* [PATCH 0/2] misc: Replace zero-length arrays with flexible array member
@ 2020-03-04 0:51 ` Philippe Mathieu-Daudé
0 siblings, 0 replies; 22+ messages in thread
From: Philippe Mathieu-Daudé @ 2020-03-04 0:51 UTC (permalink / raw)
To: qemu-devel
Cc: Fam Zheng, Peter Maydell, Michael S. Tsirkin, Jason Wang,
Yuval Shaia, Gerd Hoffmann, Stefano Stabellini, qemu-block,
David Hildenbrand, Halil Pasic, Christian Borntraeger,
Gonglei (Arei),
Anthony Perard, xen-devel, Philippe Mathieu-Daudé,
Thomas Huth, Eduardo Habkost, Paul Durrant, Eric Auger,
qemu-s390x, qemu-arm, Marc-André Lureau, John Snow,
Richard Henderson, Kevin Wolf, Xiao Guangrong, Cornelia Huck,
Laurent Vivier, Max Reitz, Igor Mammedov, Paolo Bonzini
This is a tree-wide cleanup inspired by a Linux kernel commit
(from Gustavo A. R. Silva).
--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).
The first patch is done with the help of a coccinelle semantic
patch. However Coccinelle does not recognize:
struct foo {
int stuff;
struct boo array[];
} QEMU_PACKED;
but does recognize:
struct QEMU_PACKED foo {
int stuff;
struct boo array[];
};
I'm not sure why, neither it is worth refactoring all QEMU
structures to use the attributes before the structure name,
so I did the 2nd patch manually.
Anyway this is annoying, because many structures are not handled
by coccinelle. Maybe this needs to be reported to upstream
coccinelle?
I used spatch 1.0.8 with:
-I include --include-headers \
--macro-file scripts/cocci-macro-file.h \
--keep-comments --indent 4
Regards,
Phil.
Philippe Mathieu-Daudé (2):
misc: Replace zero-length arrays with flexible array member
(automatic)
misc: Replace zero-length arrays with flexible array member (manual)
docs/interop/vhost-user.rst | 4 ++--
block/qed.h | 2 +-
bsd-user/qemu.h | 2 +-
contrib/libvhost-user/libvhost-user.h | 2 +-
hw/m68k/bootinfo.h | 2 +-
hw/scsi/srp.h | 6 +++---
hw/xen/xen_pt.h | 2 +-
include/hw/acpi/acpi-defs.h | 16 ++++++++--------
include/hw/arm/smmu-common.h | 2 +-
include/hw/boards.h | 2 +-
include/hw/i386/intel_iommu.h | 3 ++-
include/hw/s390x/event-facility.h | 2 +-
include/hw/s390x/sclp.h | 8 ++++----
include/hw/virtio/virtio-iommu.h | 2 +-
include/sysemu/cryptodev.h | 2 +-
include/tcg/tcg.h | 2 +-
pc-bios/s390-ccw/bootmap.h | 2 +-
pc-bios/s390-ccw/sclp.h | 2 +-
tests/qtest/libqos/ahci.h | 2 +-
block/linux-aio.c | 2 +-
block/vmdk.c | 2 +-
hw/acpi/nvdimm.c | 6 +++---
hw/char/sclpconsole-lm.c | 2 +-
hw/char/sclpconsole.c | 2 +-
hw/dma/soc_dma.c | 2 +-
hw/i386/x86.c | 2 +-
hw/misc/omap_l4.c | 2 +-
hw/nvram/eeprom93xx.c | 2 +-
hw/rdma/vmw/pvrdma_qp_ops.c | 4 ++--
hw/s390x/virtio-ccw.c | 2 +-
hw/usb/dev-network.c | 2 +-
hw/usb/dev-smartcard-reader.c | 4 ++--
hw/virtio/virtio.c | 4 ++--
net/queue.c | 2 +-
target/s390x/ioinst.c | 2 +-
35 files changed, 54 insertions(+), 53 deletions(-)
--
2.21.1
^ permalink raw reply [flat|nested] 22+ messages in thread
* [Xen-devel] [PATCH 0/2] misc: Replace zero-length arrays with flexible array member
@ 2020-03-04 0:51 ` Philippe Mathieu-Daudé
0 siblings, 0 replies; 22+ messages in thread
From: Philippe Mathieu-Daudé @ 2020-03-04 0:51 UTC (permalink / raw)
To: qemu-devel
Cc: Fam Zheng, Peter Maydell, Michael S. Tsirkin, Jason Wang,
Yuval Shaia, Gerd Hoffmann, Eric Blake, Stefano Stabellini,
qemu-block, David Hildenbrand, Halil Pasic,
Christian Borntraeger, Gonglei (Arei),
Marcel Apfelbaum, Anthony Perard, xen-devel,
Philippe Mathieu-Daudé,
Thomas Huth, Eduardo Habkost, Paul Durrant, Eric Auger,
qemu-s390x, qemu-arm, Marc-André Lureau, John Snow,
Richard Henderson, Kevin Wolf, Xiao Guangrong, Cornelia Huck,
Laurent Vivier, Max Reitz, Igor Mammedov, Paolo Bonzini
This is a tree-wide cleanup inspired by a Linux kernel commit
(from Gustavo A. R. Silva).
--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).
The first patch is done with the help of a coccinelle semantic
patch. However Coccinelle does not recognize:
struct foo {
int stuff;
struct boo array[];
} QEMU_PACKED;
but does recognize:
struct QEMU_PACKED foo {
int stuff;
struct boo array[];
};
I'm not sure why, neither it is worth refactoring all QEMU
structures to use the attributes before the structure name,
so I did the 2nd patch manually.
Anyway this is annoying, because many structures are not handled
by coccinelle. Maybe this needs to be reported to upstream
coccinelle?
I used spatch 1.0.8 with:
-I include --include-headers \
--macro-file scripts/cocci-macro-file.h \
--keep-comments --indent 4
Regards,
Phil.
Philippe Mathieu-Daudé (2):
misc: Replace zero-length arrays with flexible array member
(automatic)
misc: Replace zero-length arrays with flexible array member (manual)
docs/interop/vhost-user.rst | 4 ++--
block/qed.h | 2 +-
bsd-user/qemu.h | 2 +-
contrib/libvhost-user/libvhost-user.h | 2 +-
hw/m68k/bootinfo.h | 2 +-
hw/scsi/srp.h | 6 +++---
hw/xen/xen_pt.h | 2 +-
include/hw/acpi/acpi-defs.h | 16 ++++++++--------
include/hw/arm/smmu-common.h | 2 +-
include/hw/boards.h | 2 +-
include/hw/i386/intel_iommu.h | 3 ++-
include/hw/s390x/event-facility.h | 2 +-
include/hw/s390x/sclp.h | 8 ++++----
include/hw/virtio/virtio-iommu.h | 2 +-
include/sysemu/cryptodev.h | 2 +-
include/tcg/tcg.h | 2 +-
pc-bios/s390-ccw/bootmap.h | 2 +-
pc-bios/s390-ccw/sclp.h | 2 +-
tests/qtest/libqos/ahci.h | 2 +-
block/linux-aio.c | 2 +-
block/vmdk.c | 2 +-
hw/acpi/nvdimm.c | 6 +++---
hw/char/sclpconsole-lm.c | 2 +-
hw/char/sclpconsole.c | 2 +-
hw/dma/soc_dma.c | 2 +-
hw/i386/x86.c | 2 +-
hw/misc/omap_l4.c | 2 +-
hw/nvram/eeprom93xx.c | 2 +-
hw/rdma/vmw/pvrdma_qp_ops.c | 4 ++--
hw/s390x/virtio-ccw.c | 2 +-
hw/usb/dev-network.c | 2 +-
hw/usb/dev-smartcard-reader.c | 4 ++--
hw/virtio/virtio.c | 4 ++--
net/queue.c | 2 +-
target/s390x/ioinst.c | 2 +-
35 files changed, 54 insertions(+), 53 deletions(-)
--
2.21.1
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel
^ permalink raw reply [flat|nested] 22+ messages in thread
* [PATCH 1/2] misc: Replace zero-length arrays with flexible array member (automatic)
2020-03-04 0:51 ` [Xen-devel] " Philippe Mathieu-Daudé
@ 2020-03-04 0:51 ` Philippe Mathieu-Daudé
-1 siblings, 0 replies; 22+ messages in thread
From: Philippe Mathieu-Daudé @ 2020-03-04 0:51 UTC (permalink / raw)
To: qemu-devel
Cc: Fam Zheng, Peter Maydell, Michael S. Tsirkin, Jason Wang,
Yuval Shaia, Gerd Hoffmann, Stefano Stabellini, qemu-block,
David Hildenbrand, Gustavo A . R . Silva, Halil Pasic,
Christian Borntraeger, Gonglei (Arei),
Anthony Perard, xen-devel, Philippe Mathieu-Daudé,
Thomas Huth, Eduardo Habkost, Paul Durrant, Eric Auger,
qemu-s390x, qemu-arm, Marc-André Lureau, John Snow,
Richard Henderson, Kevin Wolf, Xiao Guangrong, Cornelia Huck,
Laurent Vivier, Max Reitz, Igor Mammedov, Paolo Bonzini
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, a;
type T;
@@
struct s {
...
- T a[0];
+ T a[];
};
@@
identifier s, a;
type T;
@@
struct s {
...
- 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 <gustavo@embeddedor.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
---
bsd-user/qemu.h | 2 +-
contrib/libvhost-user/libvhost-user.h | 2 +-
hw/m68k/bootinfo.h | 2 +-
hw/scsi/srp.h | 6 +++---
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 +-
pc-bios/s390-ccw/bootmap.h | 2 +-
pc-bios/s390-ccw/sclp.h | 2 +-
tests/qtest/libqos/ahci.h | 2 +-
block/linux-aio.c | 2 +-
hw/acpi/nvdimm.c | 6 +++---
hw/dma/soc_dma.c | 2 +-
hw/i386/x86.c | 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 ++--
net/queue.c | 2 +-
25 files changed, 38 insertions(+), 37 deletions(-)
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/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/scsi/srp.h b/hw/scsi/srp.h
index d27f31d2d5..54c954badd 100644
--- a/hw/scsi/srp.h
+++ b/hw/scsi/srp.h
@@ -112,7 +112,7 @@ struct srp_direct_buf {
struct srp_indirect_buf {
struct srp_direct_buf table_desc;
uint32_t len;
- struct srp_direct_buf desc_list[0];
+ struct srp_direct_buf desc_list[];
} QEMU_PACKED;
enum {
@@ -211,7 +211,7 @@ struct srp_cmd {
uint8_t reserved4;
uint8_t add_cdb_len;
uint8_t cdb[16];
- uint8_t add_data[0];
+ uint8_t add_data[];
} QEMU_PACKED;
enum {
@@ -241,7 +241,7 @@ struct srp_rsp {
uint32_t data_in_res_cnt;
uint32_t sense_data_len;
uint32_t resp_data_len;
- uint8_t data[0];
+ uint8_t data[];
} QEMU_PACKED;
#endif /* SCSI_SRP_H */
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 66b931e526..67aaa64c1b 100644
--- a/include/hw/i386/intel_iommu.h
+++ b/include/hw/i386/intel_iommu.h
@@ -118,7 +118,8 @@ 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/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;
/**
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/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/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/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 {
--
2.21.1
^ permalink raw reply related [flat|nested] 22+ messages in thread
* [Xen-devel] [PATCH 1/2] misc: Replace zero-length arrays with flexible array member (automatic)
@ 2020-03-04 0:51 ` Philippe Mathieu-Daudé
0 siblings, 0 replies; 22+ messages in thread
From: Philippe Mathieu-Daudé @ 2020-03-04 0:51 UTC (permalink / raw)
To: qemu-devel
Cc: Fam Zheng, Peter Maydell, Michael S. Tsirkin, Jason Wang,
Yuval Shaia, Gerd Hoffmann, Eric Blake, Stefano Stabellini,
qemu-block, David Hildenbrand, Gustavo A . R . Silva,
Halil Pasic, Christian Borntraeger, Gonglei (Arei),
Marcel Apfelbaum, Anthony Perard, xen-devel,
Philippe Mathieu-Daudé,
Thomas Huth, Eduardo Habkost, Paul Durrant, Eric Auger,
qemu-s390x, qemu-arm, Marc-André Lureau, John Snow,
Richard Henderson, Kevin Wolf, Xiao Guangrong, Cornelia Huck,
Laurent Vivier, Max Reitz, Igor Mammedov, Paolo Bonzini
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, a;
type T;
@@
struct s {
...
- T a[0];
+ T a[];
};
@@
identifier s, a;
type T;
@@
struct s {
...
