This corresponds to part of the functionality of the NT syscall
NtWaitForMultipleObjects(). Specifically, it implements the behaviour where
the third argument (wait_any) is TRUE, and it does not handle alertable waits.
Those features have been split out into separate patches to ease review.
This patch therefore implements the wait/wake infrastructure which comprises the
core of ntsync's functionality.
NTSYNC_IOC_WAIT_ANY is a vectored wait function similar to poll(). Unlike
poll(), it "consumes" objects when they are signaled. For semaphores, this means
decreasing one from the internal counter. At most one object can be consumed by
this function.
This wait/wake model is fundamentally different from that used anywhere else in
the kernel, and for that reason ntsync does not use any existing infrastructure,
such as futexes, kernel mutexes or semaphores, or wait_event().
Up to 64 objects can be waited on at once. As soon as one is signaled, the
object with the lowest index is consumed, and that index is returned via the
"index" field.
A timeout is supported. The timeout is passed as a u64 nanosecond value, which
represents absolute time measured against either the MONOTONIC or REALTIME clock
(controlled by the flags argument). If U64_MAX is passed, the ioctl waits
indefinitely.
This ioctl validates that all objects belong to the relevant device. This is not
necessary for any technical reason related to NTSYNC_IOC_WAIT_ANY, but will be
necessary for NTSYNC_IOC_WAIT_ALL introduced in the following patch.
Some padding fields are added for alignment and for fields which will be added
in future patches (split out to ease review).
Signed-off-by: Elizabeth Figura <zfigura@codeweavers.com>
Link: https://lore.kernel.org/r/20241213193511.457338-4-zfigura@codeweavers.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Use the more common "release" terminology, which is also the term used by NT,
instead of "post" (which is used by POSIX).
Signed-off-by: Elizabeth Figura <zfigura@codeweavers.com>
Link: https://lore.kernel.org/r/20241213193511.457338-3-zfigura@codeweavers.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Simplify the user API a bit by returning the fd as return value from the ioctl
instead of through the argument pointer.
Signed-off-by: Elizabeth Figura <zfigura@codeweavers.com>
Link: https://lore.kernel.org/r/20241213193511.457338-2-zfigura@codeweavers.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
For timer definitions like
DEFINE_TIMER(mytimer, mytimer_handler);
ctags generates tags `DEFINE_TIMER` and skips `mytimer`
because it doesn't expand the DEFINE_TIMER macro.
Configure ctags to generate tag for `mytimer`
ans skip the `DEFINE_TIMER` tag in such cases.
Signed-off-by: Costa Shulyupin <costa.shul@redhat.com>
Link: https://lore.kernel.org/r/20241209083004.911013-2-costa.shul@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
misc_minor_alloc was allocating id using ida for minor only in case of
MISC_DYNAMIC_MINOR but misc_minor_free was always freeing ids
using ida_free causing a mismatch and following warn:
> > WARNING: CPU: 0 PID: 159 at lib/idr.c:525 ida_free+0x3e0/0x41f
> > ida_free called for id=127 which is not allocated.
> > <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
...
> > [<60941eb4>] ida_free+0x3e0/0x41f
> > [<605ac993>] misc_minor_free+0x3e/0xbc
> > [<605acb82>] misc_deregister+0x171/0x1b3
misc_minor_alloc is changed to allocate id from ida for all minors
falling in the range of dynamic/ misc dynamic minors
Fixes: ab760791c0 ("char: misc: Increase the maximum number of dynamic misc devices to 1048448")
Signed-off-by: Vimal Agrawal <vimal.agrawal@sophos.com>
Reviewed-by: Dirk VanDerMerwe <dirk.vandermerwe@sophos.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20241021133812.23703-1-vimal.agrawal@sophos.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
IOCTL_VMCI_SOCKETS_VERSION and IOCTL_VMCI_SOCKETS_GET_AF_VALUE were
never implemented, because VSOCK ended up being implemented as a
generic mechanism with a static AF value. Likewise,
IOCTL_VMCI_SOCKETS_GET_LOCAL_CID ended up being implemented as
IOCTL_VM_SOCKETS_GET_LOCAL_CID.
