On Tue, Jun 16, 2026 at 9:04 AM Alex Mastro <[email protected]> wrote:
>
> On Mon, Jun 15, 2026 at 03:51:26PM -0700, David Matlack wrote:
> > On Mon, Jun 15, 2026 at 12:45 PM Alex Mastro <[email protected]> wrote:
> > >
> > > Add a calloc_assert() helper alongside the existing ioctl_assert() and
> > > snprintf_assert() helpers.
> > >
> > > Use it for VFIO selftest allocations that immediately assert a
> > > non-NULL result.
> > >
> > > Assisted-by: Codex:gpt-5.5-high
> > > Signed-off-by: Alex Mastro <[email protected]>
> > > ---
> > > tools/testing/selftests/vfio/lib/include/libvfio/assert.h | 10
> > > ++++++++++
> > > tools/testing/selftests/vfio/lib/iommu.c | 12
> > > ++++--------
> > > tools/testing/selftests/vfio/lib/iova_allocator.c | 4 +---
> > > tools/testing/selftests/vfio/lib/sysfs.c | 3 +--
> > > tools/testing/selftests/vfio/lib/vfio_pci_device.c | 6 ++----
> > > .../testing/selftests/vfio/vfio_pci_device_init_perf_test.c | 4 ++--
> > > 6 files changed, 20 insertions(+), 19 deletions(-)
> > >
> > > diff --git a/tools/testing/selftests/vfio/lib/include/libvfio/assert.h
> > > b/tools/testing/selftests/vfio/lib/include/libvfio/assert.h
> > > index 77b68c7129a6..f0490a403826 100644
> > > --- a/tools/testing/selftests/vfio/lib/include/libvfio/assert.h
> > > +++ b/tools/testing/selftests/vfio/lib/include/libvfio/assert.h
> > > @@ -3,6 +3,7 @@
> > > #define SELFTESTS_VFIO_LIB_INCLUDE_LIBVFIO_ASSERT_H
> > >
> > > #include <stdio.h>
> > > +#include <stdlib.h>
> > > #include <string.h>
> > > #include <sys/ioctl.h>
> > >
> > > @@ -45,6 +46,15 @@
> > > VFIO_LOG_AND_EXIT(_fmt, ##__VA_ARGS__); \
> > > } while (0)
> > >
> > > +#define calloc_assert(_nmemb, _size) ({ \
> > > + size_t __nmemb = (_nmemb); \
> > > + size_t __size = (_size); \
> > > + void *__ptr = calloc(__nmemb, __size); \
> > > + VFIO_ASSERT_NOT_NULL(__ptr, "calloc(%zu, %zu) failed", \
> > > + __nmemb, __size); \
> > > + __ptr; \
> > > +})
> > > +
> > > #define ioctl_assert(_fd, _op, _arg) do {
> > > \
> > > void *__arg = (_arg);
> > > \
> > > int __ret = ioctl((_fd), (_op), (__arg));
> > > \
> > > diff --git a/tools/testing/selftests/vfio/lib/iommu.c
> > > b/tools/testing/selftests/vfio/lib/iommu.c
> > > index 035dac069d60..31aba9fda8e5 100644
> > > --- a/tools/testing/selftests/vfio/lib/iommu.c
> > > +++ b/tools/testing/selftests/vfio/lib/iommu.c
> > > @@ -286,8 +286,7 @@ static struct vfio_iommu_type1_info
> > > *vfio_iommu_get_info(int container_fd)
> > > {
> > > struct vfio_iommu_type1_info *info;
> > >
> > > - info = malloc(sizeof(*info));
> > > - VFIO_ASSERT_NOT_NULL(info);
> > > + info = calloc_assert(1, sizeof(*info));
> > >
> > > *info = (struct vfio_iommu_type1_info) {
> > > .argsz = sizeof(*info),
> > > @@ -324,8 +323,7 @@ static struct iommu_iova_range
> > > *vfio_iommu_iova_ranges(struct iommu *iommu,
> > > cap_range = container_of(hdr, struct
> > > vfio_iommu_type1_info_cap_iova_range, header);
> > > VFIO_ASSERT_GT(cap_range->nr_iovas, 0);
> > >
> > > - ranges = calloc(cap_range->nr_iovas, sizeof(*ranges));
> > > - VFIO_ASSERT_NOT_NULL(ranges);
> > > + ranges = calloc_assert(cap_range->nr_iovas, sizeof(*ranges));
> > >
> > > for (u32 i = 0; i < cap_range->nr_iovas; i++) {
> > > ranges[i] = (struct iommu_iova_range){
> > > @@ -357,8 +355,7 @@ static struct iommu_iova_range
> > > *iommufd_iova_ranges(struct iommu *iommu,
> > > VFIO_ASSERT_EQ(errno, EMSGSIZE);
> > > VFIO_ASSERT_GT(query.num_iovas, 0);
> > >
> > > - ranges = calloc(query.num_iovas, sizeof(*ranges));
> > > - VFIO_ASSERT_NOT_NULL(ranges);
> > > + ranges = calloc_assert(query.num_iovas, sizeof(*ranges));
> > >
> > > query.allowed_iovas = (uintptr_t)ranges;
> > >
> > > @@ -424,8 +421,7 @@ struct iommu *iommu_init(const char *iommu_mode)
> > > struct iommu *iommu;
> > > int version;
> > >
> > > - iommu = calloc(1, sizeof(*iommu));
> > > - VFIO_ASSERT_NOT_NULL(iommu);
> > > + iommu = calloc_assert(1, sizeof(*iommu));
> > >
> > > INIT_LIST_HEAD(&iommu->dma_regions);
> > >
> > > diff --git a/tools/testing/selftests/vfio/lib/iova_allocator.c
> > > b/tools/testing/selftests/vfio/lib/iova_allocator.c
> > > index 8c1cc86b70cd..2e7d54e1b4c6 100644
> > > --- a/tools/testing/selftests/vfio/lib/iova_allocator.c
> > > +++ b/tools/testing/selftests/vfio/lib/iova_allocator.c
> > > @@ -29,8 +29,7 @@ struct iova_allocator *iova_allocator_init(struct iommu
> > > *iommu)
> > > ranges = iommu_iova_ranges(iommu, &nranges);
> > > VFIO_ASSERT_NOT_NULL(ranges);
> > >
> > > - allocator = malloc(sizeof(*allocator));
> > > - VFIO_ASSERT_NOT_NULL(allocator);
> > > + allocator = calloc_assert(1, sizeof(*allocator));
> >
> > Did you mean to replace malloc() with calloc()? Feel free to add a
> > malloc_assert().
