From: Johannes Berg <johannes@sipsolutions.net>
To: linux-um@lists.infradead.org
Cc: Johannes Berg <johannes.berg@intel.com>
Subject: [PATCH] um: init cpu_tasks[] earlier
Date: Wed, 24 Sep 2025 11:32:13 +0200 [thread overview]
Message-ID: <20250924113214.c76cd74d0583.I974f691ebb1a2b47915bd2b04cc38e5263b9447f@changeid> (raw)
From: Johannes Berg <johannes.berg@intel.com>
This is currently done in uml_finishsetup(), but e.g. with
KCOV enabled we'll crash because some init code can call
into e.g. memparse(), which has coverage annotations, and
then the checks in check_kcov_mode() crash because current
is NULL.
Simply initialize the cpu_tasks[] array statically, which
fixes the crash. For the later SMP work, it seems to have
not really caused any problems yet, but initialize all of
the entries anyway.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
arch/um/kernel/process.c | 4 +++-
arch/um/kernel/um_arch.c | 2 --
2 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/arch/um/kernel/process.c b/arch/um/kernel/process.c
index 1be644de9e41..66787619db97 100644
--- a/arch/um/kernel/process.c
+++ b/arch/um/kernel/process.c
@@ -43,7 +43,9 @@
* cares about its entry, so it's OK if another processor is modifying its
* entry.
*/
-struct task_struct *cpu_tasks[NR_CPUS];
+struct task_struct *cpu_tasks[NR_CPUS] = {
+ [0 ... NR_CPUS - 1] = &init_task,
+};
EXPORT_SYMBOL(cpu_tasks);
void free_stack(unsigned long stack, int order)
diff --git a/arch/um/kernel/um_arch.c b/arch/um/kernel/um_arch.c
index 2f5ee045bc7a..f2edd95d7663 100644
--- a/arch/um/kernel/um_arch.c
+++ b/arch/um/kernel/um_arch.c
@@ -242,8 +242,6 @@ static struct notifier_block panic_exit_notifier = {
void uml_finishsetup(void)
{
- cpu_tasks[0] = &init_task;
-
atomic_notifier_chain_register(&panic_notifier_list,
&panic_exit_notifier);
--
2.51.0
reply other threads:[~2025-09-24 9:32 UTC|newest]
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