This isn't a UAPI header, so it should be fine to remove the unused
values. I've left a comment noting IOCTL_VM_SOCKETS_GET_LOCAL_CID is
in the VMCI range to avoid unintentional reuse.
Signed-off-by: Alyssa Ross <hi@alyssa.is>
Acked-by: Vishnu Dasa <vishnu.dasa@broadcom.com>
Link: https://lore.kernel.org/r/fzdcrz4yfedokmbm22h2iwsluix4jwejwaltuwcdr6kz3yu6eu@nue5xc6ayevo
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The 'struct file' member in 'binder_task_work_cb' definition was renamed
to 'file' between patch versions but its kernel-doc reference kept the
old name 'fd'. Update the naming to fix the W=1 build warning.
Cc: Todd Kjos <tkjos@google.com>
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202501031535.erbln3A2-lkp@intel.com/
Signed-off-by: Carlos Llamas <cmllamas@google.com>
Acked-by: Todd Kjos <tkjos@google.com>
Link: https://lore.kernel.org/r/20250106192608.1107362-1-cmllamas@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When binderfs is not enabled, the binder driver parses the kernel
config to create all binder devices. All of the new binder devices
are stored in the list binder_devices.
When binderfs is enabled, the binder driver creates new binder devices
dynamically when userspace applications call BINDER_CTL_ADD ioctl. But
the devices created in this way are not stored in the same list.
This patch fixes that.
Signed-off-by: Li Li <dualli@google.com>
Acked-by: Carlos Llamas <cmllamas@google.com>
Link: https://lore.kernel.org/r/20241218212935.4162907-2-dualli@chromium.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch adds the documentation for the ABI between the Linux kernel
and userspace regarding the PPS generators.
Signed-off-by: Rodolfo Giometti <giometti@enneenne.com>
Link: https://lore.kernel.org/r/20241108073115.759039-5-giometti@enneenne.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch adds some examples about how to register a new PPS
generator in the system, and how to manage it.
Signed-off-by: Rodolfo Giometti <giometti@enneenne.com>
Reviewed-by: Bagas Sanjaya <bagasdotme@gmail.com>
Link: https://lore.kernel.org/r/20241108073115.759039-4-giometti@enneenne.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Sometimes one needs to be able not only to catch PPS signals but to
produce them also. For example, running a distributed simulation,
which requires computers' clock to be synchronized very tightly.
This patch adds PPS generators class in order to have a well-defined
interface for these devices.
Signed-off-by: Rodolfo Giometti <giometti@enneenne.com>
Link: https://lore.kernel.org/r/20241108073115.759039-2-giometti@enneenne.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
On a board running ntpd and gpsd, I'm seeing a consistent use-after-free
in sys_exit() from gpsd when rebooting:
pps pps1: removed
------------[ cut here ]------------
kobject: '(null)' (00000000db4bec24): is not initialized, yet kobject_put() is being called.
WARNING: CPU: 2 PID: 440 at lib/kobject.c:734 kobject_put+0x120/0x150
CPU: 2 UID: 299 PID: 440 Comm: gpsd Not tainted 6.11.0-rc6-00308-gb31c44928842 #1
Hardware name: Raspberry Pi 4 Model B Rev 1.1 (DT)
pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : kobject_put+0x120/0x150
lr : kobject_put+0x120/0x150
sp : ffffffc0803d3ae0
x29: ffffffc0803d3ae0 x28: ffffff8042dc9738 x27: 0000000000000001
x26: 0000000000000000 x25: ffffff8042dc9040 x24: ffffff8042dc9440
x23: ffffff80402a4620 x22: ffffff8042ef4bd0 x21: ffffff80405cb600
x20: 000000000008001b x19: ffffff8040b3b6e0 x18: 0000000000000000
x17: 0000000000000000 x16: 0000000000000000 x15: 696e6920746f6e20
x14: 7369203a29343263 x13: 205d303434542020 x12: 0000000000000000
x11: 0000000000000000 x10: 0000000000000000 x9 : 0000000000000000
x8 : 0000000000000000 x7 : 0000000000000000 x6 : 0000000000000000
x5 : 0000000000000000 x4 : 0000000000000000 x3 : 0000000000000000
x2 : 0000000000000000 x1 : 0000000000000000 x0 : 0000000000000000
Call trace:
kobject_put+0x120/0x150
cdev_put+0x20/0x3c
__fput+0x2c4/0x2d8
____fput+0x1c/0x38
task_work_run+0x70/0xfc
do_exit+0x2a0/0x924
do_group_exit+0x34/0x90
get_signal+0x7fc/0x8c0
do_signal+0x128/0x13b4
do_notify_resume+0xdc/0x160
el0_svc+0xd4/0xf8
el0t_64_sync_handler+0x140/0x14c
el0t_64_sync+0x190/0x194
---[ end trace 0000000000000000 ]---
...followed by more symptoms of corruption, with similar stacks:
refcount_t: underflow; use-after-free.
