Acked-by: Greg Ungerer <gerg@linux-m68k.org>
Acked-by: Jason A. Donenfeld <Jason@zx2c4.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> [powerpc]
Cc: Russell King <linux@armlinux.org.uk>
Cc: Vineet Gupta <vgupta@kernel.org>
Cc: Brian Cain <bcain@quicinc.com>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Dinh Nguyen <dinguyen@kernel.org>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Patch series "refactor Kconfig to consolidate KEXEC and CRASH options", v6.
The Kconfig is refactored to consolidate KEXEC and CRASH options from
various arch/<arch>/Kconfig files into new file kernel/Kconfig.kexec.
The Kconfig.kexec is now a submenu titled "Kexec and crash features"
located under "General Setup".
The following options are impacted:
- KEXEC
- KEXEC_FILE
- KEXEC_SIG
- KEXEC_SIG_FORCE
- KEXEC_IMAGE_VERIFY_SIG
- KEXEC_BZIMAGE_VERIFY_SIG
- KEXEC_JUMP
- CRASH_DUMP
Over time, these options have been copied between Kconfig files and
are very similar to one another, but with slight differences.
The following architectures are impacted by the refactor (because of
use of one or more KEXEC/CRASH options):
- arm
- arm64
- ia64
- loongarch
- m68k
- mips
- parisc
- powerpc
- riscv
- s390
- sh
- x86
More information:
In the patch series "crash: Kernel handling of CPU and memory hot
un/plug"
https://lore.kernel.org/lkml/20230503224145.7405-1-eric.devolder@oracle.com/
the new kernel feature introduces the config option CRASH_HOTPLUG.
In reviewing, Thomas Gleixner requested that the new config option
not be placed in x86 Kconfig. Rather the option needs a generic/common
home. To Thomas' point, the KEXEC and CRASH options have largely been
duplicated in the various arch/<arch>/Kconfig files, with minor
differences. This kind of proliferation is to be avoid/stopped.
https://lore.kernel.org/lkml/875y91yv63.ffs@tglx/
To that end, I have refactored the arch Kconfigs so as to consolidate
the various KEXEC and CRASH options. Generally speaking, this work has
the following themes:
- KEXEC and CRASH options are moved into new file kernel/Kconfig.kexec
- These items from arch/Kconfig:
CRASH_CORE KEXEC_CORE KEXEC_ELF HAVE_IMA_KEXEC
- These items from arch/x86/Kconfig form the common options:
KEXEC KEXEC_FILE KEXEC_SIG KEXEC_SIG_FORCE
KEXEC_BZIMAGE_VERIFY_SIG KEXEC_JUMP CRASH_DUMP
- These items from arch/arm64/Kconfig form the common options:
KEXEC_IMAGE_VERIFY_SIG
- The crash hotplug series appends CRASH_HOTPLUG to Kconfig.kexec
- The Kconfig.kexec is now a submenu titled "Kexec and crash features"
and is now listed in "General Setup" submenu from init/Kconfig.
- To control the common options, each has a new ARCH_SUPPORTS_<option>
option. These gateway options determine whether the common options
options are valid for the architecture.
- To account for the slight differences in the original architecture
coding of the common options, each now has a corresponding
ARCH_SELECTS_<option> which are used to elicit the same side effects
as the original arch/<arch>/Kconfig files for KEXEC and CRASH options.
An example, 'make menuconfig' illustrating the submenu:
> General setup > Kexec and crash features
[*] Enable kexec system call
[*] Enable kexec file based system call
[*] Verify kernel signature during kexec_file_load() syscall
[ ] Require a valid signature in kexec_file_load() syscall
[ ] Enable bzImage signature verification support
[*] kexec jump
[*] kernel crash dumps
[*] Update the crash elfcorehdr on system configuration changes
In the process of consolidating the common options, I encountered
slight differences in the coding of these options in several of the
architectures. As a result, I settled on the following solution:
- Each of the common options has a 'depends on ARCH_SUPPORTS_<option>'
statement. For example, the KEXEC_FILE option has a 'depends on
ARCH_SUPPORTS_KEXEC_FILE' statement.
This approach is needed on all common options so as to prevent
options from appearing for architectures which previously did
not allow/enable them. For example, arm supports KEXEC but not
KEXEC_FILE. The arch/arm/Kconfig does not provide
ARCH_SUPPORTS_KEXEC_FILE and so KEXEC_FILE and related options
are not available to arm.
- The boolean ARCH_SUPPORTS_<option> in effect allows the arch to
determine when the feature is allowed. Archs which don't have the
feature simply do not provide the corresponding ARCH_SUPPORTS_<option>.
For each arch, where there previously were KEXEC and/or CRASH
options, these have been replaced with the corresponding boolean
ARCH_SUPPORTS_<option>, and an appropriate def_bool statement.
For example, if the arch supports KEXEC_FILE, then the
ARCH_SUPPORTS_KEXEC_FILE simply has a 'def_bool y'. This permits
the KEXEC_FILE option to be available.
If the arch has a 'depends on' statement in its original coding
of the option, then that expression becomes part of the def_bool
expression. For example, arm64 had:
config KEXEC
depends on PM_SLEEP_SMP
and in this solution, this converts to:
config ARCH_SUPPORTS_KEXEC
def_bool PM_SLEEP_SMP
- In order to account for the architecture differences in the
coding for the common options, the ARCH_SELECTS_<option> in the
arch/<arch>/Kconfig is used. This option has a 'depends on
<option>' statement to couple it to the main option, and from
there can insert the differences from the common option and the
arch original coding of that option.
