diff options
| author | Michael Kelley <mikelley@microsoft.com> | 2019-08-01 23:53:53 +0000 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2019-08-19 21:41:19 +0200 |
| commit | d0ff14fdc987303aeeb7de6f1bd72c3749ae2a9b (patch) | |
| tree | 18e655d9824a74da64c8e3a559e374d211a5d345 /kernel | |
| parent | d1abaeb3be7b5fa6d7a1fbbd2e14e3310005c4c1 (diff) | |
| download | linux-d0ff14fdc987303aeeb7de6f1bd72c3749ae2a9b.tar.bz2 | |
genirq: Properly pair kobject_del() with kobject_add()
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@microsoft.com
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/irq/irqdesc.c | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c index 9484e88dabc2..9be995fc3c5a 100644 --- a/kernel/irq/irqdesc.c +++ b/kernel/irq/irqdesc.c @@ -295,6 +295,18 @@ static void irq_sysfs_add(int irq, struct irq_desc *desc) } } +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; @@ -325,6 +337,7 @@ 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 */ @@ -438,7 +451,7 @@ 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); /* |