Deprecate usage of AR_TKN_U32_MODULE_IN_PORTS and
AR_TKN_U32_MODULE_OUT_PORTS as the connectivity of modules is taken care
by AR_TKN_U32_MODULE_SRC_OP_PORT_ID* and AR_TKN_U32_MODULE_DST_IN_PORT_ID*
Also this property is never used in the drivers.
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@oss.qualcomm.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://patch.msgid.link/20250819100151.1294047-2-srinivas.kandagatla@oss.qualcomm.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Commit f08d0c3a71 ("pidfd: add PIDFD_SELF* sentinels to refer to own
thread/process") introduced a leak by acquiring a pid reference through
get_task_pid(), which increments pid->count but never drops it with
put_pid().
As a result, kmemleak reports unreferenced pid objects after running
tools/testing/selftests/pidfd/pidfd_test, for example:
unreferenced object 0xff1100206757a940 (size 160):
comm "pidfd_test", pid 16965, jiffies 4294853028
hex dump (first 32 bytes):
01 00 00 00 00 00 00 00 00 00 00 00 fd 57 50 04 .............WP.
5e 44 00 00 00 00 00 00 18 de 34 17 01 00 11 ff ^D........4.....
backtrace (crc cd8844d4):
kmem_cache_alloc_noprof+0x2f4/0x3f0
alloc_pid+0x54/0x3d0
copy_process+0xd58/0x1740
kernel_clone+0x99/0x3b0
__do_sys_clone3+0xbe/0x100
do_syscall_64+0x7b/0x2c0
entry_SYSCALL_64_after_hwframe+0x76/0x7e
Fix this by calling put_pid() after do_pidfd_send_signal() returns.
Fixes: f08d0c3a71 ("pidfd: add PIDFD_SELF* sentinels to refer to own thread/process")
Signed-off-by: Adrian Huang (Lenovo) <adrianhuang0701@gmail.com>
Link: https://lore.kernel.org/20250818134310.12273-1-adrianhuang0701@gmail.com
Tested-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Userspace doesn't expect a failure to list extended attributes:
$ ls -lA /sys/
ls: /sys/: No data available
ls: /sys/kernel: No data available
ls: /sys/power: No data available
ls: /sys/class: No data available
ls: /sys/devices: No data available
ls: /sys/dev: No data available
ls: /sys/hypervisor: No data available
ls: /sys/fs: No data available
ls: /sys/bus: No data available
ls: /sys/firmware: No data available
ls: /sys/block: No data available
ls: /sys/module: No data available
total 0
drwxr-xr-x 2 root root 0 Jan 1 1970 block
drwxr-xr-x 52 root root 0 Jan 1 1970 bus
drwxr-xr-x 88 root root 0 Jan 1 1970 class
drwxr-xr-x 4 root root 0 Jan 1 1970 dev
drwxr-xr-x 11 root root 0 Jan 1 1970 devices
drwxr-xr-x 3 root root 0 Jan 1 1970 firmware
drwxr-xr-x 10 root root 0 Jan 1 1970 fs
drwxr-xr-x 2 root root 0 Jul 2 09:43 hypervisor
drwxr-xr-x 14 root root 0 Jan 1 1970 kernel
drwxr-xr-x 251 root root 0 Jan 1 1970 module
drwxr-xr-x 3 root root 0 Jul 2 09:43 power
Fix it by simply reporting success when no extended attributes are
available instead of reporting ENODATA.
Link: https://lore.kernel.org/78b13bcdae82ade95e88f315682966051f461dde.camel@linaro.org
Fixes: d1f4e90260 ("kernfs: remove iattr_mutex") # mainline only
Reported-by: André Draszik <andre.draszik@linaro.org>
Link: https://lore.kernel.org/20250819-ahndung-abgaben-524a535f8101@brauner
Signed-off-by: Christian Brauner <brauner@kernel.org>
The coredump_parse() function is bool type. It should return true on
success and false on failure. The cn_printf() returns zero on success
or negative error codes. This mismatch means that when "return err;"
here, it is treated as success instead of failure. Change it to return
false instead.