For example, a few archs enable CRYPTO and CRYTPO_SHA256 for
KEXEC_FILE. These require a ARCH_SELECTS_KEXEC_FILE and
'select CRYPTO' and 'select CRYPTO_SHA256' statements.
Illustrating the option relationships:
For each of the common KEXEC and CRASH options:
ARCH_SUPPORTS_<option> <- <option> <- ARCH_SELECTS_<option>
<option> # in Kconfig.kexec
ARCH_SUPPORTS_<option> # in arch/<arch>/Kconfig, as needed
ARCH_SELECTS_<option> # in arch/<arch>/Kconfig, as needed
For example, KEXEC:
ARCH_SUPPORTS_KEXEC <- KEXEC <- ARCH_SELECTS_KEXEC
KEXEC # in Kconfig.kexec
ARCH_SUPPORTS_KEXEC # in arch/<arch>/Kconfig, as needed
ARCH_SELECTS_KEXEC # in arch/<arch>/Kconfig, as needed
To summarize, the ARCH_SUPPORTS_<option> permits the <option> to be
enabled, and the ARCH_SELECTS_<option> handles side effects (ie.
select statements).
Examples:
A few examples to show the new strategy in action:
===== x86 (minus the help section) =====
Original:
config KEXEC
bool "kexec system call"
select KEXEC_CORE
config KEXEC_FILE
bool "kexec file based system call"
select KEXEC_CORE
select HAVE_IMA_KEXEC if IMA
depends on X86_64
depends on CRYPTO=y
depends on CRYPTO_SHA256=y
config ARCH_HAS_KEXEC_PURGATORY
def_bool KEXEC_FILE
config KEXEC_SIG
bool "Verify kernel signature during kexec_file_load() syscall"
depends on KEXEC_FILE
config KEXEC_SIG_FORCE
bool "Require a valid signature in kexec_file_load() syscall"
depends on KEXEC_SIG
config KEXEC_BZIMAGE_VERIFY_SIG
bool "Enable bzImage signature verification support"
depends on KEXEC_SIG
depends on SIGNED_PE_FILE_VERIFICATION
select SYSTEM_TRUSTED_KEYRING
config CRASH_DUMP
bool "kernel crash dumps"
depends on X86_64 || (X86_32 && HIGHMEM)
config KEXEC_JUMP
bool "kexec jump"
depends on KEXEC && HIBERNATION
help
becomes...
New:
config ARCH_SUPPORTS_KEXEC
def_bool y
config ARCH_SUPPORTS_KEXEC_FILE
def_bool X86_64 && CRYPTO && CRYPTO_SHA256
config ARCH_SELECTS_KEXEC_FILE
def_bool y
depends on KEXEC_FILE
select HAVE_IMA_KEXEC if IMA
config ARCH_SUPPORTS_KEXEC_PURGATORY
def_bool KEXEC_FILE
config ARCH_SUPPORTS_KEXEC_SIG
def_bool y
config ARCH_SUPPORTS_KEXEC_SIG_FORCE
def_bool y
config ARCH_SUPPORTS_KEXEC_BZIMAGE_VERIFY_SIG
def_bool y
config ARCH_SUPPORTS_KEXEC_JUMP
def_bool y
config ARCH_SUPPORTS_CRASH_DUMP
def_bool X86_64 || (X86_32 && HIGHMEM)
===== powerpc (minus the help section) =====
Original:
config KEXEC
bool "kexec system call"
depends on PPC_BOOK3S || PPC_E500 || (44x && !SMP)
select KEXEC_CORE
config KEXEC_FILE
bool "kexec file based system call"
select KEXEC_CORE
select HAVE_IMA_KEXEC if IMA
select KEXEC_ELF
depends on PPC64
depends on CRYPTO=y
depends on CRYPTO_SHA256=y
config ARCH_HAS_KEXEC_PURGATORY
def_bool KEXEC_FILE
config CRASH_DUMP
bool "Build a dump capture kernel"
depends on PPC64 || PPC_BOOK3S_32 || PPC_85xx || (44x && !SMP)
select RELOCATABLE if PPC64 || 44x || PPC_85xx
becomes...
New:
config ARCH_SUPPORTS_KEXEC
def_bool PPC_BOOK3S || PPC_E500 || (44x && !SMP)
config ARCH_SUPPORTS_KEXEC_FILE
def_bool PPC64 && CRYPTO=y && CRYPTO_SHA256=y
config ARCH_SUPPORTS_KEXEC_PURGATORY
def_bool KEXEC_FILE
config ARCH_SELECTS_KEXEC_FILE
def_bool y
depends on KEXEC_FILE
select KEXEC_ELF
select HAVE_IMA_KEXEC if IMA
config ARCH_SUPPORTS_CRASH_DUMP
def_bool PPC64 || PPC_BOOK3S_32 || PPC_85xx || (44x && !SMP)
config ARCH_SELECTS_CRASH_DUMP
def_bool y
depends on CRASH_DUMP
select RELOCATABLE if PPC64 || 44x || PPC_85xx
Testing Approach and Results
There are 388 config files in the arch/<arch>/configs directories.
