[PATCH] um: init cpu_tasks[] earlier

Johannes Berg johannes at sipsolutions.net
Wed Sep 24 02:32:13 PDT 2025


From: Johannes Berg <johannes.berg at 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 at 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




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