| Message ID | 20210303070639.1430-1-yuzenghui@huawei.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | multi-process: Initialize variables declared with g_auto* | expand |
> On Mar 3, 2021, at 2:06 AM, Zenghui Yu <yuzenghui@huawei.com> wrote: > > Quote docs/devel/style.rst (section "Automatic memory deallocation"): > > * Variables declared with g_auto* MUST always be initialized, > otherwise the cleanup function will use uninitialized stack memory > > Initialize @name properly to get rid of the compilation error: > > ../hw/remote/proxy.c: In function 'pci_proxy_dev_realize': > /usr/include/glib-2.0/glib/glib-autocleanups.h:28:3: error: 'name' may be used uninitialized in this function [-Werror=maybe-uninitialized] > g_free (*pp); > ^~~~~~~~~~~~ > ../hw/remote/proxy.c:350:30: note: 'name' was declared here > g_autofree char *name; > ^~~~ > > Signed-off-by: Zenghui Yu <yuzenghui@huawei.com> > --- > hw/remote/memory.c | 3 +-- > hw/remote/proxy.c | 3 +-- > 2 files changed, 2 insertions(+), 4 deletions(-) > > diff --git a/hw/remote/memory.c b/hw/remote/memory.c > index 32085b1e05..f5f735c15a 100644 > --- a/hw/remote/memory.c > +++ b/hw/remote/memory.c > @@ -43,9 +43,8 @@ void remote_sysmem_reconfig(MPQemuMsg *msg, Error **errp) > remote_sysmem_reset(); > > for (region = 0; region < msg->num_fds; region++) { > - g_autofree char *name; > + g_autofree char *name = g_strdup_printf("remote-mem-%u", suffix++); > subregion = g_new(MemoryRegion, 1); > - name = g_strdup_printf("remote-mem-%u", suffix++); > memory_region_init_ram_from_fd(subregion, NULL, > name, sysmem_info->sizes[region], > true, msg->fds[region], > diff --git a/hw/remote/proxy.c b/hw/remote/proxy.c > index 4fa4be079d..6dda705fc2 100644 > --- a/hw/remote/proxy.c > +++ b/hw/remote/proxy.c > @@ -347,13 +347,12 @@ static void probe_pci_info(PCIDevice *dev, Error **errp) > PCI_BASE_ADDRESS_SPACE_IO : PCI_BASE_ADDRESS_SPACE_MEMORY; > > if (size) { > - g_autofree char *name; > + g_autofree char *name = g_strdup_printf("bar-region-%d", i); > pdev->region[i].dev = pdev; > pdev->region[i].present = true; > if (type == PCI_BASE_ADDRESS_SPACE_MEMORY) { > pdev->region[i].memory = true; > } > - name = g_strdup_printf("bar-region-%d", i); > memory_region_init_io(&pdev->region[i].mr, OBJECT(pdev), > &proxy_mr_ops, &pdev->region[i], > name, size); > -- > 2.19.1 Reviewed-by: Jagannathan Raman <jag.raman@oracle.com> >
Hi, On 3/3/21 8:06 AM, Zenghui Yu wrote: > Quote docs/devel/style.rst (section "Automatic memory deallocation"): > > * Variables declared with g_auto* MUST always be initialized, > otherwise the cleanup function will use uninitialized stack memory > > Initialize @name properly to get rid of the compilation error: > > ../hw/remote/proxy.c: In function 'pci_proxy_dev_realize': > /usr/include/glib-2.0/glib/glib-autocleanups.h:28:3: error: 'name' may be used uninitialized in this function [-Werror=maybe-uninitialized] > g_free (*pp); > ^~~~~~~~~~~~ > ../hw/remote/proxy.c:350:30: note: 'name' was declared here > g_autofree char *name; > ^~~~ > > Signed-off-by: Zenghui Yu <yuzenghui@huawei.com> > --- > hw/remote/memory.c | 3 +-- > hw/remote/proxy.c | 3 +-- > 2 files changed, 2 insertions(+), 4 deletions(-) > > diff --git a/hw/remote/memory.c b/hw/remote/memory.c > index 32085b1e05..f5f735c15a 100644 > --- a/hw/remote/memory.c > +++ b/hw/remote/memory.c > @@ -43,9 +43,8 @@ void remote_sysmem_reconfig(MPQemuMsg *msg, Error **errp) > remote_sysmem_reset(); > > for (region = 0; region < msg->num_fds; region++) { Could you move the suffix iteration out of the loop? for (region = 0; region < msg->num_fds; region++, suffix++) { > - g_autofree char *name; > + g_autofree char *name = g_strdup_printf("remote-mem-%u", suffix++); > subregion = g_new(MemoryRegion, 1); > - name = g_strdup_printf("remote-mem-%u", suffix++); > memory_region_init_ram_from_fd(subregion, NULL, > name, sysmem_info->sizes[region], > true, msg->fds[region],