Fixes: a5715af549 ("coredump: make coredump_parse() return bool")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Link: https://lore.kernel.org/aKRGu14w5vPSZLgv@stanley.mountain
Signed-off-by: Christian Brauner <brauner@kernel.org>
There's issue as follows:
BUG: KASAN: stack-out-of-bounds in end_buffer_read_sync+0xe3/0x110
Read of size 8 at addr ffffc9000168f7f8 by task swapper/3/0
CPU: 3 UID: 0 PID: 0 Comm: swapper/3 Not tainted 6.16.0-862.14.0.6.x86_64
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)
Call Trace:
<IRQ>
dump_stack_lvl+0x55/0x70
print_address_description.constprop.0+0x2c/0x390
print_report+0xb4/0x270
kasan_report+0xb8/0xf0
end_buffer_read_sync+0xe3/0x110
end_bio_bh_io_sync+0x56/0x80
blk_update_request+0x30a/0x720
scsi_end_request+0x51/0x2b0
scsi_io_completion+0xe3/0x480
? scsi_device_unbusy+0x11e/0x160
blk_complete_reqs+0x7b/0x90
handle_softirqs+0xef/0x370
irq_exit_rcu+0xa5/0xd0
sysvec_apic_timer_interrupt+0x6e/0x90
</IRQ>
Above issue happens when do ntfs3 filesystem mount, issue may happens
as follows:
mount IRQ
ntfs_fill_super
read_cache_page
do_read_cache_folio
filemap_read_folio
mpage_read_folio
do_mpage_readpage
ntfs_get_block_vbo
bh_read
submit_bh
wait_on_buffer(bh);
blk_complete_reqs
scsi_io_completion
scsi_end_request
blk_update_request
end_bio_bh_io_sync
end_buffer_read_sync
__end_buffer_read_notouch
unlock_buffer
wait_on_buffer(bh);--> return will return to caller
put_bh
--> trigger stack-out-of-bounds
In the mpage_read_folio() function, the stack variable 'map_bh' is
passed to ntfs_get_block_vbo(). Once unlock_buffer() unlocks and
wait_on_buffer() returns to continue processing, the stack variable
is likely to be reclaimed. Consequently, during the end_buffer_read_sync()
process, calling put_bh() may result in stack overrun.
If the bh is not allocated on the stack, it belongs to a folio. Freeing
a buffer head which belongs to a folio is done by drop_buffers() which
will fail to free buffers which are still locked. So it is safe to call
put_bh() before __end_buffer_read_notouch().
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Ye Bin <yebin10@huawei.com>
Link: https://lore.kernel.org/20250811141830.343774-1-yebin@huaweicloud.com
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
to simplify the code.
Note that only tpid and max_fds really need rcu_read_lock(), we could move
task_ppid_nr_ns/task_tgid_nr_ns/task_numa_group_id/get_task_cred outside of
rcu read section.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Link: https://lore.kernel.org/20250810173620.GA20007@redhat.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
task_pid_vnr(another_task) will crash if the caller was already reaped.
The pid_alive(current) check can't really help, the parent/debugger can
call release_task() right after this check.
This also means that even task_ppid_nr_ns(current, NULL) is not safe,
pid_alive() only ensures that it is safe to dereference ->real_parent.
Change __task_pid_nr_ns() to ensure ns != NULL.
Originally-by: 高翔 <gaoxiang17@xiaomi.com>
Link: https://lore.kernel.org/all/20250802022123.3536934-1-gxxa03070307@gmail.com/
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Link: https://lore.kernel.org/20250810173604.GA19991@redhat.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
This files is maintained by Christian Brauner, thus add it to the
relevant MAINTAINERS entry.
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/20250714124637.1905722-2-aliceryhl@google.com
Acked-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Update call sites in the fs subsystem to import `ARef` and
`AlwaysRefCounted` from `sync::aref` instead of `types`.
This aligns with the ongoing effort to move `ARef` and
`AlwaysRefCounted` to sync.
Suggested-by: Benno Lossin <lossin@kernel.org>
Link: https://github.com/Rust-for-Linux/linux/issues/1173
Acked-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Shankari Anand <shankari.ak0208@gmail.com>
Link: https://lore.kernel.org/20250814100101.304408-1-shankari.ak0208@gmail.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
Tegra186 contains two pin controllers. Document their compatible strings
and describe the list of pins and functions that they provide.
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Aaron Kling <webgeek1234@gmail.com>
Link: https://lore.kernel.org/20250812-tegra186-pinctrl-v3-1-115714eeecb1@gmail.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
The current gpio driver for RP1 shows only the very first register
from sysfs, e.g.:
$ cat /sys/kernel/debug/regmap/1f000d0000.gpio-rp1-pinctrl/registers
0: 0abe0000
Add the correct ranges to the regmap configuration.
