* [PATCH] migration/qemu-file: Fix maybe uninitialized on qemu_get_buffer_in_place()
@ 2021-01-28 13:06 Wainer dos Santos Moschetta
2021-01-28 17:16 ` Dr. David Alan Gilbert
0 siblings, 1 reply; 6+ messages in thread
From: Wainer dos Santos Moschetta @ 2021-01-28 13:06 UTC (permalink / raw)
To: qemu-devel; +Cc: dgilbert, quintela
Fixed error when compiling migration/qemu-file.c with -Werror=maybe-uninitialized
as shown here:
../migration/qemu-file.c: In function 'qemu_get_buffer_in_place':
../migration/qemu-file.c:604:18: error: 'src' may be used uninitialized in this function [-Werror=maybe-uninitialized]
604 | *buf = src;
| ~~~~~^~~~~
cc1: all warnings being treated as errors
Signed-off-by: Wainer dos Santos Moschetta <wainersm@redhat.com>
---
Passed on CI: https://gitlab.com/wainersm/qemu/-/pipelines/247801576
migration/qemu-file.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/migration/qemu-file.c b/migration/qemu-file.c
index be21518c57..d6e03dbc0e 100644
--- a/migration/qemu-file.c
+++ b/migration/qemu-file.c
@@ -595,7 +595,7 @@ size_t qemu_get_buffer_in_place(QEMUFile *f, uint8_t **buf, size_t size)
{
if (size < IO_BUF_SIZE) {
size_t res;
- uint8_t *src;
+ uint8_t *src = NULL;
res = qemu_peek_buffer(f, &src, size, 0);
--
2.28.0
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [PATCH] migration/qemu-file: Fix maybe uninitialized on qemu_get_buffer_in_place()
2021-01-28 13:06 [PATCH] migration/qemu-file: Fix maybe uninitialized on qemu_get_buffer_in_place() Wainer dos Santos Moschetta
@ 2021-01-28 17:16 ` Dr. David Alan Gilbert
2021-01-28 18:07 ` Philippe Mathieu-Daudé
2021-02-04 14:33 ` Dr. David Alan Gilbert
0 siblings, 2 replies; 6+ messages in thread
From: Dr. David Alan Gilbert @ 2021-01-28 17:16 UTC (permalink / raw)
To: Wainer dos Santos Moschetta; +Cc: qemu-devel, quintela
* Wainer dos Santos Moschetta (wainersm@redhat.com) wrote:
> Fixed error when compiling migration/qemu-file.c with -Werror=maybe-uninitialized
> as shown here:
>
> ../migration/qemu-file.c: In function 'qemu_get_buffer_in_place':
> ../migration/qemu-file.c:604:18: error: 'src' may be used uninitialized in this function [-Werror=maybe-uninitialized]
> 604 | *buf = src;
> | ~~~~~^~~~~
> cc1: all warnings being treated as errors
>
> Signed-off-by: Wainer dos Santos Moschetta <wainersm@redhat.com>
Yes, I think I had a discussion with someone about this recently but
can't find it; the compiler is technically correct, but the only time
it's unitialised is the case where it's result doesn't matter.
Still, to shut the compiler up:
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> ---
> Passed on CI: https://gitlab.com/wainersm/qemu/-/pipelines/247801576
>
> migration/qemu-file.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/migration/qemu-file.c b/migration/qemu-file.c
> index be21518c57..d6e03dbc0e 100644
> --- a/migration/qemu-file.c
> +++ b/migration/qemu-file.c
> @@ -595,7 +595,7 @@ size_t qemu_get_buffer_in_place(QEMUFile *f, uint8_t **buf, size_t size)
> {
> if (size < IO_BUF_SIZE) {
> size_t res;
> - uint8_t *src;
> + uint8_t *src = NULL;
>
> res = qemu_peek_buffer(f, &src, size, 0);
>
> --
> 2.28.0
>
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] migration/qemu-file: Fix maybe uninitialized on qemu_get_buffer_in_place()
2021-01-28 17:16 ` Dr. David Alan Gilbert
@ 2021-01-28 18:07 ` Philippe Mathieu-Daudé
2021-01-28 18:18 ` Wainer dos Santos Moschetta
2021-01-28 18:36 ` Dr. David Alan Gilbert
2021-02-04 14:33 ` Dr. David Alan Gilbert
1 sibling, 2 replies; 6+ messages in thread
From: Philippe Mathieu-Daudé @ 2021-01-28 18:07 UTC (permalink / raw)
To: Dr. David Alan Gilbert, Wainer dos Santos Moschetta
Cc: Thomas Huth, qemu-devel, quintela
On 1/28/21 6:16 PM, Dr. David Alan Gilbert wrote:
> * Wainer dos Santos Moschetta (wainersm@redhat.com) wrote:
>> Fixed error when compiling migration/qemu-file.c with -Werror=maybe-uninitialized
>> as shown here:
>>
>> ../migration/qemu-file.c: In function 'qemu_get_buffer_in_place':
>> ../migration/qemu-file.c:604:18: error: 'src' may be used uninitialized in this function [-Werror=maybe-uninitialized]
>> 604 | *buf = src;
>> | ~~~~~^~~~~
>> cc1: all warnings being treated as errors
>>
>> Signed-off-by: Wainer dos Santos Moschetta <wainersm@redhat.com>
>
> Yes, I think I had a discussion with someone about this recently but
> can't find it;
Maybe with Thomas, he reported that 2 years ago when building with -O3:
https://www.mail-archive.com/qemu-devel@nongnu.org/msg599522.html
> the compiler is technically correct, but the only time
> it's unitialised is the case where it's result doesn't matter.
