| Message ID | 20210315080032.152210-1-mrezanin@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] Add missing initialization for g_autofree variables | expand |
On 15/03/2021 09.00, mrezanin@redhat.com wrote: > From: Miroslav Rezanina <mrezanin@redhat.com> > > When declaring g_autofree variable without inicialization, compiler > will raise "may be used uninitialized in this function" warning due > to automatic free handling. > > This is mentioned in docs/devel/style.rst (quote from section > "Automatic memory deallocation"): > > * Variables declared with g_auto* MUST always be initialized, > otherwise the cleanup function will use uninitialized stack memory > > Add inicialization to NULL for these declaration to prevent this > warning. > > Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com> > > --- > * From v1: > -- Removed fixes in hw/remote/memory.c and hw/remote/proxy.c > fixed by patch sent by Zenghui Yu (multi-process: Initialize > variables declared with g_auto*) > --- > hw/s390x/s390-pci-vfio.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/hw/s390x/s390-pci-vfio.c b/hw/s390x/s390-pci-vfio.c > index ead4f222d5..0ee7dc21f2 100644 > --- a/hw/s390x/s390-pci-vfio.c > +++ b/hw/s390x/s390-pci-vfio.c > @@ -29,7 +29,7 @@ > */ > bool s390_pci_update_dma_avail(int fd, unsigned int *avail) > { > - g_autofree struct vfio_iommu_type1_info *info; > + g_autofree struct vfio_iommu_type1_info *info = NULL; > uint32_t argsz; > > assert(avail); I'd maybe rather rework the functions like this: diff --git a/hw/s390x/s390-pci-vfio.c b/hw/s390x/s390-pci-vfio.c index ead4f222d5..1fe71fd93f 100644 --- a/hw/s390x/s390-pci-vfio.c +++ b/hw/s390x/s390-pci-vfio.c @@ -29,14 +29,11 @@ */ bool s390_pci_update_dma_avail(int fd, unsigned int *avail) { - g_autofree struct vfio_iommu_type1_info *info; - uint32_t argsz; + uint32_t argsz = sizeof(struct vfio_iommu_type1_info); + g_autofree struct vfio_iommu_type1_info *info = g_malloc0(argsz); assert(avail); - argsz = sizeof(struct vfio_iommu_type1_info); - info = g_malloc0(argsz); - /* * If the specified argsz is not large enough to contain all capabilities * it will be updated upon return from the ioctl. Retry until we have > @@ -230,7 +230,7 @@ static void s390_pci_read_pfip(S390PCIBusDevice *pbdev, > */ > void s390_pci_get_clp_info(S390PCIBusDevice *pbdev) > { > - g_autofree struct vfio_device_info *info; > + g_autofree struct vfio_device_info *info = NULL; > VFIOPCIDevice *vfio_pci; > uint32_t argsz; > int fd; > Anyway, Reviewed-by: Thomas Huth <thuth@redhat.com>
On Mon, Mar 15, 2021 at 09:08:01AM +0100, Thomas Huth wrote: > On 15/03/2021 09.00, mrezanin@redhat.com wrote: > > From: Miroslav Rezanina <mrezanin@redhat.com> > > > > When declaring g_autofree variable without inicialization, compiler > > will raise "may be used uninitialized in this function" warning due > > to automatic free handling. > > > > This is mentioned in docs/devel/style.rst (quote from section > > "Automatic memory deallocation"): > > > > * Variables declared with g_auto* MUST always be initialized, > > otherwise the cleanup function will use uninitialized stack memory > > > > Add inicialization to NULL for these declaration to prevent this > > warning. > > > > Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com> > > > > --- > > * From v1: > > -- Removed fixes in hw/remote/memory.c and hw/remote/proxy.c > > fixed by patch sent by Zenghui Yu (multi-process: Initialize > > variables declared with g_auto*) > > --- > > hw/s390x/s390-pci-vfio.c | 4 ++-- > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > diff --git a/hw/s390x/s390-pci-vfio.c b/hw/s390x/s390-pci-vfio.c > > index ead4f222d5..0ee7dc21f2 100644 > > --- a/hw/s390x/s390-pci-vfio.c > > +++ b/hw/s390x/s390-pci-vfio.c > > @@ -29,7 +29,7 @@ > > */ > > bool s390_pci_update_dma_avail(int fd, unsigned int *avail) > > { > > - g_autofree struct vfio_iommu_type1_info *info; > > + g_autofree struct vfio_iommu_type1_info *info = NULL; > > uint32_t argsz; > > assert(avail); > > I'd maybe rather rework the functions like this: > > diff --git a/hw/s390x/s390-pci-vfio.c b/hw/s390x/s390-pci-vfio.c > index ead4f222d5..1fe71fd93f 100644 > --- a/hw/s390x/s390-pci-vfio.c > +++ b/hw/s390x/s390-pci-vfio.c > @@ -29,14 +29,11 @@ > */ > bool s390_pci_update_dma_avail(int fd, unsigned int *avail) > { > - g_autofree struct vfio_iommu_type1_info *info; > - uint32_t argsz; > + uint32_t argsz = sizeof(struct vfio_iommu_type1_info); > + g_autofree struct vfio_iommu_type1_info *info = g_malloc0(argsz); > assert(avail); > - argsz = sizeof(struct vfio_iommu_type1_info); > - info = g_malloc0(argsz); > - Hi Thomas, I thought about it but for some reason I miss-read the code and though that avail is used for calculating argsz and didn't want to use it before assert. I'll send new version with this change. > /* > * If the specified argsz is not large enough to contain all capabilities > * it will be updated upon return from the ioctl. Retry until we have > > > @@ -230,7 +230,7 @@ static void s390_pci_read_pfip(S390PCIBusDevice *pbdev, > > */ > > void s390_pci_get_clp_info(S390PCIBusDevice *pbdev) > > { > > - g_autofree struct vfio_device_info *info; > > + g_autofree struct vfio_device_info *info = NULL; > > VFIOPCIDevice *vfio_pci; > > uint32_t argsz; > > int fd; > > > > Anyway, > Reviewed-by: Thomas Huth <thuth@redhat.com> > >
diff --git a/hw/s390x/s390-pci-vfio.c b/hw/s390x/s390-pci-vfio.c index ead4f222d5..0ee7dc21f2 100644 --- a/hw/s390x/s390-pci-vfio.c +++ b/hw/s390x/s390-pci-vfio.c @@ -29,7 +29,7 @@ */ bool s390_pci_update_dma_avail(int fd, unsigned int *avail) { - g_autofree struct vfio_iommu_type1_info *info; + g_autofree struct vfio_iommu_type1_info *info = NULL; uint32_t argsz; assert(avail); @@ -230,7 +230,7 @@ static void s390_pci_read_pfip(S390PCIBusDevice *pbdev, */ void s390_pci_get_clp_info(S390PCIBusDevice *pbdev) { - g_autofree struct vfio_device_info *info; + g_autofree struct vfio_device_info *info = NULL; VFIOPCIDevice *vfio_pci; uint32_t argsz; int fd;