- 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 <gustavo@embeddedor.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
---
bsd-user/qemu.h | 2 +-
contrib/libvhost-user/libvhost-user.h | 2 +-
hw/m68k/bootinfo.h | 2 +-
hw/scsi/srp.h | 6 +++---
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 +-
pc-bios/s390-ccw/bootmap.h | 2 +-
pc-bios/s390-ccw/sclp.h | 2 +-
tests/qtest/libqos/ahci.h | 2 +-
block/linux-aio.c | 2 +-
hw/acpi/nvdimm.c | 6 +++---
hw/dma/soc_dma.c | 2 +-
hw/i386/x86.c | 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 ++--
net/queue.c | 2 +-
25 files changed, 38 insertions(+), 37 deletions(-)
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/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/scsi/srp.h b/hw/scsi/srp.h
index d27f31d2d5..54c954badd 100644
--- a/hw/scsi/srp.h
+++ b/hw/scsi/srp.h
@@ -112,7 +112,7 @@ struct srp_direct_buf {
struct srp_indirect_buf {
struct srp_direct_buf table_desc;
uint32_t len;
- struct srp_direct_buf desc_list[0];
+ struct srp_direct_buf desc_list[];
} QEMU_PACKED;
enum {
@@ -211,7 +211,7 @@ struct srp_cmd {
uint8_t reserved4;
uint8_t add_cdb_len;
uint8_t cdb[16];
- uint8_t add_data[0];
+ uint8_t add_data[];
} QEMU_PACKED;
enum {
@@ -241,7 +241,7 @@ struct srp_rsp {
uint32_t data_in_res_cnt;
uint32_t sense_data_len;
uint32_t resp_data_len;
- uint8_t data[0];
+ uint8_t data[];
} QEMU_PACKED;
#endif /* SCSI_SRP_H */
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 66b931e526..67aaa64c1b 100644
--- a/include/hw/i386/intel_iommu.h
+++ b/include/hw/i386/intel_iommu.h
@@ -118,7 +118,8 @@ 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/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;
/**
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/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/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/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 {
--
2.21.1
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel
^ permalink raw reply related [flat|nested] 22+ messages in thread
* [PATCH 2/2] misc: Replace zero-length arrays with flexible array member (manual)
2020-03-04 0:51 ` [Xen-devel] " Philippe Mathieu-Daudé
@ 2020-03-04 0:58 ` Philippe Mathieu-Daudé
-1 siblings, 0 replies; 22+ messages in thread
From: Philippe Mathieu-Daudé @ 2020-03-04 0:58 UTC (permalink / raw)
To: qemu-devel
Cc: Fam Zheng, Peter Maydell, Michael S. Tsirkin, Jason Wang,
Yuval Shaia, Gerd Hoffmann, Stefano Stabellini, qemu-block,
David Hildenbrand, Gustavo A . R . Silva, Halil Pasic,
Christian Borntraeger, Gonglei (Arei),
Anthony Perard, xen-devel, Philippe Mathieu-Daudé,
Thomas Huth, Eduardo Habkost, Paul Durrant, Eric Auger,
qemu-s390x, qemu-arm, Marc-André Lureau, John Snow,
Richard Henderson, Kevin Wolf, Xiao Guangrong, Cornelia Huck,
Laurent Vivier, Max Reitz, Igor Mammedov, Paolo Bonzini
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 command (then manual analysis):
git grep -F '[0];'
[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 <gustavo@embeddedor.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
---
docs/interop/vhost-user.rst | 4 ++--
block/qed.h | 2 +-
include/hw/acpi/acpi-defs.h | 4 ++--
include/hw/boards.h | 2 +-
include/hw/s390x/event-facility.h | 2 +-
include/hw/s390x/sclp.h | 8 ++++----
block/vmdk.c | 2 +-
hw/char/sclpconsole-lm.c | 2 +-
hw/char/sclpconsole.c | 2 +-
hw/s390x/virtio-ccw.c | 2 +-
target/s390x/ioinst.c | 2 +-
11 files changed, 16 insertions(+), 16 deletions(-)
diff --git a/docs/interop/vhost-user.rst b/docs/interop/vhost-user.rst
index 401652397c..3b1b6602c7 100644
--- a/docs/interop/vhost-user.rst
+++ b/docs/interop/vhost-user.rst
@@ -568,7 +568,7 @@ For split virtqueue, queue region can be implemented as:
uint16_t used_idx;
/* Used to track the state of each descriptor in descriptor table */
- DescStateSplit desc[0];
+ DescStateSplit desc[];
} QueueRegionSplit;
To track inflight I/O, the queue region should be processed as follows:
@@ -690,7 +690,7 @@ For packed virtqueue, queue region can be implemented as:
uint8_t padding[7];
/* Used to track the state of each descriptor fetched from descriptor ring */
- DescStatePacked desc[0];
+ DescStatePacked desc[];
} QueueRegionPacked;
To track inflight I/O, the queue region should be processed as follows:
diff --git a/block/qed.h b/block/qed.h
index 42c115d822..87428ba00e 100644
--- a/block/qed.h
+++ b/block/qed.h
@@ -103,7 +103,7 @@ typedef struct {
} QEMU_PACKED QEDHeader;
typedef struct {
- uint64_t offsets[0]; /* in bytes */
+ uint64_t offsets[]; /* in bytes */
} QEDTable;
/* The L2 cache is a simple write-through cache for L2 structures */
diff --git a/include/hw/acpi/acpi-defs.h b/include/hw/acpi/acpi-defs.h
index 19f7ba7b70..c13327fa78 100644
--- a/include/hw/acpi/acpi-defs.h
+++ b/include/hw/acpi/acpi-defs.h
@@ -152,7 +152,7 @@ typedef struct AcpiSerialPortConsoleRedirection
*/
struct AcpiRsdtDescriptorRev1 {
ACPI_TABLE_HEADER_DEF /* ACPI common table header */
- uint32_t table_offset_entry[0]; /* Array of pointers to other */
+ uint32_t table_offset_entry[]; /* Array of pointers to other */
/* ACPI tables */
} QEMU_PACKED;
typedef struct AcpiRsdtDescriptorRev1 AcpiRsdtDescriptorRev1;
@@ -162,7 +162,7 @@ typedef struct AcpiRsdtDescriptorRev1 AcpiRsdtDescriptorRev1;
*/
struct AcpiXsdtDescriptorRev2 {
ACPI_TABLE_HEADER_DEF /* ACPI common table header */
- uint64_t table_offset_entry[0]; /* Array of pointers to other */
+ uint64_t table_offset_entry[]; /* Array of pointers to other */
/* ACPI tables */
} QEMU_PACKED;
typedef struct AcpiXsdtDescriptorRev2 AcpiXsdtDescriptorRev2;
diff --git a/include/hw/boards.h b/include/hw/boards.h
index 9bc42dfb22..c96120d15f 100644
--- a/include/hw/boards.h
+++ b/include/hw/boards.h
@@ -71,7 +71,7 @@ typedef struct CPUArchId {
*/
typedef struct {
int len;
- CPUArchId cpus[0];
+ CPUArchId cpus[];
} CPUArchIdList;
/**
diff --git a/include/hw/s390x/event-facility.h b/include/hw/s390x/event-facility.h
index bdc32a3c09..700a610f33 100644
--- a/include/hw/s390x/event-facility.h
+++ b/include/hw/s390x/event-facility.h
@@ -122,7 +122,7 @@ typedef struct MDBO {
typedef struct MDB {
MdbHeader header;
- MDBO mdbo[0];
+ MDBO mdbo[];
} QEMU_PACKED MDB;
typedef struct SclpMsg {
diff --git a/include/hw/s390x/sclp.h b/include/hw/s390x/sclp.h
index c54413b78c..cd7b24359f 100644
--- a/include/hw/s390x/sclp.h
+++ b/include/hw/s390x/sclp.h
@@ -132,7 +132,7 @@ typedef struct ReadInfo {
uint16_t highest_cpu;
uint8_t _reserved5[124 - 122]; /* 122-123 */
uint32_t hmfai;
- struct CPUEntry entries[0];
+ struct CPUEntry entries[];
} QEMU_PACKED ReadInfo;
typedef struct ReadCpuInfo {
@@ -142,7 +142,7 @@ typedef struct ReadCpuInfo {
uint16_t nr_standby; /* 12-13 */
uint16_t offset_standby; /* 14-15 */
uint8_t reserved0[24-16]; /* 16-23 */
- struct CPUEntry entries[0];
+ struct CPUEntry entries[];
} QEMU_PACKED ReadCpuInfo;
typedef struct ReadStorageElementInfo {
@@ -151,7 +151,7 @@ typedef struct ReadStorageElementInfo {
uint16_t assigned;
uint16_t standby;
uint8_t _reserved0[16 - 14]; /* 14-15 */
- uint32_t entries[0];
+ uint32_t entries[];
} QEMU_PACKED ReadStorageElementInfo;
typedef struct AttachStorageElement {
@@ -159,7 +159,7 @@ typedef struct AttachStorageElement {
uint8_t _reserved0[10 - 8]; /* 8-9 */
uint16_t assigned;
uint8_t _reserved1[16 - 12]; /* 12-15 */
- uint32_t entries[0];
+ uint32_t entries[];
} QEMU_PACKED AttachStorageElement;
typedef struct AssignStorage {
diff --git a/block/vmdk.c b/block/vmdk.c
index 20e909d997..8466051bc9 100644
--- a/block/vmdk.c
+++ b/block/vmdk.c
@@ -187,7 +187,7 @@ typedef struct VmdkMetaData {
typedef struct VmdkGrainMarker {
uint64_t lba;
uint32_t size;
- uint8_t data[0];
+ uint8_t data[];
} QEMU_PACKED VmdkGrainMarker;
enum {
diff --git a/hw/char/sclpconsole-lm.c b/hw/char/sclpconsole-lm.c
index c420dc066e..2b5f37b6a2 100644
--- a/hw/char/sclpconsole-lm.c
+++ b/hw/char/sclpconsole-lm.c
@@ -31,7 +31,7 @@
typedef struct OprtnsCommand {
EventBufferHeader header;
MDMSU message_unit;
- char data[0];
+ char data[];
} QEMU_PACKED OprtnsCommand;
/* max size for line-mode data in 4K SCCB page */
diff --git a/hw/char/sclpconsole.c b/hw/char/sclpconsole.c
index 1fa124dab9..5c7664905e 100644
--- a/hw/char/sclpconsole.c
+++ b/hw/char/sclpconsole.c
@@ -25,7 +25,7 @@
typedef struct ASCIIConsoleData {
EventBufferHeader ebh;
- char data[0];
+ char data[];
} QEMU_PACKED ASCIIConsoleData;
/* max size for ASCII data in 4K SCCB page */
diff --git a/hw/s390x/virtio-ccw.c b/hw/s390x/virtio-ccw.c
index 50cf95b781..64f928fc7d 100644
--- a/hw/s390x/virtio-ccw.c
+++ b/hw/s390x/virtio-ccw.c
@@ -193,7 +193,7 @@ typedef struct VirtioThinintInfo {
typedef struct VirtioRevInfo {
uint16_t revision;
uint16_t length;
- uint8_t data[0];
+ uint8_t data[];
} QEMU_PACKED VirtioRevInfo;
/* Specify where the virtqueues for the subchannel are in guest memory. */
diff --git a/target/s390x/ioinst.c b/target/s390x/ioinst.c
index c437a1d8c6..0e840cc579 100644
--- a/target/s390x/ioinst.c
+++ b/target/s390x/ioinst.c
@@ -347,7 +347,7 @@ typedef struct ChscResp {
uint16_t len;
uint16_t code;
uint32_t param;
- char data[0];
+ char data[];
} QEMU_PACKED ChscResp;
#define CHSC_MIN_RESP_LEN 0x0008
--
2.21.1
^ permalink raw reply related [flat|nested] 22+ messages in thread
* [Xen-devel] [PATCH 2/2] misc: Replace zero-length arrays with flexible array member (manual)
@ 2020-03-04 0:58 ` Philippe Mathieu-Daudé
0 siblings, 0 replies; 22+ messages in thread
From: Philippe Mathieu-Daudé @ 2020-03-04 0:58 UTC (permalink / raw)
To: qemu-devel
Cc: Fam Zheng, Peter Maydell, Michael S. Tsirkin, Jason Wang,
Yuval Shaia, Gerd Hoffmann, Eric Blake, Stefano Stabellini,
qemu-block, David Hildenbrand, Gustavo A . R . Silva,
Halil Pasic, Christian Borntraeger, Gonglei (Arei),
Marcel Apfelbaum, Anthony Perard, xen-devel,
Philippe Mathieu-Daudé,
Thomas Huth, Eduardo Habkost, Paul Durrant, Eric Auger,
qemu-s390x, qemu-arm, Marc-André Lureau, John Snow,
Richard Henderson, Kevin Wolf, Xiao Guangrong, Cornelia Huck,
Laurent Vivier, Max Reitz, Igor Mammedov, Paolo Bonzini
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 command (then manual analysis):
git grep -F '[0];'
[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 <gustavo@embeddedor.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
---
docs/interop/vhost-user.rst | 4 ++--
block/qed.h | 2 +-
include/hw/acpi/acpi-defs.h | 4 ++--
include/hw/boards.h | 2 +-
include/hw/s390x/event-facility.h | 2 +-
include/hw/s390x/sclp.h | 8 ++++----
block/vmdk.c | 2 +-
hw/char/sclpconsole-lm.c | 2 +-
hw/char/sclpconsole.c | 2 +-
hw/s390x/virtio-ccw.c | 2 +-
target/s390x/ioinst.c | 2 +-
11 files changed, 16 insertions(+), 16 deletions(-)
diff --git a/docs/interop/vhost-user.rst b/docs/interop/vhost-user.rst
index 401652397c..3b1b6602c7 100644
--- a/docs/interop/vhost-user.rst
+++ b/docs/interop/vhost-user.rst
@@ -568,7 +568,7 @@ For split virtqueue, queue region can be implemented as:
uint16_t used_idx;
/* Used to track the state of each descriptor in descriptor table */