>
> Still, to shut the compiler up:
>
>
> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
>
>> ---
>> Passed on CI: https://gitlab.com/wainersm/qemu/-/pipelines/247801576
>>
>> migration/qemu-file.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/migration/qemu-file.c b/migration/qemu-file.c
>> index be21518c57..d6e03dbc0e 100644
>> --- a/migration/qemu-file.c
>> +++ b/migration/qemu-file.c
>> @@ -595,7 +595,7 @@ size_t qemu_get_buffer_in_place(QEMUFile *f, uint8_t **buf, size_t size)
>> {
>> if (size < IO_BUF_SIZE) {
>> size_t res;
>> - uint8_t *src;
>> + uint8_t *src = NULL;
>>
>> res = qemu_peek_buffer(f, &src, size, 0);
>>
>> --
>> 2.28.0
>>
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] migration/qemu-file: Fix maybe uninitialized on qemu_get_buffer_in_place()
2021-01-28 18:07 ` Philippe Mathieu-Daudé
@ 2021-01-28 18:18 ` Wainer dos Santos Moschetta
2021-01-28 18:36 ` Dr. David Alan Gilbert
1 sibling, 0 replies; 6+ messages in thread
From: Wainer dos Santos Moschetta @ 2021-01-28 18:18 UTC (permalink / raw)
To: Philippe Mathieu-Daudé, Dr. David Alan Gilbert
Cc: Thomas Huth, qemu-devel, quintela
Hi,
On 1/28/21 3:07 PM, Philippe Mathieu-Daudé wrote:
> On 1/28/21 6:16 PM, Dr. David Alan Gilbert wrote:
>> * Wainer dos Santos Moschetta (wainersm@redhat.com) wrote:
>>> Fixed error when compiling migration/qemu-file.c with -Werror=maybe-uninitialized
>>> as shown here:
>>>
>>> ../migration/qemu-file.c: In function 'qemu_get_buffer_in_place':
>>> ../migration/qemu-file.c:604:18: error: 'src' may be used uninitialized in this function [-Werror=maybe-uninitialized]
>>> 604 | *buf = src;
>>> | ~~~~~^~~~~
>>> cc1: all warnings being treated as errors
>>>
>>> Signed-off-by: Wainer dos Santos Moschetta <wainersm@redhat.com>
>> Yes, I think I had a discussion with someone about this recently but
>> can't find it;
> Maybe with Thomas, he reported that 2 years ago when building with -O3:
> https://www.mail-archive.com/qemu-devel@nongnu.org/msg599522.html
I saw that error when compiling QEMU with -O3 as well.
>
>> the compiler is technically correct, but the only time
>> it's unitialised is the case where it's result doesn't matter.
>>
>> Still, to shut the compiler up:
>>
>>
>> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Thanks David!
>>
>>> ---
>>> Passed on CI: https://gitlab.com/wainersm/qemu/-/pipelines/247801576
>>>
>>> migration/qemu-file.c | 2 +-
>>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/migration/qemu-file.c b/migration/qemu-file.c
>>> index be21518c57..d6e03dbc0e 100644
>>> --- a/migration/qemu-file.c
>>> +++ b/migration/qemu-file.c
>>> @@ -595,7 +595,7 @@ size_t qemu_get_buffer_in_place(QEMUFile *f, uint8_t **buf, size_t size)
>>> {
>>> if (size < IO_BUF_SIZE) {
>>> size_t res;
>>> - uint8_t *src;
>>> + uint8_t *src = NULL;
>>>
>>> res = qemu_peek_buffer(f, &src, size, 0);
>>>
>>> --
>>> 2.28.0
>>>
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] migration/qemu-file: Fix maybe uninitialized on qemu_get_buffer_in_place()
2021-01-28 18:07 ` Philippe Mathieu-Daudé
2021-01-28 18:18 ` Wainer dos Santos Moschetta
@ 2021-01-28 18:36 ` Dr. David Alan Gilbert
1 sibling, 0 replies; 6+ messages in thread
From: Dr. David Alan Gilbert @ 2021-01-28 18:36 UTC (permalink / raw)
To: Philippe Mathieu-Daudé
Cc: Thomas Huth, qemu-devel, Wainer dos Santos Moschetta, quintela
* Philippe Mathieu-Daudé (philmd@redhat.com) wrote:
> On 1/28/21 6:16 PM, Dr. David Alan Gilbert wrote:
> > * Wainer dos Santos Moschetta (wainersm@redhat.com) wrote:
> >> Fixed error when compiling migration/qemu-file.c with -Werror=maybe-uninitialized
> >> as shown here:
> >>
> >> ../migration/qemu-file.c: In function 'qemu_get_buffer_in_place':
> >> ../migration/qemu-file.c:604:18: error: 'src' may be used uninitialized in this function [-Werror=maybe-uninitialized]
> >> 604 | *buf = src;
> >> | ~~~~~^~~~~
> >> cc1: all warnings being treated as errors
> >>
> >> Signed-off-by: Wainer dos Santos Moschetta <wainersm@redhat.com>
> >
> > Yes, I think I had a discussion with someone about this recently but
> > can't find it;
>
> Maybe with Thomas, he reported that 2 years ago when building with -O3:
> https://www.mail-archive.com/qemu-devel@nongnu.org/msg599522.html
I've got this vague memory I've had a conversation much much more
recently; like in the last month or two but I can't find it.