For each of these config files, a .config is generated both before and
after this Kconfig series, and checked for equivalence. This approach
allows for a rather rapid check of all architectures and a wide
variety of configs wrt/ KEXEC and CRASH, and avoids requiring
compiling for all architectures and running kernels and run-time
testing.
For each config file, the olddefconfig, allnoconfig and allyesconfig
targets are utilized. In testing the randconfig has revealed problems
as well, but is not used in the before and after equivalence check
since one can not generate the "same" .config for before and after,
even if using the same KCONFIG_SEED since the option list is
different.
As such, the following script steps compare the before and after
of 'make olddefconfig'. The new symbols introduced by this series
are filtered out, but otherwise the config files are PASS only if
they were equivalent, and FAIL otherwise.
The script performs the test by doing the following:
# Obtain the "golden" .config output for given config file
# Reset test sandbox
git checkout master
git branch -D test_Kconfig
git checkout -B test_Kconfig master
make distclean
# Write out updated config
cp -f <config file> .config
make ARCH=<arch> olddefconfig
# Track each item in .config, LHSB is "golden"
scoreboard .config
# Obtain the "changed" .config output for given config file
# Reset test sandbox
make distclean
# Apply this Kconfig series
git am <this Kconfig series>
# Write out updated config
cp -f <config file> .config
make ARCH=<arch> olddefconfig
# Track each item in .config, RHSB is "changed"
scoreboard .config
# Determine test result
# Filter-out new symbols introduced by this series
# Filter-out symbol=n which not in either scoreboard
# Compare LHSB "golden" and RHSB "changed" scoreboards and issue PASS/FAIL
The script was instrumental during the refactoring of Kconfig as it
continually revealed problems. The end result being that the solution
presented in this series passes all configs as checked by the script,
with the following exceptions:
- arch/ia64/configs/zx1_config with olddefconfig
This config file has:
# CONFIG_KEXEC is not set
CONFIG_CRASH_DUMP=y
and this refactor now couples KEXEC to CRASH_DUMP, so it is not
possible to enable CRASH_DUMP without KEXEC.
- arch/sh/configs/* with allyesconfig
The arch/sh/Kconfig codes CRASH_DUMP as dependent upon BROKEN_ON_MMU
(which clearly is not meant to be set). This symbol is not provided
but with the allyesconfig it is set to yes which enables CRASH_DUMP.
But KEXEC is coded as dependent upon MMU, and is set to no in
arch/sh/mm/Kconfig, so KEXEC is not enabled.
This refactor now couples KEXEC to CRASH_DUMP, so it is not
possible to enable CRASH_DUMP without KEXEC.
While the above exceptions are not equivalent to their original,
the config file produced is valid (and in fact better wrt/ CRASH_DUMP
handling).
This patch (of 14)
The config options for kexec and crash features are consolidated
into new file kernel/Kconfig.kexec. Under the "General Setup" submenu
is a new submenu "Kexec and crash handling". All the kexec and
crash options that were once in the arch-dependent submenu "Processor
type and features" are now consolidated in the new submenu.
The following options are impacted:
- KEXEC
- KEXEC_FILE
- KEXEC_SIG
- KEXEC_SIG_FORCE
- KEXEC_BZIMAGE_VERIFY_SIG
- KEXEC_JUMP
- CRASH_DUMP
The three main options are KEXEC, KEXEC_FILE and CRASH_DUMP.
Architectures specify support of certain KEXEC and CRASH features with
similarly named new ARCH_SUPPORTS_<option> config options.
Architectures can utilize the new ARCH_SELECTS_<option> config
options to specify additional components when <option> is enabled.
To summarize, the ARCH_SUPPORTS_<option> permits the <option> to be
enabled, and the ARCH_SELECTS_<option> handles side effects (ie.
select statements).
Link: https://lkml.kernel.org/r/20230712161545.87870-1-eric.devolder@oracle.com
Link: https://lkml.kernel.org/r/20230712161545.87870-2-eric.devolder@oracle.com
Signed-off-by: Eric DeVolder <eric.devolder@oracle.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Baoquan He <bhe@redhat.com>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Cc. "H. Peter Anvin" <hpa@zytor.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Dave Hansen <dave.hansen@linux.intel.com> # for x86
Cc: Frederic Weisbecker <frederic@kernel.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hari Bathini <hbathini@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Juerg Haefliger <juerg.haefliger@canonical.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Marc Aurèle La France <tsi@tuyoix.net>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Cc: Sami Tolvanen <samitolvanen@google.com>
Cc: Sebastian Reichel <sebastian.reichel@collabora.com>
Cc: Sourabh Jain <sourabhjain@linux.ibm.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: WANG Xuerui <kernel@xen0n.name>
Cc: Will Deacon <will@kernel.org>
Cc: Xin Li <xin3.li@intel.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Zhen Lei <thunder.leizhen@huawei.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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All callers of show_mem() pass 0 and NULL, so we can remove the two
arguments by directly calling __show_mem(0, NULL, MAX_NR_ZONES - 1) in
show_mem().
Link: https://lkml.kernel.org/r/20230630062253.189440-1-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Add an optional timeout arg to 'rootwait' as the maximum time in
seconds to wait for the root device to show up before attempting
forced mount of the root filesystem.
Use case:
In case of device mapper usage for the rootfs (e.g. root=/dev/dm-0),
if the mapper is not able to create the virtual block for any reason
(wrong arguments, bad dm-verity signature, etc), the `rootwait` param
causes the kernel to wait forever. It may however be desirable to only
wait for a given time and then panic (force mount) to cause device reset.