- DescStateSplit desc[0];
+ DescStateSplit desc[];
} QueueRegionSplit;
To track inflight I/O, the queue region should be processed as follows:
@@ -690,7 +690,7 @@ For packed virtqueue, queue region can be implemented as:
uint8_t padding[7];
/* Used to track the state of each descriptor fetched from descriptor ring */
- DescStatePacked desc[0];
+ DescStatePacked desc[];
} QueueRegionPacked;
To track inflight I/O, the queue region should be processed as follows:
diff --git a/block/qed.h b/block/qed.h
index 42c115d822..87428ba00e 100644
--- a/block/qed.h
+++ b/block/qed.h
@@ -103,7 +103,7 @@ typedef struct {
} QEMU_PACKED QEDHeader;
typedef struct {
- uint64_t offsets[0]; /* in bytes */
+ uint64_t offsets[]; /* in bytes */
} QEDTable;
/* The L2 cache is a simple write-through cache for L2 structures */
diff --git a/include/hw/acpi/acpi-defs.h b/include/hw/acpi/acpi-defs.h
index 19f7ba7b70..c13327fa78 100644
--- a/include/hw/acpi/acpi-defs.h
+++ b/include/hw/acpi/acpi-defs.h
@@ -152,7 +152,7 @@ typedef struct AcpiSerialPortConsoleRedirection
*/
struct AcpiRsdtDescriptorRev1 {
ACPI_TABLE_HEADER_DEF /* ACPI common table header */
- uint32_t table_offset_entry[0]; /* Array of pointers to other */
+ uint32_t table_offset_entry[]; /* Array of pointers to other */
/* ACPI tables */
} QEMU_PACKED;
typedef struct AcpiRsdtDescriptorRev1 AcpiRsdtDescriptorRev1;
@@ -162,7 +162,7 @@ typedef struct AcpiRsdtDescriptorRev1 AcpiRsdtDescriptorRev1;
*/
struct AcpiXsdtDescriptorRev2 {
ACPI_TABLE_HEADER_DEF /* ACPI common table header */
- uint64_t table_offset_entry[0]; /* Array of pointers to other */
+ uint64_t table_offset_entry[]; /* Array of pointers to other */
/* ACPI tables */
} QEMU_PACKED;
typedef struct AcpiXsdtDescriptorRev2 AcpiXsdtDescriptorRev2;
diff --git a/include/hw/boards.h b/include/hw/boards.h
index 9bc42dfb22..c96120d15f 100644
--- a/include/hw/boards.h
+++ b/include/hw/boards.h
@@ -71,7 +71,7 @@ typedef struct CPUArchId {
*/
typedef struct {
int len;
- CPUArchId cpus[0];
+ CPUArchId cpus[];
} CPUArchIdList;
/**
diff --git a/include/hw/s390x/event-facility.h b/include/hw/s390x/event-facility.h
index bdc32a3c09..700a610f33 100644
--- a/include/hw/s390x/event-facility.h
+++ b/include/hw/s390x/event-facility.h
@@ -122,7 +122,7 @@ typedef struct MDBO {
typedef struct MDB {
MdbHeader header;
- MDBO mdbo[0];
+ MDBO mdbo[];
} QEMU_PACKED MDB;
typedef struct SclpMsg {
diff --git a/include/hw/s390x/sclp.h b/include/hw/s390x/sclp.h
index c54413b78c..cd7b24359f 100644
--- a/include/hw/s390x/sclp.h
+++ b/include/hw/s390x/sclp.h
@@ -132,7 +132,7 @@ typedef struct ReadInfo {
uint16_t highest_cpu;
uint8_t _reserved5[124 - 122]; /* 122-123 */
uint32_t hmfai;
- struct CPUEntry entries[0];
+ struct CPUEntry entries[];
} QEMU_PACKED ReadInfo;
typedef struct ReadCpuInfo {
@@ -142,7 +142,7 @@ typedef struct ReadCpuInfo {
uint16_t nr_standby; /* 12-13 */
uint16_t offset_standby; /* 14-15 */
uint8_t reserved0[24-16]; /* 16-23 */
- struct CPUEntry entries[0];
+ struct CPUEntry entries[];
} QEMU_PACKED ReadCpuInfo;
typedef struct ReadStorageElementInfo {
@@ -151,7 +151,7 @@ typedef struct ReadStorageElementInfo {
uint16_t assigned;
uint16_t standby;
uint8_t _reserved0[16 - 14]; /* 14-15 */
- uint32_t entries[0];
+ uint32_t entries[];
} QEMU_PACKED ReadStorageElementInfo;
typedef struct AttachStorageElement {
@@ -159,7 +159,7 @@ typedef struct AttachStorageElement {
uint8_t _reserved0[10 - 8]; /* 8-9 */
uint16_t assigned;
uint8_t _reserved1[16 - 12]; /* 12-15 */
- uint32_t entries[0];
+ uint32_t entries[];
} QEMU_PACKED AttachStorageElement;
typedef struct AssignStorage {
diff --git a/block/vmdk.c b/block/vmdk.c
index 20e909d997..8466051bc9 100644
--- a/block/vmdk.c
+++ b/block/vmdk.c
@@ -187,7 +187,7 @@ typedef struct VmdkMetaData {
typedef struct VmdkGrainMarker {
uint64_t lba;
uint32_t size;
- uint8_t data[0];
+ uint8_t data[];
} QEMU_PACKED VmdkGrainMarker;
enum {
diff --git a/hw/char/sclpconsole-lm.c b/hw/char/sclpconsole-lm.c
index c420dc066e..2b5f37b6a2 100644
--- a/hw/char/sclpconsole-lm.c
+++ b/hw/char/sclpconsole-lm.c
@@ -31,7 +31,7 @@
typedef struct OprtnsCommand {
EventBufferHeader header;
MDMSU message_unit;
- char data[0];
+ char data[];
} QEMU_PACKED OprtnsCommand;
/* max size for line-mode data in 4K SCCB page */
diff --git a/hw/char/sclpconsole.c b/hw/char/sclpconsole.c
index 1fa124dab9..5c7664905e 100644
--- a/hw/char/sclpconsole.c
+++ b/hw/char/sclpconsole.c
@@ -25,7 +25,7 @@
typedef struct ASCIIConsoleData {
EventBufferHeader ebh;
- char data[0];
+ char data[];
} QEMU_PACKED ASCIIConsoleData;
/* max size for ASCII data in 4K SCCB page */
diff --git a/hw/s390x/virtio-ccw.c b/hw/s390x/virtio-ccw.c
index 50cf95b781..64f928fc7d 100644
--- a/hw/s390x/virtio-ccw.c
+++ b/hw/s390x/virtio-ccw.c
@@ -193,7 +193,7 @@ typedef struct VirtioThinintInfo {
typedef struct VirtioRevInfo {
uint16_t revision;
uint16_t length;
- uint8_t data[0];
+ uint8_t data[];
} QEMU_PACKED VirtioRevInfo;
/* Specify where the virtqueues for the subchannel are in guest memory. */
diff --git a/target/s390x/ioinst.c b/target/s390x/ioinst.c
index c437a1d8c6..0e840cc579 100644
--- a/target/s390x/ioinst.c
+++ b/target/s390x/ioinst.c
@@ -347,7 +347,7 @@ typedef struct ChscResp {
uint16_t len;
uint16_t code;
uint32_t param;
- char data[0];
+ char data[];
} QEMU_PACKED ChscResp;
#define CHSC_MIN_RESP_LEN 0x0008
--
2.21.1
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel
^ permalink raw reply related [flat|nested] 22+ messages in thread
* Re: [PATCH 2/2] misc: Replace zero-length arrays with flexible array member (manual)
2020-03-04 0:58 ` [Xen-devel] " Philippe Mathieu-Daudé
@ 2020-03-04 8:19 ` David Hildenbrand
-1 siblings, 0 replies; 22+ messages in thread
From: David Hildenbrand @ 2020-03-04 8:19 UTC (permalink / raw)
To: Philippe Mathieu-Daudé, qemu-devel
Cc: Fam Zheng, Peter Maydell, Michael S. Tsirkin, Jason Wang,
Yuval Shaia, Gerd Hoffmann, Stefano Stabellini, qemu-block,
Paul Durrant, Gustavo A . R . Silva, Halil Pasic,
Christian Borntraeger, Gonglei (Arei),
Anthony Perard, Marc-André Lureau, Thomas Huth,
Eduardo Habkost, Eric Auger, qemu-s390x, qemu-arm, xen-devel,
John Snow, Richard Henderson, Kevin Wolf, Xiao Guangrong,
Cornelia Huck, Laurent Vivier, Max Reitz, Igor Mammedov,
Paolo Bonzini
On 04.03.20 01:58, Philippe Mathieu-Daudé wrote:
> 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 command (then manual analysis):
>
> git grep -F '[0];'
>
> [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 <gustavo@embeddedor.com>
> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> ---
> docs/interop/vhost-user.rst | 4 ++--
> block/qed.h | 2 +-
> include/hw/acpi/acpi-defs.h | 4 ++--
> include/hw/boards.h | 2 +-
> include/hw/s390x/event-facility.h | 2 +-
> include/hw/s390x/sclp.h | 8 ++++----
> block/vmdk.c | 2 +-
> hw/char/sclpconsole-lm.c | 2 +-
> hw/char/sclpconsole.c | 2 +-
> hw/s390x/virtio-ccw.c | 2 +-
> target/s390x/ioinst.c | 2 +-
> 11 files changed, 16 insertions(+), 16 deletions(-)
>
> diff --git a/docs/interop/vhost-user.rst b/docs/interop/vhost-user.rst
> index 401652397c..3b1b6602c7 100644
> --- a/docs/interop/vhost-user.rst
> +++ b/docs/interop/vhost-user.rst
> @@ -568,7 +568,7 @@ For split virtqueue, queue region can be implemented as:
> uint16_t used_idx;
>
> /* Used to track the state of each descriptor in descriptor table */
> - DescStateSplit desc[0];
> + DescStateSplit desc[];
> } QueueRegionSplit;
>
> To track inflight I/O, the queue region should be processed as follows:
> @@ -690,7 +690,7 @@ For packed virtqueue, queue region can be implemented as:
> uint8_t padding[7];
>
> /* Used to track the state of each descriptor fetched from descriptor ring */
> - DescStatePacked desc[0];
> + DescStatePacked desc[];
> } QueueRegionPacked;
>
> To track inflight I/O, the queue region should be processed as follows:
> diff --git a/block/qed.h b/block/qed.h
> index 42c115d822..87428ba00e 100644
> --- a/block/qed.h
> +++ b/block/qed.h
> @@ -103,7 +103,7 @@ typedef struct {
> } QEMU_PACKED QEDHeader;
>
> typedef struct {
> - uint64_t offsets[0]; /* in bytes */
> + uint64_t offsets[]; /* in bytes */
> } QEDTable;
>
> /* The L2 cache is a simple write-through cache for L2 structures */
> diff --git a/include/hw/acpi/acpi-defs.h b/include/hw/acpi/acpi-defs.h
> index 19f7ba7b70..c13327fa78 100644
> --- a/include/hw/acpi/acpi-defs.h
> +++ b/include/hw/acpi/acpi-defs.h
> @@ -152,7 +152,7 @@ typedef struct AcpiSerialPortConsoleRedirection
> */
> struct AcpiRsdtDescriptorRev1 {
> ACPI_TABLE_HEADER_DEF /* ACPI common table header */
> - uint32_t table_offset_entry[0]; /* Array of pointers to other */
> + uint32_t table_offset_entry[]; /* Array of pointers to other */
> /* ACPI tables */
> } QEMU_PACKED;
> typedef struct AcpiRsdtDescriptorRev1 AcpiRsdtDescriptorRev1;
> @@ -162,7 +162,7 @@ typedef struct AcpiRsdtDescriptorRev1 AcpiRsdtDescriptorRev1;
> */
> struct AcpiXsdtDescriptorRev2 {
> ACPI_TABLE_HEADER_DEF /* ACPI common table header */
> - uint64_t table_offset_entry[0]; /* Array of pointers to other */
> + uint64_t table_offset_entry[]; /* Array of pointers to other */
> /* ACPI tables */
> } QEMU_PACKED;
> typedef struct AcpiXsdtDescriptorRev2 AcpiXsdtDescriptorRev2;
> diff --git a/include/hw/boards.h b/include/hw/boards.h
> index 9bc42dfb22..c96120d15f 100644
> --- a/include/hw/boards.h
> +++ b/include/hw/boards.h
> @@ -71,7 +71,7 @@ typedef struct CPUArchId {
> */
> typedef struct {
> int len;
> - CPUArchId cpus[0];
> + CPUArchId cpus[];
> } CPUArchIdList;
>
> /**
> diff --git a/include/hw/s390x/event-facility.h b/include/hw/s390x/event-facility.h
> index bdc32a3c09..700a610f33 100644
> --- a/include/hw/s390x/event-facility.h
> +++ b/include/hw/s390x/event-facility.h
> @@ -122,7 +122,7 @@ typedef struct MDBO {
>
> typedef struct MDB {
> MdbHeader header;
> - MDBO mdbo[0];
> + MDBO mdbo[];
> } QEMU_PACKED MDB;
>
> typedef struct SclpMsg {
> diff --git a/include/hw/s390x/sclp.h b/include/hw/s390x/sclp.h
> index c54413b78c..cd7b24359f 100644
> --- a/include/hw/s390x/sclp.h
> +++ b/include/hw/s390x/sclp.h
> @@ -132,7 +132,7 @@ typedef struct ReadInfo {
> uint16_t highest_cpu;
> uint8_t _reserved5[124 - 122]; /* 122-123 */
> uint32_t hmfai;
> - struct CPUEntry entries[0];
> + struct CPUEntry entries[];
> } QEMU_PACKED ReadInfo;
>
> typedef struct ReadCpuInfo {
> @@ -142,7 +142,7 @@ typedef struct ReadCpuInfo {
> uint16_t nr_standby; /* 12-13 */
> uint16_t offset_standby; /* 14-15 */
> uint8_t reserved0[24-16]; /* 16-23 */
> - struct CPUEntry entries[0];
> + struct CPUEntry entries[];
> } QEMU_PACKED ReadCpuInfo;
>
> typedef struct ReadStorageElementInfo {
> @@ -151,7 +151,7 @@ typedef struct ReadStorageElementInfo {
> uint16_t assigned;
> uint16_t standby;
> uint8_t _reserved0[16 - 14]; /* 14-15 */
> - uint32_t entries[0];
> + uint32_t entries[];
> } QEMU_PACKED ReadStorageElementInfo;
>
> typedef struct AttachStorageElement {
> @@ -159,7 +159,7 @@ typedef struct AttachStorageElement {