On Wed, Mar 03, 2021 at 03:06:39PM +0800, Zenghui Yu wrote: > Quote docs/devel/style.rst (section "Automatic memory deallocation"): > > * Variables declared with g_auto* MUST always be initialized, > otherwise the cleanup function will use uninitialized stack memory > > Initialize @name properly to get rid of the compilation error: > > ../hw/remote/proxy.c: In function 'pci_proxy_dev_realize': > /usr/include/glib-2.0/glib/glib-autocleanups.h:28:3: error: 'name' may be used uninitialized in this function [-Werror=maybe-uninitialized] > g_free (*pp); > ^~~~~~~~~~~~ > ../hw/remote/proxy.c:350:30: note: 'name' was declared here > g_autofree char *name; > ^~~~ This is a bit wierd. There should only be risk of uninitialized variable if there is a 'return' or 'goto' statement between the variable declaration and and initialization, which is not the case in either scenario here. What OS distro and compiler + version are you seeing this with ? Also we seem to be lacking any gitlab CI job to test with the multiprocess feature enabled Regards, Daniel
On 3/3/21 11:17 AM, Daniel P. Berrangé wrote: > On Wed, Mar 03, 2021 at 03:06:39PM +0800, Zenghui Yu wrote: >> Quote docs/devel/style.rst (section "Automatic memory deallocation"): >> >> * Variables declared with g_auto* MUST always be initialized, >> otherwise the cleanup function will use uninitialized stack memory >> >> Initialize @name properly to get rid of the compilation error: >> >> ../hw/remote/proxy.c: In function 'pci_proxy_dev_realize': >> /usr/include/glib-2.0/glib/glib-autocleanups.h:28:3: error: 'name' may be used uninitialized in this function [-Werror=maybe-uninitialized] >> g_free (*pp); >> ^~~~~~~~~~~~ >> ../hw/remote/proxy.c:350:30: note: 'name' was declared here >> g_autofree char *name; >> ^~~~ > > This is a bit wierd. There should only be risk of uninitialized > variable if there is a 'return' or 'goto' statement between the > variable declaration and and initialization, which is not the > case in either scenario here. See also commit 076b2fadb58 ("gdbstub: fix compiler complaining"). > > What OS distro and compiler + version are you seeing this with ? > > Also we seem to be lacking any gitlab CI job to test with the > multiprocess feature enabled > > Regards, > Daniel >
> On Mar 3, 2021, at 5:17 AM, Daniel P. Berrangé <berrange@redhat.com> wrote: > > On Wed, Mar 03, 2021 at 03:06:39PM +0800, Zenghui Yu wrote: >> Quote docs/devel/style.rst (section "Automatic memory deallocation"): >> >> * Variables declared with g_auto* MUST always be initialized, >> otherwise the cleanup function will use uninitialized stack memory >> >> Initialize @name properly to get rid of the compilation error: >> >> ../hw/remote/proxy.c: In function 'pci_proxy_dev_realize': >> /usr/include/glib-2.0/glib/glib-autocleanups.h:28:3: error: 'name' may be used uninitialized in this function [-Werror=maybe-uninitialized] >> g_free (*pp); >> ^~~~~~~~~~~~ >> ../hw/remote/proxy.c:350:30: note: 'name' was declared here >> g_autofree char *name; >> ^~~~ > > This is a bit wierd. There should only be risk of