Zero and negative number is not a valid IRQ for in-kernel code and the irq_of_parse_and_map() function returns zero on error. So this check for valid IRQs should only accept values > 0.
Cc: stable@vger.kernel.org Fixes: f7578496a671 ("of/irq: Use irq_of_parse_and_map()") Signed-off-by: Ma Ke make24@iscas.ac.cn --- drivers/i2c/busses/i2c-cpm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/i2c/busses/i2c-cpm.c b/drivers/i2c/busses/i2c-cpm.c index 4794ec066eb0..41e3c95c0ef7 100644 --- a/drivers/i2c/busses/i2c-cpm.c +++ b/drivers/i2c/busses/i2c-cpm.c @@ -435,7 +435,7 @@ static int cpm_i2c_setup(struct cpm_i2c *cpm) init_waitqueue_head(&cpm->i2c_wait);
cpm->irq = irq_of_parse_and_map(ofdev->dev.of_node, 0); - if (!cpm->irq) + if (cpm->irq <= 0) return -EINVAL;
/* Install interrupt handler. */
Le 30/08/2024 à 16:21, Ma Ke a écrit :
Zero and negative number is not a valid IRQ for in-kernel code and the irq_of_parse_and_map() function returns zero on error. So this check for valid IRQs should only accept values > 0.
unsigned int irq_of_parse_and_map(struct device_node *node, int index);
I can't see how an 'unsigned int' can be negative.
Christophe
Cc: stable@vger.kernel.org Fixes: f7578496a671 ("of/irq: Use irq_of_parse_and_map()") Signed-off-by: Ma Ke make24@iscas.ac.cn
drivers/i2c/busses/i2c-cpm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/i2c/busses/i2c-cpm.c b/drivers/i2c/busses/i2c-cpm.c index 4794ec066eb0..41e3c95c0ef7 100644 --- a/drivers/i2c/busses/i2c-cpm.c +++ b/drivers/i2c/busses/i2c-cpm.c @@ -435,7 +435,7 @@ static int cpm_i2c_setup(struct cpm_i2c *cpm) init_waitqueue_head(&cpm->i2c_wait); cpm->irq = irq_of_parse_and_map(ofdev->dev.of_node, 0);
- if (!cpm->irq)
- if (cpm->irq <= 0) return -EINVAL;
/* Install interrupt handler. */
On Tue, Sep 03, 2024 at 06:56:41PM GMT, Christophe Leroy wrote:
Le 30/08/2024 à 16:21, Ma Ke a écrit :
Zero and negative number is not a valid IRQ for in-kernel code and the irq_of_parse_and_map() function returns zero on error. So this check for valid IRQs should only accept values > 0.
unsigned int irq_of_parse_and_map(struct device_node *node, int index);
I can't see how an 'unsigned int' can be negative.
hehe... correct... even though looks like we are walking on a slackline, relying too much that no one in the future, inside irq_of_parse_and_map() (and various callers), someone will try to fit an -ENOSOMETHING into the unsigned int.
I wouldn't mind something like this[*] to ensure I can sleep soundly.
Thanks for the review, Andi
[*] diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c index cea8f6874b1fb..df44a8ffa6843 100644 --- a/kernel/irq/irqdomain.c +++ b/kernel/irq/irqdomain.c @@ -954,6 +954,8 @@ unsigned int irq_create_fwspec_mapping(struct irq_fwspec *fwspec) out: mutex_unlock(&domain->root->mutex);
+ BUG_ON(virq < 0); + return virq; } EXPORT_SYMBOL_GPL(irq_create_fwspec_mapping);
Christophe
Cc: stable@vger.kernel.org Fixes: f7578496a671 ("of/irq: Use irq_of_parse_and_map()") Signed-off-by: Ma Ke make24@iscas.ac.cn
drivers/i2c/busses/i2c-cpm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/i2c/busses/i2c-cpm.c b/drivers/i2c/busses/i2c-cpm.c index 4794ec066eb0..41e3c95c0ef7 100644 --- a/drivers/i2c/busses/i2c-cpm.c +++ b/drivers/i2c/busses/i2c-cpm.c @@ -435,7 +435,7 @@ static int cpm_i2c_setup(struct cpm_i2c *cpm) init_waitqueue_head(&cpm->i2c_wait); cpm->irq = irq_of_parse_and_map(ofdev->dev.of_node, 0);
- if (!cpm->irq)
- if (cpm->irq <= 0) return -EINVAL; /* Install interrupt handler. */
On Fri, Aug 30 2024 at 22:21, Ma Ke wrote:
Zero and negative number is not a valid IRQ for in-kernel code and the irq_of_parse_and_map() function returns zero on error. So this check for valid IRQs should only accept values > 0.
The subsystem prefix is wrong. This changes drivers/i2c/busses/i2c-cpm.c and has nothing to do with of/irq. Sure, the problem has been caused by the commit below, but that's a different thing.
Cc: stable@vger.kernel.org Fixes: f7578496a671 ("of/irq: Use irq_of_parse_and_map()") Signed-off-by: Ma Ke make24@iscas.ac.cn
drivers/i2c/busses/i2c-cpm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/i2c/busses/i2c-cpm.c b/drivers/i2c/busses/i2c-cpm.c index 4794ec066eb0..41e3c95c0ef7 100644 --- a/drivers/i2c/busses/i2c-cpm.c +++ b/drivers/i2c/busses/i2c-cpm.c @@ -435,7 +435,7 @@ static int cpm_i2c_setup(struct cpm_i2c *cpm) init_waitqueue_head(&cpm->i2c_wait); cpm->irq = irq_of_parse_and_map(ofdev->dev.of_node, 0);
- if (!cpm->irq)
- if (cpm->irq <= 0) return -EINVAL;
The function _cannot return a negative number:
extern unsigned int irq_of_parse_and_map(struct device_node *node, int index);
So what is this actually fixing?
Thanks,
tglx
linux-stable-mirror@lists.linaro.org
-
Andi Shyti -
Christophe Leroy -
Ma Ke -
Thomas Gleixner