| Message ID | 20210128130625.569900-1-wainersm@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | migration/qemu-file: Fix maybe uninitialized on qemu_get_buffer_in_place() | expand |
* 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 >
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 >>
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 >>>
* 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) 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 > >
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);
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(-)