uninitialized > variable if there is a 'return' or 'goto' statement between the > variable declaration and and initialization, which is not the > case in either scenario here. > > What OS distro and compiler + version are you seeing this with ? > > Also we seem to be lacking any gitlab CI job to test with the > multiprocess feature enabled Hi Daniel, Concerning gitlab CI, it looks like we are running acceptance tests as part of it. "acceptance-system-fedora" runs it on fedora. Is it sufficient to have multiprocess tests as part acceptance tests suite or do you prefer to have a separate test in gitlab CI? Thank you! — Jag > > Regards, > Daniel > -- > |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| > |: https://libvirt.org -o- https://fstop138.berrange.com :| > |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :| >
On Wed, Mar 03, 2021 at 02:24:04PM +0000, Jag Raman wrote: > > > > On Mar 3, 2021, at 5:17 AM, Daniel P. Berrangé <berrange@redhat.com> wrote: > > > > On Wed, Mar 03, 2021 at 03:06:39PM +0800, Zenghui Yu wrote: > >> Quote docs/devel/style.rst (section "Automatic memory deallocation"): > >> > >> * Variables declared with g_auto* MUST always be initialized, > >> otherwise the cleanup function will use uninitialized stack memory > >> > >> Initialize @name properly to get rid of the compilation error: > >> > >> ../hw/remote/proxy.c: In function 'pci_proxy_dev_realize': > >> /usr/include/glib-2.0/glib/glib-autocleanups.h:28:3: error: 'name' may be used uninitialized in this function [-Werror=maybe-uninitialized] > >> g_free (*pp); > >> ^~~~~~~~~~~~ > >> ../hw/remote/proxy.c:350:30: note: 'name' was declared here > >> g_autofree char *name; > >> ^~~~ > > > > This is a bit wierd. There should only be risk of uninitialized > > variable if there is a 'return' or 'goto' statement between the > > variable declaration and and initialization, which is not the > > case in either scenario here. > > > > What OS distro and compiler + version are you seeing this with ? > > > > Also we seem to be lacking any gitlab CI job to test with the > > multiprocess feature enabled > > Hi Daniel, > > Concerning gitlab CI, it looks like we are running acceptance tests as > part of it. "acceptance-system-fedora" runs it on fedora. > > Is it sufficient to have multiprocess tests as part acceptance tests suite > or do you prefer to have a separate test in gitlab CI? No problem. it is just me getting confused. I was looking for a CI job with --enable-multiprocess, not realizing it is enabled by default on Linux in configure Regards, Daniel
> On Mar 3, 2021, at 9:26 AM, Daniel P. Berrangé <berrange@redhat.com> wrote: > > On Wed, Mar 03, 2021 at 02:24:04PM +0000, Jag Raman wrote: >> >> >>> On Mar 3, 2021, at 5:17 AM, Daniel P. Berrangé <berrange@redhat.com> wrote: >>> >>> On Wed, Mar 03, 2021 at 03:06:39PM +0800, Zenghui Yu wrote: >>>> Quote docs/devel/style.rst (section "Automatic memory deallocation"): >>>> >>>> * Variables declared with g_auto* MUST always be initialized, >>>> otherwise the cleanup function will use uninitialized stack memory >>>> >>>> Initialize @name properly to get rid of the compilation error: >>>> >>>> ../hw/remote/proxy.c: In function 'pci_proxy_dev_realize': >>>> /usr/include/glib-2.0/glib/glib-autocleanups.h:28:3: error: 'name' may be used uninitialized in this function [-Werror=maybe-uninitialized] >>>> g_free (*pp); >>>> ^~~~~~~~~~~~ >>>> ../hw/remote/proxy.c:350:30: note: 'name' was declared here >>>> g_autofree char *name; >>>> ^~~~ >>> >>> This is a bit wierd. There should only be risk of uninitialized >>> variable if there is a 'return' or 'goto' statement between the >>> variable declaration and and initialization, which is not the >>> case in either scenario here. >>> >>> What OS distro and compiler + version are you seeing this with ? >>> >>> Also we seem to be lacking any gitlab CI job to test with the >>> multiprocess feature enabled >> >> Hi Daniel, >> >> Concerning gitlab CI, it looks like we are running acceptance tests as >> part of it. "acceptance-system-fedora" runs it on fedora. >> >> Is it sufficient to have multiprocess tests as part acceptance tests suite >> or do you prefer to have a separate test in gitlab CI? > > No problem. it is just me getting confused. I was looking for a CI job > with --enable-multiprocess, not realizing it is enabled by default > on Linux in configure Thank you for confirming! — Jag > > > Regards, > Daniel > -- > |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| > |: https://libvirt.org -o- https://fstop138.berrange.com :| > |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :| >
On 2021/3/3 18:17, Daniel P. Berrangé wrote: > This is a bit wierd. There should only be risk of uninitialized > variable if there is a 'return' or 'goto' statement between the > variable declaration and and initialization, which is not the > case in either scenario here. > > What OS distro and compiler + version are you seeing this with ? This was noticed when compiling QEMU with gcc-7.3.0 on CentOS. Thanks, Zenghui
diff --git a/hw/remote/memory.c b/hw/remote/memory.c index 32085b1e05..f5f735c15a 100644 --- a/hw/remote/memory.c +++ b/hw/remote/memory.c @@ -43,9 +43,8 @@ void remote_sysmem_reconfig(MPQemuMsg *msg, Error **errp) remote_sysmem_reset(); for (region = 0; region < msg->num_fds; region++) { - g_autofree char *name; + g_autofree char *name = g_strdup_printf("remote-mem-%u", suffix++); subregion = g_new(MemoryRegion, 1); - name = g_strdup_printf("remote-mem-%u", suffix++); memory_region_init_ram_from_fd(subregion, NULL, name, sysmem_info->sizes[region], true, msg->fds[region], diff --git a/hw/remote/proxy.c b/hw/remote/proxy.c index 4fa4be079d..6dda705fc2 100644 --- a/hw/remote/proxy.c +++ b/hw/remote/proxy.c @@ -347,13 +347,12 @@ static void probe_pci_info(PCIDevice *dev, Error **errp) PCI_BASE_ADDRESS_SPACE_IO : PCI_BASE_ADDRESS_SPACE_MEMORY; if (size) { - g_autofree char *name; + g_autofree char *name = g_strdup_printf("bar-region-%d", i); pdev->region[i].dev = pdev; pdev->region[i].present = true; if (type == PCI_BASE_ADDRESS_SPACE_MEMORY) { pdev->region[i].memory = true; } - name = g_strdup_printf("bar-region-%d", i); memory_region_init_io(&pdev->region[i].mr, OBJECT(pdev), &proxy_mr_ops, &pdev->region[i], name, size);
Quote docs/devel/style.rst (section "Automatic memory deallocation"): * Variables declared with g_auto* MUST always be initialized, otherwise the cleanup function will use uninitialized stack memory Initialize @name properly to get rid of the compilation error: ../hw/remote/proxy.c: In function 'pci_proxy_dev_realize': /usr/include/glib-2.0/glib/glib-autocleanups.h:28:3: error: 'name' may be used uninitialized in this function [-Werror=maybe-uninitialized] g_free (*pp); ^~~~~~~~~~~~ ../hw/remote/proxy.c:350:30: note: 'name' was declared here g_autofree char *name; ^~~~ Signed-off-by: Zenghui Yu <yuzenghui@huawei.com> --- hw/remote/memory.c | 3 +-- hw/remote/proxy.c | 3 +-- 2 files changed, 2 insertions(+), 4 deletions(-)