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| author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2020-02-13 01:50:48 +0100 |
|---|---|---|
| committer | Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> | 2020-03-06 11:18:31 +0100 |
| commit | 067fb6c97e7e6a503c058b1f7509bfa709d05ed4 (patch) | |
| tree | 475f6a00ab16eaba9713418cb29c383825277287 /drivers/pci | |
| parent | PCI: hv: Add support for protocol 1.3 and support PCI_BUS_RELATIONS2 (diff) | |
| download | linux-067fb6c97e7e6a503c058b1f7509bfa709d05ed4.tar.xz linux-067fb6c97e7e6a503c058b1f7509bfa709d05ed4.zip | |
PCI: hv: Replace zero-length array with flexible-array member
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][2],
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
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Dexuan Cui <decui@microsoft.com>
Diffstat (limited to 'drivers/pci')
| -rw-r--r-- | drivers/pci/controller/pci-hyperv.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c index 98d377677bdb..88fd39254e0c 100644 --- a/drivers/pci/controller/pci-hyperv.c +++ b/drivers/pci/controller/pci-hyperv.c @@ -283,7 +283,7 @@ struct pci_packet { int resp_packet_size); void *compl_ctxt; - struct pci_message message[0]; + struct pci_message message[]; }; /* @@ -319,13 +319,13 @@ struct pci_bus_d0_entry { struct pci_bus_relations { struct pci_incoming_message incoming; u32 device_count; - struct pci_function_description func[0]; + struct pci_function_description func[]; } __packed; struct pci_bus_relations2 { struct pci_incoming_message incoming; u32 device_count; - struct pci_function_description2 func[0]; + struct pci_function_description2 func[]; } __packed; struct pci_q_res_req_response { @@ -551,7 +551,7 @@ struct hv_pcidev_description { struct hv_dr_state { struct list_head list_entry; u32 device_count; - struct hv_pcidev_description func[0]; + struct hv_pcidev_description func[]; }; enum hv_pcichild_state { |