Re: Re: [PATCH 5/5] powerpc/8xx: fix possible object reference leak
From: <hidden>
Date: 2019-03-23 05:51:14
Hi, Christophe,
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The call to of_find_compatible_node returns a node pointer with refcount incremented thus it must be explicitly decremented after the last usage. irq_domain_add_linear also calls of_node_get to increase refcount, so irq_domain will not be affected when it is released.Should you have a: Fixes: a8db8cf0d894 ("irq_domain: Replace irq_alloc_host() with revmap-specific initializers") If not, it means your change is in contradiction with commit b1725c9319aa ("[POWERPC] arch/powerpc/sysdev: Add missing of_node_put")
Thank you very much. This problem existed before this commit (a8db8cf0d894). and the SmPL we used is: https://lkml.org/lkml/2019/3/14/880 We are still improving this SmPL, and it is somewhat different from the script used by b1725c9319aa ("[POWERPC] arch/powerpc/sysdev: Add missing of_node_put").
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Detected by coccinelle with the following warnings: ./arch/powerpc/platforms/8xx/pic.c:158:1-7: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 136, but without a corresponding object release within this function. arch/powerpc/platforms/8xx/pic.c | 1 + 1 file changed, 1 insertion(+)diff --git a/arch/powerpc/platforms/8xx/pic.c b/arch/powerpc/platforms/8xx/pic.c index 8d5a25d..13d880b 100644 --- a/arch/powerpc/platforms/8xx/pic.c +++ b/arch/powerpc/platforms/8xx/pic.c@@ -155,6 +155,7 @@ int mpc8xx_pic_init(void) ret = -ENOMEM; goto out; } + of_node_put(np); return 0; out:I guess it would be better as follows:--- a/arch/powerpc/platforms/8xx/pic.c +++ b/arch/powerpc/platforms/8xx/pic.c@@ -153,9 +153,7 @@ int mpc8xx_pic_init(void)if (mpc8xx_pic_host == NULL) { printk(KERN_ERR "MPC8xx PIC: failed to allocate irq host!\n"); ret = -ENOMEM; - goto out; } - return 0; out: of_node_put(np);
OK. Thank you. We will fix it soon. Thanks and regards, Wen