This gives the bootloader a chance to detect the problem and to take some
measures, such as marking the booted partition as bad (for A/B case) or
entering a recovery mode.
In success case, mounting happens as soon as the root device is ready,
unlike the existing 'rootdelay' parameter which performs an unconditional
pause.
Signed-off-by: Loic Poulain <loic.poulain@linaro.org>
Message-Id: <20230813082349.513386-1-loic.poulain@linaro.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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During boot, to initialize unbound CPU pods, wq_pod_init() was called from
workqueue_init(). This is early enough for NUMA nodes to be set up but
before SMP is brought up and CPU topology information is populated.
Workqueue is in the process of improving CPU locality for unbound workqueues
and will need access to topology information during pod init. This adds a
new init function workqueue_init_topology() which is called after CPU
topology information is available and replaces wq_pod_init().
As unbound CPU pods are now initialized after workqueues are activated, we
need to revisit the workqueues to apply the pod configuration. Workqueues
which are created before workqueue_init_topology() are set up so that they
always use the default worker pool. After pods are set up in
workqueue_init_topology(), wq_update_pod() is called on all existing
workqueues to update the pool associations accordingly.
Note that wq_update_pod_attrs_buf allocation is moved to
workqueue_init_early(). This isn't necessary right now but enables further
generalization of pod handling in the future.
This patch changes the initialization sequence but the end result should be
the same.
Signed-off-by: Tejun Heo <tj@kernel.org>
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Users of KERNFS should select it to enforce its being built, so
do this to prevent a build error.
In file included from ../kernel/sched/build_utility.c:97:
../kernel/sched/psi.c: In function 'psi_trigger_poll':
../kernel/sched/psi.c:1479:17: error: implicit declaration of function 'kernfs_generic_poll' [-Werror=implicit-function-declaration]
1479 | kernfs_generic_poll(t->of, wait);
Fixes: aff037078eca ("sched/psi: use kernfs polling functions for PSI trigger polling")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Suren Baghdasaryan <surenb@google.com>
Link: lore.kernel.org/r/202307310732.r65EQFY0-lkp@intel.com
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git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild updates from Masahiro Yamada:
- Remove the deprecated rule to build *.dtbo from *.dts
- Refactor section mismatch detection in modpost
- Fix bogus ARM section mismatch detections
- Fix error of 'make gtags' with O= option
- Add Clang's target triple to KBUILD_CPPFLAGS to fix a build error
with the latest LLVM version
- Rebuild the built-in initrd when KBUILD_BUILD_TIMESTAMP is changed
- Ignore more compiler-generated symbols for kallsyms
- Fix 'make local*config' to handle the ${CONFIG_FOO} form in Makefiles
- Enable more kernel-doc warnings with W=2
- Refactor <linux/export.h> by generating KSYMTAB data by modpost
- Deprecate <asm/export.h> and <asm-generic/export.h>
- Remove the EXPORT_DATA_SYMBOL macro
- Move the check for static EXPORT_SYMBOL back to modpost, which makes
the build faster
- Re-implement CONFIG_TRIM_UNUSED_KSYMS with one-pass algorithm
- Warn missing MODULE_DESCRIPTION when building modules with W=1
- Make 'make clean' robust against too long argument error
- Exclude more objects from GCOV to fix CFI failures with GCOV
- Allow 'make modules_install' to install modules.builtin and
modules.builtin.modinfo even when CONFIG_MODULES is disabled
- Include modules.builtin and modules.builtin.modinfo in the
linux-image Debian package even when CONFIG_MODULES is disabled
- Revive "Entering directory" logging for the latest Make version
* tag 'kbuild-v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (72 commits)
modpost: define more R_ARM_* for old distributions
kbuild: revive "Entering directory" for Make >= 4.4.1
kbuild: set correct abs_srctree and abs_objtree for package builds
scripts/mksysmap: Ignore prefixed KCFI symbols
kbuild: deb-pkg: remove the CONFIG_MODULES check in buildeb
kbuild: builddeb: always make modules_install, to install modules.builtin*
modpost: continue even with unknown relocation type
modpost: factor out Elf_Sym pointer calculation to section_rel()
modpost: factor out inst location calculation to section_rel()
kbuild: Disable GCOV for *.mod.o
kbuild: Fix CFI failures with GCOV
kbuild: make clean rule robust against too long argument error
script: modpost: emit a warning when the description is missing
kbuild: make modules_install copy modules.builtin(.modinfo)
linux/export.h: rename 'sec' argument to 'license'
modpost: show offset from symbol for section mismatch warnings
modpost: merge two similar section mismatch warnings
kbuild: implement CONFIG_TRIM_UNUSED_KSYMS without recursion
modpost: use null string instead of NULL pointer for default namespace
modpost: squash sym_update_namespace() into sym_add_exported()
...
