From f7795e4096d8bd1c767c5ddb450fa859ff20490e Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= Date: Wed, 4 Mar 2020 16:38:15 +0100 Subject: [PATCH] misc: Replace zero-length arrays with flexible array member (automatic) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Description copied from Linux kernel commit from Gustavo A. R. Silva (see [3]): --v-- description start --v-- The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member [1], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being unadvertenly introduced [2] to the Linux codebase from now on. --^-- description end --^-- Do the similar housekeeping in the QEMU codebase (which uses C99 since commit 7be41675f7cb). All these instances of code were found with the help of the following Coccinelle script: @@ identifier s, m, a; type t, T; @@ struct s { ... t m; - T a[0]; + T a[]; }; @@ identifier s, m, a; type t, T; @@ struct s { ... t m; - T a[0]; + T a[]; } QEMU_PACKED; [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=76497732932f [3] https://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux.git/commit/?id=17642a2fbd2c1 Inspired-by: Gustavo A. R. Silva Reviewed-by: David Hildenbrand Signed-off-by: Philippe Mathieu-Daudé Signed-off-by: Paolo Bonzini --- block/linux-aio.c | 2 +- bsd-user/qemu.h | 2 +- contrib/libvhost-user/libvhost-user.h | 2 +- hw/acpi/nvdimm.c | 6 +++--- hw/dma/soc_dma.c | 2 +- hw/i386/x86.c | 2 +- hw/m68k/bootinfo.h | 2 +- hw/misc/omap_l4.c | 2 +- hw/nvram/eeprom93xx.c | 2 +- hw/rdma/vmw/pvrdma_qp_ops.c | 4 ++-- hw/usb/dev-network.c | 2 +- hw/usb/dev-smartcard-reader.c | 4 ++-- hw/virtio/virtio.c | 4 ++-- hw/xen/xen_pt.h | 2 +- include/hw/acpi/acpi-defs.h | 12 ++++++------ include/hw/arm/smmu-common.h | 2 +- include/hw/i386/intel_iommu.h | 3 ++- include/hw/virtio/virtio-iommu.h | 2 +- include/sysemu/cryptodev.h | 2 +- include/tcg/tcg.h | 2 +- net/queue.c | 2 +- pc-bios/s390-ccw/bootmap.h | 2 +- pc-bios/s390-ccw/sclp.h | 2 +- tests/qtest/libqos/ahci.h | 2 +- 24 files changed, 35 insertions(+), 34 deletions(-) diff --git a/block/linux-aio.c b/block/linux-aio.c index 91204a25a2..3c0527c2bf 100644 --- a/block/linux-aio.c +++ b/block/linux-aio.c @@ -121,7 +121,7 @@ struct aio_ring { unsigned incompat_features; unsigned header_length; /* size of aio_ring */ - struct io_event io_events[0]; + struct io_event io_events[]; }; /** diff --git a/bsd-user/qemu.h b/bsd-user/qemu.h index 09e8aed9c7..f8bb1e5459 100644 --- a/bsd-user/qemu.h +++ b/bsd-user/qemu.h @@ -95,7 +95,7 @@ typedef struct TaskState { struct sigqueue *first_free; /* first free siginfo queue entry */ int signal_pending; /* non zero if a signal may be pending */ - uint8_t stack[0]; + uint8_t stack[]; } __attribute__((aligned(16))) TaskState; void init_task_state(TaskState *ts); diff --git a/contrib/libvhost-user/libvhost-user.h b/contrib/libvhost-user/libvhost-user.h index 6fc8000e99..f30394fab6 100644 --- a/contrib/libvhost-user/libvhost-user.h +++ b/contrib/libvhost-user/libvhost-user.h @@ -286,7 +286,7 @@ typedef struct VuVirtqInflight { uint16_t used_idx; /* Used to track the state of each descriptor in descriptor table */ - VuDescStateSplit desc[0]; + VuDescStateSplit desc[]; } VuVirtqInflight; typedef struct VuVirtqInflightDesc { diff --git a/hw/acpi/nvdimm.c b/hw/acpi/nvdimm.c index 5219dd0e2e..eb6a37b14e 100644 --- a/hw/acpi/nvdimm.c +++ b/hw/acpi/nvdimm.c @@ -485,7 +485,7 @@ struct NvdimmFuncGetLabelDataOut { /* the size of buffer filled by QEMU. */ uint32_t len; uint32_t func_ret_status; /* return status code. */ - uint8_t out_buf[0]; /* the data got via Get Namesapce Label function. */ + uint8_t out_buf[]; /* the data got via Get Namesapce Label function. */ } QEMU_PACKED; typedef struct NvdimmFuncGetLabelDataOut NvdimmFuncGetLabelDataOut; QEMU_BUILD_BUG_ON(sizeof(NvdimmFuncGetLabelDataOut) > NVDIMM_DSM_MEMORY_SIZE); @@ -493,7 +493,7 @@ QEMU_BUILD_BUG_ON(sizeof(NvdimmFuncGetLabelDataOut) > NVDIMM_DSM_MEMORY_SIZE); struct NvdimmFuncSetLabelDataIn { uint32_t offset; /* the offset in the namespace label data area. */ uint32_t length; /* the size of data is to be written via the function. */ - uint8_t in_buf[0]; /* the data written to label data area. */ + uint8_t in_buf[]; /* the data written to label data area. */ } QEMU_PACKED; typedef struct NvdimmFuncSetLabelDataIn NvdimmFuncSetLabelDataIn; QEMU_BUILD_BUG_ON(sizeof(NvdimmFuncSetLabelDataIn) + @@ -510,7 +510,7 @@ struct NvdimmFuncReadFITOut { /* the size of buffer filled by QEMU. */ uint32_t len; uint32_t func_ret_status; /* return status code. */ - uint8_t fit[0]; /* the FIT data. */ + uint8_t fit[]; /* the FIT data. */ } QEMU_PACKED; typedef struct NvdimmFuncReadFITOut NvdimmFuncReadFITOut; QEMU_BUILD_BUG_ON(sizeof(NvdimmFuncReadFITOut) > NVDIMM_DSM_MEMORY_SIZE); diff --git a/hw/dma/soc_dma.c b/hw/dma/soc_dma.c index c3e41581b6..3a430057f5 100644 --- a/hw/dma/soc_dma.c +++ b/hw/dma/soc_dma.c @@ -80,7 +80,7 @@ struct dma_s { } *memmap; int memmap_size; - struct soc_dma_ch_s ch[0]; + struct soc_dma_ch_s ch[]; }; static void soc_dma_ch_schedule(struct soc_dma_ch_s *ch, int delay_bytes) diff --git a/hw/i386/x86.c b/hw/i386/x86.c index 7f38e6ba8b..08246523f2 100644 --- a/hw/i386/x86.c +++ b/hw/i386/x86.c @@ -328,7 +328,7 @@ struct setup_data { uint64_t next; uint32_t type; uint32_t len; - uint8_t data[0]; + uint8_t data[]; } __attribute__((packed)); diff --git a/hw/m68k/bootinfo.h b/hw/m68k/bootinfo.h index 5f8ded2686..c954270aad 100644 --- a/hw/m68k/bootinfo.h +++ b/hw/m68k/bootinfo.h @@ -14,7 +14,7 @@ struct bi_record { uint16_t tag; /* tag ID */ uint16_t size; /* size of record */ - uint32_t data[0]; /* data */ + uint32_t