Signed-off-by: Andrea della Porta <andrea.porta@suse.com>
Link: https://lore.kernel.org/20250812092618.14270-1-andrea.porta@suse.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Mount options (uid, gid, mode) are silently ignored when debugfs is
mounted. This is a regression introduced during the conversion to the
new mount API.
When the mount API conversion was done, the parsed options were never
applied to the superblock when it was reused. As a result, the mount
options were ignored when debugfs was mounted.
Fix this by following the same pattern as the tracefs fix in commit
e4d32142d1 ("tracing: Fix tracefs mount options"). Call
debugfs_reconfigure() in debugfs_get_tree() to apply the mount options
to the superblock after it has been created or reused.
As an example, with the bug the "mode" mount option is ignored:
$ mount -o mode=0666 -t debugfs debugfs /tmp/debugfs_test
$ mount | grep debugfs_test
debugfs on /tmp/debugfs_test type debugfs (rw,relatime)
$ ls -ld /tmp/debugfs_test
drwx------ 25 root root 0 Aug 4 14:16 /tmp/debugfs_test
With the fix applied, it works as expected:
$ mount -o mode=0666 -t debugfs debugfs /tmp/debugfs_test
$ mount | grep debugfs_test
debugfs on /tmp/debugfs_test type debugfs (rw,relatime,mode=666)
$ ls -ld /tmp/debugfs_test
drw-rw-rw- 37 root root 0 Aug 2 17:28 /tmp/debugfs_test
Fixes: a20971c187 ("vfs: Convert debugfs to use the new mount API")
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=220406
Cc: stable@vger.kernel.org
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Charalampos Mitrodimas <charmitro@posteo.net>
Link: https://lore.kernel.org/20250816-debugfs-mount-opts-v3-1-d271dad57b5b@posteo.net
Signed-off-by: Christian Brauner <brauner@kernel.org>
Update call sites in `pid_namespace.rs` to import
`AlwaysRefCounted` from `sync::aref` instead of `types`.
This aligns with the ongoing effort to move `ARef` and
`AlwaysRefCounted` to `sync`.
Suggested-by: Benno Lossin <lossin@kernel.org>
Link: https://github.com/Rust-for-Linux/linux/issues/1173
Signed-off-by: Shankari Anand <shankari.ak0208@gmail.com>
Link: https://lore.kernel.org/20250816122323.11657-1-shankari.ak0208@gmail.com
Reviewed-by: Benno Lossin <lossin@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
In get_channel(), the reference obtained by bus_find_device_by_name()
was dropped via put_device() before accessing the device's driver data
Move put_device() after usage to avoid potential issues.
Fixes: 2485055394 ("staging: most: core: drop device reference")
Cc: stable <stable@kernel.org>
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Link: https://lore.kernel.org/r/20250804082955.3621026-1-linmq006@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The `insn_rw_emulate_bits()` function is used as a default handler for
`INSN_READ` instructions for subdevices that have a handler for
`INSN_BITS` but not for `INSN_READ`. Similarly, it is used as a default
handler for `INSN_WRITE` instructions for subdevices that have a handler
for `INSN_BITS` but not for `INSN_WRITE`. It works by emulating the
`INSN_READ` or `INSN_WRITE` instruction handling with a constructed
`INSN_BITS` instruction. However, `INSN_READ` and `INSN_WRITE`
instructions are supposed to be able read or write multiple samples,
indicated by the `insn->n` value, but `insn_rw_emulate_bits()` currently
only handles a single sample. For `INSN_READ`, the comedi core will
copy `insn->n` samples back to user-space. (That triggered KASAN
kernel-infoleak errors when `insn->n` was greater than 1, but that is
being fixed more generally elsewhere in the comedi core.)
Make `insn_rw_emulate_bits()` either handle `insn->n` samples, or return
an error, to conform to the general expectation for `INSN_READ` and
`INSN_WRITE` handlers.
Fixes: ed9eccbe89 ("Staging: add comedi core")
Cc: stable <stable@kernel.org> # 5.13+
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Link: https://lore.kernel.org/r/20250725141034.87297-1-abbotti@mev.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
syzbot reports a KMSAN kernel-infoleak in `do_insn_ioctl()`. A kernel
buffer is allocated to hold `insn->n` samples (each of which is an
`unsigned int`). For some instruction types, `insn->n` samples are
copied back to user-space, unless an error code is being returned. The
problem is that not all the instruction handlers that need to return
data to userspace fill in the whole `insn->n` samples, so that there is
an information leak. There is a similar syzbot report for
`do_insnlist_ioctl()`, although it does not have a reproducer for it at
the time of writing.