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git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull non-mm updates from Andrew Morton:
- Arnd Bergmann has fixed a bunch of -Wmissing-prototypes in top-level
directories
- Douglas Anderson has added a new "buddy" mode to the hardlockup
detector. It permits the detector to work on architectures which
cannot provide the required interrupts, by having CPUs periodically
perform checks on other CPUs
- Zhen Lei has enhanced kexec's ability to support two crash regions
- Petr Mladek has done a lot of cleanup on the hard lockup detector's
Kconfig entries
- And the usual bunch of singleton patches in various places
* tag 'mm-nonmm-stable-2023-06-24-19-23' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (72 commits)
kernel/time/posix-stubs.c: remove duplicated include
ocfs2: remove redundant assignment to variable bit_off
watchdog/hardlockup: fix typo in config HARDLOCKUP_DETECTOR_PREFER_BUDDY
powerpc: move arch_trigger_cpumask_backtrace from nmi.h to irq.h
devres: show which resource was invalid in __devm_ioremap_resource()
watchdog/hardlockup: define HARDLOCKUP_DETECTOR_ARCH
watchdog/sparc64: define HARDLOCKUP_DETECTOR_SPARC64
watchdog/hardlockup: make HAVE_NMI_WATCHDOG sparc64-specific
watchdog/hardlockup: declare arch_touch_nmi_watchdog() only in linux/nmi.h
watchdog/hardlockup: make the config checks more straightforward
watchdog/hardlockup: sort hardlockup detector related config values a logical way
watchdog/hardlockup: move SMP barriers from common code to buddy code
watchdog/buddy: simplify the dependency for HARDLOCKUP_DETECTOR_PREFER_BUDDY
watchdog/buddy: don't copy the cpumask in watchdog_next_cpu()
watchdog/buddy: cleanup how watchdog_buddy_check_hardlockup() is called
watchdog/hardlockup: remove softlockup comment in touch_nmi_watchdog()
watchdog/hardlockup: in watchdog_hardlockup_check() use cpumask_copy()
watchdog/hardlockup: don't use raw_cpu_ptr() in watchdog_hardlockup_kick()
watchdog/hardlockup: HAVE_NMI_WATCHDOG must implement watchdog_hardlockup_probe()
watchdog/hardlockup: keep kernel.nmi_watchdog sysctl as 0444 if probe fails
...
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|
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull mm updates from Andrew Morton:
- Yosry Ahmed brought back some cgroup v1 stats in OOM logs
- Yosry has also eliminated cgroup's atomic rstat flushing
- Nhat Pham adds the new cachestat() syscall. It provides userspace
with the ability to query pagecache status - a similar concept to
mincore() but more powerful and with improved usability
- Mel Gorman provides more optimizations for compaction, reducing the
prevalence of page rescanning
- Lorenzo Stoakes has done some maintanance work on the
get_user_pages() interface
- Liam Howlett continues with cleanups and maintenance work to the
maple tree code. Peng Zhang also does some work on maple tree
- Johannes Weiner has done some cleanup work on the compaction code
- David Hildenbrand has contributed additional selftests for
get_user_pages()
- Thomas Gleixner has contributed some maintenance and optimization
work for the vmalloc code
- Baolin Wang has provided some compaction cleanups,
- SeongJae Park continues maintenance work on the DAMON code
- Huang Ying has done some maintenance on the swap code's usage of
device refcounting
- Christoph Hellwig has some cleanups for the filemap/directio code
- Ryan Roberts provides two patch series which yield some
rationalization of the kernel's access to pte entries - use the
provided APIs rather than open-coding accesses
- Lorenzo Stoakes has some fixes to the interaction between pagecache
and directio access to file mappings
- John Hubbard has a series of fixes to the MM selftesting code
- ZhangPeng continues the folio conversion campaign
- Hugh Dickins has been working on the pagetable handling code, mainly
with a view to reducing the load on the mmap_lock
- Catalin Marinas has reduced the arm64 kmalloc() minimum alignment
from 128 to 8
- Domenico Cerasuolo has improved the zswap reclaim mechanism by
reorganizing the LRU management
- Matthew Wilcox provides some fixups to make gfs2 work better with the
buffer_head code
- Vishal Moola also has done some folio conversion work
- Matthew Wilcox has removed the remnants of the pagevec code - their
functionality is migrated over to struct folio_batch
* tag 'mm-stable-2023-06-24-19-15' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (380 commits)
mm/hugetlb: remove hugetlb_set_page_subpool()
mm: nommu: correct the range of mmap_sem_read_lock in task_mem()
hugetlb: revert use of page_cache_next_miss()
Revert "page cache: fix page_cache_next/prev_miss off by one"
mm/vmscan: fix root proactive reclaim unthrottling unbalanced node
mm: memcg: rename and document global_reclaim()
mm: kill [add|del]_page_to_lru_list()
mm: compaction: convert to use a folio in isolate_migratepages_block()
mm: zswap: fix double invalidate with exclusive loads
mm: remove unnecessary pagevec includes
mm: remove references to pagevec
mm: rename invalidate_mapping_pagevec to mapping_try_invalidate
mm: remove struct pagevec
net: convert sunrpc from pagevec to folio_batch
i915: convert i915_gpu_error to use a folio_batch
pagevec: rename fbatch_count()
mm: remove check_move_unevictable_pages()
drm: convert drm_gem_put_pages() to use a folio_batch
i915: convert shmem_sg_free_table() to use a folio_batch
scatterlist: add sg_set_folio()
...
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull objtool updates from Ingo Molar:
"Build footprint & performance improvements:
- Reduce memory usage with CONFIG_DEBUG_INFO=y
In the worst case of an allyesconfig+CONFIG_DEBUG_INFO=y kernel,
DWARF creates almost 200 million relocations, ballooning objtool's
peak heap usage to 53GB. These patches reduce that to 25GB.