kernel BUG at lib/list_debug.c:62!
Kernel panic - not syncing: Oops - BUG: Fatal exception
This happens because pps_device_destruct() frees the pps_device with the
embedded cdev immediately after calling cdev_del(), but, as the comment
above cdev_del() notes, fops for previously opened cdevs are still
callable even after cdev_del() returns. I think this bug has always
been there: I can't explain why it suddenly started happening every time
I reboot this particular board.
In commit d953e0e837 ("pps: Fix a use-after free bug when
unregistering a source."), George Spelvin suggested removing the
embedded cdev. That seems like the simplest way to fix this, so I've
implemented his suggestion, using __register_chrdev() with pps_idr
becoming the source of truth for which minor corresponds to which
device.
But now that pps_idr defines userspace visibility instead of cdev_add(),
we need to be sure the pps->dev refcount can't reach zero while
userspace can still find it again. So, the idr_remove() call moves to
pps_unregister_cdev(), and pps_idr now holds a reference to pps->dev.
pps_core: source serial1 got cdev (251:1)
<...>
pps pps1: removed
pps_core: unregistering pps1
pps_core: deallocating pps1
Fixes: d953e0e837 ("pps: Fix a use-after free bug when unregistering a source.")
Cc: stable@vger.kernel.org
Signed-off-by: Calvin Owens <calvin@wbinvd.org>
Reviewed-by: Michal Schmidt <mschmidt@redhat.com>
Link: https://lore.kernel.org/r/a17975fd5ae99385791929e563f72564edbcf28f.1731383727.git.calvin@wbinvd.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In the commit 202318d376
slimbus documentation was added but it missed
the update in this file. Currently get_maintainer script
is missing the main maintainer.
Signed-off-by: anish kumar <yesanishhere@gmail.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20241230143354.266154-3-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reorganize kerneldoc parameter names to match the parameter
order in the function header.
Problems identified using Coccinelle.
Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20241230143354.266154-2-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Document QFPROM compatible for Qualcomm QCS8300. It provides access
functions for QFPROM data to rest of the drivers via nvmem interface.
Signed-off-by: Jingyi Wang <quic_jingyw@quicinc.com>
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20241230143035.265518-12-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add a new reserved-memory node, containing bootloader config with MAC
addresses for both ethernet instances of the SoC.
Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20241230143035.265518-8-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Mobileye EyeQ5 has a non-volatile memory region which
gets used to store MAC addresses. Its format includes
a prefix 12-byte header and a suffix 4-byte CRC.
Add an optional ->checksum() callback inside match data;
it runs CRC32 onto the content.
Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20241230143035.265518-7-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The private structure used by the rmem driver contains
a `size` field that is unused. Remove it.
Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20241230143035.265518-6-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
memory_read_from_buffer() is a weird choice; it:
- is made for iteration with ppos a pointer.
- does futile error checking in our case.
- does NOT ensure we read exactly N bytes.
Replace it by:
1. A check that (offset + bytes) lands inside the region and,
2. a plain memcpy().
Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20241230143035.265518-5-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Both ->reg_read() and ->reg_write() return values are not easy to
deduce. Explicit that they should return zero on success (and negative
values otherwise).
Such callbacks, in some alternative world, could return the number of
bytes in the success case. That would be translated to errors in the
nvmem core because of checks like:
ret = nvmem->reg_write(nvmem->priv, offset, val, bytes);
if (ret) {
// error case
}
This mistake is not just theoretical, see commit
28b008751a ("nvmem: rmem: Fix return value of rmem_read()").
Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20241230143035.265518-4-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
On Mobileye EyeQ5, the bootloader will put MAC addresses into memory.
Declare that as reserved memory to be used by the kernel, exposing
nvmem cells. That region has a 12-byte header and a 4-byte trailing CRC.
Acked-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20241230143035.265518-3-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The sysfs core now allows instances of 'struct bin_attribute' to be
moved into read-only memory. Make use of that to protect them against
accidental or malicious modifications.
Also adapt the dynamic sysfs cell logic to handle the const attributes.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20241230143035.265518-2-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Modifying the size of the global bin_attribute instance can be racy.
Instead use the new .bin_size callback to do so safely.
For this to work move the initialization of c2dev->ops before the call
to device_create() as the size callback will need access to it.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://lore.kernel.org/r/20241221-sysfs-const-bin_attr-misc-drivers-v2-4-ba5e79fe8771@weissschuh.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The sysfs core now allows instances of 'struct bin_attribute' to be
moved into read-only memory. Make use of that to protect them against
accidental or malicious modifications.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Acked-by: Andrew Donnellan <ajd@linux.ibm.com>
Link: https://lore.kernel.org/r/20241221-sysfs-const-bin_attr-misc-drivers-v2-2-ba5e79fe8771@weissschuh.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The sysfs core now allows instances of 'struct bin_attribute' to be
moved into read-only memory. Make use of that to protect them against
accidental or malicious modifications.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Acked-by: Andrew Donnellan <ajd@linux.ibm.com>
Link: https://lore.kernel.org/r/20241221-sysfs-const-bin_attr-misc-drivers-v2-1-ba5e79fe8771@weissschuh.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Use per-vma locking in the shrinker's callback when reclaiming pages,
similar to the page installation logic. This minimizes contention with
unrelated vmas improving performance. The mmap_sem is still acquired if
the per-vma lock cannot be obtained.
Cc: Suren Baghdasaryan <surenb@google.com>
Suggested-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Carlos Llamas <cmllamas@google.com>
Link: https://lore.kernel.org/r/20241210143114.661252-10-cmllamas@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Instead of always overriding errors with -ENOMEM, propagate the specific
error code returned by vm_insert_page(). This allows for more accurate
error logs and handling.
Cc: Suren Baghdasaryan <surenb@google.com>
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Carlos Llamas <cmllamas@google.com>
Link: https://lore.kernel.org/r/20241210143114.661252-9-cmllamas@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Use per-vma locking for concurrent page installations, this minimizes
contention with unrelated vmas improving performance. The mmap_lock is
still acquired when needed though, e.g. before get_user_pages_remote().
Many thanks to Barry Song who posted a similar approach [1].
Link: https://lore.kernel.org/all/20240902225009.34576-1-21cnbao@gmail.com/ [1]
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Barry Song <v-songbaohua@oppo.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Carlos Llamas <cmllamas@google.com>
Link: https://lore.kernel.org/r/20241210143114.661252-8-cmllamas@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The alloc->buffer field in struct binder_alloc stores the starting
address of the mapped vma, rename this field to alloc->vm_start to
better reflect its purpose. It also avoids confusion with the binder
buffer concept, e.g. transaction->buffer.
No functional changes in this patch.
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Carlos Llamas <cmllamas@google.com>
Link: https://lore.kernel.org/r/20241210143114.661252-7-cmllamas@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
It is unsafe to use alloc->vma outside of the mmap_sem. Instead, add a
new boolean alloc->mapped to save the vma state (mapped or unmmaped) and
use this as a replacement for alloc->vma to validate several paths.
Using the alloc->vma caused several performance and security issues in
the past. Now that it has been replaced with either vm_lookup() or the
alloc->mapped state, we can finally remove it.
Cc: Minchan Kim <minchan@kernel.org>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Carlos Llamas <cmllamas@google.com>
Link: https://lore.kernel.org/r/20241210143114.661252-6-cmllamas@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Instead of pre-allocating an entire array of struct binder_lru_page in
alloc->pages, install the shrinker metadata under page->private. This
ensures the memory is allocated and released as needed alongside pages.
