[PATCH] docs: use flexible array members, not zero-length

From: Stephen Kitt
Date: Fri Sep 27 2019 - 12:58:46 EST

Update the docs throughout to remove zero-length arrays, replacing
them with C99 flexible array members. GCC will then ensure that the
arrays are always the last element in the struct.

Signed-off-by: Stephen Kitt <steve@xxxxxxx>
Cc: Gustavo A. R. Silva <gustavo@xxxxxxxxxxxxxx>
---
Documentation/bpf/btf.rst | 2 +-
Documentation/digsig.txt | 4 ++--
Documentation/driver-api/connector.rst | 2 +-
Documentation/driver-api/usb/URB.rst | 2 +-
.../filesystems/autofs-mount-control.txt | 2 +-
Documentation/filesystems/autofs.txt | 2 +-
Documentation/filesystems/fiemap.txt | 2 +-
Documentation/hwspinlock.txt | 2 +-
Documentation/networking/can.rst | 2 +-
Documentation/networking/rxrpc.txt | 2 +-
Documentation/remoteproc.txt | 4 ++--
Documentation/virt/kvm/api.txt | 24 +++++++++----------
Documentation/x86/boot.rst | 4 ++--
13 files changed, 27 insertions(+), 27 deletions(-)

diff --git a/Documentation/bpf/btf.rst b/Documentation/bpf/btf.rst
index 4d565d202ce3..24ce50fc1fc1 100644
--- a/Documentation/bpf/btf.rst
+++ b/Documentation/bpf/btf.rst
@@ -670,7 +670,7 @@ func_info for each specific ELF section.::
__u32 sec_name_off; /* offset to section name */
__u32 num_info;
/* Followed by num_info * record_size number of bytes */
- __u8 data[0];
+ __u8 data[];
};

Here, num_info must be greater than 0.
diff --git a/Documentation/digsig.txt b/Documentation/digsig.txt
index f6a8902d3ef7..d7479f98a27e 100644
--- a/Documentation/digsig.txt
+++ b/Documentation/digsig.txt
@@ -31,7 +31,7 @@ Public key and signature consist of header and MPIs::
time_t timestamp; /* key made, always 0 for now */
uint8_t algo;
uint8_t nmpi;
- char mpi[0];
+ char mpi[];
} __packed;

struct signature_hdr {
@@ -41,7 +41,7 @@ Public key and signature consist of header and MPIs::
uint8_t hash;
uint8_t keyid[8];
uint8_t nmpi;
- char mpi[0];
+ char mpi[];
} __packed;

keyid equals to SHA1[12-19] over the total key content.
diff --git a/Documentation/driver-api/connector.rst b/Documentation/driver-api/connector.rst
index c100c7482289..1f187028c7e1 100644
--- a/Documentation/driver-api/connector.rst
+++ b/Documentation/driver-api/connector.rst
@@ -49,7 +49,7 @@ be dereferenced to `struct cn_msg *`::
__u32 ack;

__u32 len; /* Length of the following data */
- __u8 data[0];
+ __u8 data[];
};

Connector interfaces
diff --git a/Documentation/driver-api/usb/URB.rst b/Documentation/driver-api/usb/URB.rst
index 61a54da9fce9..8aca9c39e9a0 100644
--- a/Documentation/driver-api/usb/URB.rst
+++ b/Documentation/driver-api/usb/URB.rst
@@ -82,7 +82,7 @@ Some of the fields in struct :c:type:`urb` are::

// ISO only: packets are only "best effort"; each can have errors
int error_count; // number of errors
- struct usb_iso_packet_descriptor iso_frame_desc[0];
+ struct usb_iso_packet_descriptor iso_frame_desc[];
};

Your driver must create the "pipe" value using values from the appropriate
diff --git a/Documentation/filesystems/autofs-mount-control.txt b/Documentation/filesystems/autofs-mount-control.txt
index acc02fc57993..1c5cf1ecd90d 100644
--- a/Documentation/filesystems/autofs-mount-control.txt
+++ b/Documentation/filesystems/autofs-mount-control.txt
@@ -194,7 +194,7 @@ struct autofs_dev_ioctl {
struct args_ismountpoint ismountpoint;
};