> uint8_t _reserved0[10 - 8]; /* 8-9 */
> uint16_t assigned;
> uint8_t _reserved1[16 - 12]; /* 12-15 */
> - uint32_t entries[0];
> + uint32_t entries[];
> } QEMU_PACKED AttachStorageElement;
>
> typedef struct AssignStorage {
> diff --git a/block/vmdk.c b/block/vmdk.c
> index 20e909d997..8466051bc9 100644
> --- a/block/vmdk.c
> +++ b/block/vmdk.c
> @@ -187,7 +187,7 @@ typedef struct VmdkMetaData {
> typedef struct VmdkGrainMarker {
> uint64_t lba;
> uint32_t size;
> - uint8_t data[0];
> + uint8_t data[];
> } QEMU_PACKED VmdkGrainMarker;
>
> enum {
> diff --git a/hw/char/sclpconsole-lm.c b/hw/char/sclpconsole-lm.c
> index c420dc066e..2b5f37b6a2 100644
> --- a/hw/char/sclpconsole-lm.c
> +++ b/hw/char/sclpconsole-lm.c
> @@ -31,7 +31,7 @@
> typedef struct OprtnsCommand {
> EventBufferHeader header;
> MDMSU message_unit;
> - char data[0];
> + char data[];
> } QEMU_PACKED OprtnsCommand;
>
> /* max size for line-mode data in 4K SCCB page */
> diff --git a/hw/char/sclpconsole.c b/hw/char/sclpconsole.c
> index 1fa124dab9..5c7664905e 100644
> --- a/hw/char/sclpconsole.c
> +++ b/hw/char/sclpconsole.c
> @@ -25,7 +25,7 @@
>
> typedef struct ASCIIConsoleData {
> EventBufferHeader ebh;
> - char data[0];
> + char data[];
> } QEMU_PACKED ASCIIConsoleData;
>
> /* max size for ASCII data in 4K SCCB page */
> diff --git a/hw/s390x/virtio-ccw.c b/hw/s390x/virtio-ccw.c
> index 50cf95b781..64f928fc7d 100644
> --- a/hw/s390x/virtio-ccw.c
> +++ b/hw/s390x/virtio-ccw.c
> @@ -193,7 +193,7 @@ typedef struct VirtioThinintInfo {
> typedef struct VirtioRevInfo {
> uint16_t revision;
> uint16_t length;
> - uint8_t data[0];
> + uint8_t data[];
> } QEMU_PACKED VirtioRevInfo;
>
> /* Specify where the virtqueues for the subchannel are in guest memory. */
> diff --git a/target/s390x/ioinst.c b/target/s390x/ioinst.c
> index c437a1d8c6..0e840cc579 100644
> --- a/target/s390x/ioinst.c
> +++ b/target/s390x/ioinst.c
> @@ -347,7 +347,7 @@ typedef struct ChscResp {
> uint16_t len;
> uint16_t code;
> uint32_t param;
> - char data[0];
> + char data[];
> } QEMU_PACKED ChscResp;
>
> #define CHSC_MIN_RESP_LEN 0x0008
>
Reviewed-by: David Hildenbrand <david@redhat.com>
--
Thanks,
David / dhildenb
^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [Xen-devel] [PATCH 2/2] misc: Replace zero-length arrays with flexible array member (manual)
@ 2020-03-04 8:19 ` David Hildenbrand
0 siblings, 0 replies; 22+ messages in thread
From: David Hildenbrand @ 2020-03-04 8:19 UTC (permalink / raw)
To: Philippe Mathieu-Daudé, qemu-devel
Cc: Fam Zheng, Peter Maydell, Michael S. Tsirkin, Jason Wang,
Yuval Shaia, Gerd Hoffmann, Eric Blake, Stefano Stabellini,
qemu-block, Paul Durrant, Gustavo A . R . Silva, Halil Pasic,
Christian Borntraeger, Gonglei (Arei),
Marcel Apfelbaum, Anthony Perard, Marc-André Lureau,
Thomas Huth, Eduardo Habkost, Eric Auger, qemu-s390x, qemu-arm,
xen-devel, John Snow, Richard Henderson, Kevin Wolf,
Xiao Guangrong, Cornelia Huck, Laurent Vivier, Max Reitz,
Igor Mammedov, Paolo Bonzini
On 04.03.20 01:58, Philippe Mathieu-Daudé wrote:
> 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 command (then manual analysis):
>
> git grep -F '[0];'
>
> [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 <gustavo@embeddedor.com>
> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> ---
> docs/interop/vhost-user.rst | 4 ++--
> block/qed.h | 2 +-
> include/hw/acpi/acpi-defs.h | 4 ++--
> include/hw/boards.h | 2 +-
> include/hw/s390x/event-facility.h | 2 +-
> include/hw/s390x/sclp.h | 8 ++++----
> block/vmdk.c | 2 +-
> hw/char/sclpconsole-lm.c | 2 +-
> hw/char/sclpconsole.c | 2 +-
> hw/s390x/virtio-ccw.c | 2 +-
> target/s390x/ioinst.c | 2 +-
> 11 files changed, 16 insertions(+), 16 deletions(-)
>
> diff --git a/docs/interop/vhost-user.rst b/docs/interop/vhost-user.rst
> index 401652397c..3b1b6602c7 100644
> --- a/docs/interop/vhost-user.rst
> +++ b/docs/interop/vhost-user.rst
> @@ -568,7 +568,7 @@ For split virtqueue, queue region can be implemented as:
> uint16_t used_idx;
>
> /* Used to track the state of each descriptor in descriptor table */
> - DescStateSplit desc[0];
> + DescStateSplit desc[];
> } QueueRegionSplit;
>
> To track inflight I/O, the queue region should be processed as follows:
> @@ -690,7 +690,7 @@ For packed virtqueue, queue region can be implemented as:
> uint8_t padding[7];
>
> /* Used to track the state of each descriptor fetched from descriptor ring */
> - DescStatePacked desc[0];
> + DescStatePacked desc[];
> } QueueRegionPacked;
>
> To track inflight I/O, the queue region should be processed as follows:
> diff --git a/block/qed.h b/block/qed.h
> index 42c115d822..87428ba00e 100644
> --- a/block/qed.h
> +++ b/block/qed.h
> @@ -103,7 +103,7 @@ typedef struct {
> } QEMU_PACKED QEDHeader;
>
> typedef struct {
> - uint64_t offsets[0]; /* in bytes */
> + uint64_t offsets[]; /* in bytes */
> } QEDTable;
>
> /* The L2 cache is a simple write-through cache for L2 structures */
> diff --git a/include/hw/acpi/acpi-defs.h b/include/hw/acpi/acpi-defs.h
> index 19f7ba7b70..c13327fa78 100644
> --- a/include/hw/acpi/acpi-defs.h
> +++ b/include/hw/acpi/acpi-defs.h
> @@ -152,7 +152,7 @@ typedef struct AcpiSerialPortConsoleRedirection
> */
> struct AcpiRsdtDescriptorRev1 {
> ACPI_TABLE_HEADER_DEF /* ACPI common table header */
> - uint32_t table_offset_entry[0]; /* Array of pointers to other */
> + uint32_t table_offset_entry[]; /* Array of pointers to other */
> /* ACPI tables */
> } QEMU_PACKED;
> typedef struct AcpiRsdtDescriptorRev1 AcpiRsdtDescriptorRev1;
> @@ -162,7 +162,7 @@ typedef struct AcpiRsdtDescriptorRev1 AcpiRsdtDescriptorRev1;
> */
> struct AcpiXsdtDescriptorRev2 {
> ACPI_TABLE_HEADER_DEF /* ACPI common table header */
> - uint64_t table_offset_entry[0]; /* Array of pointers to other */
> + uint64_t table_offset_entry[]; /* Array of pointers to other */
> /* ACPI tables */
> } QEMU_PACKED;
> typedef struct AcpiXsdtDescriptorRev2 AcpiXsdtDescriptorRev2;
> diff --git a/include/hw/boards.h b/include/hw/boards.h
> index 9bc42dfb22..c96120d15f 100644
> --- a/include/hw/boards.h
> +++ b/include/hw/boards.h
> @@ -71,7 +71,7 @@ typedef struct CPUArchId {
> */
> typedef struct {
> int len;
> - CPUArchId cpus[0];
> + CPUArchId cpus[];
> } CPUArchIdList;
>
> /**
> diff --git a/include/hw/s390x/event-facility.h b/include/hw/s390x/event-facility.h
> index bdc32a3c09..700a610f33 100644
> --- a/include/hw/s390x/event-facility.h
> +++ b/include/hw/s390x/event-facility.h
> @@ -122,7 +122,7 @@ typedef struct MDBO {
>
> typedef struct MDB {
> MdbHeader header;
> - MDBO mdbo[0];
> + MDBO mdbo[];
> } QEMU_PACKED MDB;
>
> typedef struct SclpMsg {
> diff --git a/include/hw/s390x/sclp.h b/include/hw/s390x/sclp.h
> index c54413b78c..cd7b24359f 100644
> --- a/include/hw/s390x/sclp.h
> +++ b/include/hw/s390x/sclp.h
> @@ -132,7 +132,7 @@ typedef struct ReadInfo {
> uint16_t highest_cpu;
> uint8_t _reserved5[124 - 122]; /* 122-123 */
> uint32_t hmfai;
> - struct CPUEntry entries[0];
> + struct CPUEntry entries[];
> } QEMU_PACKED ReadInfo;
>
> typedef struct ReadCpuInfo {
> @@ -142,7 +142,7 @@ typedef struct ReadCpuInfo {
> uint16_t nr_standby; /* 12-13 */
> uint16_t offset_standby; /* 14-15 */
> uint8_t reserved0[24-16]; /* 16-23 */
> - struct CPUEntry entries[0];
> + struct CPUEntry entries[];
> } QEMU_PACKED ReadCpuInfo;
>
> typedef struct ReadStorageElementInfo {
> @@ -151,7 +151,7 @@ typedef struct ReadStorageElementInfo {
> uint16_t assigned;
> uint16_t standby;
> uint8_t _reserved0[16 - 14]; /* 14-15 */
> - uint32_t entries[0];
> + uint32_t entries[];
> } QEMU_PACKED ReadStorageElementInfo;
>
> typedef struct AttachStorageElement {
> @@ -159,7 +159,7 @@ typedef struct AttachStorageElement {
> uint8_t _reserved0[10 - 8]; /* 8-9 */
> uint16_t assigned;
> uint8_t _reserved1[16 - 12]; /* 12-15 */
> - uint32_t entries[0];
> + uint32_t entries[];
> } QEMU_PACKED AttachStorageElement;
>
> typedef struct AssignStorage {
> diff --git a/block/vmdk.c b/block/vmdk.c
> index 20e909d997..8466051bc9 100644
> --- a/block/vmdk.c
> +++ b/block/vmdk.c
> @@ -187,7 +187,7 @@ typedef struct VmdkMetaData {
> typedef struct VmdkGrainMarker {
> uint64_t lba;
> uint32_t size;
> - uint8_t data[0];
> + uint8_t data[];
> } QEMU_PACKED VmdkGrainMarker;
>
> enum {
> diff --git a/hw/char/sclpconsole-lm.c b/hw/char/sclpconsole-lm.c
> index c420dc066e..2b5f37b6a2 100644
> --- a/hw/char/sclpconsole-lm.c
> +++ b/hw/char/sclpconsole-lm.c
> @@ -31,7 +31,7 @@
> typedef struct OprtnsCommand {
> EventBufferHeader header;
> MDMSU message_unit;
> - char data[0];
> + char data[];
> } QEMU_PACKED OprtnsCommand;
>
> /* max size for line-mode data in 4K SCCB page */
> diff --git a/hw/char/sclpconsole.c b/hw/char/sclpconsole.c
> index 1fa124dab9..5c7664905e 100644
> --- a/hw/char/sclpconsole.c
> +++ b/hw/char/sclpconsole.c
> @@ -25,7 +25,7 @@
>
> typedef struct ASCIIConsoleData {
> EventBufferHeader ebh;
> - char data[0];
> + char data[];
> } QEMU_PACKED ASCIIConsoleData;
>
> /* max size for ASCII data in 4K SCCB page */
> diff --git a/hw/s390x/virtio-ccw.c b/hw/s390x/virtio-ccw.c
> index 50cf95b781..64f928fc7d 100644
> --- a/hw/s390x/virtio-ccw.c
> +++ b/hw/s390x/virtio-ccw.c
> @@ -193,7 +193,7 @@ typedef struct VirtioThinintInfo {
> typedef struct VirtioRevInfo {
> uint16_t revision;
> uint16_t length;
> - uint8_t data[0];
> + uint8_t data[];
> } QEMU_PACKED VirtioRevInfo;
>
> /* Specify where the virtqueues for the subchannel are in guest memory. */
> diff --git a/target/s390x/ioinst.c b/target/s390x/ioinst.c
> index c437a1d8c6..0e840cc579 100644
> --- a/target/s390x/ioinst.c
> +++ b/target/s390x/ioinst.c
> @@ -347,7 +347,7 @@ typedef struct ChscResp {
> uint16_t len;
> uint16_t code;
> uint32_t param;
> - char data[0];
> + char data[];
> } QEMU_PACKED ChscResp;
>
> #define CHSC_MIN_RESP_LEN 0x0008
>
Reviewed-by: David Hildenbrand <david@redhat.com>
--
Thanks,
David / dhildenb
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel
^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [PATCH 1/2] misc: Replace zero-length arrays with flexible array member (automatic)
2020-03-04 0:51 ` [Xen-devel] " Philippe Mathieu-Daudé
@ 2020-03-04 8:19 ` David Hildenbrand
-1 siblings, 0 replies; 22+ messages in thread
From: David Hildenbrand @ 2020-03-04 8:19 UTC (permalink / raw)
To: Philippe Mathieu-Daudé, qemu-devel
Cc: Fam Zheng, Peter Maydell, Michael S. Tsirkin, Jason Wang,
Yuval Shaia, Gerd Hoffmann, Stefano Stabellini, qemu-block,
Paul Durrant, Gustavo A . R . Silva, Halil Pasic,
Christian Borntraeger, Gonglei (Arei),
Anthony Perard, Marc-André Lureau, Thomas Huth,
Eduardo Habkost, Eric Auger, qemu-s390x, qemu-arm, xen-devel,
John Snow, Richard Henderson, Kevin Wolf, Xiao Guangrong,
Cornelia Huck, Laurent Vivier, Max Reitz, Igor Mammedov,
Paolo Bonzini
On 04.03.20 01:51, Philippe Mathieu-Daudé wrote:
> 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, a;
> type T;
> @@
> struct s {
> ...
> - T a[0];
> + T a[];
> };
> @@
> identifier s, a;
> type T;
> @@
> struct s {
> ...