One culprit is `insn_rw_emulate_bits()` which is used as the handler for
`INSN_READ` or `INSN_WRITE` instructions for subdevices that do not have
a specific handler for that instruction, but do have an `INSN_BITS`
handler. For `INSN_READ` it only fills in at most 1 sample, so if
`insn->n` is greater than 1, the remaining `insn->n - 1` samples copied
to userspace will be uninitialized kernel data.
Another culprit is `vm80xx_ai_insn_read()` in the "vm80xx" driver. It
never returns an error, even if it fails to fill the buffer.
Fix it in `do_insn_ioctl()` and `do_insnlist_ioctl()` by making sure
that uninitialized parts of the allocated buffer are zeroed before
handling each instruction.
Thanks to Arnaud Lecomte for their fix to `do_insn_ioctl()`. That fix
replaced the call to `kmalloc_array()` with `kcalloc()`, but it is not
always necessary to clear the whole buffer.
Fixes: ed9eccbe89 ("Staging: add comedi core")
Reported-by: syzbot+a5e45f768aab5892da5d@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=a5e45f768aab5892da5d
Reported-by: syzbot+fb4362a104d45ab09cf9@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=fb4362a104d45ab09cf9
Cc: stable <stable@kernel.org> # 5.13+
Cc: Arnaud Lecomte <contact@arnaud-lcm.com>
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Link: https://lore.kernel.org/r/20250725125324.80276-1-abbotti@mev.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The reproducer passed in an irq number(0x80008000) that was too large,
which triggered the oob.
Added an interrupt number check to prevent users from passing in an irq
number that was too large.
If `it->options[1]` is 31, then `1 << it->options[1]` is still invalid
because it shifts a 1-bit into the sign bit (which is UB in C).
Possible solutions include reducing the upper bound on the
`it->options[1]` value to 30 or lower, or using `1U << it->options[1]`.
The old code would just not attempt to request the IRQ if the
`options[1]` value were invalid. And it would still configure the
device without interrupts even if the call to `request_irq` returned an
error. So it would be better to combine this test with the test below.
Fixes: fff4620724 ("staging: comedi: pcl726: enable the interrupt support code")
Cc: stable <stable@kernel.org> # 5.13+
Reported-by: syzbot+5cd373521edd68bebcb3@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=5cd373521edd68bebcb3
Tested-by: syzbot+5cd373521edd68bebcb3@syzkaller.appspotmail.com
Signed-off-by: Edward Adam Davis <eadavis@qq.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Link: https://lore.kernel.org/r/tencent_3C66983CC1369E962436264A50759176BF09@qq.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In cdx_rpmsg_probe(), strscpy() is incorrectly called with the length of
the source string (excluding the NUL terminator) rather than the size of
the destination buffer. This results in one character less being copied
from 'cdx_rpmsg_id_table[0].name' to 'chinfo.name'.
Use the destination buffer size instead to ensure the name is copied
correctly.
Cc: stable <stable@kernel.org>
Fixes: 2a226927d9 ("cdx: add rpmsg communication channel for CDX")
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Link: https://lore.kernel.org/r/20250806090512.121260-2-thorsten.blum@linux.dev
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dma_map_sgtable() returns only 0 or the error code. Read sgt->nents to
get the number of mapped segments.
Fixes: 37e0070322 ("zynq_fpga: use sgtable-based scatterlist wrappers")
Reported-by: Pavel Pisa <pisa@fel.cvut.cz>
Closes: https://lore.kernel.org/linux-fpga/202508041548.22955.pisa@fel.cvut.cz/
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Xu Yilun <yilun.xu@linux.intel.com>
Tested-by: Pavel Pisa <pisa@fel.cvut.cz>
Link: https://lore.kernel.org/r/20250806070605.1920909-2-yilun.xu@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add a tracepoint to capture the same details that are being sent through
the generic netlink interface during transaction failures. This provides
a useful debugging tool to observe the events independently from the
netlink listeners.
Signed-off-by: Carlos Llamas <cmllamas@google.com>
Link: https://lore.kernel.org/r/20250727182932.2499194-6-cmllamas@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add "transaction_report" to the binderfs feature list, to help userspace
determine if the "BINDER_CMD_REPORT" generic netlink api is supported by
the binder driver.