- char path[0];
+ char path[];
};

The ioctlfd field is a mount point file descriptor of an autofs mount
diff --git a/Documentation/filesystems/autofs.txt b/Documentation/filesystems/autofs.txt
index 3af38c7fd26d..0766089b81f1 100644
--- a/Documentation/filesystems/autofs.txt
+++ b/Documentation/filesystems/autofs.txt
@@ -455,7 +455,7 @@ Each ioctl is passed a pointer to an `autofs_dev_ioctl` structure:
struct args_ismountpoint ismountpoint;
};

- char path[0];
+ char path[];
};

For the **OPEN_MOUNT** and **IS_MOUNTPOINT** commands, the target
diff --git a/Documentation/filesystems/fiemap.txt b/Documentation/filesystems/fiemap.txt
index f6d9c99103a4..172c94377fb3 100644
--- a/Documentation/filesystems/fiemap.txt
+++ b/Documentation/filesystems/fiemap.txt
@@ -22,7 +22,7 @@ struct fiemap {
* mapped (out) */
__u32 fm_extent_count; /* size of fm_extents array (in) */
__u32 fm_reserved;
- struct fiemap_extent fm_extents[0]; /* array of mapped extents (out) */
+ struct fiemap_extent fm_extents[]; /* array of mapped extents (out) */
};


diff --git a/Documentation/hwspinlock.txt b/Documentation/hwspinlock.txt
index 6f03713b7003..a37e7c24ff26 100644
--- a/Documentation/hwspinlock.txt
+++ b/Documentation/hwspinlock.txt
@@ -439,7 +439,7 @@ implementation using the hwspin_lock_register() API.
const struct hwspinlock_ops *ops;
int base_id;
int num_locks;
- struct hwspinlock lock[0];
+ struct hwspinlock lock[];
};

struct hwspinlock_device contains an array of hwspinlock structs, each
diff --git a/Documentation/networking/can.rst b/Documentation/networking/can.rst
index 2fd0b51a8c52..ceb40a9d2044 100644
--- a/Documentation/networking/can.rst
+++ b/Documentation/networking/can.rst
@@ -705,7 +705,7 @@ The broadcast manager sends responses to user space in the same form:
struct timeval ival1, ival2; /* count and subsequent interval */
canid_t can_id; /* unique can_id for task */
__u32 nframes; /* number of can_frames following */
- struct can_frame frames[0];
+ struct can_frame frames[];
};

The aligned payload 'frames' uses the same basic CAN frame structure defined
diff --git a/Documentation/networking/rxrpc.txt b/Documentation/networking/rxrpc.txt
index 180e07d956a7..b1fff6870c1b 100644
--- a/Documentation/networking/rxrpc.txt
+++ b/Documentation/networking/rxrpc.txt
@@ -518,7 +518,7 @@ form:
uint8_t kvno; /* key version number */
uint8_t __pad[3];
uint8_t session_key[8]; /* DES session key */
- uint8_t ticket[0]; /* the encrypted ticket */
+ uint8_t ticket[]; /* the encrypted ticket */
};

Where the ticket blob is just appended to the above structure.
diff --git a/Documentation/remoteproc.txt b/Documentation/remoteproc.txt
index 03c3d2e568b0..77b1493759b2 100644
--- a/Documentation/remoteproc.txt
+++ b/Documentation/remoteproc.txt
@@ -274,7 +274,7 @@ The resource table begins with this header::
u32 ver;
u32 num;
u32 reserved[2];
- u32 offset[0];
+ u32 offset[];
} __packed;

Immediately following this header are the resource entries themselves,
@@ -291,7 +291,7 @@ each of which begins with the following resource entry header::
*/
struct fw_rsc_hdr {
u32 type;
- u8 data[0];
+ u8 data[];
} __packed;