> - 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 <gustavo@embeddedor.com>
> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> ---
> bsd-user/qemu.h | 2 +-
> contrib/libvhost-user/libvhost-user.h | 2 +-
> hw/m68k/bootinfo.h | 2 +-
> hw/scsi/srp.h | 6 +++---
> 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 +-
> pc-bios/s390-ccw/bootmap.h | 2 +-
> pc-bios/s390-ccw/sclp.h | 2 +-
> tests/qtest/libqos/ahci.h | 2 +-
> block/linux-aio.c | 2 +-
> hw/acpi/nvdimm.c | 6 +++---
> hw/dma/soc_dma.c | 2 +-
> hw/i386/x86.c | 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 ++--
> net/queue.c | 2 +-
> 25 files changed, 38 insertions(+), 37 deletions(-)
>
> 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/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/scsi/srp.h b/hw/scsi/srp.h
> index d27f31d2d5..54c954badd 100644
> --- a/hw/scsi/srp.h
> +++ b/hw/scsi/srp.h
> @@ -112,7 +112,7 @@ struct srp_direct_buf {
> struct srp_indirect_buf {
> struct srp_direct_buf table_desc;
> uint32_t len;
> - struct srp_direct_buf desc_list[0];
> + struct srp_direct_buf desc_list[];
> } QEMU_PACKED;
>
> enum {
> @@ -211,7 +211,7 @@ struct srp_cmd {
> uint8_t reserved4;
> uint8_t add_cdb_len;
> uint8_t cdb[16];
> - uint8_t add_data[0];
> + uint8_t add_data[];
> } QEMU_PACKED;
>
> enum {
> @@ -241,7 +241,7 @@ struct srp_rsp {
> uint32_t data_in_res_cnt;
> uint32_t sense_data_len;
> uint32_t resp_data_len;
> - uint8_t data[0];
> + uint8_t data[];
> } QEMU_PACKED;
>
> #endif /* SCSI_SRP_H */
> 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 66b931e526..67aaa64c1b 100644
> --- a/include/hw/i386/intel_iommu.h
> +++ b/include/hw/i386/intel_iommu.h
> @@ -118,7 +118,8 @@ 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/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;
>
> /**
> 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/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/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/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 {
>
Reviewed-by: David Hildenbrand <david@redhat.com>
--
Thanks,
David / dhildenb
^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [Xen-devel] [PATCH 1/2] misc: Replace zero-length arrays with flexible array member (automatic)
@ 2020-03-04 8:19 ` David Hildenbrand
0 siblings, 0 replies; 22+ messages in thread
From: David Hildenbrand @ 2020-03-04 8:19 UTC (permalink / raw)
To: Philippe Mathieu-Daudé, qemu-devel
Cc: Fam Zheng, Peter Maydell, Michael S. Tsirkin, Jason Wang,
Yuval Shaia, Gerd Hoffmann, Eric Blake, Stefano Stabellini,
qemu-block, Paul Durrant, Gustavo A . R . Silva, Halil Pasic,
Christian Borntraeger, Gonglei (Arei),
Marcel Apfelbaum, Anthony Perard, Marc-André Lureau,
Thomas Huth, Eduardo Habkost, Eric Auger, qemu-s390x, qemu-arm,
xen-devel, John Snow, Richard Henderson, Kevin Wolf,
Xiao Guangrong, Cornelia Huck, Laurent Vivier, Max Reitz,
Igor Mammedov, Paolo Bonzini
On 04.03.20 01:51, Philippe Mathieu-Daudé wrote:
> 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, a;
> type T;
> @@
> struct s {
> ...
> - T a[0];
> + T a[];
> };
> @@
> identifier s, a;
> type T;
> @@
> struct s {
> ...
> - 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 <gustavo@embeddedor.com>
> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> ---
> bsd-user/qemu.h | 2 +-
> contrib/libvhost-user/libvhost-user.h | 2 +-
> hw/m68k/bootinfo.h | 2 +-
> hw/scsi/srp.h | 6 +++---
> 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 +-
> pc-bios/s390-ccw/bootmap.h | 2 +-
> pc-bios/s390-ccw/sclp.h | 2 +-
> tests/qtest/libqos/ahci.h | 2 +-
> block/linux-aio.c | 2 +-
> hw/acpi/nvdimm.c | 6 +++---
> hw/dma/soc_dma.c | 2 +-
> hw/i386/x86.c | 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 ++--
> net/queue.c | 2 +-
> 25 files changed, 38 insertions(+), 37 deletions(-)
>
> 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/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/scsi/srp.h b/hw/scsi/srp.h
> index d27f31d2d5..54c954badd 100644
> --- a/hw/scsi/srp.h
> +++ b/hw/scsi/srp.h
> @@ -112,7 +112,7 @@ struct srp_direct_buf {
> struct srp_indirect_buf {
> struct srp_direct_buf table_desc;
> uint32_t len;
> - struct srp_direct_buf desc_list[0];
> + struct srp_direct_buf desc_list[];
> } QEMU_PACKED;
>
> enum {
> @@ -211,7 +211,7 @@ struct srp_cmd {
> uint8_t reserved4;
> uint8_t add_cdb_len;
> uint8_t cdb[16];
> - uint8_t add_data[0];
> + uint8_t add_data[];
> } QEMU_PACKED;
>
> enum {
> @@ -241,7 +241,7 @@ struct srp_rsp {
> uint32_t data_in_res_cnt;
> uint32_t sense_data_len;
> uint32_t resp_data_len;
> - uint8_t data[0];
> + uint8_t data[];
> } QEMU_PACKED;
>
> #endif /* SCSI_SRP_H */
> 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 66b931e526..67aaa64c1b 100644
> --- a/include/hw/i386/intel_iommu.h
> +++ b/include/hw/i386/intel_iommu.h
> @@ -118,7 +118,8 @@ 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/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;
>
> /**
> 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/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/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/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 {
>
Reviewed-by: David Hildenbrand <david@redhat.com>
--
Thanks,
David / dhildenb
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel
^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [PATCH 2/2] misc: Replace zero-length arrays with flexible array member (manual)
2020-03-04 0:58 ` [Xen-devel] " Philippe Mathieu-Daudé
@ 2020-03-04 9:00 ` Philippe Mathieu-Daudé
-1 siblings, 0 replies; 22+ messages in thread
From: Philippe Mathieu-Daudé @ 2020-03-04 9:00 UTC (permalink / raw)
To: qemu-devel
Cc: Fam Zheng, Peter Maydell, Michael S. Tsirkin, Jason Wang,
Yuval Shaia, Gerd Hoffmann, Stefano Stabellini, qemu-block,
David Hildenbrand, Gustavo A . R . Silva, Halil Pasic,
Christian Borntraeger, Gonglei (Arei),
Anthony Perard, xen-devel, Thomas Huth, Eduardo Habkost,
Paul Durrant, Eric Auger, qemu-s390x, qemu-arm,
Marc-André Lureau, John Snow, Richard Henderson, Kevin Wolf,
Xiao Guangrong, Cornelia Huck, Laurent Vivier, Max Reitz,
Igor Mammedov, Paolo Bonzini
On 3/4/20 1:58 AM, Philippe Mathieu-Daudé wrote:
> 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 command (then manual analysis):
>
> git grep -F '[0];'
>
> [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 <gustavo@embeddedor.com>
> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> ---
> docs/interop/vhost-user.rst | 4 ++--
> block/qed.h | 2 +-
> include/hw/acpi/acpi-defs.h | 4 ++--
> include/hw/boards.h | 2 +-
> include/hw/s390x/event-facility.h | 2 +-
> include/hw/s390x/sclp.h | 8 ++++----
> block/vmdk.c | 2 +-
> hw/char/sclpconsole-lm.c | 2 +-
> hw/char/sclpconsole.c | 2 +-
> hw/s390x/virtio-ccw.c | 2 +-
> target/s390x/ioinst.c | 2 +-
> 11 files changed, 16 insertions(+), 16 deletions(-)
>
> diff --git a/docs/interop/vhost-user.rst b/docs/interop/vhost-user.rst
> index 401652397c..3b1b6602c7 100644
> --- a/docs/interop/vhost-user.rst
> +++ b/docs/interop/vhost-user.rst
> @@ -568,7 +568,7 @@ For split virtqueue, queue region can be implemented as:
> uint16_t used_idx;
>
> /* Used to track the state of each descriptor in descriptor table */
> - DescStateSplit desc[0];
> + DescStateSplit desc[];
> } QueueRegionSplit;
>
> To track inflight I/O, the queue region should be processed as follows:
> @@ -690,7 +690,7 @@ For packed virtqueue, queue region can be implemented as:
> uint8_t padding[7];
>
> /* Used to track the state of each descriptor fetched from descriptor ring */
> - DescStatePacked desc[0];
> + DescStatePacked desc[];
> } QueueRegionPacked;
>
> To track inflight I/O, the queue region should be processed as follows:
> diff --git a/block/qed.h b/block/qed.h
> index 42c115d822..87428ba00e 100644
> --- a/block/qed.h
> +++ b/block/qed.h
> @@ -103,7 +103,7 @@ typedef struct {
> } QEMU_PACKED QEDHeader;
>
> typedef struct {
> - uint64_t offsets[0]; /* in bytes */
> + uint64_t offsets[]; /* in bytes */
Apparently this one is incorrect, it triggers:
GCC:
block/qed.h:106:14: error: flexible array member in otherwise empty struct
Clang:
block/qed.h:106:14: error: flexible array member 'offsets' not allowed
in otherwise empty struct
> } QEDTable;
>
> /* The L2 cache is a simple write-through cache for L2 structures */
> diff --git a/include/hw/acpi/acpi-defs.h b/include/hw/acpi/acpi-defs.h
> index 19f7ba7b70..c13327fa78 100644
> --- a/include/hw/acpi/acpi-defs.h
> +++ b/include/hw/acpi/acpi-defs.h
> @@ -152,7 +152,7 @@ typedef struct AcpiSerialPortConsoleRedirection
> */
> struct AcpiRsdtDescriptorRev1 {
> ACPI_TABLE_HEADER_DEF /* ACPI common table header */
> - uint32_t table_offset_entry[0]; /* Array of pointers to other */
> + uint32_t table_offset_entry[]; /* Array of pointers to other */
> /* ACPI tables */
> } QEMU_PACKED;
> typedef struct AcpiRsdtDescriptorRev1 AcpiRsdtDescriptorRev1;
> @@ -162,7 +162,7 @@ typedef struct AcpiRsdtDescriptorRev1 AcpiRsdtDescriptorRev1;
> */
> struct AcpiXsdtDescriptorRev2 {
> ACPI_TABLE_HEADER_DEF /* ACPI common table header */
> - uint64_t table_offset_entry[0]; /* Array of pointers to other */
> + uint64_t table_offset_entry[]; /* Array of pointers to other */
> /* ACPI tables */
> } QEMU_PACKED;
> typedef struct AcpiXsdtDescriptorRev2 AcpiXsdtDescriptorRev2;
> diff --git a/include/hw/boards.h b/include/hw/boards.h
> index 9bc42dfb22..c96120d15f 100644
> --- a/include/hw/boards.h
> +++ b/include/hw/boards.h
> @@ -71,7 +71,7 @@ typedef struct CPUArchId {
> */
> typedef struct {
> int len;
> - CPUArchId cpus[0];
> + CPUArchId cpus[];
> } CPUArchIdList;
>
> /**
> diff --git a/include/hw/s390x/event-facility.h b/include/hw/s390x/event-facility.h
> index bdc32a3c09..700a610f33 100644
> --- a/include/hw/s390x/event-facility.h
> +++ b/include/hw/s390x/event-facility.h
> @@ -122,7 +122,7 @@ typedef struct MDBO {
>
> typedef struct MDB {
> MdbHeader header;
> - MDBO mdbo[0];
> + MDBO mdbo[];
> } QEMU_PACKED MDB;
>
> typedef struct SclpMsg {
> diff --git a/include/hw/s390x/sclp.h b/include/hw/s390x/sclp.h
> index c54413b78c..cd7b24359f 100644
> --- a/include/hw/s390x/sclp.h
> +++ b/include/hw/s390x/sclp.h
> @@ -132,7 +132,7 @@ typedef struct ReadInfo {
> uint16_t highest_cpu;
> uint8_t _reserved5[124 - 122]; /* 122-123 */
> uint32_t hmfai;
> - struct CPUEntry entries[0];
> + struct CPUEntry entries[];
> } QEMU_PACKED ReadInfo;
>
> typedef struct ReadCpuInfo {
> @@ -142,7 +142,7 @@ typedef struct ReadCpuInfo {
> uint16_t nr_standby; /* 12-13 */
> uint16_t offset_standby; /* 14-15 */
> uint8_t reserved0[24-16]; /* 16-23 */
> - struct CPUEntry entries[0];
> + struct CPUEntry entries[];
> } QEMU_PACKED ReadCpuInfo;
>
> typedef struct ReadStorageElementInfo {
> @@ -151,7 +151,7 @@ typedef struct ReadStorageElementInfo {
> uint16_t assigned;
> uint16_t standby;
> uint8_t _reserved0[16 - 14]; /* 14-15 */
> - uint32_t entries[0];
> + uint32_t entries[];
> } QEMU_PACKED ReadStorageElementInfo;
>
> typedef struct AttachStorageElement {
> @@ -159,7 +159,7 @@ typedef struct AttachStorageElement {
> uint8_t _reserved0[10 - 8]; /* 8-9 */
> uint16_t assigned;
> uint8_t _reserved1[16 - 12]; /* 12-15 */
> - uint32_t entries[0];
> + uint32_t entries[];
> } QEMU_PACKED AttachStorageElement;
>
> typedef struct AssignStorage {
> diff --git a/block/vmdk.c b/block/vmdk.c
> index 20e909d997..8466051bc9 100644
> --- a/block/vmdk.c
> +++ b/block/vmdk.c
> @@ -187,7 +187,7 @@ typedef struct VmdkMetaData {
> typedef struct VmdkGrainMarker {
> uint64_t lba;
> uint32_t size;
> - uint8_t data[0];
> + uint8_t data[];
> } QEMU_PACKED VmdkGrainMarker;
>
> enum {
> diff --git a/hw/char/sclpconsole-lm.c b/hw/char/sclpconsole-lm.c
> index c420dc066e..2b5f37b6a2 100644
> --- a/hw/char/sclpconsole-lm.c
> +++ b/hw/char/sclpconsole-lm.c
> @@ -31,7 +31,7 @@
> typedef struct OprtnsCommand {
> EventBufferHeader header;
> MDMSU message_unit;
> - char data[0];
> + char data[];
> } QEMU_PACKED OprtnsCommand;
>
> /* max size for line-mode data in 4K SCCB page */
> diff --git a/hw/char/sclpconsole.c b/hw/char/sclpconsole.c
> index 1fa124dab9..5c7664905e 100644
