| Message ID | 4BD145B0.8080102@kernel.org |
|---|---|
| State | Not Applicable |
| Delegated to: | David Miller |
| Headers | show |
On 04/23/2010 03:01 AM, Tejun Heo wrote: > Hello, Jeff. > > On 04/23/2010 08:43 AM, Jeff Garzik wrote: >> On Fri, Apr 23, 2010 at 08:30:28AM +0200, Tejun Heo wrote: >>> On 04/22/2010 03:23 AM, Fang Wenqi wrote: >>>> Sorry that the title should be: >>>> "fix uninitialized variable warning" >>>> >>>> not >>>> "fix unused variable warning" >>>> >>>> Need I re-send the patch mail ? >>> >>> Yes, please do so. gcc 4.4.1 generates a spurious warning on it too. >>> >>> Acked-by: Tejun Heo<tj@kernel.org> >> >> It's not a spurious warning. The code failed to fully initialize all >> fields of the ata_taskfile structure, prior to copying the ata_taskfile >> structure into qc->result_tf. > > Hmmmm.... right, I've always thought it was gcc not noticing the > structure is being initialized in ata_eh_read_log_10h() but it > actually is noticing much more, so something like the following is > more appropriate? > > Subject: libata: fully initialize @tf in ata_eh_read_log_10h() > > ata_eh_read_log_10h() filled @tf only partially. It didn't cause any > correctness issues but triggered spruious uninitialized variable > warning. Do ata_tf_init() before filling in @tf. > > Signed-off-by: Tejun Heo<tj@kernel.org> Sorry, I should have also pointed out that a fix went upstream to Linus in the last batch of fixes... Jeff -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 04/23/2010 03:52 PM, Jeff Garzik wrote: > Sorry, I should have also pointed out that a fix went upstream to Linus > in the last batch of fixes... Oh, as long as the annoying warning goes away, there's nothing to be sorry about. :-) Thanks.
Hello. Jeff Garzik wrote: >>>>> Sorry that the title should be: >>>>> "fix uninitialized variable warning" >>>>> >>>>> not >>>>> "fix unused variable warning" >>>>> >>>>> Need I re-send the patch mail ? >>>> >>>> Yes, please do so. gcc 4.4.1 generates a spurious warning on it too. >>>> >>>> Acked-by: Tejun Heo<tj@kernel.org> >>> >>> It's not a spurious warning. The code failed to fully initialize all >>> fields of the ata_taskfile structure, prior to copying the ata_taskfile >>> structure into qc->result_tf. >> >> Hmmmm.... right, I've always thought it was gcc not noticing the >> structure is being initialized in ata_eh_read_log_10h() but it >> actually is noticing much more, so something like the following is >> more appropriate? >> >> Subject: libata: fully initialize @tf in ata_eh_read_log_10h() >> >> ata_eh_read_log_10h() filled @tf only partially. It didn't cause any >> correctness issues but triggered spruious uninitialized variable >> warning. Do ata_tf_init() before filling in @tf. >> >> Signed-off-by: Tejun Heo<tj@kernel.org> > > Sorry, I should have also pointed out that a fix went upstream to > Linus in the last batch of fixes... I thought Tejun was fixing a different function, no? > Jeff MBR, Sergei -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 04/23/2010 10:07 AM, Sergei Shtylyov wrote: > Hello. > > Jeff Garzik wrote: > >>>>>> Sorry that the title should be: >>>>>> "fix uninitialized variable warning" >>>>>> >>>>>> not >>>>>> "fix unused variable warning" >>>>>> >>>>>> Need I re-send the patch mail ? >>>>> >>>>> Yes, please do so. gcc 4.4.1 generates a spurious warning on it too. >>>>> >>>>> Acked-by: Tejun Heo<tj@kernel.org> >>>> >>>> It's not a spurious warning. The code failed to fully initialize all >>>> fields of the ata_taskfile structure, prior to copying the ata_taskfile >>>> structure into qc->result_tf. >>> >>> Hmmmm.... right, I've always thought it was gcc not noticing the >>> structure is being initialized in ata_eh_read_log_10h() but it >>> actually is noticing much more, so something like the following is >>> more appropriate? >>> >>> Subject: libata: fully initialize @tf in ata_eh_read_log_10h() >>> >>> ata_eh_read_log_10h() filled @tf only partially. It didn't cause any >>> correctness issues but triggered spruious uninitialized variable >>> warning. Do ata_tf_init() before filling in @tf. >>> >>> Signed-off-by: Tejun Heo<tj@kernel.org> >> >> Sorry, I should have also pointed out that a fix went upstream to >> Linus in the last batch of fixes... > > I thought Tejun was fixing a different function, no? Tejun put the fix in the callee; I put the fix in the caller, who instantiated the automatic variable. Either way, the same region of memory gets initialized. Jeff -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c index 9f6cfac..fa7e902 100644 --- a/drivers/ata/libata-eh.c +++ b/drivers/ata/libata-eh.c @@ -1434,6 +1434,7 @@ static int ata_eh_read_log_10h(struct ata_device *dev, *tag = buf[0] & 0x1f; + ata_tf_init(dev, tf); tf->command = buf[2]; tf->feature = buf[3]; tf->lbal = buf[4];