data[]; /* data */ }; /* machine independent tags */ diff --git a/hw/misc/omap_l4.c b/hw/misc/omap_l4.c index 61b6df564a..54aeaecd69 100644 --- a/hw/misc/omap_l4.c +++ b/hw/misc/omap_l4.c @@ -24,7 +24,7 @@ struct omap_l4_s { MemoryRegion *address_space; hwaddr base; int ta_num; - struct omap_target_agent_s ta[0]; + struct omap_target_agent_s ta[]; }; struct omap_l4_s *omap_l4_init(MemoryRegion *address_space, diff --git a/hw/nvram/eeprom93xx.c b/hw/nvram/eeprom93xx.c index 07f09549ed..ca6f591c84 100644 --- a/hw/nvram/eeprom93xx.c +++ b/hw/nvram/eeprom93xx.c @@ -86,7 +86,7 @@ struct _eeprom_t { uint8_t addrbits; uint16_t size; uint16_t data; - uint16_t contents[0]; + uint16_t contents[]; }; /* Code for saving and restoring of EEPROM state. */ diff --git a/hw/rdma/vmw/pvrdma_qp_ops.c b/hw/rdma/vmw/pvrdma_qp_ops.c index bd6db858de..8050287a6c 100644 --- a/hw/rdma/vmw/pvrdma_qp_ops.c +++ b/hw/rdma/vmw/pvrdma_qp_ops.c @@ -34,13 +34,13 @@ typedef struct CompHandlerCtx { /* Send Queue WQE */ typedef struct PvrdmaSqWqe { struct pvrdma_sq_wqe_hdr hdr; - struct pvrdma_sge sge[0]; + struct pvrdma_sge sge[]; } PvrdmaSqWqe; /* Recv Queue WQE */ typedef struct PvrdmaRqWqe { struct pvrdma_rq_wqe_hdr hdr; - struct pvrdma_sge sge[0]; + struct pvrdma_sge sge[]; } PvrdmaRqWqe; /* diff --git a/hw/usb/dev-network.c b/hw/usb/dev-network.c index 9a78ad928b..6210427544 100644 --- a/hw/usb/dev-network.c +++ b/hw/usb/dev-network.c @@ -626,7 +626,7 @@ static const uint32_t oid_supported_list[] = struct rndis_response { QTAILQ_ENTRY(rndis_response) entries; uint32_t length; - uint8_t buf[0]; + uint8_t buf[]; }; typedef struct USBNetState { diff --git a/hw/usb/dev-smartcard-reader.c b/hw/usb/dev-smartcard-reader.c index 02693a26ad..ef72738ced 100644 --- a/hw/usb/dev-smartcard-reader.c +++ b/hw/usb/dev-smartcard-reader.c @@ -227,7 +227,7 @@ typedef struct QEMU_PACKED CCID_Parameter { typedef struct QEMU_PACKED CCID_DataBlock { CCID_BULK_IN b; uint8_t bChainParameter; - uint8_t abData[0]; + uint8_t abData[]; } CCID_DataBlock; /* 6.1.4 PC_to_RDR_XfrBlock */ @@ -235,7 +235,7 @@ typedef struct QEMU_PACKED CCID_XferBlock { CCID_Header hdr; uint8_t bBWI; /* Block Waiting Timeout */ uint16_t wLevelParameter; /* XXX currently unused */ - uint8_t abData[0]; + uint8_t abData[]; } CCID_XferBlock; typedef struct QEMU_PACKED CCID_IccPowerOn { diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c index b2d415e5dd..b6c8ef5bc0 100644 --- a/hw/virtio/virtio.c +++ b/hw/virtio/virtio.c @@ -54,7 +54,7 @@ typedef struct VRingAvail { uint16_t flags; uint16_t idx; - uint16_t ring[0]; + uint16_t ring[]; } VRingAvail; typedef struct VRingUsedElem @@ -67,7 +67,7 @@ typedef struct VRingUsed { uint16_t flags; uint16_t idx; - VRingUsedElem ring[0]; + VRingUsedElem ring[]; } VRingUsed; typedef struct VRingMemoryRegionCaches { diff --git