Signed-off-by: Li Li <dualli@google.com>
Signed-off-by: Carlos Llamas <cmllamas@google.com>
Link: https://lore.kernel.org/r/20250727182932.2499194-5-cmllamas@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Introduce a generic netlink multicast event to report binder transaction
failures to userspace. This allows subscribers to monitor these events
and take appropriate actions, such as stopping a misbehaving application
that is spamming a service with huge amount of transactions.
The multicast event contains full details of the failed transactions,
including the sender/target PIDs, payload size and specific error code.
This interface is defined using a YAML spec, from which the UAPI and
kernel headers and source are auto-generated.
Signed-off-by: Li Li <dualli@google.com>
Signed-off-by: Carlos Llamas <cmllamas@google.com>
Link: https://lore.kernel.org/r/20250727182932.2499194-4-cmllamas@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Replace the t->need_reply flag with the more descriptive t->is_async and
and t->is_reply flags. The 'need_reply' flag was only used for debugging
purposes and the new flags can be used to distinguish between the type
of transactions too: sync, async and reply.
For now, only update the logging in print_binder_transaction_ilocked().
However, the new flags can be used in the future to replace the current
patterns and improve readability. e.g.:
- if (!reply && !(tr->flags & TF_ONE_WAY))
+ if (t->is_async)
This patch is in preparation for binder's generic netlink implementation
and no functional changes are intended.
Signed-off-by: Carlos Llamas <cmllamas@google.com>
Link: https://lore.kernel.org/r/20250727182932.2499194-3-cmllamas@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Move the allocation of 'struct binder_transaction' to the beginning of
the binder_transaction() function, along with the initialization of all
the members that are known at that time. This minor refactoring helps to
consolidate the usage of transaction information at later points.
This patch is in preparation for binder's generic netlink implementation
and no functional changes are intended.
Signed-off-by: Carlos Llamas <cmllamas@google.com>
Link: https://lore.kernel.org/r/20250727182932.2499194-2-cmllamas@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add sysfs ABI documentation for the STMicroelectronics M24LR device,
covering both the control interface (e.g., unlock, password update, UID,
total sectors, and SSS entries) and EEPROM access via the nvmem subsystem.
Signed-off-by: Abd-Alrhman Masalkhi <abd.masalkhi@gmail.com>
Link: https://lore.kernel.org/r/20250717063934.5083-4-abd.masalkhi@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
adds support for STMicroelectronics M24LRxx devices, which expose
two separate I2C addresses: one for system control and one for EEPROM
access. The driver implements both a sysfs-based interface for control
registers (e.g. UID, password authentication) and an nvmem provider
for EEPROM access.
Signed-off-by: Abd-Alrhman Masalkhi <abd.masalkhi@gmail.com>
Link: https://lore.kernel.org/r/20250717063934.5083-3-abd.masalkhi@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add support for STMicroelectronics M24LR RFID/NFC EEPROM chips.
These devices use two I2C addresses: the primary address provides
access to control and system parameter registers, while the
secondary address is used for EEPROM access.
Signed-off-by: Abd-Alrhman Masalkhi <abd.masalkhi@gmail.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20250717063934.5083-2-abd.masalkhi@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Macro APC_MINOR is defined as MISC_DYNAMIC_MINOR to request dynamic
minor, but its name 'APC_MINOR' looks like fixed minor.
Remove the macro definition and directly use MISC_DYNAMIC_MINOR instead.
Signed-off-by: Zijun Hu <zijun.hu@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20250714-rfc_miscdev-v6-8-2ed949665bde@oss.qualcomm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
misc_open() may request module for miscdevice with dynamic minor, which
is meaningless since:
- The dynamic minor allocated is unknown in advance without registering
miscdevice firstly.
- Macro MODULE_ALIAS_MISCDEV() is not applicable for dynamic minor.
Fix by only requesting module for miscdevice with fixed minor.
Acked-by: Thadeu Lima de Souza Cascardo <cascardo@igalia.com>
Signed-off-by: Zijun Hu <zijun.hu@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20250714-rfc_miscdev-v6-6-2ed949665bde@oss.qualcomm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
For miscdevice who wants dynamic minor, it may fail to be registered again
without reinitialization after being de-registered, which is illustrated
by kunit test case miscdev_test_dynamic_reentry() newly added.
