From: Michael Kelley mikelley@microsoft.com
commit d0ff14fdc987303aeeb7de6f1bd72c3749ae2a9b upstream.
If alloc_descs() fails before irq_sysfs_init() has run, free_desc() in the cleanup path will call kobject_del() even though the kobject has not been added with kobject_add().
Fix this by making the call to kobject_del() conditional on whether irq_sysfs_init() has run.
This problem surfaced because commit aa30f47cf666 ("kobject: Add support for default attribute groups to kobj_type") makes kobject_del() stricter about pairing with kobject_add(). If the pairing is incorrrect, a WARNING and backtrace occur in sysfs_remove_group() because there is no parent.
[ tglx: Add a comment to the code and make it work with CONFIG_SYSFS=n ]
Fixes: ecb3f394c5db ("genirq: Expose interrupt information through sysfs") Signed-off-by: Michael Kelley mikelley@microsoft.com Signed-off-by: Thomas Gleixner tglx@linutronix.de Acked-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/1564703564-4116-1-git-send-email-mikelley@microsof... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- kernel/irq/irqdesc.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-)
--- a/kernel/irq/irqdesc.c +++ b/kernel/irq/irqdesc.c @@ -267,6 +267,18 @@ static void irq_sysfs_add(int irq, struc } }
+static void irq_sysfs_del(struct irq_desc *desc) +{ + /* + * If irq_sysfs_init() has not yet been invoked (early boot), then + * irq_kobj_base is NULL and the descriptor was never added. + * kobject_del() complains about a object with no parent, so make + * it conditional. + */ + if (irq_kobj_base) + kobject_del(&desc->kobj); +} + static int __init irq_sysfs_init(void) { struct irq_desc *desc; @@ -297,6 +309,7 @@ static struct kobj_type irq_kobj_type = };
static void irq_sysfs_add(int irq, struct irq_desc *desc) {} +static void irq_sysfs_del(struct irq_desc *desc) {}
#endif /* CONFIG_SYSFS */
@@ -406,7 +419,7 @@ static void free_desc(unsigned int irq) * The sysfs entry must be serialized against a concurrent * irq_sysfs_init() as well. */ - kobject_del(&desc->kobj); + irq_sysfs_del(desc); delete_irq_desc(irq);
/*