By converting the alloc->pages[] into an array of struct page pointers,
we can access these pages directly and only reference the shrinker
metadata where it's being used (e.g. inside the shrinker's callback).
Rename struct binder_lru_page to struct binder_shrinker_mdata to better
reflect its purpose. Add convenience functions that wrap the allocation
and freeing of pages along with their shrinker metadata.
Note I've reworked this patch to avoid using page->lru and page->index
directly, as Matthew pointed out that these are being removed [1].
Link: https://lore.kernel.org/all/ZzziucEm3np6e7a0@casper.infradead.org/ [1]
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Carlos Llamas <cmllamas@google.com>
Link: https://lore.kernel.org/r/20241210143114.661252-5-cmllamas@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The numa node id for binder pages is currently being derived from the
lru entry under struct binder_lru_page. However, this object doesn't
reflect the node id of the struct page items allocated separately.
Instead, select the correct node id from the page itself. This was made
possible since commit 0a97c01cd2 ("list_lru: allow explicit memcg and
NUMA node selection").
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Carlos Llamas <cmllamas@google.com>
Link: https://lore.kernel.org/r/20241210143114.661252-4-cmllamas@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Allow multiple callers to install pages simultaneously by switching the
mmap_sem from write-mode to read-mode. Races to the same PTE are handled
using get_user_pages_remote() to retrieve the already installed page.
This method significantly reduces contention in the mmap semaphore.
To ensure safety, vma_lookup() is used (instead of alloc->vma) to avoid
operating on an isolated VMA. In addition, zap_page_range_single() is
called under the alloc->mutex to avoid racing with the shrinker.
Many thanks to Barry Song who posted a similar approach [1].
Link: https://lore.kernel.org/all/20240902225009.34576-1-21cnbao@gmail.com/ [1]
Cc: David Hildenbrand <david@redhat.com>
Cc: Barry Song <v-songbaohua@oppo.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Carlos Llamas <cmllamas@google.com>
Link: https://lore.kernel.org/r/20241210143114.661252-3-cmllamas@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit 7710e2cca3.
In preparation for concurrent page installations, restore the original
alloc->mutex which will serialize zap_page_range_single() against page
installations in subsequent patches (instead of the mmap_sem).
Resolved trivial conflicts with commit 2c10a20f5e ("binder_alloc: Fix
sleeping function called from invalid context") and commit da0c02516c
("mm/list_lru: simplify the list_lru walk callback function").
Cc: Mukesh Ojha <quic_mojha@quicinc.com>
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Carlos Llamas <cmllamas@google.com>
Link: https://lore.kernel.org/r/20241210143114.661252-2-cmllamas@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When one is too lazy to use an LSP to conduct look-ups on struct
definitions, one might use the ever useful `struct <name> {` search
string. However this doesn't work with `struct miscdevice {` because
of a stray double space. Assuming that this wasn't intentional, let's
simply remove it.
Signed-off-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/20241223151843.472645-1-lee@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
- Limit EFI zboot to GZIP and ZSTD before it comes in wider use
- Fix inconsistent error when looking up a non-existent file in efivarfs
with a name that does not adhere to the NAME-GUID format
- Drop some unused code
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Merge tag 'efi-fixes-for-v6.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi
Pull EFI fixes from Ard Biesheuvel:
- Limit EFI zboot to GZIP and ZSTD before it comes in wider use
- Fix inconsistent error when looking up a non-existent file in
efivarfs with a name that does not adhere to the NAME-GUID format
- Drop some unused code
* tag 'efi-fixes-for-v6.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi:
efi/esrt: remove esre_attribute::store()
efivarfs: Fix error on non-existent file
efi/zboot: Limit compression options to GZIP and ZSTD
We have these fixes for hosts: PNX used the wrong unit for timeouts,
Nomadik was missing a sentinel, and RIIC was missing rounding up.
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Merge tag 'i2c-for-6.13-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux
Pull i2c fixes from Wolfram Sang:
"i2c host fixes: PNX used the wrong unit for timeouts, Nomadik was
missing a sentinel, and RIIC was missing rounding up"
* tag 'i2c-for-6.13-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
i2c: riic: Always round-up when calculating bus period
i2c: nomadik: Add missing sentinel to match table
i2c: pnx: Fix timeout in wait functions