a/hw/xen/xen_pt.h b/hw/xen/xen_pt.h index 9167bbaf6d..179775db7b 100644 --- a/hw/xen/xen_pt.h +++ b/hw/xen/xen_pt.h @@ -203,7 +203,7 @@ typedef struct XenPTMSIX { uint64_t mmio_base_addr; MemoryRegion mmio; void *phys_iomem_base; - XenPTMSIXEntry msix_entry[0]; + XenPTMSIXEntry msix_entry[]; } XenPTMSIX; struct XenPCIPassthroughState { diff --git a/include/hw/acpi/acpi-defs.h b/include/hw/acpi/acpi-defs.h index 57a3f58b0c..19f7ba7b70 100644 --- a/include/hw/acpi/acpi-defs.h +++ b/include/hw/acpi/acpi-defs.h @@ -518,7 +518,7 @@ struct AcpiDmarDeviceScope { struct { uint8_t device; uint8_t function; - } path[0]; + } path[]; } QEMU_PACKED; typedef struct AcpiDmarDeviceScope AcpiDmarDeviceScope; @@ -530,7 +530,7 @@ struct AcpiDmarHardwareUnit { uint8_t reserved; uint16_t pci_segment; /* The PCI Segment associated with this unit */ uint64_t address; /* Base address of remapping hardware register-set */ - AcpiDmarDeviceScope scope[0]; + AcpiDmarDeviceScope scope[]; } QEMU_PACKED; typedef struct AcpiDmarHardwareUnit AcpiDmarHardwareUnit; @@ -541,7 +541,7 @@ struct AcpiDmarRootPortATS { uint8_t flags; uint8_t reserved; uint16_t pci_segment; - AcpiDmarDeviceScope scope[0]; + AcpiDmarDeviceScope scope[]; } QEMU_PACKED; typedef struct AcpiDmarRootPortATS AcpiDmarRootPortATS; @@ -604,7 +604,7 @@ typedef struct AcpiIortMemoryAccess AcpiIortMemoryAccess; struct AcpiIortItsGroup { ACPI_IORT_NODE_HEADER_DEF uint32_t its_count; - uint32_t identifiers[0]; + uint32_t identifiers[]; } QEMU_PACKED; typedef struct AcpiIortItsGroup AcpiIortItsGroup; @@ -621,7 +621,7 @@ struct AcpiIortSmmu3 { uint32_t pri_gsiv; uint32_t gerr_gsiv; uint32_t sync_gsiv; - AcpiIortIdMapping id_mapping_array[0]; + AcpiIortIdMapping id_mapping_array[]; } QEMU_PACKED; typedef struct AcpiIortSmmu3 AcpiIortSmmu3; @@ -630,7 +630,7 @@ struct AcpiIortRC { AcpiIortMemoryAccess memory_properties; uint32_t ats_attribute; uint32_t pci_segment_number; - AcpiIortIdMapping id_mapping_array[0]; + AcpiIortIdMapping id_mapping_array[]; } QEMU_PACKED; typedef struct AcpiIortRC AcpiIortRC; diff --git a/include/hw/arm/smmu-common.h b/include/hw/arm/smmu-common.h index 1f37844e5c..ca4a4b1ad1 100644 --- a/include/hw/arm/smmu-common.h +++ b/include/hw/arm/smmu-common.h @@ -85,7 +85,7 @@ typedef struct SMMUDevice { typedef struct SMMUPciBus { PCIBus *bus; - SMMUDevice *pbdev[0]; /* Parent array is sparse, so dynamically alloc */ + SMMUDevice *pbdev[]; /* Parent array is sparse, so dynamically alloc */ } SMMUPciBus; typedef struct SMMUIOTLBKey { diff --git a/include/hw/i386/intel_iommu.h b/include/hw/i386/intel_iommu.h index a1c4afcda5..3870052f5f 100644 --- a/include/hw/i386/intel_iommu.h +++ b/include/hw/i386/intel_iommu.h @@ -114,7 +114,8 @@ struct VTDAddressSpace { struct VTDBus { PCIBus* bus; /* A reference to the bus to provide translation