Some resources entries are mere announcements, where the host is informed
diff --git a/Documentation/virt/kvm/api.txt b/Documentation/virt/kvm/api.txt
index 136f1eef3712..0b8955152362 100644
--- a/Documentation/virt/kvm/api.txt
+++ b/Documentation/virt/kvm/api.txt
@@ -192,7 +192,7 @@ Errors:

struct kvm_msr_list {
__u32 nmsrs; /* number of msrs in entries */
- __u32 indices[0];
+ __u32 indices[];
};

The user fills in the size of the indices array in nmsrs, and in return
@@ -566,7 +566,7 @@ struct kvm_msrs {
__u32 nmsrs; /* number of msrs in entries */
__u32 pad;

- struct kvm_msr_entry entries[0];
+ struct kvm_msr_entry entries[];
};

struct kvm_msr_entry {
@@ -626,7 +626,7 @@ struct kvm_cpuid_entry {
struct kvm_cpuid {
__u32 nent;
__u32 padding;
- struct kvm_cpuid_entry entries[0];
+ struct kvm_cpuid_entry entries[];
};


@@ -649,7 +649,7 @@ signal mask.
/* for KVM_SET_SIGNAL_MASK */
struct kvm_signal_mask {
__u32 len;
- __u8 sigset[0];
+ __u8 sigset[];
};


@@ -1403,7 +1403,7 @@ Returns: 0 on success, -1 on error
struct kvm_cpuid2 {
__u32 nent;
__u32 padding;
- struct kvm_cpuid_entry2 entries[0];
+ struct kvm_cpuid_entry2 entries[];
};

#define KVM_CPUID_FLAG_SIGNIFCANT_INDEX BIT(0)
@@ -1516,7 +1516,7 @@ On arm/arm64, GSI routing has the following limitation:
struct kvm_irq_routing {
__u32 nr;
__u32 flags;
- struct kvm_irq_routing_entry entries[0];
+ struct kvm_irq_routing_entry entries[];
};

No flags are specified so far, the corresponding field must be set to zero.
@@ -2868,7 +2868,7 @@ Errors:

struct kvm_reg_list {
__u64 n; /* number of registers in reg[] */
- __u64 reg[0];
+ __u64 reg[];
};

This ioctl returns the guest registers that are supported for the
@@ -2997,7 +2997,7 @@ Returns: 0 on success, -1 on error
struct kvm_cpuid2 {
__u32 nent;
__u32 flags;
- struct kvm_cpuid_entry2 entries[0];
+ struct kvm_cpuid_entry2 entries[];
};

The member 'flags' is used for passing flags from userspace.
@@ -3889,8 +3889,8 @@ struct kvm_nested_state {
} hdr;

union {
- struct kvm_vmx_nested_state_data vmx[0];
- struct kvm_svm_nested_state_data svm[0];
+ struct kvm_vmx_nested_state_data vmx[];
+ struct kvm_svm_nested_state_data svm[];
} data;
};

@@ -4016,7 +4016,7 @@ Returns: 0 on success, -1 on error
struct kvm_cpuid2 {
__u32 nent;
__u32 padding;
- struct kvm_cpuid_entry2 entries[0];
+ struct kvm_cpuid_entry2 entries[];
};

struct kvm_cpuid_entry2 {
@@ -4110,7 +4110,7 @@ struct kvm_pmu_event_filter {
__u32 fixed_counter_bitmap;
__u32 flags;
__u32 pad[4];
- __u64 events[0];
+ __u64 events[];
};

This ioctl restricts the set of PMU events that the guest can program.
diff --git a/Documentation/x86/boot.rst b/Documentation/x86/boot.rst
index 08a2f100c0e6..1110c1a7337b 100644
--- a/Documentation/x86/boot.rst
+++ b/Documentation/x86/boot.rst
@@ -790,13 +790,13 @@ Protocol: 2.09+
The 64-bit physical pointer to NULL terminated single linked list of
struct setup_data. This is used to define a more extensible boot
parameters passing mechanism. The definition of struct setup_data is
- as follow::
+ as follows::

struct setup_data {
u64 next;
u32 type;
u32 len;
- u8 data[0];
+ u8 data[];
};

Where, the next is a 64-bit physical pointer to the next node of
--
2.20.1