On a distro-type kernel with kernel IBT enabled, they reduce
objtool's peak heap usage from 4.2GB to 2.8GB.
These changes also improve the runtime significantly.
Debuggability improvements:
- Add the unwind_debug command-line option, for more extend unwinding
debugging output
- Limit unreachable warnings to once per function
- Add verbose option for disassembling affected functions
- Include backtrace in verbose mode
- Detect missing __noreturn annotations
- Ignore exc_double_fault() __noreturn warnings
- Remove superfluous global_noreturns entries
- Move noreturn function list to separate file
- Add __kunit_abort() to noreturns
Unwinder improvements:
- Allow stack operations in UNWIND_HINT_UNDEFINED regions
- drm/vmwgfx: Add unwind hints around RBP clobber
Cleanups:
- Move the x86 entry thunk restore code into thunk functions
- x86/unwind/orc: Use swap() instead of open coding it
- Remove unnecessary/unused variables
Fixes for modern stack canary handling"
* tag 'objtool-core-2023-06-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (42 commits)
x86/orc: Make the is_callthunk() definition depend on CONFIG_BPF_JIT=y
objtool: Skip reading DWARF section data
objtool: Free insns when done
objtool: Get rid of reloc->rel[a]
objtool: Shrink elf hash nodes
objtool: Shrink reloc->sym_reloc_entry
objtool: Get rid of reloc->jump_table_start
objtool: Get rid of reloc->addend
objtool: Get rid of reloc->type
objtool: Get rid of reloc->offset
objtool: Get rid of reloc->idx
objtool: Get rid of reloc->list
objtool: Allocate relocs in advance for new rela sections
objtool: Add for_each_reloc()
objtool: Don't free memory in elf_close()
objtool: Keep GElf_Rel[a] structs synced
objtool: Add elf_create_section_pair()
objtool: Add mark_sec_changed()
objtool: Fix reloc_hash size
objtool: Consolidate rel/rela handling
...
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ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 boot updates from Thomas Gleixner:
"Initialize FPU late.
Right now FPU is initialized very early during boot. There is no real
requirement to do so. The only requirement is to have it done before
alternatives are patched.
That's done in check_bugs() which does way more than what the function
name suggests.
So first rename check_bugs() to arch_cpu_finalize_init() which makes
it clear what this is about.
Move the invocation of arch_cpu_finalize_init() earlier in
start_kernel() as it has to be done before fork_init() which needs to
know the FPU register buffer size.
With those prerequisites the FPU initialization can be moved into
arch_cpu_finalize_init(), which removes it from the early and fragile
part of the x86 bringup"
* tag 'x86-boot-2023-06-26' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mem_encrypt: Unbreak the AMD_MEM_ENCRYPT=n build
x86/fpu: Move FPU initialization into arch_cpu_finalize_init()
x86/fpu: Mark init functions __init
x86/fpu: Remove cpuinfo argument from init functions
x86/init: Initialize signal frame size late
init, x86: Move mem_encrypt_init() into arch_cpu_finalize_init()
init: Invoke arch_cpu_finalize_init() earlier
init: Remove check_bugs() leftovers
um/cpu: Switch to arch_cpu_finalize_init()
sparc/cpu: Switch to arch_cpu_finalize_init()
sh/cpu: Switch to arch_cpu_finalize_init()
mips/cpu: Switch to arch_cpu_finalize_init()
m68k/cpu: Switch to arch_cpu_finalize_init()
loongarch/cpu: Switch to arch_cpu_finalize_init()
ia64/cpu: Switch to arch_cpu_finalize_init()
ARM: cpu: Switch to arch_cpu_finalize_init()
x86/cpu: Switch to arch_cpu_finalize_init()
init: Provide arch_cpu_finalize_init()
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Pull block updates from Jens Axboe:
- NVMe pull request via Keith:
- Various cleanups all around (Irvin, Chaitanya, Christophe)
- Better struct packing (Christophe JAILLET)
- Reduce controller error logs for optional commands (Keith)
- Support for >=64KiB block sizes (Daniel Gomez)
- Fabrics fixes and code organization (Max, Chaitanya, Daniel
Wagner)
- bcache updates via Coly:
- Fix a race at init time (Mingzhe Zou)
- Misc fixes and cleanups (Andrea, Thomas, Zheng, Ye)
- use page pinning in the block layer for dio (David)
- convert old block dio code to page pinning (David, Christoph)
- cleanups for pktcdvd (Andy)
- cleanups for rnbd (Guoqing)
- use the unchecked __bio_add_page() for the initial single page
additions (Johannes)
- fix overflows in the Amiga partition handling code (Michael)
- improve mq-deadline zoned device support (Bart)
- keep passthrough requests out of the IO schedulers (Christoph, Ming)
- improve support for flush requests, making them less special to deal
with (Christoph)
- add bdev holder ops and shutdown methods (Christoph)
- fix the name_to_dev_t() situation and use cases (Christoph)
- decouple the block open flags from fmode_t (Christoph)
- ublk updates and cleanups, including adding user copy support (Ming)
- BFQ sanity checking (Bart)
- convert brd from radix to xarray (Pankaj)
- constify various structures (Thomas, Ivan)
- more fine grained persistent reservation ioctl capability checks
(Jingbo)
- misc fixes and cleanups (Arnd, Azeem, Demi, Ed, Hengqi, Hou, Jan,
Jordy, Li, Min, Yu, Zhong, Waiman)
* tag 'for-6.5/block-2023-06-23' of git://git.kernel.dk/linux: (266 commits)
scsi/sg: don't grab scsi host module reference
ext4: Fix warning in blkdev_put()
block: don't return -EINVAL for not found names in devt_from_devname
cdrom: Fix spectre-v1 gadget
block: Improve kernel-doc headers
blk-mq: don't insert passthrough request into sw queue
bsg: make bsg_class a static const structure
ublk: make ublk_chr_class a static const structure
aoe: make aoe_class a static const structure
block/rnbd: make all 'class' structures const
block: fix the exclusive open mask in disk_scan_partitions
block: add overflow checks for Amiga partition support
block: change all __u32 annotations to __be32 in affs_hardblocks.h
block: fix signed int overflow in Amiga partition support
block: add capacity validation in bdev_add_partition()
block: fine-granular CAP_SYS_ADMIN for Persistent Reservation
block: disallow Persistent Reservation on partitions
reiserfs: fix blkdev_put() warning from release_journal_dev()
block: fix wrong mode for blkdev_get_by_dev() from disk_scan_partitions()
block: document the holder argument to blkdev_get_by_path
...