Dave
> > the compiler is technically correct, but the only time
> > it's unitialised is the case where it's result doesn't matter.
> >
> > Still, to shut the compiler up:
> >
> >
> > Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> >
> >> ---
> >> Passed on CI: https://gitlab.com/wainersm/qemu/-/pipelines/247801576
> >>
> >> migration/qemu-file.c | 2 +-
> >> 1 file changed, 1 insertion(+), 1 deletion(-)
> >>
> >> diff --git a/migration/qemu-file.c b/migration/qemu-file.c
> >> index be21518c57..d6e03dbc0e 100644
> >> --- a/migration/qemu-file.c
> >> +++ b/migration/qemu-file.c
> >> @@ -595,7 +595,7 @@ size_t qemu_get_buffer_in_place(QEMUFile *f, uint8_t **buf, size_t size)
> >> {
> >> if (size < IO_BUF_SIZE) {
> >> size_t res;
> >> - uint8_t *src;
> >> + uint8_t *src = NULL;
> >>
> >> res = qemu_peek_buffer(f, &src, size, 0);
> >>
> >> --
> >> 2.28.0
> >>
>
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] migration/qemu-file: Fix maybe uninitialized on qemu_get_buffer_in_place()
2021-01-28 17:16 ` Dr. David Alan Gilbert
2021-01-28 18:07 ` Philippe Mathieu-Daudé
@ 2021-02-04 14:33 ` Dr. David Alan Gilbert
1 sibling, 0 replies; 6+ messages in thread
From: Dr. David Alan Gilbert @ 2021-02-04 14:33 UTC (permalink / raw)
To: Wainer dos Santos Moschetta; +Cc: qemu-devel, quintela
* Dr. David Alan Gilbert (dgilbert@redhat.com) wrote:
> * Wainer dos Santos Moschetta (wainersm@redhat.com) wrote:
> > Fixed error when compiling migration/qemu-file.c with -Werror=maybe-uninitialized
> > as shown here:
> >
> > ../migration/qemu-file.c: In function 'qemu_get_buffer_in_place':
> > ../migration/qemu-file.c:604:18: error: 'src' may be used uninitialized in this function [-Werror=maybe-uninitialized]
> > 604 | *buf = src;
> > | ~~~~~^~~~~
> > cc1: all warnings being treated as errors
> >
> > Signed-off-by: Wainer dos Santos Moschetta <wainersm@redhat.com>
>
> Yes, I think I had a discussion with someone about this recently but
> can't find it; the compiler is technically correct, but the only time
> it's unitialised is the case where it's result doesn't matter.
>
> Still, to shut the compiler up:
>
>
> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Queued
>
> > ---
> > Passed on CI: https://gitlab.com/wainersm/qemu/-/pipelines/247801576
> >
> > migration/qemu-file.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/migration/qemu-file.c b/migration/qemu-file.c
> > index be21518c57..d6e03dbc0e 100644
> > --- a/migration/qemu-file.c
> > +++ b/migration/qemu-file.c
> > @@ -595,7 +595,7 @@ size_t qemu_get_buffer_in_place(QEMUFile *f, uint8_t **buf, size_t size)
> > {
> > if (size < IO_BUF_SIZE) {
> > size_t res;
> > - uint8_t *src;
> > + uint8_t *src = NULL;
> >
> > res = qemu_peek_buffer(f, &src, size, 0);
> >
> > --
> > 2.28.0
> >
> --
> Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
>
>
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2021-02-04 14:36 UTC | newest]
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2021-01-28 13:06 [PATCH] migration/qemu-file: Fix maybe uninitialized on qemu_get_buffer_in_place() Wainer dos Santos Moschetta
2021-01-28 17:16 ` Dr. David Alan Gilbert
2021-01-28 18:07 ` Philippe Mathieu-Daudé
2021-01-28 18:18 ` Wainer dos Santos Moschetta
2021-01-28 18:36 ` Dr. David Alan Gilbert
2021-02-04 14:33 ` Dr. David Alan Gilbert
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