for */ - VTDAddressSpace *dev_as[0]; /* A table of VTDAddressSpace objects indexed by devfn */ + /* A table of VTDAddressSpace objects indexed by devfn */ + VTDAddressSpace *dev_as[]; }; struct VTDIOTLBEntry { diff --git a/include/hw/virtio/virtio-iommu.h b/include/hw/virtio/virtio-iommu.h index 6f67f1020a..e653004d7c 100644 --- a/include/hw/virtio/virtio-iommu.h +++ b/include/hw/virtio/virtio-iommu.h @@ -41,7 +41,7 @@ typedef struct IOMMUDevice { typedef struct IOMMUPciBus { PCIBus *bus; - IOMMUDevice *pbdev[0]; /* Parent array is sparse, so dynamically alloc */ + IOMMUDevice *pbdev[]; /* Parent array is sparse, so dynamically alloc */ } IOMMUPciBus; typedef struct VirtIOIOMMU { diff --git a/include/sysemu/cryptodev.h b/include/sysemu/cryptodev.h index a9afb7e5b5..35eab06d0e 100644 --- a/include/sysemu/cryptodev.h +++ b/include/sysemu/cryptodev.h @@ -143,7 +143,7 @@ typedef struct CryptoDevBackendSymOpInfo { uint8_t *dst; uint8_t *aad_data; uint8_t *digest_result; - uint8_t data[0]; + uint8_t data[]; } CryptoDevBackendSymOpInfo; typedef struct CryptoDevBackendClass { diff --git a/include/tcg/tcg.h b/include/tcg/tcg.h index 54e5446880..c48bd76b0a 100644 --- a/include/tcg/tcg.h +++ b/include/tcg/tcg.h @@ -267,7 +267,7 @@ struct TCGLabel { typedef struct TCGPool { struct TCGPool *next; int size; - uint8_t data[0] __attribute__ ((aligned)); + uint8_t data[] __attribute__ ((aligned)); } TCGPool; #define TCG_POOL_CHUNK_SIZE 32768 diff --git a/net/queue.c b/net/queue.c index 61276ca4be..0164727e39 100644 --- a/net/queue.c +++ b/net/queue.c @@ -46,7 +46,7 @@ struct NetPacket { unsigned flags; int size; NetPacketSent *sent_cb; - uint8_t data[0]; + uint8_t data[]; }; struct NetQueue { diff --git a/pc-bios/s390-ccw/bootmap.h b/pc-bios/s390-ccw/bootmap.h index 94f53a5f1e..12a0166aae 100644 --- a/pc-bios/s390-ccw/bootmap.h +++ b/pc-bios/s390-ccw/bootmap.h @@ -136,7 +136,7 @@ typedef struct BootMapScriptHeader { typedef struct BootMapScript { BootMapScriptHeader header; - BootMapScriptEntry entry[0]; + BootMapScriptEntry entry[]; } __attribute__ ((packed)) BootMapScript; /* diff --git a/pc-bios/s390-ccw/sclp.h b/pc-bios/s390-ccw/sclp.h index 8450161ba7..64b53cad29 100644 --- a/pc-bios/s390-ccw/sclp.h +++ b/pc-bios/s390-ccw/sclp.h @@ -95,7 +95,7 @@ typedef struct EventBufferHeader { typedef struct WriteEventData { SCCBHeader h; EventBufferHeader ebh; - char data[0]; + char data[]; } __attribute__((packed)) WriteEventData; typedef struct ReadEventData { diff --git a/tests/qtest/libqos/ahci.h b/tests/qtest/libqos/ahci.h index f05b3e5fce..44ab1104b5 100644 --- a/tests/qtest/libqos/ahci.h +++ b/tests/qtest/libqos/ahci.h @@ -351,7 +351,7 @@ typedef struct AHCIQState { typedef struct FIS { uint8_t fis_type; uint8_t flags; - char data[0]; + char data[]; } __attribute__((__packed__)) FIS; /**