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With GCOV_PROFILE_ALL, Clang injects __llvm_gcov_* functions to
each object file, and the functions are indirectly called during
boot. However, when code is injected to object files that are not
part of vmlinux.o, it's also not processed by objtool, which breaks
CFI hash randomization as the hashes in these files won't be
included in the .cfi_sites section and thus won't be randomized.
Similarly to commit 42633ed852de ("kbuild: Fix CFI hash
randomization with KASAN"), disable GCOV for .vmlinux.export.o and
init/version-timestamp.o to avoid emitting unnecessary functions to
object files that don't otherwise have executable code.
Fixes: 0c3e806ec0f9 ("x86/cfi: Add boot time hash randomization")
Reported-by: Joe Fradley <joefradley@google.com>
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
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Invoke the X86ism mem_encrypt_init() from X86 arch_cpu_finalize_init() and
remove the weak fallback from the core code.
No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20230613224545.670360645@linutronix.de
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X86 is reworking the boot process so that initializations which are not
required during early boot can be moved into the late boot process and out
of the fragile and restricted initial boot phase.
arch_cpu_finalize_init() is the obvious place to do such initializations,
but arch_cpu_finalize_init() is invoked too late in start_kernel() e.g. for
initializing the FPU completely. fork_init() requires that the FPU is
initialized as the size of task_struct on X86 depends on the size of the
required FPU register buffer.
Fortunately none of the init calls between calibrate_delay() and
arch_cpu_finalize_init() is relevant for the functionality of
arch_cpu_finalize_init().
Invoke it right after calibrate_delay() where everything which is relevant
for arch_cpu_finalize_init() has been set up already.
No functional change intended.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Link: https://lore.kernel.org/r/20230613224545.612182854@linutronix.de
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Everything is converted over to arch_cpu_finalize_init(). Remove the
check_bugs() leftovers including the empty stubs in asm-generic, alpha,
parisc, powerpc and xtensa.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Link: https://lore.kernel.org/r/20230613224545.553215951@linutronix.de
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check_bugs() has become a dumping ground for all sorts of activities to
finalize the CPU initialization before running the rest of the init code.
Most are empty, a few do actual bug checks, some do alternative patching
and some cobble a CPU advertisement string together....
Aside of that the current implementation requires duplicated function
declaration and mostly empty header files for them.
Provide a new function arch_cpu_finalize_init(). Provide a generic
declaration if CONFIG_ARCH_HAS_CPU_FINALIZE_INIT is selected and a stub
inline otherwise.
This requires a temporary #ifdef in start_kernel() which will be removed
along with check_bugs() once the architectures are converted over.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20230613224544.957805717@linutronix.de
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Booting with the QEMU command line:
"qemu-system-x86_64 -append root=/dev/vda rootfstype=ext4 ..."
will panic if ext4 is not builtin and a request to load the ext4 module
fails.
[ 1.729006] VFS: Cannot open root device "vda" or unknown-block(253,0): error -19
[ 1.730603] Please append a correct "root=" boot option; here are the available partitions:
[ 1.732323] fd00 256000 vda
[ 1.732329] driver: virtio_blk
[ 1.734194] Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(253,0)
[ 1.734771] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.4.0-rc2+ #53
[ 1.735194] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.10.2-1ubuntu1 04/01/2014
[ 1.735772] Call Trace:
[ 1.735950] <TASK>
[ 1.736113] dump_stack_lvl+0x32/0x50
[ 1.736367] panic+0x108/0x310
[ 1.736570] mount_block_root+0x161/0x310
[ 1.736849] ? rdinit_setup+0x40/0x40
[ 1.737088] prepare_namespace+0x10c/0x180
[ 1.737393] kernel_init_freeable+0x354/0x450
[ 1.737707] ? rest_init+0xd0/0xd0
[ 1.737945] kernel_init+0x16/0x130
[ 1.738196] ret_from_fork+0x1f/0x30
As a hint, print all the bdev fstypes which are available.
