Re: [PATCH 5/5] sound/aoa: Add kmalloc NULL tests
At Thu, 30 Jul 2009 16:29:54 +0200 (CEST), Julia Lawall wrote: On Thu, 30 Jul 2009, Johannes Berg wrote: On Thu, 2009-07-30 at 16:11 +0200, Julia Lawall wrote: From: Julia Lawall ju...@diku.dk Check that the result of kzalloc is not NULL before a dereference. irq_client = kzalloc(sizeof(struct pmf_irq_client), GFP_KERNEL); + if (!irq_client) { + err = -ENOMEM; + printk(KERN_ERR snd-aoa: gpio layer failed to + register %s irq (%d)\n, name, err); + goto out_unlock; + } Looks good, thanks, but I'd really drop the printk if only to not have the string there, that doesn't really seem interesting. The printk is based on similar error handling code a few lines later: But another problem is that the same error message is reused although the error condition is totally different. The kzalloc NULL isn't about the registration error. So, it's rather confusing. However, for this particular error path, I agree with Johannes; we can skip the error message since the error code ENOMEM is obvious. thanks, Takashi if (err) { printk(KERN_ERR snd-aoa: gpio layer failed to register %s irq (%d)\n, name, err); kfree(irq_client); goto out_unlock; } Should the printk be removed in this case as well? Or is it ok to fail silently in one case and not in the other? julia -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
Re: [PATCH 5/5] sound/aoa: Add kmalloc NULL tests
On Fri, 31 Jul 2009, Takashi Iwai wrote: At Thu, 30 Jul 2009 16:29:54 +0200 (CEST), Julia Lawall wrote: On Thu, 30 Jul 2009, Johannes Berg wrote: On Thu, 2009-07-30 at 16:11 +0200, Julia Lawall wrote: From: Julia Lawall ju...@diku.dk Check that the result of kzalloc is not NULL before a dereference. irq_client = kzalloc(sizeof(struct pmf_irq_client), GFP_KERNEL); + if (!irq_client) { + err = -ENOMEM; + printk(KERN_ERR snd-aoa: gpio layer failed to +register %s irq (%d)\n, name, err); + goto out_unlock; + } Looks good, thanks, but I'd really drop the printk if only to not have the string there, that doesn't really seem interesting. The printk is based on similar error handling code a few lines later: But another problem is that the same error message is reused although the error condition is totally different. The kzalloc NULL isn't about the registration error. So, it's rather confusing. However, for this particular error path, I agree with Johannes; we can skip the error message since the error code ENOMEM is obvious. OK, I will send a new patch. julia ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
Re: [PATCH 5/5] sound/aoa: Add kmalloc NULL tests
From: Julia Lawall ju...@diku.dk Check that the result of kzalloc is not NULL before a dereference. The semantic match that finds this problem is as follows: (http://www.emn.fr/x-info/coccinelle/) // smpl @@ expression *x; identifier f; constant char *C; @@ x = \(kmalloc\|kcalloc\|kzalloc\)(...); ... when != x == NULL when != x != NULL when != (x || ...) ( kfree(x) | f(...,C,...,x,...) | *f(...,x,...) | *x-f ) // /smpl Signed-off-by: Julia Lawall ju...@diku.dk --- sound/aoa/core/gpio-pmf.c |4 1 files changed, 4 insertions(+), 0 deletions(-) diff --git a/var/linuxes/linux-next/sound/aoa/core/gpio-pmf.c b/var/julia/linuxcopy/sound/aoa/core/gpio-pmf.c index 5ca2220..1dd0c28 100644 --- a/var/linuxes/linux-next/sound/aoa/core/gpio-pmf.c +++ b/var/julia/linuxcopy/sound/aoa/core/gpio-pmf.c @@ -182,6 +182,10 @@ static int pmf_set_notify(struct gpio_runtime *rt, if (!old notify) { irq_client = kzalloc(sizeof(struct pmf_irq_client), GFP_KERNEL); + if (!irq_client) { + err = -ENOMEM; + goto out_unlock; + } irq_client-data = notif; irq_client-handler = pmf_handle_notify_irq; irq_client-owner = THIS_MODULE; ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
Re: [PATCH 5/5] sound/aoa: Add kmalloc NULL tests
At Fri, 31 Jul 2009 08:32:03 +0200 (CEST), Julia Lawall wrote: From: Julia Lawall ju...@diku.dk Check that the result of kzalloc is not NULL before a dereference. The semantic match that finds this problem is as follows: (http://www.emn.fr/x-info/coccinelle/) // smpl @@ expression *x; identifier f; constant char *C; @@ x = \(kmalloc\|kcalloc\|kzalloc\)(...); ... when != x == NULL when != x != NULL when != (x || ...) ( kfree(x) | f(...,C,...,x,...) | *f(...,x,...) | *x-f ) // /smpl Signed-off-by: Julia Lawall ju...@diku.dk Applied now. But, please fix the path of the file correctly applicable to linux kernel tree at the next time. It includes /var/x/y, and confuses git am totally. thanks, Takashi --- sound/aoa/core/gpio-pmf.c |4 1 files changed, 4 insertions(+), 0 deletions(-) diff --git a/var/linuxes/linux-next/sound/aoa/core/gpio-pmf.c b/var/julia/linuxcopy/sound/aoa/core/gpio-pmf.c index 5ca2220..1dd0c28 100644 --- a/var/linuxes/linux-next/sound/aoa/core/gpio-pmf.c +++ b/var/julia/linuxcopy/sound/aoa/core/gpio-pmf.c @@ -182,6 +182,10 @@ static int pmf_set_notify(struct gpio_runtime *rt, if (!old notify) { irq_client = kzalloc(sizeof(struct pmf_irq_client), GFP_KERNEL); + if (!irq_client) { + err = -ENOMEM; + goto out_unlock; + } irq_client-data = notif; irq_client-handler = pmf_handle_notify_irq; irq_client-owner = THIS_MODULE; ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
Re: [PATCH 5/5] sound/aoa: Add kmalloc NULL tests
On Thu, 30 Jul 2009, Johannes Berg wrote: On Thu, 2009-07-30 at 16:11 +0200, Julia Lawall wrote: From: Julia Lawall ju...@diku.dk Check that the result of kzalloc is not NULL before a dereference. irq_client = kzalloc(sizeof(struct pmf_irq_client), GFP_KERNEL); + if (!irq_client) { + err = -ENOMEM; + printk(KERN_ERR snd-aoa: gpio layer failed to +register %s irq (%d)\n, name, err); + goto out_unlock; + } Looks good, thanks, but I'd really drop the printk if only to not have the string there, that doesn't really seem interesting. The printk is based on similar error handling code a few lines later: if (err) { printk(KERN_ERR snd-aoa: gpio layer failed to register %s irq (%d)\n, name, err); kfree(irq_client); goto out_unlock; } Should the printk be removed in this case as well? Or is it ok to fail silently in one case and not in the other? julia ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
Re: [PATCH 5/5] sound/aoa: Add kmalloc NULL tests
On Thu, 2009-07-30 at 16:11 +0200, Julia Lawall wrote: From: Julia Lawall ju...@diku.dk Check that the result of kzalloc is not NULL before a dereference. irq_client = kzalloc(sizeof(struct pmf_irq_client), GFP_KERNEL); + if (!irq_client) { + err = -ENOMEM; + printk(KERN_ERR snd-aoa: gpio layer failed to + register %s irq (%d)\n, name, err); + goto out_unlock; + } Looks good, thanks, but I'd really drop the printk if only to not have the string there, that doesn't really seem interesting. johannes signature.asc Description: This is a digitally signed message part ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev