Previously, non-generic attributes (polling_interval, timer) used separate
create/delete logic, leading to race conditions during concurrent access in
creation/deletion. Multi-threaded operations also caused inconsistencies
between governor capabilities and attribute states.
1.Use is_visible + sysfs_update_group() to unify management of these
attributes, eliminating creation/deletion races.
2.Add locks and validation to these attributes, ensuring consistency
between current governor capabilities and attribute operations in
multi-threaded environments.
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Reviewed-by: Jie Zhan <zhanjie9@hisilicon.com>
Signed-off-by: Pengjie Zhang <zhangpengjie2@huawei.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Link: https://www.spinics.net/lists/kernel/msg5967745.html
This was done entirely with mindless brute force, using
git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' |
xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/'
to convert the new alloc_obj() users that had a simple GFP_KERNEL
argument to just drop that argument.
Note that due to the extreme simplicity of the scripting, any slightly
more complex cases spread over multiple lines would not be triggered:
they definitely exist, but this covers the vast bulk of the cases, and
the resulting diff is also then easier to check automatically.
For the same reason the 'flex' versions will be done as a separate
conversion.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:
Single allocations: kmalloc(sizeof(TYPE), ...)
are replaced with: kmalloc_obj(TYPE, ...)
Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with: kmalloc_objs(TYPE, COUNT, ...)
Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...)
(where TYPE may also be *VAR)
The resulting allocations no longer return "void *", instead returning
"TYPE *".
Signed-off-by: Kees Cook <kees@kernel.org>
Commit 96ffcdf239 ("PM / devfreq: Remove redundant governor_name from
struct devfreq") removes governor_name and uses governor->name to replace
it. But devfreq->governor may be NULL and directly using
devfreq->governor->name may cause null pointer exception. Move the check of
governor to before using governor->name.
Fixes: 96ffcdf239 ("PM / devfreq: Remove redundant governor_name from struct devfreq")
Signed-off-by: Lifeng Zheng <zhenglifeng1@huawei.com>
Link: https://lore.kernel.org/lkml/20250421030020.3108405-5-zhenglifeng1@huawei.com/
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Fix buffer overflow in trans_stat_show().
Convert simple snprintf to the more secure scnprintf with size of
PAGE_SIZE.
Add condition checking if we are exceeding PAGE_SIZE and exit early from
loop. Also add at the end a warning that we exceeded PAGE_SIZE and that
stats is disabled.
Return -EFBIG in the case where we don't have enough space to write the
full transition table.
Also document in the ABI that this function can return -EFBIG error.
Link: https://lore.kernel.org/all/20231024183016.14648-2-ansuelsmth@gmail.com/
Cc: stable@vger.kernel.org
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218041
Fixes: e552bbaf5b ("PM / devfreq: Add sysfs node for representing frequency transition information.")
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
srcu_init_notifier_head() allocates resources that need to be released
with a srcu_cleanup_notifier_head() call.
Reported by kmemleak.
Fixes: 0fe3a66410 ("PM / devfreq: Add new DEVFREQ_TRANSITION_NOTIFIER notifier")
Cc: <stable@vger.kernel.org>
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Dhruva Gole <d-gole@ti.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Current kernel-doc comment doesn't specify the default timer used for the
load monitoring. Also, it uses the term "default delayed work" which could
be misunderstood as "default delayer timer". So reword the comment to
clearly specify the default timer and also reword the last sentence to make
it more understandable.
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
The member void *data in the structure devfreq can be overwrite
by governor_userspace. For example:
1. The device driver assigned the devfreq governor to simple_ondemand
by the function devfreq_add_device() and init the devfreq member
void *data to a pointer of a static structure devfreq_simple_ondemand_data
by the function devfreq_add_device().
2. The user changed the devfreq governor to userspace by the command
"echo userspace > /sys/class/devfreq/.../governor".
3. The governor userspace alloced a dynamic memory for the struct
userspace_data and assigend the member void *data of devfreq to
this memory by the function userspace_init().
4. The user changed the devfreq governor back to simple_ondemand
by the command "echo simple_ondemand > /sys/class/devfreq/.../governor".
5. The governor userspace exited and assigned the member void *data
in the structure devfreq to NULL by the function userspace_exit().
6. The governor simple_ondemand fetched the static information of
devfreq_simple_ondemand_data in the function
devfreq_simple_ondemand_func() but the member void *data of devfreq was
assigned to NULL by the function userspace_exit().
7. The information of upthreshold and downdifferential is lost
and the governor simple_ondemand can't work correctly.
The member void *data in the structure devfreq is designed for
a static pointer used in a governor and inited by the function
devfreq_add_device(). This patch add an element named governor_data
in the devfreq structure which can be used by a governor(E.g userspace)
who want to assign a private data to do some private things.
Fixes: ce26c5bb95 ("PM / devfreq: Add basic governors")
Cc: stable@vger.kernel.org # 5.10+
Reviewed-by: Chanwoo Choi <cwchoi00@gmail.com>
Acked-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Kant Fan <kant@allwinnertech.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
There are 4 warnings there:
drivers/devfreq/devfreq.c:707: warning: Function parameter or member 'val' not described in 'qos_min_notifier_call'
drivers/devfreq/devfreq.c:707: warning: Function parameter or member 'ptr' not described in 'qos_min_notifier_call'
drivers/devfreq/devfreq.c:717: warning: Function parameter or member 'val' not described in 'qos_max_notifier_call'
drivers/devfreq/devfreq.c:717: warning: Function parameter or member 'ptr' not described in 'qos_max_notifier_call'
It turns that neither val nor ptr are actually used on those
function, so document as such.
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
On a devfreq PROBE_DEFER, the freq_table in the driver profile struct,
is never reset and may be leaved in an undefined state.
This comes from the fact that we store the freq_table in the driver
profile struct that is commonly defined as static and not reset on
PROBE_DEFER.
We currently skip the reinit of the freq_table if we found
it's already defined since a driver may declare his own freq_table.
This logic is flawed in the case devfreq core generate a freq_table, set
it in the profile struct and then PROBE_DEFER, freeing the freq_table.
In this case devfreq will found a NOT NULL freq_table that has been
freed, skip the freq_table generation and probe the driver based on the
wrong table.
To fix this and correctly handle PROBE_DEFER, use a local freq_table and
max_state in the devfreq struct and never modify the freq_table present
in the profile struct if it does provide it.
Fixes: 0ec09ac2ce ("PM / devfreq: Set the freq_table of devfreq device")
Cc: stable@vger.kernel.org
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Don't print warning when a governor PROBE_DEFER as it's not a real
GOV_START fail.
Fixes: a03dacb031 ("PM / devfreq: Add cpu based scaling support to passive governor")
Signed-off-by: Christian 'Ansuel' Marangi <ansuelsmth@gmail.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Suppose devfreq_update_status() failure in devfreq_set_target() is not a
critical error, reduces the log severity.
Signed-off-by: Tzung-Bi Shih <tzungbi@google.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Pengjie Zhang
Andy Shevchenko
Linus Torvalds
Kees Cook
Dmitry Baryshkov
Jie Zhan
Chanwoo Choi
Lifeng Zheng
Mukesh Ojha
Christian Marangi
Manivannan Sadhasivam
Boris Brezillon
Greg Kroah-Hartman
ye xingchen
Kant Fan
Mauro Carvalho Chehab
Tzung-Bi Shih
Rafael J. Wysocki