Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

Detect races on global variables #203

Open
dvyukov opened this issue Sep 18, 2015 · 0 comments
Open

Detect races on global variables #203

dvyukov opened this issue Sep 18, 2015 · 0 comments
Labels
enhancement KTSAN KTSAN-related issues wontfix

Comments

@dvyukov
Copy link
Collaborator

dvyukov commented Sep 18, 2015

subj
melver referenced this issue in google/ktsan Nov 4, 2019
@sudeep-holla @rafaeljw
cpufreq: Cancel policy update work scheduled before freeing
6941051 
Scheduled policy update work may end up racing with the freeing of the
policy and unregistering the driver.

One possible race is as below, where the cpufreq_driver is unregistered,
but the scheduled work gets executed at later stage when, cpufreq_driver
is NULL (i.e. after freeing the policy and driver).

Unable to handle kernel NULL pointer dereference at virtual address 0000001c
pgd = (ptrval)
[0000001c] *pgd=80000080204003, *pmd=00000000
Internal error: Oops: 206 [#1] SMP THUMB2
Modules linked in:
CPU: 0 PID: 34 Comm: kworker/0:1 Not tainted 5.4.0-rc3-00006-g67f5a8081a4b #86
Hardware name: ARM-Versatile Express
Workqueue: events handle_update
PC is at cpufreq_set_policy+0x58/0x228
LR is at dev_pm_qos_read_value+0x77/0xac
Control: 70c5387d  Table: 80203000  DAC: fffffffd
Process kworker/0:1 (pid: 34, stack limit = 0x(ptrval))
	(cpufreq_set_policy) from (refresh_frequency_limits.part.24+0x37/0x48)
	(refresh_frequency_limits.part.24) from (handle_update+0x2f/0x38)
	(handle_update) from (process_one_work+0x16d/0x3cc)
	(process_one_work) from (worker_thread+0xff/0x414)
	(worker_thread) from (kthread+0xff/0x100)
	(kthread) from (ret_from_fork+0x11/0x28)

Fixes: 67d874c ("cpufreq: Register notifiers with the PM QoS framework")
Signed-off-by: Sudeep Holla <[email protected]>
[ rjw: Cancel the work before dropping the QoS requests ]
Acked-by: Viresh Kumar <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>
@xairy xairy transferred this issue from google/ktsan Dec 23, 2021
@xairy xairy added enhancement KTSAN KTSAN-related issues labels Dec 23, 2021
@melver melver added the wontfix label Jan 25, 2022
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Assignees
No one assigned
Labels
enhancement KTSAN KTSAN-related issues wontfix
Projects
None yet
Milestone
No milestone
Development

No branches or pull requests
3 participants
@melver @dvyukov @xairy