lkml.org 
[lkml]   [2019]   [Sep]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 1/3] genirq/irqdomain: Check for existing mapping in irq_domain_associate()
Date
From: Alexander Sverdlin <alexander.sverdlin@nokia.com>

irq_domain_associate() is the only place where irq_find_mapping() can be
used reliably (under irq_domain_mutex) to make a decision if the mapping
shall be created or not. Other calls to irq_find_mapping() (not under
any lock) cannot be used for this purpose and lead to race conditions in
particular inside irq_create_mapping().

Give the callers of irq_domain_associate() an ability to detect existing
domain reliably by examining the return value.

Cc: stable@vger.kernel.org
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@nokia.com>
---
kernel/irq/irqdomain.c | 11 +++++++++++
1 file changed, 11 insertions(+)

diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
index 3078d0e..7bc07b6 100644
--- a/kernel/irq/irqdomain.c
+++ b/kernel/irq/irqdomain.c
@@ -532,6 +532,7 @@ int irq_domain_associate(struct irq_domain *domain, unsigned int virq,
irq_hw_number_t hwirq)
{
struct irq_data *irq_data = irq_get_irq_data(virq);
+ unsigned int eirq;
int ret;

if (WARN(hwirq >= domain->hwirq_max,
@@ -543,6 +544,16 @@ int irq_domain_associate(struct irq_domain *domain, unsigned int virq,
return -EINVAL;

mutex_lock(&irq_domain_mutex);
+
+ /* Check if mapping already exists */
+ eirq = irq_find_mapping(domain, hwirq);
+ if (eirq) {
+ mutex_unlock(&irq_domain_mutex);
+ pr_debug("%s: conflicting mapping for hwirq 0x%x\n",
+ domain->name, (int)hwirq);
+ return -EBUSY;
+ }
+
irq_data->hwirq = hwirq;
irq_data->domain = domain;
if (domain->ops->map) {
--
2.4.6
\
 
 \ /
  Last update: 2019-09-12 11:45    [W:0.116 / U:0.520 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site