There is a real case found by cascardo when a part of minor range were
contained by range [0, 255):
1) wmi/dell-smbios registered minor 122, and acpi_thermal_rel registered
minor 123
2) unbind "int3400 thermal" driver from its device, this will de-register
acpi_thermal_rel
3) rmmod then insmod dell_smbios again, now wmi/dell-smbios is using minor
123
4) bind the device to "int3400 thermal" driver again, acpi_thermal_rel
fails to register.
Some drivers may reuse the miscdevice structure after they are deregistered
If the intention is to allocate a dynamic minor, if the minor number is not
reset to MISC_DYNAMIC_MINOR before calling misc_register(), it will try to
register a previously dynamically allocated minor number, which may have
been registered by a different driver.
One such case is the acpi_thermal_rel misc device, registered by the
int3400 thermal driver. If the device is unbound from the driver and later
bound, if there was another dynamic misc device registered in between, it
would fail to register the acpi_thermal_rel misc device. Other drivers
behave similarly.
Actually, this kind of issue is prone to happen if APIs
misc_register()/misc_deregister() are invoked by driver's
probe()/remove() separately.
Instead of fixing all the drivers, just reset the minor member to
MISC_DYNAMIC_MINOR in misc_deregister() in case it was a dynamically
allocated minor number, as error handling of misc_register() does.
Cc: Thadeu Lima de Souza Cascardo <cascardo@igalia.com>
Signed-off-by: Zijun Hu <zijun.hu@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20250714-rfc_miscdev-v6-5-2ed949665bde@oss.qualcomm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
For miscdevice who wants dynamic minor, add a cast to test if it can be
successfully registered again without reinitialization:
1) Provide Both miscdevice @dev_A and @dev_B want to request dynamic
minor by initializing their minor to MISC_DYNAMIC_MINOR.
2) Register then de-register @dev_A.
3) Register @dev_B.
4) Register @dev_A again without reinitialization.
5) Check if @dev_A can be successfully registered.
Signed-off-by: Zijun Hu <zijun.hu@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20250714-rfc_miscdev-v6-4-2ed949665bde@oss.qualcomm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently, It is allowed to register miscdevice with minor > 255
which is defined by macro MISC_DYNAMIC_MINOR, and cause:
- Chaos regarding division and management of minor codes.
- Registering failure if the minor was allocated to other dynamic request.
Fortunately, in-kernel users have not had such usage yet.
Fix by refusing to register miscdevice whose minor > 255.
Also bring in a very simple minor code space division and management:
< 255 : Fixed minor code
== 255 : Indicator to request dynamic minor code
> 255 : Dynamic minor code requested, 1048320 minor codes totally
And all fixed minors allocated should be registered in 'linux/miscdevice.h'
Signed-off-by: Zijun Hu <zijun.hu@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20250714-rfc_miscdev-v6-3-2ed949665bde@oss.qualcomm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Adapt and add test cases for next change which regards minor whose
value > macro MISC_DYNAMIC_MINOR as invalid parameter when register
miscdevice, hence get a simple minor space division below:
< MISC_DYNAMIC_MINOR: fixed minor code
== MISC_DYNAMIC_MINOR: indicator to request dynamic minor code
> MISC_DYNAMIC_MINOR: dynamic minor code requested
Signed-off-by: Zijun Hu <zijun.hu@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20250714-rfc_miscdev-v6-2-2ed949665bde@oss.qualcomm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/misc/misc_minor_kunit.c is to test APIs defined in
drivers/char/misc.c, but is not in the same directory as the later.
Move misc_minor_kunit.c to drivers/char/.
Signed-off-by: Zijun Hu <zijun.hu@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20250714-rfc_miscdev-v6-1-2ed949665bde@oss.qualcomm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Update the import of `ARef` in misc_device sample to use
`sync::aref` instead of `types`.
This is part of the ongoing effort to move `ARef` and
`AlwaysRefCounted` to the `sync` module for better modularity
and type organization.
Suggested-by: Benno Lossin <lossin@kernel.org>
Link: https://github.com/Rust-for-Linux/linux/issues/1173
Signed-off-by: Shankari Anand <shankari.ak0208@gmail.com>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Link: https://lore.kernel.org/r/20250818132806.134248-1-shankari.ak0208@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Remove hard-coded strings by using the str_enabled_disabled() helper
function and silence the following Coccinelle/coccicheck warning
reported by string_choices.cocci:
opportunity for str_enabled_disabled(value)
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Acked-by: John Stultz <jstultz@google.com>
Link: https://lore.kernel.org/r/20250813180108.209096-2-thorsten.blum@linux.dev
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
