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| author | Daniel Jordan <daniel.m.jordan@oracle.com> | 2026-03-13 18:24:33 +0300 |
|---|---|---|
| committer | Herbert Xu <herbert@gondor.apana.org.au> | 2026-03-22 05:17:59 +0300 |
| commit | c8c4a2972f83c8b68ff03b43cecdb898939ff851 (patch) | |
| tree | cd12a5a42720f36159949a86a30ef5ed9595aa5e /include | |
| parent | 7fc31dd86415fc04c71b8fd4743ad63183e8565f (diff) | |
| download | linux-c8c4a2972f83c8b68ff03b43cecdb898939ff851.tar.xz | |
padata: Put CPU offline callback in ONLINE section to allow failure
syzbot reported the following warning:
DEAD callback error for CPU1
WARNING: kernel/cpu.c:1463 at _cpu_down+0x759/0x1020 kernel/cpu.c:1463, CPU#0: syz.0.1960/14614
at commit 4ae12d8bd9a8 ("Merge tag 'kbuild-fixes-7.0-2' of git://git.kernel.org/pub/scm/linux/kernel/git/kbuild/linux")
which tglx traced to padata_cpu_dead() given it's the only
sub-CPUHP_TEARDOWN_CPU callback that returns an error.
Failure isn't allowed in hotplug states before CPUHP_TEARDOWN_CPU
so move the CPU offline callback to the ONLINE section where failure is
possible.
Fixes: 894c9ef9780c ("padata: validate cpumask without removed CPU during offline")
Reported-by: syzbot+123e1b70473ce213f3af@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/69af0a05.050a0220.310d8.002f.GAE@google.com/
Debugged-by: Thomas Gleixner <tglx@kernel.org>
Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/cpuhotplug.h | 1 | ||||
| -rw-r--r-- | include/linux/padata.h | 8 |
2 files changed, 4 insertions, 5 deletions
diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h index 62cd7b35a29c..22ba327ec227 100644 --- a/include/linux/cpuhotplug.h +++ b/include/linux/cpuhotplug.h @@ -92,7 +92,6 @@ enum cpuhp_state { CPUHP_NET_DEV_DEAD, CPUHP_IOMMU_IOVA_DEAD, CPUHP_AP_ARM_CACHE_B15_RAC_DEAD, - CPUHP_PADATA_DEAD, CPUHP_AP_DTPM_CPU_DEAD, CPUHP_RANDOM_PREPARE, CPUHP_WORKQUEUE_PREP, diff --git a/include/linux/padata.h b/include/linux/padata.h index 765f2778e264..b6232bea6edf 100644 --- a/include/linux/padata.h +++ b/include/linux/padata.h @@ -149,23 +149,23 @@ struct padata_mt_job { /** * struct padata_instance - The overall control structure. * - * @cpu_online_node: Linkage for CPU online callback. - * @cpu_dead_node: Linkage for CPU offline callback. + * @cpuhp_node: Linkage for CPU hotplug callbacks. * @parallel_wq: The workqueue used for parallel work. * @serial_wq: The workqueue used for serial work. * @pslist: List of padata_shell objects attached to this instance. * @cpumask: User supplied cpumasks for parallel and serial works. + * @validate_cpumask: Internal cpumask used to validate @cpumask during hotplug. * @kobj: padata instance kernel object. * @lock: padata instance lock. * @flags: padata flags. */ struct padata_instance { - struct hlist_node cpu_online_node; - struct hlist_node cpu_dead_node; + struct hlist_node cpuhp_node; struct workqueue_struct *parallel_wq; struct workqueue_struct *serial_wq; struct list_head pslist; struct padata_cpumask cpumask; + cpumask_var_t validate_cpumask; struct kobject kobj; struct mutex lock; u8 flags; |