> --- a/hw/char/sclpconsole.c
> +++ b/hw/char/sclpconsole.c
> @@ -25,7 +25,7 @@
>
> typedef struct ASCIIConsoleData {
> EventBufferHeader ebh;
> - char data[0];
> + char data[];
> } QEMU_PACKED ASCIIConsoleData;
>
> /* max size for ASCII data in 4K SCCB page */
> diff --git a/hw/s390x/virtio-ccw.c b/hw/s390x/virtio-ccw.c
> index 50cf95b781..64f928fc7d 100644
> --- a/hw/s390x/virtio-ccw.c
> +++ b/hw/s390x/virtio-ccw.c
> @@ -193,7 +193,7 @@ typedef struct VirtioThinintInfo {
> typedef struct VirtioRevInfo {
> uint16_t revision;
> uint16_t length;
> - uint8_t data[0];
> + uint8_t data[];
> } QEMU_PACKED VirtioRevInfo;
>
> /* Specify where the virtqueues for the subchannel are in guest memory. */
> diff --git a/target/s390x/ioinst.c b/target/s390x/ioinst.c
> index c437a1d8c6..0e840cc579 100644
> --- a/target/s390x/ioinst.c
> +++ b/target/s390x/ioinst.c
> @@ -347,7 +347,7 @@ typedef struct ChscResp {
> uint16_t len;
> uint16_t code;
> uint32_t param;
> - char data[0];
> + char data[];
> } QEMU_PACKED ChscResp;
>
> #define CHSC_MIN_RESP_LEN 0x0008
>
^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [Xen-devel] [PATCH 2/2] misc: Replace zero-length arrays with flexible array member (manual)
@ 2020-03-04 9:00 ` Philippe Mathieu-Daudé
0 siblings, 0 replies; 22+ messages in thread
From: Philippe Mathieu-Daudé @ 2020-03-04 9:00 UTC (permalink / raw)
To: qemu-devel
Cc: Fam Zheng, Peter Maydell, Michael S. Tsirkin, Jason Wang,
Yuval Shaia, Gerd Hoffmann, Eric Blake, Stefano Stabellini,
qemu-block, David Hildenbrand, Gustavo A . R . Silva,
Halil Pasic, Christian Borntraeger, Gonglei (Arei),
Marcel Apfelbaum, Anthony Perard, xen-devel, Thomas Huth,
Eduardo Habkost, Paul Durrant, Eric Auger, qemu-s390x, qemu-arm,
Marc-André Lureau, John Snow, Richard Henderson, Kevin Wolf,
Xiao Guangrong, Cornelia Huck, Laurent Vivier, Max Reitz,
Igor Mammedov, Paolo Bonzini
On 3/4/20 1:58 AM, Philippe Mathieu-Daudé wrote:
> 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 command (then manual analysis):
>
> git grep -F '[0];'
>
> [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 <gustavo@embeddedor.com>
> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> ---
> docs/interop/vhost-user.rst | 4 ++--
> block/qed.h | 2 +-
> include/hw/acpi/acpi-defs.h | 4 ++--
> include/hw/boards.h | 2 +-
> include/hw/s390x/event-facility.h | 2 +-
> include/hw/s390x/sclp.h | 8 ++++----
> block/vmdk.c | 2 +-
> hw/char/sclpconsole-lm.c | 2 +-
> hw/char/sclpconsole.c | 2 +-
> hw/s390x/virtio-ccw.c | 2 +-
> target/s390x/ioinst.c | 2 +-
> 11 files changed, 16 insertions(+), 16 deletions(-)
>
> diff --git a/docs/interop/vhost-user.rst b/docs/interop/vhost-user.rst
> index 401652397c..3b1b6602c7 100644
> --- a/docs/interop/vhost-user.rst
> +++ b/docs/interop/vhost-user.rst
> @@ -568,7 +568,7 @@ For split virtqueue, queue region can be implemented as:
> uint16_t used_idx;
>
> /* Used to track the state of each descriptor in descriptor table */
> - DescStateSplit desc[0];
> + DescStateSplit desc[];
> } QueueRegionSplit;
>
> To track inflight I/O, the queue region should be processed as follows:
> @@ -690,7 +690,7 @@ For packed virtqueue, queue region can be implemented as:
> uint8_t padding[7];
>
> /* Used to track the state of each descriptor fetched from descriptor ring */
> - DescStatePacked desc[0];
> + DescStatePacked desc[];
> } QueueRegionPacked;
>
> To track inflight I/O, the queue region should be processed as follows:
> diff --git a/block/qed.h b/block/qed.h
> index 42c115d822..87428ba00e 100644
> --- a/block/qed.h
> +++ b/block/qed.h
> @@ -103,7 +103,7 @@ typedef struct {
> } QEMU_PACKED QEDHeader;
>
> typedef struct {
> - uint64_t offsets[0]; /* in bytes */
> + uint64_t offsets[]; /* in bytes */
Apparently this one is incorrect, it triggers:
GCC:
block/qed.h:106:14: error: flexible array member in otherwise empty struct
Clang:
block/qed.h:106:14: error: flexible array member 'offsets' not allowed
in otherwise empty struct
> } QEDTable;
>
> /* The L2 cache is a simple write-through cache for L2 structures */
> diff --git a/include/hw/acpi/acpi-defs.h b/include/hw/acpi/acpi-defs.h
> index 19f7ba7b70..c13327fa78 100644
> --- a/include/hw/acpi/acpi-defs.h
> +++ b/include/hw/acpi/acpi-defs.h
> @@ -152,7 +152,7 @@ typedef struct AcpiSerialPortConsoleRedirection
> */
> struct AcpiRsdtDescriptorRev1 {
> ACPI_TABLE_HEADER_DEF /* ACPI common table header */
> - uint32_t table_offset_entry[0]; /* Array of pointers to other */
> + uint32_t table_offset_entry[]; /* Array of pointers to other */
> /* ACPI tables */
> } QEMU_PACKED;
> typedef struct AcpiRsdtDescriptorRev1 AcpiRsdtDescriptorRev1;
> @@ -162,7 +162,7 @@ typedef struct AcpiRsdtDescriptorRev1 AcpiRsdtDescriptorRev1;
> */
> struct AcpiXsdtDescriptorRev2 {
> ACPI_TABLE_HEADER_DEF /* ACPI common table header */
> - uint64_t table_offset_entry[0]; /* Array of pointers to other */
> + uint64_t table_offset_entry[]; /* Array of pointers to other */
> /* ACPI tables */
> } QEMU_PACKED;
> typedef struct AcpiXsdtDescriptorRev2 AcpiXsdtDescriptorRev2;
> diff --git a/include/hw/boards.h b/include/hw/boards.h
> index 9bc42dfb22..c96120d15f 100644
> --- a/include/hw/boards.h
> +++ b/include/hw/boards.h
> @@ -71,7 +71,7 @@ typedef struct CPUArchId {
> */
> typedef struct {
> int len;
> - CPUArchId cpus[0];
> + CPUArchId cpus[];
> } CPUArchIdList;
>
> /**
> diff --git a/include/hw/s390x/event-facility.h b/include/hw/s390x/event-facility.h
> index bdc32a3c09..700a610f33 100644
> --- a/include/hw/s390x/event-facility.h
> +++ b/include/hw/s390x/event-facility.h
> @@ -122,7 +122,7 @@ typedef struct MDBO {
>
> typedef struct MDB {
> MdbHeader header;
> - MDBO mdbo[0];
> + MDBO mdbo[];
> } QEMU_PACKED MDB;
>
> typedef struct SclpMsg {
> diff --git a/include/hw/s390x/sclp.h b/include/hw/s390x/sclp.h
> index c54413b78c..cd7b24359f 100644
> --- a/include/hw/s390x/sclp.h
> +++ b/include/hw/s390x/sclp.h
> @@ -132,7 +132,7 @@ typedef struct ReadInfo {
> uint16_t highest_cpu;
> uint8_t _reserved5[124 - 122]; /* 122-123 */
> uint32_t hmfai;
> - struct CPUEntry entries[0];
> + struct CPUEntry entries[];
> } QEMU_PACKED ReadInfo;
>
> typedef struct ReadCpuInfo {
> @@ -142,7 +142,7 @@ typedef struct ReadCpuInfo {
> uint16_t nr_standby; /* 12-13 */
> uint16_t offset_standby; /* 14-15 */
> uint8_t reserved0[24-16]; /* 16-23 */
> - struct CPUEntry entries[0];
> + struct CPUEntry entries[];
> } QEMU_PACKED ReadCpuInfo;
>
> typedef struct ReadStorageElementInfo {
> @@ -151,7 +151,7 @@ typedef struct ReadStorageElementInfo {
> uint16_t assigned;
> uint16_t standby;
> uint8_t _reserved0[16 - 14]; /* 14-15 */
> - uint32_t entries[0];
> + uint32_t entries[];
> } QEMU_PACKED ReadStorageElementInfo;
>
> typedef struct AttachStorageElement {
> @@ -159,7 +159,7 @@ typedef struct AttachStorageElement {
> uint8_t _reserved0[10 - 8]; /* 8-9 */
> uint16_t assigned;
> uint8_t _reserved1[16 - 12]; /* 12-15 */
> - uint32_t entries[0];
> + uint32_t entries[];
> } QEMU_PACKED AttachStorageElement;
>
> typedef struct AssignStorage {
> diff --git a/block/vmdk.c b/block/vmdk.c
> index 20e909d997..8466051bc9 100644
> --- a/block/vmdk.c
> +++ b/block/vmdk.c
> @@ -187,7 +187,7 @@ typedef struct VmdkMetaData {
> typedef struct VmdkGrainMarker {
> uint64_t lba;
> uint32_t size;
> - uint8_t data[0];
> + uint8_t data[];
> } QEMU_PACKED VmdkGrainMarker;
>
> enum {
> diff --git a/hw/char/sclpconsole-lm.c b/hw/char/sclpconsole-lm.c
> index c420dc066e..2b5f37b6a2 100644
> --- a/hw/char/sclpconsole-lm.c
> +++ b/hw/char/sclpconsole-lm.c
> @@ -31,7 +31,7 @@
> typedef struct OprtnsCommand {
> EventBufferHeader header;
> MDMSU message_unit;
> - char data[0];
> + char data[];
> } QEMU_PACKED OprtnsCommand;
>
> /* max size for line-mode data in 4K SCCB page */
> diff --git a/hw/char/sclpconsole.c b/hw/char/sclpconsole.c
> index 1fa124dab9..5c7664905e 100644
> --- a/hw/char/sclpconsole.c
> +++ b/hw/char/sclpconsole.c
> @@ -25,7 +25,7 @@
>
> typedef struct ASCIIConsoleData {
> EventBufferHeader ebh;
> - char data[0];
> + char data[];
> } QEMU_PACKED ASCIIConsoleData;
>
> /* max size for ASCII data in 4K SCCB page */
> diff --git a/hw/s390x/virtio-ccw.c b/hw/s390x/virtio-ccw.c
> index 50cf95b781..64f928fc7d 100644
> --- a/hw/s390x/virtio-ccw.c
> +++ b/hw/s390x/virtio-ccw.c
> @@ -193,7 +193,7 @@ typedef struct VirtioThinintInfo {
> typedef struct VirtioRevInfo {
> uint16_t revision;
> uint16_t length;
> - uint8_t data[0];
> + uint8_t data[];
> } QEMU_PACKED VirtioRevInfo;
>
> /* Specify where the virtqueues for the subchannel are in guest memory. */
> diff --git a/target/s390x/ioinst.c b/target/s390x/ioinst.c
> index c437a1d8c6..0e840cc579 100644
> --- a/target/s390x/ioinst.c
> +++ b/target/s390x/ioinst.c
> @@ -347,7 +347,7 @@ typedef struct ChscResp {
> uint16_t len;
> uint16_t code;
> uint32_t param;
> - char data[0];
> + char data[];
> } QEMU_PACKED ChscResp;
>
> #define CHSC_MIN_RESP_LEN 0x0008
>
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel
^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [PATCH 0/2] misc: Replace zero-length arrays with flexible array member
2020-03-04 0:51 ` [Xen-devel] " Philippe Mathieu-Daudé
@ 2020-03-04 11:14 ` Paolo Bonzini
-1 siblings, 0 replies; 22+ messages in thread
From: Paolo Bonzini @ 2020-03-04 11:14 UTC (permalink / raw)
To: Philippe Mathieu-Daudé, qemu-devel
Cc: Fam Zheng, Peter Maydell, Michael S. Tsirkin, Jason Wang,
Yuval Shaia, Gerd Hoffmann, Stefano Stabellini, qemu-block,
David Hildenbrand, Halil Pasic, Christian Borntraeger,
Gonglei (Arei),
Anthony Perard, Marc-André Lureau, Thomas Huth,
Eduardo Habkost, Paul Durrant, Eric Auger, qemu-s390x, qemu-arm,
xen-devel, John Snow, Richard Henderson, Kevin Wolf,
Xiao Guangrong, Cornelia Huck, Laurent Vivier, Max Reitz,
Igor Mammedov
On 04/03/20 01:51, Philippe Mathieu-Daudé wrote:
> This is a tree-wide cleanup inspired by a Linux kernel commit
> (from Gustavo A. R. Silva).
>
> --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).
>
> The first patch is done with the help of a coccinelle semantic
> patch. However Coccinelle does not recognize:
>
> struct foo {
> int stuff;
> struct boo array[];
> } QEMU_PACKED;
>
> but does recognize:
>
> struct QEMU_PACKED foo {
> int stuff;
> struct boo array[];
> };
>
> I'm not sure why, neither it is worth refactoring all QEMU
> structures to use the attributes before the structure name,
> so I did the 2nd patch manually.
>
> Anyway this is annoying, because many structures are not handled
> by coccinelle. Maybe this needs to be reported to upstream
> coccinelle?
>
> I used spatch 1.0.8 with:
>
> -I include --include-headers \
> --macro-file scripts/cocci-macro-file.h \
> --keep-comments --indent 4
>
> Regards,
>
> Phil.
>
> Philippe Mathieu-Daudé (2):
> misc: Replace zero-length arrays with flexible array member
> (automatic)
> misc: Replace zero-length arrays with flexible array member (manual)
>
> docs/interop/vhost-user.rst | 4 ++--
> block/qed.h | 2 +-
> bsd-user/qemu.h | 2 +-
> contrib/libvhost-user/libvhost-user.h | 2 +-
> hw/m68k/bootinfo.h | 2 +-
> hw/scsi/srp.h | 6 +++---
> hw/xen/xen_pt.h | 2 +-
> include/hw/acpi/acpi-defs.h | 16 ++++++++--------
> include/hw/arm/smmu-common.h | 2 +-
> include/hw/boards.h | 2 +-
> include/hw/i386/intel_iommu.h | 3 ++-
> include/hw/s390x/event-facility.h | 2 +-
> include/hw/s390x/sclp.h | 8 ++++----
> include/hw/virtio/virtio-iommu.h | 2 +-
> include/sysemu/cryptodev.h | 2 +-
> include/tcg/tcg.h | 2 +-
> pc-bios/s390-ccw/bootmap.h | 2 +-
> pc-bios/s390-ccw/sclp.h | 2 +-
> tests/qtest/libqos/ahci.h | 2 +-
> block/linux-aio.c | 2 +-
> block/vmdk.c | 2 +-
> hw/acpi/nvdimm.c | 6 +++---
> hw/char/sclpconsole-lm.c | 2 +-
> hw/char/sclpconsole.c | 2 +-
> hw/dma/soc_dma.c | 2 +-
> hw/i386/x86.c | 2 +-
> hw/misc/omap_l4.c | 2 +-
> hw/nvram/eeprom93xx.c | 2 +-
> hw/rdma/vmw/pvrdma_qp_ops.c | 4 ++--
> hw/s390x/virtio-ccw.c | 2 +-
> hw/usb/dev-network.c | 2 +-
> hw/usb/dev-smartcard-reader.c | 4 ++--
> hw/virtio/virtio.c | 4 ++--
> net/queue.c | 2 +-
> target/s390x/ioinst.c | 2 +-
> 35 files changed, 54 insertions(+), 53 deletions(-)
>
Queued (minus the qed part).