[akpm@linux-foundation.org: fix spelling in printk message]
Link: https://lkml.kernel.org/r/20230518035321.1672-1-angus.chen@jaguarmicro.com
Signed-off-by: Angus Chen <angus.chen@jaguarmicro.com>
Acked-by: Nick Desaulniers <ndesaulniers@google.com>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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cifs_root_data() is defined in cifs and called from early init code, but
lacks a global prototype:
fs/cifs/cifsroot.c:83:12: error: no previous prototype for 'cifs_root_data'
Move the declaration from do_mounts.c into an appropriate header.
Link: https://lkml.kernel.org/r/20230517131102.934196-13-arnd@kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Eric Paris <eparis@redhat.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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The init/main.c file contains some extern declarations for functions
defined in architecture code, and it defines some other functions that are
called from architecture code with a custom prototype. Both of those
result in warnings with 'make W=1':
init/calibrate.c:261:37: error: no previous prototype for 'calibrate_delay_is_known' [-Werror=missing-prototypes]
init/main.c:790:20: error: no previous prototype for 'mem_encrypt_init' [-Werror=missing-prototypes]
init/main.c:792:20: error: no previous prototype for 'poking_init' [-Werror=missing-prototypes]
arch/arm64/kernel/irq.c:122:13: error: no previous prototype for 'init_IRQ' [-Werror=missing-prototypes]
arch/arm64/kernel/time.c:55:13: error: no previous prototype for 'time_init' [-Werror=missing-prototypes]
arch/x86/kernel/process.c:935:13: error: no previous prototype for 'arch_post_acpi_subsys_init' [-Werror=missing-prototypes]
init/calibrate.c:261:37: error: no previous prototype for 'calibrate_delay_is_known' [-Werror=missing-prototypes]
kernel/fork.c:991:20: error: no previous prototype for 'arch_task_cache_init' [-Werror=missing-prototypes]
Add prototypes for all of these in include/linux/init.h or another
appropriate header, and remove the duplicate declarations from
architecture specific code.
[sfr@canb.auug.org.au: declare time_init_early()]
Link: https://lkml.kernel.org/r/20230519124311.5167221c@canb.auug.org.au
Link: https://lkml.kernel.org/r/20230517131102.934196-12-arnd@kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Eric Paris <eparis@redhat.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
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There is currently no good way to query the page cache state of large file
sets and directory trees. There is mincore(), but it scales poorly: the
kernel writes out a lot of bitmap data that userspace has to aggregate,
when the user really doesn not care about per-page information in that
case. The user also needs to mmap and unmap each file as it goes along,
which can be quite slow as well.
Some use cases where this information could come in handy:
* Allowing database to decide whether to perform an index scan or
direct table queries based on the in-memory cache state of the
index.
* Visibility into the writeback algorithm, for performance issues
diagnostic.
* Workload-aware writeback pacing: estimating IO fulfilled by page
cache (and IO to be done) within a range of a file, allowing for
more frequent syncing when and where there is IO capacity, and
batching when there is not.
* Computing memory usage of large files/directory trees, analogous to
the du tool for disk usage.
More information about these use cases could be found in the following
thread:
https://lore.kernel.org/lkml/20230315170934.GA97793@cmpxchg.org/
This patch implements a new syscall that queries cache state of a file and
summarizes the number of cached pages, number of dirty pages, number of
pages marked for writeback, number of (recently) evicted pages, etc. in a
given range. Currently, the syscall is only wired in for x86
architecture.
NAME
cachestat - query the page cache statistics of a file.
SYNOPSIS
#include <sys/mman.h>
struct cachestat_range {
__u64 off;
__u64 len;
};
struct cachestat {
__u64 nr_cache;
__u64 nr_dirty;
__u64 nr_writeback;
__u64 nr_evicted;
__u64 nr_recently_evicted;
};
int cachestat(unsigned int fd, struct cachestat_range *cstat_range,
struct cachestat *cstat, unsigned int flags);
DESCRIPTION
cachestat() queries the number of cached pages, number of dirty
pages, number of pages marked for writeback, number of evicted
pages, number of recently evicted pages, in the bytes range given by
`off` and `len`.
An evicted page is a page that is previously in the page cache but
has been evicted since. A page is recently evicted if its last
eviction was recent enough that its reentry to the cache would
indicate that it is actively being used by the system, and that
there is memory pressure on the system.
These values are returned in a cachestat struct, whose address is
given by the `cstat` argument.
The `off` and `len` arguments must be non-negative integers. If
`len` > 0, the queried range is [`off`, `off` + `len`]. If `len` ==
0, we will query in the range from `off` to the end of the file.
The `flags` argument is unused for now, but is included for future
extensibility. User should pass 0 (i.e no flag specified).
Currently, hugetlbfs is not supported.
Because the status of a page can change after cachestat() checks it
but before it returns to the application, the returned values may
contain stale information.
RETURN VALUE
On success, cachestat returns 0. On error, -1 is returned, and errno
is set to indicate the error.
ERRORS
EFAULT cstat or cstat_args points to an invalid address.
EINVAL invalid flags.
EBADF invalid file descriptor.
EOPNOTSUPP file descriptor is of a hugetlbfs file
[nphamcs@gmail.com: replace rounddown logic with the existing helper]
Link: https://lkml.kernel.org/r/20230504022044.3675469-1-nphamcs@gmail.com
Link: https://lkml.kernel.org/r/20230503013608.2431726-3-nphamcs@gmail.com
Signed-off-by: Nhat Pham <nphamcs@gmail.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Brian Foster <bfoster@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