>
> Yes! Since all malloc() can be expressed as calloc() (because we shouldn't
> care
> about potentially redundant zeroing overhead), I think the single
> calloc_assert() is fine.
I agree the extra zeroing overhead is not a big deal for these
allocations. But it is odd to see calloc being used where it is not
needed, and there may be future users that truly want a
malloc_assert() over calloc_assert(). Let's just add a malloc_assert()
in this patch. It should be a simple change.
>
> >
> > >
> > > *allocator = (struct iova_allocator){
> > > .ranges = ranges,
> > > @@ -90,4 +89,3 @@ iova_t iova_allocator_alloc(struct iova_allocator
> > > *allocator, size_t size)
> > > allocator->range_offset = 0;
> > > }
> > > }
> > > -
> > > diff --git a/tools/testing/selftests/vfio/lib/sysfs.c
> > > b/tools/testing/selftests/vfio/lib/sysfs.c
> > > index 11415448b2e2..98a46a2543cd 100644
> > > --- a/tools/testing/selftests/vfio/lib/sysfs.c
> > > +++ b/tools/testing/selftests/vfio/lib/sysfs.c
> > > @@ -107,8 +107,7 @@ char *sysfs_sriov_vf_bdf_get(const char *pf_bdf, int
> > > i)
> > > char *out_vf_bdf;
> > >
> > > /* Fit "0000:00:00.0" */
> > > - out_vf_bdf = calloc(16, sizeof(char));
> > > - VFIO_ASSERT_NOT_NULL(out_vf_bdf);
> > > + out_vf_bdf = calloc_assert(16, sizeof(char));
> > >
> > > snprintf_assert(path, PATH_MAX,
> > > "/sys/bus/pci/devices/%s/virtfn%d", pf_bdf, i);
> > > readlink_base(path, "%s", out_vf_bdf);
> > > diff --git a/tools/testing/selftests/vfio/lib/vfio_pci_device.c
> > > b/tools/testing/selftests/vfio/lib/vfio_pci_device.c
> > > index 94dc5fcecbeb..eb40f7159bae 100644
> > > --- a/tools/testing/selftests/vfio/lib/vfio_pci_device.c
> > > +++ b/tools/testing/selftests/vfio/lib/vfio_pci_device.c
> > > @@ -343,8 +343,7 @@ const char *vfio_pci_get_cdev_path(const char *bdf)
> > > char *cdev_path;
> > > DIR *dir;
> > >
> > > - cdev_path = calloc(PATH_MAX, 1);
> > > - VFIO_ASSERT_NOT_NULL(cdev_path);
> > > + cdev_path = calloc_assert(PATH_MAX, 1);
> > >
> > > snprintf_assert(dir_path, sizeof(dir_path),
> > > "/sys/bus/pci/devices/%s/vfio-dev/", bdf);
> > >
> > > @@ -425,8 +424,7 @@ struct vfio_pci_device *vfio_pci_device_alloc(const
> > > char *bdf, struct iommu *iom
> > > {
> > > struct vfio_pci_device *device;
> > >
> > > - device = calloc(1, sizeof(*device));
> > > - VFIO_ASSERT_NOT_NULL(device);
> > > + device = calloc_assert(1, sizeof(*device));
> > >
> > > VFIO_ASSERT_NOT_NULL(iommu);
> > > device->iommu = iommu;
> > > diff --git
> > > a/tools/testing/selftests/vfio/vfio_pci_device_init_perf_test.c
> > > b/tools/testing/selftests/vfio/vfio_pci_device_init_perf_test.c
> > > index 33b0c31fe2ed..e1a54e153cd3 100644
> > > --- a/tools/testing/selftests/vfio/vfio_pci_device_init_perf_test.c
> > > +++ b/tools/testing/selftests/vfio/vfio_pci_device_init_perf_test.c
> > > @@ -45,8 +45,8 @@ FIXTURE_SETUP(vfio_pci_device_init_perf_test)
> > > int i;
> > >
> > > self->iommu = iommu_init(variant->iommu_mode);
> > > - self->threads = calloc(nr_devices, sizeof(self->threads[0]));
> > > - self->thread_args = calloc(nr_devices,
> > > sizeof(self->thread_args[0]));
> > > + self->threads = calloc_assert(nr_devices,
> > > sizeof(self->threads[0]));
> > > + self->thread_args = calloc_assert(nr_devices,
> > > sizeof(self->thread_args[0]));
> > >
> > > pthread_barrier_init(&self->barrier, NULL, nr_devices);
> > >
> > >
> > > --
> > > 2.53.0-Meta
> > >
