Merge tag 'kvmarm-fixes-6.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 fixes for 6.12, take #1

- Fix pKVM error path on init, making sure we do not change critical
  system registers as we're about to fail

- Make sure that the host's vector length is at capped by a value
  common to all CPUs

- Fix kvm_has_feat*() handling of "negative" features, as the current
  code is pretty broken

- Promote Joey to the status of official reviewer, while James steps
  down -- hopefully only temporarly

1 files changed, 24 insertions, 1 deletions

diff --git a/kernel/printk/printk_safe.c b/kernel/printk/printk_safe.c
index 6d10927a07d8..2b35a9d3919d 100644
--- a/kernel/printk/printk_safe.c
+++ b/kernel/printk/printk_safe.c
@@ -26,6 +26,29 @@ void __printk_safe_exit(void)
 	this_cpu_dec(printk_context);
 }
 
+void __printk_deferred_enter(void)
+{
+	cant_migrate();
+	__printk_safe_enter();
+}
+
+void __printk_deferred_exit(void)
+{
+	cant_migrate();
+	__printk_safe_exit();
+}
+
+bool is_printk_legacy_deferred(void)
+{
+	/*
+	 * The per-CPU variable @printk_context can be read safely in any
+	 * context. CPU migration is always disabled when set.
+	 */
+	return (force_legacy_kthread() ||
+		this_cpu_read(printk_context) ||
+		in_nmi());
+}
+
 asmlinkage int vprintk(const char *fmt, va_list args)
 {
 #ifdef CONFIG_KGDB_KDB
@@ -38,7 +61,7 @@ asmlinkage int vprintk(const char *fmt, va_list args)
 	 * Use the main logbuf even in NMI. But avoid calling console
 	 * drivers that might have their own locks.
 	 */
-	if (this_cpu_read(printk_context) || in_nmi())
+	if (is_printk_legacy_deferred())
 		return vprintk_deferred(fmt, args);
 
 	/* No obstacles. */