* [PATCH v4 1/2] vfio: selftests: Add allocation assert helpers
2026-06-17 18:57 [PATCH v4 0/2] vfio: selftests: Add allocation assert helpers and avoid VLAs Alex Mastro
@ 2026-06-17 18:58 ` Alex Mastro
2026-06-17 18:58 ` [PATCH v4 2/2] vfio: selftests: Avoid VLAs Alex Mastro
2026-06-17 22:55 ` [PATCH v4 0/2] vfio: selftests: Add allocation assert helpers and avoid VLAs David Matlack
2 siblings, 0 replies; 4+ messages in thread
From: Alex Mastro @ 2026-06-17 18:58 UTC (permalink / raw)
To: Alex Williamson, David Matlack, Shuah Khan,
Raghavendra Rao Ananta, Vipin Sharma
Cc: kvm, linux-kselftest, linux-kernel, Shuah Khan, Alex Mastro
Add {malloc,calloc}_assert() helpers alongside the existing *_assert()
helpers.
Use them for VFIO selftest allocations that immediately assert a
non-NULL result.
Assisted-by: Codex:gpt-5.5-high
Signed-off-by: Alex Mastro <amastro@fb.com>
---
.../selftests/vfio/lib/include/libvfio/assert.h | 18 ++++++++++++++++++
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 ++----
.../selftests/vfio/vfio_pci_device_init_perf_test.c | 4 ++--
6 files changed, 28 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..9fff88f6e4e1 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 +46,23 @@
VFIO_LOG_AND_EXIT(_fmt, ##__VA_ARGS__); \
} while (0)
+#define malloc_assert(_size) ({ \
+ size_t __size = (_size); \
+ void *__ptr = malloc(__size); \
+ VFIO_ASSERT_NOT_NULL(__ptr, "malloc(%zu) failed", \
+ __size); \
+ __ptr; \
+})
+
+#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..b6f3c5c84e01 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 = malloc_assert(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..4a660f636f49 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 = malloc_assert(sizeof(*allocator));
*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
^ permalink raw reply related [flat|nested] 4+ messages in thread* [PATCH v4 2/2] vfio: selftests: Avoid VLAs
2026-06-17 18:57 [PATCH v4 0/2] vfio: selftests: Add allocation assert helpers and avoid VLAs Alex Mastro
2026-06-17 18:58 ` [PATCH v4 1/2] vfio: selftests: Add allocation assert helpers Alex Mastro
@ 2026-06-17 18:58 ` Alex Mastro
2026-06-17 22:55 ` [PATCH v4 0/2] vfio: selftests: Add allocation assert helpers and avoid VLAs David Matlack
2 siblings, 0 replies; 4+ messages in thread
From: Alex Mastro @ 2026-06-17 18:58 UTC (permalink / raw)
To: Alex Williamson, David Matlack, Shuah Khan,
Raghavendra Rao Ananta, Vipin Sharma
Cc: kvm, linux-kselftest, linux-kernel, Shuah Khan, Alex Mastro
Allocate VFIO ioctl requests dynamically instead of using VLAs. GCC 11.5.0
rejects initialized VLAs with:
error: variable-sized object may not be initialized
The replaced stack u8 arrays also do not guarantee native struct alignment
for the aliased pointers.
Fixes: 19faf6fd969c ("vfio: selftests: Add a helper library for VFIO selftests")
Fixes: 20face8c75ff ("vfio: selftests: Add helper to set/override a vf_token")
Assisted-by: Codex:gpt-5.5-high
Reviewed-by: Vipin Sharma <vipinsh@google.com>
Reviewed-by: David Matlack <dmatlack@google.com>
Signed-off-by: Alex Mastro <amastro@fb.com>
---
tools/testing/selftests/vfio/lib/vfio_pci_device.c | 26 +++++++++++++---------
1 file changed, 15 insertions(+), 11 deletions(-)
diff --git a/tools/testing/selftests/vfio/lib/vfio_pci_device.c b/tools/testing/selftests/vfio/lib/vfio_pci_device.c
index eb40f7159bae..28868343f2ab 100644
--- a/tools/testing/selftests/vfio/lib/vfio_pci_device.c
+++ b/tools/testing/selftests/vfio/lib/vfio_pci_device.c
@@ -30,13 +30,11 @@
static void vfio_pci_irq_set(struct vfio_pci_device *device,
u32 index, u32 vector, u32 count, int *fds)
{
- u8 buf[sizeof(struct vfio_irq_set) + sizeof(int) * count];
- struct vfio_irq_set *irq = (void *)&buf;
- int *irq_fds = (void *)&irq->data;
+ size_t argsz = sizeof(struct vfio_irq_set) + sizeof(int) * count;
+ struct vfio_irq_set *irq;
- memset(buf, 0, sizeof(buf));
-
- irq->argsz = sizeof(buf);
+ irq = calloc_assert(1, argsz);
+ irq->argsz = argsz;
irq->flags = VFIO_IRQ_SET_ACTION_TRIGGER;
irq->index = index;
irq->start = vector;
@@ -44,12 +42,13 @@ static void vfio_pci_irq_set(struct vfio_pci_device *device,
if (count) {
irq->flags |= VFIO_IRQ_SET_DATA_EVENTFD;
- memcpy(irq_fds, fds, sizeof(int) * count);
+ memcpy(irq->data, fds, sizeof(int) * count);
} else {
irq->flags |= VFIO_IRQ_SET_DATA_NONE;
}
ioctl_assert(device->fd, VFIO_DEVICE_SET_IRQS, irq);
+ free(irq);
}
void vfio_pci_irq_trigger(struct vfio_pci_device *device, u32 index, u32 vector)
@@ -118,15 +117,20 @@ static void vfio_pci_irq_get(struct vfio_pci_device *device, u32 index,
static int vfio_device_feature_ioctl(int fd, u32 flags, void *data,
size_t data_size)
{
- u8 buffer[sizeof(struct vfio_device_feature) + data_size] = {};
- struct vfio_device_feature *feature = (void *)buffer;
+ size_t argsz = sizeof(struct vfio_device_feature) + data_size;
+ struct vfio_device_feature *feature;
+ int ret;
+ feature = calloc_assert(1, argsz);
memcpy(feature->data, data, data_size);
- feature->argsz = sizeof(buffer);
+ feature->argsz = argsz;
feature->flags = flags;
- return ioctl(fd, VFIO_DEVICE_FEATURE, feature);
+ ret = ioctl(fd, VFIO_DEVICE_FEATURE, feature);
+ free(feature);
+
+ return ret;
}
static void vfio_device_feature_set(int fd, u16 feature, void *data, size_t data_size)
--
2.53.0-Meta
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