Re: [PATCH v2 17/20] vfio: Use g_autofree in all call site of vfio_get_region_info()

["Cédric Le Goater" <clg@redhat.com>]

On 5/22/24 06:40, Zhenzhong Duan wrote:
> There are some exceptions when pointer to vfio_region_info is reused.
> In that case, the pointed memory is freed manually.
> 
> Suggested-by: Cédric Le Goater <clg@redhat.com>
> Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>


Reviewed-by: Cédric Le Goater <clg@redhat.com>

Thanks,

C.


> ---
>   hw/vfio/helpers.c |  7 ++-----
>   hw/vfio/igd.c     |  5 ++---
>   hw/vfio/pci.c     | 13 +++----------
>   3 files changed, 7 insertions(+), 18 deletions(-)
> 
> diff --git a/hw/vfio/helpers.c b/hw/vfio/helpers.c
> index 4b079dc383..27ea26aa48 100644
> --- a/hw/vfio/helpers.c
> +++ b/hw/vfio/helpers.c
> @@ -343,7 +343,7 @@ static int vfio_setup_region_sparse_mmaps(VFIORegion *region,
>   int vfio_region_setup(Object *obj, VFIODevice *vbasedev, VFIORegion *region,
>                         int index, const char *name)
>   {
> -    struct vfio_region_info *info;
> +    g_autofree struct vfio_region_info *info = NULL;
>       int ret;
>   
>       ret = vfio_get_region_info(vbasedev, index, &info);
> @@ -376,8 +376,6 @@ int vfio_region_setup(Object *obj, VFIODevice *vbasedev, VFIORegion *region,
>           }
>       }
>   
> -    g_free(info);
> -
>       trace_vfio_region_setup(vbasedev->name, index, name,
>                               region->flags, region->fd_offset, region->size);
>       return 0;
> @@ -594,14 +592,13 @@ int vfio_get_dev_region_info(VFIODevice *vbasedev, uint32_t type,
>   
>   bool vfio_has_region_cap(VFIODevice *vbasedev, int region, uint16_t cap_type)
>   {
> -    struct vfio_region_info *info = NULL;
> +    g_autofree struct vfio_region_info *info = NULL;
>       bool ret = false;
>   
>       if (!vfio_get_region_info(vbasedev, region, &info)) {
>           if (vfio_get_region_info_cap(info, cap_type)) {
>               ret = true;
>           }
> -        g_free(info);
>       }
>   
>       return ret;
> diff --git a/hw/vfio/igd.c b/hw/vfio/igd.c
> index 402fc5ce1d..1e79202f2b 100644
> --- a/hw/vfio/igd.c
> +++ b/hw/vfio/igd.c
> @@ -367,8 +367,8 @@ static const MemoryRegionOps vfio_igd_index_quirk = {
>   
>   void vfio_probe_igd_bar4_quirk(VFIOPCIDevice *vdev, int nr)
>   {
> -    struct vfio_region_info *rom = NULL, *opregion = NULL,
> -                            *host = NULL, *lpc = NULL;
> +    g_autofree struct vfio_region_info *rom = NULL;
> +    struct vfio_region_info *opregion = NULL, *host = NULL, *lpc = NULL;
>       VFIOQuirk *quirk;
>       VFIOIGDQuirk *igd;
>       PCIDevice *lpc_bridge;
> @@ -609,7 +609,6 @@ void vfio_probe_igd_bar4_quirk(VFIOPCIDevice *vdev, int nr)
>       trace_vfio_pci_igd_bdsm_enabled(vdev->vbasedev.name, ggms_mb + gms_mb);
>   
>   out:
> -    g_free(rom);
>       g_free(opregion);
>       g_free(host);
>       g_free(lpc);
> diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
> index 35ad9b582f..74a79bdf61 100644
> --- a/hw/vfio/pci.c
> +++ b/hw/vfio/pci.c
> @@ -879,7 +879,7 @@ static void vfio_update_msi(VFIOPCIDevice *vdev)
>   
>   static void vfio_pci_load_rom(VFIOPCIDevice *vdev)
>   {
> -    struct vfio_region_info *reg_info;
> +    g_autofree struct vfio_region_info *reg_info = NULL;
>       uint64_t size;
>       off_t off = 0;
>       ssize_t bytes;
> @@ -897,8 +897,6 @@ static void vfio_pci_load_rom(VFIOPCIDevice *vdev)
>       vdev->rom_size = size = reg_info->size;
>       vdev->rom_offset = reg_info->offset;
>   
> -    g_free(reg_info);
> -
>       if (!vdev->rom_size) {
>           vdev->rom_read_failed = true;
>           error_report("vfio-pci: Cannot read device rom at "
> @@ -2668,7 +2666,7 @@ static VFIODeviceOps vfio_pci_ops = {
>   bool vfio_populate_vga(VFIOPCIDevice *vdev, Error **errp)
>   {
>       VFIODevice *vbasedev = &vdev->vbasedev;
> -    struct vfio_region_info *reg_info;
> +    g_autofree struct vfio_region_info *reg_info = NULL;
>       int ret;
>   
>       ret = vfio_get_region_info(vbasedev, VFIO_PCI_VGA_REGION_INDEX, &reg_info);
> @@ -2685,7 +2683,6 @@ bool vfio_populate_vga(VFIOPCIDevice *vdev, Error **errp)
>           error_setg(errp, "unexpected VGA info, flags 0x%lx, size 0x%lx",
>                      (unsigned long)reg_info->flags,
>                      (unsigned long)reg_info->size);
> -        g_free(reg_info);
>           return false;
>       }
>   
> @@ -2694,8 +2691,6 @@ bool vfio_populate_vga(VFIOPCIDevice *vdev, Error **errp)
>       vdev->vga->fd_offset = reg_info->offset;
>       vdev->vga->fd = vdev->vbasedev.fd;
>   
> -    g_free(reg_info);
> -
>       vdev->vga->region[QEMU_PCI_VGA_MEM].offset = QEMU_PCI_VGA_MEM_BASE;
>       vdev->vga->region[QEMU_PCI_VGA_MEM].nr = QEMU_PCI_VGA_MEM;
>       QLIST_INIT(&vdev->vga->region[QEMU_PCI_VGA_MEM].quirks);
> @@ -2736,7 +2731,7 @@ bool vfio_populate_vga(VFIOPCIDevice *vdev, Error **errp)
>   static bool vfio_populate_device(VFIOPCIDevice *vdev, Error **errp)
>   {
>       VFIODevice *vbasedev = &vdev->vbasedev;
> -    struct vfio_region_info *reg_info;
> +    g_autofree struct vfio_region_info *reg_info = NULL;
>       struct vfio_irq_info irq_info = { .argsz = sizeof(irq_info) };
>       int i, ret = -1;
>   
> @@ -2790,8 +2785,6 @@ static bool vfio_populate_device(VFIOPCIDevice *vdev, Error **errp)
>       }
>       vdev->config_offset = reg_info->offset;
>   
> -    g_free(reg_info);
> -
>       if (vdev->features & VFIO_FEATURE_ENABLE_VGA) {
>           if (!vfio_populate_vga(vdev, errp)) {
>               error_append_hint(errp, "device does not support "