Paolo
^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [Xen-devel] [PATCH 0/2] misc: Replace zero-length arrays with flexible array member
@ 2020-03-04 11:14 ` Paolo Bonzini
0 siblings, 0 replies; 22+ messages in thread
From: Paolo Bonzini @ 2020-03-04 11:14 UTC (permalink / raw)
To: Philippe Mathieu-Daudé, qemu-devel
Cc: Fam Zheng, Peter Maydell, Michael S. Tsirkin, Jason Wang,
Yuval Shaia, Gerd Hoffmann, Eric Blake, Stefano Stabellini,
qemu-block, David Hildenbrand, Halil Pasic,
Christian Borntraeger, Gonglei (Arei),
Marcel Apfelbaum, Anthony Perard, Marc-André Lureau,
Thomas Huth, Eduardo Habkost, Paul Durrant, Eric Auger,
qemu-s390x, qemu-arm, xen-devel, John Snow, Richard Henderson,
Kevin Wolf, Xiao Guangrong, Cornelia Huck, Laurent Vivier,
Max Reitz, Igor Mammedov
On 04/03/20 01:51, Philippe Mathieu-Daudé wrote:
> This is a tree-wide cleanup inspired by a Linux kernel commit
> (from Gustavo A. R. Silva).
>
> --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).
>
> The first patch is done with the help of a coccinelle semantic
> patch. However Coccinelle does not recognize:
>
> struct foo {
> int stuff;
> struct boo array[];
> } QEMU_PACKED;
>
> but does recognize:
>
> struct QEMU_PACKED foo {
> int stuff;
> struct boo array[];
> };
>
> I'm not sure why, neither it is worth refactoring all QEMU
> structures to use the attributes before the structure name,
> so I did the 2nd patch manually.
>
> Anyway this is annoying, because many structures are not handled
> by coccinelle. Maybe this needs to be reported to upstream
> coccinelle?
>
> I used spatch 1.0.8 with:
>
> -I include --include-headers \
> --macro-file scripts/cocci-macro-file.h \
> --keep-comments --indent 4
>
> Regards,
>
> Phil.
>
> Philippe Mathieu-Daudé (2):
> misc: Replace zero-length arrays with flexible array member
> (automatic)
> misc: Replace zero-length arrays with flexible array member (manual)
>
> docs/interop/vhost-user.rst | 4 ++--
> block/qed.h | 2 +-
> bsd-user/qemu.h | 2 +-
> contrib/libvhost-user/libvhost-user.h | 2 +-
> hw/m68k/bootinfo.h | 2 +-
> hw/scsi/srp.h | 6 +++---
> hw/xen/xen_pt.h | 2 +-
> include/hw/acpi/acpi-defs.h | 16 ++++++++--------
> include/hw/arm/smmu-common.h | 2 +-
> include/hw/boards.h | 2 +-
> include/hw/i386/intel_iommu.h | 3 ++-
> include/hw/s390x/event-facility.h | 2 +-
> include/hw/s390x/sclp.h | 8 ++++----
> include/hw/virtio/virtio-iommu.h | 2 +-
> include/sysemu/cryptodev.h | 2 +-
> include/tcg/tcg.h | 2 +-
> pc-bios/s390-ccw/bootmap.h | 2 +-
> pc-bios/s390-ccw/sclp.h | 2 +-
> tests/qtest/libqos/ahci.h | 2 +-
> block/linux-aio.c | 2 +-
> block/vmdk.c | 2 +-
> hw/acpi/nvdimm.c | 6 +++---
> hw/char/sclpconsole-lm.c | 2 +-
> hw/char/sclpconsole.c | 2 +-
> hw/dma/soc_dma.c | 2 +-
> hw/i386/x86.c | 2 +-
> hw/misc/omap_l4.c | 2 +-
> hw/nvram/eeprom93xx.c | 2 +-
> hw/rdma/vmw/pvrdma_qp_ops.c | 4 ++--
> hw/s390x/virtio-ccw.c | 2 +-
> hw/usb/dev-network.c | 2 +-
> hw/usb/dev-smartcard-reader.c | 4 ++--
> hw/virtio/virtio.c | 4 ++--
> net/queue.c | 2 +-
> target/s390x/ioinst.c | 2 +-
> 35 files changed, 54 insertions(+), 53 deletions(-)
>
Queued (minus the qed part).
Paolo
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel
^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [PATCH 1/2] misc: Replace zero-length arrays with flexible array member (automatic)
2020-03-04 0:51 ` [Xen-devel] " Philippe Mathieu-Daudé
@ 2020-03-04 13:12 ` Philippe Mathieu-Daudé
-1 siblings, 0 replies; 22+ messages in thread
From: Philippe Mathieu-Daudé @ 2020-03-04 13:12 UTC (permalink / raw)
To: qemu-devel
Cc: Fam Zheng, Peter Maydell, Michael S. Tsirkin, Jason Wang,
Yuval Shaia, Gerd Hoffmann, Stefano Stabellini, qemu-block,
David Hildenbrand, Gustavo A . R . Silva, Halil Pasic,
Christian Borntraeger, Gonglei (Arei),
Anthony Perard, xen-devel, Thomas Huth, Eduardo Habkost,
Paul Durrant, Eric Auger, qemu-s390x, qemu-arm,
Marc-André Lureau, John Snow, Richard Henderson, Kevin Wolf,
Xiao Guangrong, Cornelia Huck, Laurent Vivier, Max Reitz,
Igor Mammedov, Paolo Bonzini
On 3/4/20 1:51 AM, Philippe Mathieu-Daudé wrote:
> 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, a;
> type T;
> @@
> struct s {
> ...
> - T a[0];
> + T a[];
> };
> @@
> identifier s, a;
> type T;
> @@
> struct s {
> ...
> - 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 <gustavo@embeddedor.com>
> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> ---
> bsd-user/qemu.h | 2 +-
> contrib/libvhost-user/libvhost-user.h | 2 +-
> hw/m68k/bootinfo.h | 2 +-
> hw/scsi/srp.h | 6 +++---
> 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 +-
> pc-bios/s390-ccw/bootmap.h | 2 +-
> pc-bios/s390-ccw/sclp.h | 2 +-
> tests/qtest/libqos/ahci.h | 2 +-
> block/linux-aio.c | 2 +-
> hw/acpi/nvdimm.c | 6 +++---
> hw/dma/soc_dma.c | 2 +-
> hw/i386/x86.c | 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 ++--
> net/queue.c | 2 +-
> 25 files changed, 38 insertions(+), 37 deletions(-)
>
[...]
> diff --git a/hw/scsi/srp.h b/hw/scsi/srp.h
> index d27f31d2d5..54c954badd 100644
> --- a/hw/scsi/srp.h
> +++ b/hw/scsi/srp.h
> @@ -112,7 +112,7 @@ struct srp_direct_buf {
> struct srp_indirect_buf {
> struct srp_direct_buf table_desc;
> uint32_t len;
> - struct srp_direct_buf desc_list[0];
> + struct srp_direct_buf desc_list[];
> } QEMU_PACKED;
>
> enum {
> @@ -211,7 +211,7 @@ struct srp_cmd {
> uint8_t reserved4;
> uint8_t add_cdb_len;
> uint8_t cdb[16];
> - uint8_t add_data[0];
> + uint8_t add_data[];
> } QEMU_PACKED;
>
> enum {
> @@ -241,7 +241,7 @@ struct srp_rsp {
> uint32_t data_in_res_cnt;
> uint32_t sense_data_len;
> uint32_t resp_data_len;
> - uint8_t data[0];
> + uint8_t data[];
> } QEMU_PACKED;
hw/scsi/spapr_vscsi.c:69:29: error: field 'iu' with variable sized type
'union viosrp_iu' not at the end of a struct or class is a GNU extension
[-Werror,-Wgnu-variable-sized-type-not-at-end]
union viosrp_iu iu;
^
Yay we found a bug! Thanks Gustavo :)
union srp_iu {
struct srp_login_req login_req;
struct srp_login_rsp login_rsp;
struct srp_login_rej login_rej;
struct srp_i_logout i_logout;
struct srp_t_logout t_logout;
struct srp_tsk_mgmt tsk_mgmt;
struct srp_cmd cmd;
struct srp_rsp rsp;
uint8_t reserved[SRP_MAX_IU_LEN];
};
union viosrp_iu {
union srp_iu srp;
union mad_iu mad;
};
typedef struct vscsi_req {
vscsi_crq crq;
union viosrp_iu iu;
/* SCSI request tracking */
SCSIRequest *sreq;
uint32_t qtag; /* qemu tag != srp tag */
bool active;
bool writing;
bool dma_error;
uint32_t data_len;
uint32_t senselen;
uint8_t sense[SCSI_SENSE_BUF_SIZE];
/* RDMA related bits */
uint8_t dma_fmt;
uint16_t local_desc;
uint16_t total_desc;
uint16_t cdb_offset;
uint16_t cur_desc_num;
uint16_t cur_desc_offset;
} vscsi_req;
>
> #endif /* SCSI_SRP_H */
[...]
^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [Xen-devel] [PATCH 1/2] misc: Replace zero-length arrays with flexible array member (automatic)
@ 2020-03-04 13:12 ` Philippe Mathieu-Daudé
0 siblings, 0 replies; 22+ messages in thread
From: Philippe Mathieu-Daudé @ 2020-03-04 13:12 UTC (permalink / raw)
To: qemu-devel
Cc: Fam Zheng, Peter Maydell, Michael S. Tsirkin, Jason Wang,
Yuval Shaia, Gerd Hoffmann, Eric Blake, Stefano Stabellini,
qemu-block, David Hildenbrand, Gustavo A . R . Silva,
Halil Pasic, Christian Borntraeger, Gonglei (Arei),
Marcel Apfelbaum, Anthony Perard, xen-devel, Thomas Huth,
Eduardo Habkost, Paul Durrant, Eric Auger, qemu-s390x, qemu-arm,
Marc-André Lureau, John Snow, Richard Henderson, Kevin Wolf,
Xiao Guangrong, Cornelia Huck, Laurent Vivier, Max Reitz,
Igor Mammedov, Paolo Bonzini
On 3/4/20 1:51 AM, Philippe Mathieu-Daudé wrote:
> 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, a;
> type T;
> @@
> struct s {
> ...
> - T a[0];
> + T a[];
> };
> @@
> identifier s, a;
> type T;
> @@
> struct s {
> ...
> - 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 <gustavo@embeddedor.com>
> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> ---
> bsd-user/qemu.h | 2 +-
> contrib/libvhost-user/libvhost-user.h | 2 +-
> hw/m68k/bootinfo.h | 2 +-
> hw/scsi/srp.h | 6 +++---
> 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 +-
> pc-bios/s390-ccw/bootmap.h | 2 +-
> pc-bios/s390-ccw/sclp.h | 2 +-
> tests/qtest/libqos/ahci.h | 2 +-
> block/linux-aio.c | 2 +-
> hw/acpi/nvdimm.c | 6 +++---
> hw/dma/soc_dma.c | 2 +-
> hw/i386/x86.c | 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 ++--
> net/queue.c | 2 +-
> 25 files changed, 38 insertions(+), 37 deletions(-)
>
[...]
> diff --git a/hw/scsi/srp.h b/hw/scsi/srp.h
> index d27f31d2d5..54c954badd 100644
> --- a/hw/scsi/srp.h
> +++ b/hw/scsi/srp.h
> @@ -112,7 +112,7 @@ struct srp_direct_buf {
> struct srp_indirect_buf {
> struct srp_direct_buf table_desc;
> uint32_t len;
> - struct srp_direct_buf desc_list[0];
> + struct srp_direct_buf desc_list[];
> } QEMU_PACKED;
>
> enum {
> @@ -211,7 +211,7 @@ struct srp_cmd {
> uint8_t reserved4;
> uint8_t add_cdb_len;
> uint8_t cdb[16];
> - uint8_t add_data[0];
> + uint8_t add_data[];
> } QEMU_PACKED;
>
> enum {
> @@ -241,7 +241,7 @@ struct srp_rsp {
> uint32_t data_in_res_cnt;
> uint32_t sense_data_len;
> uint32_t resp_data_len;
> - uint8_t data[0];
> + uint8_t data[];
> } QEMU_PACKED;
hw/scsi/spapr_vscsi.c:69:29: error: field 'iu' with variable sized type
'union viosrp_iu' not at the end of a struct or class is a GNU extension
[-Werror,-Wgnu-variable-sized-type-not-at-end]
union viosrp_iu iu;
^
Yay we found a bug! Thanks Gustavo :)
union srp_iu {
struct srp_login_req login_req;
struct srp_login_rsp login_rsp;
struct srp_login_rej login_rej;
struct srp_i_logout i_logout;
struct srp_t_logout t_logout;
struct srp_tsk_mgmt tsk_mgmt;
struct srp_cmd cmd;
struct srp_rsp rsp;
uint8_t reserved[SRP_MAX_IU_LEN];
};
union viosrp_iu {
union srp_iu srp;
union mad_iu mad;
};
typedef struct vscsi_req {
vscsi_crq crq;
union viosrp_iu iu;
/* SCSI request tracking */
SCSIRequest *sreq;
uint32_t qtag; /* qemu tag != srp tag */
bool active;
bool writing;
bool dma_error;
uint32_t data_len;
uint32_t senselen;
uint8_t sense[SCSI_SENSE_BUF_SIZE];
/* RDMA related bits */
uint8_t dma_fmt;
uint16_t local_desc;
uint16_t total_desc;
uint16_t cdb_offset;
uint16_t cur_desc_num;
uint16_t cur_desc_offset;
} vscsi_req;
>
> #endif /* SCSI_SRP_H */
[...]
