linux-kernel - Re: [PATCH v4] clocksource: timer-sp804: Fix read_current_timer() issue when clock source is not registered

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <e6a629c8-cd4d-4e0f-ac2a-61fe74327ffb@roeck-us.net>
Date: Mon, 15 Dec 2025 21:48:39 -0800
From: Guenter Roeck <linux@...ck-us.net>
To: stephen.eta.zhou@...il.com
Cc: daniel.lezcano@...aro.org, linux-kernel@...r.kernel.org,
 tglx@...utronix.de
Subject: Re: [PATCH v4] clocksource: timer-sp804: Fix read_current_timer()
 issue when clock source is not registered

On 12/15/25 21:38, stephen.eta.zhou@...il.com wrote:
> Hi Guenter,
> 
> On Mon, 15 Dec 2025 15:18:37 -0800, Guenter Roeck wrote:
>> This patch results in a crash when trying to boot integratorcp in qemu.
> 
> Thank you for pointing out the problem.
> 
>> sp804_read_delay_timer_read from read_current_timer+0x24/0x44
>>
>> This is not surprising since sp804_read_delay_timer_read() calls
>> sp804_read() which dereferences sched_clkevt. sched_clkevt is not
>> initialized for integratorcp.
> 
> Thank you for pointing out this issue.
> I will work on fixing it and submit a new patch as soon as possible.
> 

The realview-pbx-a9 target it also affected. Bisect log below.

Guenter

---
# bad: [559e608c46553c107dbba19dae0854af7b219400] Merge tag 'ntfs3_for_6.19' of https://github.com/Paragon-Software-Group/linux-ntfs3
# good: [7d0a66e4bb9081d75c82ec4957c50034cb0ea449] Linux 6.18
git bisect start '559e608c4655' 'v6.18'
# bad: [015e7b0b0e8e51f7321ec2aafc1d7fc0a8a5536f] Merge tag 'bpf-next-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
git bisect bad 015e7b0b0e8e51f7321ec2aafc1d7fc0a8a5536f
# bad: [2547f79b0b0cd969ae6f736890af4ebd9368cda5] Merge tag 's390-6.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
git bisect bad 2547f79b0b0cd969ae6f736890af4ebd9368cda5
# good: [63e6995005be8ceb8a1d56a18df1a1a40c28356d] Merge tag 'objtool-core-2025-12-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
git bisect good 63e6995005be8ceb8a1d56a18df1a1a40c28356d
# good: [15b87bec89cb227b55b3689bf5de31b85cf88559] Merge tag 'irq-drivers-2025-11-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
git bisect good 15b87bec89cb227b55b3689bf5de31b85cf88559
# bad: [54de197c9a5e8f522cb0a472e68e3e9888c91aa3] Merge tag 'x86_sgx_for_6.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
git bisect bad 54de197c9a5e8f522cb0a472e68e3e9888c91aa3
# bad: [49219bba0149157774b7091c3ea9ad22b2114285] Merge tag 'edac_updates_for_v6.19_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/ras/ras
git bisect bad 49219bba0149157774b7091c3ea9ad22b2114285
# bad: [d42e504a555d0da2a10001e697f0c8a7f633fb05] Merge tag 'timers-core-2025-11-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
git bisect bad d42e504a555d0da2a10001e697f0c8a7f633fb05
# bad: [5028f42416eaec08d3f6aa4f98ccca669b3f8ab3] Merge tag 'timers-clocksource-2025-11-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
git bisect bad 5028f42416eaec08d3f6aa4f98ccca669b3f8ab3
# bad: [627f3f3716a3591f5e6a6bd124c95eef85444080] clocksource/drivers/rda: Add sched_clock_register for RDA8810PL SoC
git bisect bad 627f3f3716a3591f5e6a6bd124c95eef85444080
# bad: [62524f285c11d6e6168ad31b586143755b27b2e5] clocksource/drivers/sh_cmt: Always leave device running after probe
git bisect bad 62524f285c11d6e6168ad31b586143755b27b2e5
# bad: [640594a04f119338019b0aeed70c7301216595b3] clocksource/drivers/timer-sp804: Fix read_current_timer() issue when clock source is not registered
git bisect bad 640594a04f119338019b0aeed70c7301216595b3
# good: [576c564ec3bb60e571c705a71907d7c0c039e6c0] clocksource/drivers/sprd: Enable register for timer counter from 32 bit to 64 bit
git bisect good 576c564ec3bb60e571c705a71907d7c0c039e6c0
# first bad commit: [640594a04f119338019b0aeed70c7301216595b3] clocksource/drivers/timer-sp804: Fix read_current_timer() issue when clock source is not registered