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel
^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [PATCH 1/2] misc: Replace zero-length arrays with flexible array member (automatic)
2020-03-04 13:12 ` [Xen-devel] " Philippe Mathieu-Daudé
@ 2020-03-04 13:44 ` Paolo Bonzini
-1 siblings, 0 replies; 22+ messages in thread
From: Paolo Bonzini @ 2020-03-04 13:44 UTC (permalink / raw)
To: Philippe Mathieu-Daudé, qemu-devel
Cc: Fam Zheng, Peter Maydell, Michael S. Tsirkin, Jason Wang,
Yuval Shaia, Gerd Hoffmann, Stefano Stabellini, qemu-block,
David Hildenbrand, Gustavo A . R . Silva, Halil Pasic,
Christian Borntraeger, Gonglei (Arei),
Anthony Perard, Marc-André Lureau, David Gibson,
Thomas Huth, Eduardo Habkost, Paul Durrant, Eric Auger,
qemu-s390x, qemu-arm, xen-devel, John Snow, Richard Henderson,
Kevin Wolf, Xiao Guangrong, Cornelia Huck, Laurent Vivier,
Max Reitz, Igor Mammedov
On 04/03/20 14:12, Philippe Mathieu-Daudé wrote:
>
> hw/scsi/spapr_vscsi.c:69:29: error: field 'iu' with variable sized type
> 'union viosrp_iu' not at the end of a struct or class is a GNU extension
> [-Werror,-Wgnu-variable-sized-type-not-at-end]
> union viosrp_iu iu;
> ^
>
> Yay we found a bug! Thanks Gustavo :)
>
> union srp_iu {
> struct srp_login_req login_req;
> struct srp_login_rsp login_rsp;
> struct srp_login_rej login_rej;
> struct srp_i_logout i_logout;
> struct srp_t_logout t_logout;
> struct srp_tsk_mgmt tsk_mgmt;
> struct srp_cmd cmd;
> struct srp_rsp rsp;
> uint8_t reserved[SRP_MAX_IU_LEN];
> };
It's variable-sized but it's okay as long as the total size doesn't
exceed SRP_MAX_IU_LEN. So it's not a bug, but I agree it's a time bomb.
Moving the field last should work, but it would still be quite
dangerous code.
Paolo
^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [Xen-devel] [PATCH 1/2] misc: Replace zero-length arrays with flexible array member (automatic)
@ 2020-03-04 13:44 ` Paolo Bonzini
0 siblings, 0 replies; 22+ messages in thread
From: Paolo Bonzini @ 2020-03-04 13:44 UTC (permalink / raw)
To: Philippe Mathieu-Daudé, qemu-devel
Cc: Fam Zheng, Peter Maydell, Michael S. Tsirkin, Jason Wang,
Yuval Shaia, Gerd Hoffmann, Eric Blake, Stefano Stabellini,
qemu-block, David Hildenbrand, Gustavo A . R . Silva,
Halil Pasic, Christian Borntraeger, Gonglei (Arei),
Marcel Apfelbaum, Anthony Perard, Marc-André Lureau,
David Gibson, Thomas Huth, Eduardo Habkost, Paul Durrant,
Eric Auger, qemu-s390x, qemu-arm, xen-devel, John Snow,
Richard Henderson, Kevin Wolf, Xiao Guangrong, Cornelia Huck,
Laurent Vivier, Max Reitz, Igor Mammedov
On 04/03/20 14:12, Philippe Mathieu-Daudé wrote:
>
> hw/scsi/spapr_vscsi.c:69:29: error: field 'iu' with variable sized type
> 'union viosrp_iu' not at the end of a struct or class is a GNU extension
> [-Werror,-Wgnu-variable-sized-type-not-at-end]
> union viosrp_iu iu;
> ^
>
> Yay we found a bug! Thanks Gustavo :)
>
> union srp_iu {
> struct srp_login_req login_req;
> struct srp_login_rsp login_rsp;
> struct srp_login_rej login_rej;
> struct srp_i_logout i_logout;
> struct srp_t_logout t_logout;
> struct srp_tsk_mgmt tsk_mgmt;
> struct srp_cmd cmd;
> struct srp_rsp rsp;
> uint8_t reserved[SRP_MAX_IU_LEN];
> };
It's variable-sized but it's okay as long as the total size doesn't
exceed SRP_MAX_IU_LEN. So it's not a bug, but I agree it's a time bomb.
Moving the field last should work, but it would still be quite
dangerous code.
Paolo
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel
^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [PATCH 1/2] misc: Replace zero-length arrays with flexible array member (automatic)
2020-03-04 13:44 ` [Xen-devel] " Paolo Bonzini
@ 2020-03-04 14:12 ` Philippe Mathieu-Daudé
-1 siblings, 0 replies; 22+ messages in thread
From: Philippe Mathieu-Daudé @ 2020-03-04 14:12 UTC (permalink / raw)
To: Paolo Bonzini, qemu-devel
Cc: Fam Zheng, Peter Maydell, Michael S. Tsirkin, Jason Wang,
Yuval Shaia, Gerd Hoffmann, Stefano Stabellini, qemu-block,
David Hildenbrand, Gustavo A . R . Silva, Halil Pasic,
Christian Borntraeger, Gonglei (Arei),
Anthony Perard, Marc-André Lureau, David Gibson,
Thomas Huth, Eduardo Habkost, Paul Durrant, Eric Auger,
qemu-s390x, qemu-arm, xen-devel, John Snow, Richard Henderson,
Kevin Wolf, Xiao Guangrong, Cornelia Huck, Laurent Vivier,
Max Reitz, Igor Mammedov
On 3/4/20 2:44 PM, Paolo Bonzini wrote:
> On 04/03/20 14:12, Philippe Mathieu-Daudé wrote:
>>
>> hw/scsi/spapr_vscsi.c:69:29: error: field 'iu' with variable sized type
>> 'union viosrp_iu' not at the end of a struct or class is a GNU extension
>> [-Werror,-Wgnu-variable-sized-type-not-at-end]
>> union viosrp_iu iu;
>> ^
>>
>> Yay we found a bug! Thanks Gustavo :)
>>
>> union srp_iu {
>> struct srp_login_req login_req;
>> struct srp_login_rsp login_rsp;
>> struct srp_login_rej login_rej;
>> struct srp_i_logout i_logout;
>> struct srp_t_logout t_logout;
>> struct srp_tsk_mgmt tsk_mgmt;
>> struct srp_cmd cmd;
>> struct srp_rsp rsp;
>> uint8_t reserved[SRP_MAX_IU_LEN];
>> };
>
> It's variable-sized but it's okay as long as the total size doesn't
> exceed SRP_MAX_IU_LEN. So it's not a bug, but I agree it's a time bomb.
> Moving the field last should work, but it would still be quite
> dangerous code.
Yeah I reached the same conclusion.
I'll send a fix for the dangerous code.
Do you want to drop this series, or only the change in 'struct srp_rsp'
(or in all hw/scsi/srp.h). Actually I guess it makes sense I move the
'hw/scsi/srp.h' changes with the series cleaning dangerous code.
^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [Xen-devel] [PATCH 1/2] misc: Replace zero-length arrays with flexible array member (automatic)
@ 2020-03-04 14:12 ` Philippe Mathieu-Daudé
0 siblings, 0 replies; 22+ messages in thread
From: Philippe Mathieu-Daudé @ 2020-03-04 14:12 UTC (permalink / raw)
To: Paolo Bonzini, qemu-devel
Cc: Fam Zheng, Peter Maydell, Michael S. Tsirkin, Jason Wang,
Yuval Shaia, Gerd Hoffmann, Eric Blake, Stefano Stabellini,
qemu-block, David Hildenbrand, Gustavo A . R . Silva,
Halil Pasic, Christian Borntraeger, Gonglei (Arei),
Marcel Apfelbaum, Anthony Perard, Marc-André Lureau,
David Gibson, Thomas Huth, Eduardo Habkost, Paul Durrant,
Eric Auger, qemu-s390x, qemu-arm, xen-devel, John Snow,
Richard Henderson, Kevin Wolf, Xiao Guangrong, Cornelia Huck,
Laurent Vivier, Max Reitz, Igor Mammedov
On 3/4/20 2:44 PM, Paolo Bonzini wrote:
> On 04/03/20 14:12, Philippe Mathieu-Daudé wrote:
>>
>> hw/scsi/spapr_vscsi.c:69:29: error: field 'iu' with variable sized type
>> 'union viosrp_iu' not at the end of a struct or class is a GNU extension
>> [-Werror,-Wgnu-variable-sized-type-not-at-end]
>> union viosrp_iu iu;
>> ^
>>
>> Yay we found a bug! Thanks Gustavo :)
>>
>> union srp_iu {
>> struct srp_login_req login_req;
>> struct srp_login_rsp login_rsp;
>> struct srp_login_rej login_rej;
>> struct srp_i_logout i_logout;
>> struct srp_t_logout t_logout;
>> struct srp_tsk_mgmt tsk_mgmt;
>> struct srp_cmd cmd;
>> struct srp_rsp rsp;
>> uint8_t reserved[SRP_MAX_IU_LEN];
>> };
>
> It's variable-sized but it's okay as long as the total size doesn't
> exceed SRP_MAX_IU_LEN. So it's not a bug, but I agree it's a time bomb.
> Moving the field last should work, but it would still be quite
> dangerous code.
Yeah I reached the same conclusion.
I'll send a fix for the dangerous code.
Do you want to drop this series, or only the change in 'struct srp_rsp'
(or in all hw/scsi/srp.h). Actually I guess it makes sense I move the
'hw/scsi/srp.h' changes with the series cleaning dangerous code.
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^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [PATCH 1/2] misc: Replace zero-length arrays with flexible array member (automatic)
2020-03-04 14:12 ` [Xen-devel] " Philippe Mathieu-Daudé
@ 2020-03-04 14:19 ` Paolo Bonzini
-1 siblings, 0 replies; 22+ messages in thread
From: Paolo Bonzini @ 2020-03-04 14:19 UTC (permalink / raw)
To: Philippe Mathieu-Daudé, qemu-devel
Cc: Fam Zheng, Peter Maydell, Michael S. Tsirkin, Jason Wang,
Yuval Shaia, Gerd Hoffmann, Stefano Stabellini, qemu-block,
David Hildenbrand, Gustavo A . R . Silva, Halil Pasic,
Christian Borntraeger, Gonglei (Arei),
Anthony Perard, Marc-André Lureau, David Gibson,
Thomas Huth, Eduardo Habkost, Paul Durrant, Eric Auger,
qemu-s390x, qemu-arm, xen-devel, John Snow, Richard Henderson,
Kevin Wolf, Xiao Guangrong, Cornelia Huck, Laurent Vivier,
Max Reitz, Igor Mammedov
On 04/03/20 15:12, Philippe Mathieu-Daudé wrote:
> I'll send a fix for the dangerous code.
> Do you want to drop this series, or only the change in 'struct srp_rsp'
> (or in all hw/scsi/srp.h). Actually I guess it makes sense I move the
> 'hw/scsi/srp.h' changes with the series cleaning dangerous code.
As you prefer, it's not urgent to merge it.
Paolo
^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [Xen-devel] [PATCH 1/2] misc: Replace zero-length arrays with flexible array member (automatic)
@ 2020-03-04 14:19 ` Paolo Bonzini
0 siblings, 0 replies; 22+ messages in thread
From: Paolo Bonzini @ 2020-03-04 14:19 UTC (permalink / raw)
To: Philippe Mathieu-Daudé, qemu-devel
Cc: Fam Zheng, Peter Maydell, Michael S. Tsirkin, Jason Wang,
Yuval Shaia, Gerd Hoffmann, Eric Blake, Stefano Stabellini,
qemu-block, David Hildenbrand, Gustavo A . R . Silva,
Halil Pasic, Christian Borntraeger, Gonglei (Arei),
Marcel Apfelbaum, Anthony Perard, Marc-André Lureau,
David Gibson, Thomas Huth, Eduardo Habkost, Paul Durrant,
Eric Auger, qemu-s390x, qemu-arm, xen-devel, John Snow,
Richard Henderson, Kevin Wolf, Xiao Guangrong, Cornelia Huck,
Laurent Vivier, Max Reitz, Igor Mammedov
On 04/03/20 15:12, Philippe Mathieu-Daudé wrote:
> I'll send a fix for the dangerous code.
> Do you want to drop this series, or only the change in 'struct srp_rsp'
> (or in all hw/scsi/srp.h). Actually I guess it makes sense I move the
> 'hw/scsi/srp.h' changes with the series cleaning dangerous code.
As you prefer, it's not urgent to merge it.
Paolo
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel
^ permalink raw reply [flat|nested] 22+ messages in thread
end of thread, other threads:[~2020-03-04 14:20 UTC | newest]
Thread overview: 22+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-03-04 0:51 [PATCH 0/2] misc: Replace zero-length arrays with flexible array member Philippe Mathieu-Daudé
2020-03-04 0:51 ` [Xen-devel] " Philippe Mathieu-Daudé
2020-03-04 0:51 ` [PATCH 1/2] misc: Replace zero-length arrays with flexible array member (automatic) Philippe Mathieu-Daudé
2020-03-04 0:51 ` [Xen-devel] " Philippe Mathieu-Daudé
2020-03-04 8:19 ` David Hildenbrand
2020-03-04 8:19 ` [Xen-devel] " David Hildenbrand
2020-03-04 13:12 ` Philippe Mathieu-Daudé
2020-03-04 13:12 ` [Xen-devel] " Philippe Mathieu-Daudé
2020-03-04 13:44 ` Paolo Bonzini
2020-03-04 13:44 ` [Xen-devel] " Paolo Bonzini
2020-03-04 14:12 ` Philippe Mathieu-Daudé
2020-03-04 14:12 ` [Xen-devel] " Philippe Mathieu-Daudé
2020-03-04 14:19 ` Paolo Bonzini
2020-03-04 14:19 ` [Xen-devel] " Paolo Bonzini
2020-03-04 0:58 ` [PATCH 2/2] misc: Replace zero-length arrays with flexible array member (manual) Philippe Mathieu-Daudé
2020-03-04 0:58 ` [Xen-devel] " Philippe Mathieu-Daudé
2020-03-04 8:19 ` David Hildenbrand
2020-03-04 8:19 ` [Xen-devel] " David Hildenbrand
2020-03-04 9:00 ` Philippe Mathieu-Daudé
2020-03-04 9:00 ` [Xen-devel] " Philippe Mathieu-Daudé
2020-03-04 11:14 ` [PATCH 0/2] misc: Replace zero-length arrays with flexible array member Paolo Bonzini
2020-03-04 11:14 ` [Xen-devel] " Paolo Bonzini
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