Pull flexible-array member conversion from Gustavo Silva:
"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]
sizeof(flexible-array-member) triggers a warning because flexible
array members have incomplete type[1]. There are some instances of
code in which the sizeof operator is being incorrectly/erroneously
applied to zero-length arrays and the result is zero. Such instances
may be hiding some bugs. So, this work (flexible-array member
convertions) will also help to get completely rid of those sorts of
issues.
Notice that all of these patches have been baking in linux-next for
quite a while now and, 238 more of these patches have already been
merged into 5.7-rc1.
There are a couple hundred more of these issues waiting to be
addressed in the whole codebase"
[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")
* tag 'flexible-array-member-5.7-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux: (28 commits)
xattr.h: Replace zero-length array with flexible-array member
uapi: linux: fiemap.h: Replace zero-length array with flexible-array member
uapi: linux: dlm_device.h: Replace zero-length array with flexible-array member
tpm_eventlog.h: Replace zero-length array with flexible-array member
ti_wilink_st.h: Replace zero-length array with flexible-array member
swap.h: Replace zero-length array with flexible-array member
skbuff.h: Replace zero-length array with flexible-array member
sched: topology.h: Replace zero-length array with flexible-array member
rslib.h: Replace zero-length array with flexible-array member
rio.h: Replace zero-length array with flexible-array member
posix_acl.h: Replace zero-length array with flexible-array member
platform_data: wilco-ec.h: Replace zero-length array with flexible-array member
memcontrol.h: Replace zero-length array with flexible-array member
list_lru.h: Replace zero-length array with flexible-array member
lib: cpu_rmap: Replace zero-length array with flexible-array member
irq.h: Replace zero-length array with flexible-array member
ihex.h: Replace zero-length array with flexible-array member
igmp.h: Replace zero-length array with flexible-array member
genalloc.h: Replace zero-length array with flexible-array member
ethtool.h: Replace zero-length array with flexible-array member
...
struct work_struct bip_work; /* I/O completion */
struct bio_vec *bip_vec;
- struct bio_vec bip_inline_vecs[0];/* embedded bvec array */
+ struct bio_vec bip_inline_vecs[];/* embedded bvec array */
};
#if defined(CONFIG_BLK_DEV_INTEGRITY)
* blocking (BLK_MQ_F_BLOCKING). Must be the last member - see also
* blk_mq_hw_ctx_size().
*/
- struct srcu_struct srcu[0];
+ struct srcu_struct srcu[];
};
/**
* double allocations for a small number of bio_vecs. This member
* MUST obviously be kept at the very end of the bio.
*/
- struct bio_vec bi_inline_vecs[0];
+ struct bio_vec bi_inline_vecs[];
};
#define BIO_RESET_BYTES offsetof(struct bio, bi_max_vecs)
u8 client;
__le16 flags;
__le32 can_id;
- u8 d[0];
+ u8 d[];
};
/* uCAN error types */
u8 client;
__le16 flags;
__le32 can_id;
- u8 d[0];
+ u8 d[];
};
/* build the cmd opcode_channel field with respect to the correct endianness */
struct {
u16 index;
u16 dist;
- } near[0];
+ } near[];
};
#define CPU_RMAP_DIST_INF 0xffff
uint32_t timestamp; /* key made, always 0 for now */
uint8_t algo;
uint8_t nmpi;
- char mpi[0];
+ char mpi[];
} __packed;
struct signature_hdr {
uint8_t hash;
uint8_t keyid[8];
uint8_t nmpi;
- char mpi[0];
+ char mpi[];
} __packed;
#if defined(CONFIG_SIGNATURE) || defined(CONFIG_SIGNATURE_MODULE)
s64 d_off;
unsigned short d_reclen;
unsigned char d_type;
- char d_name[0];
+ char d_name[];
};
#endif
struct device edev;
struct enclosure_component_callbacks *cb;
int components;
- struct enclosure_component component[0];
+ struct enclosure_component component[];
};
static inline struct enclosure_device *
struct em_perf_domain {
struct em_cap_state *table;
int nr_cap_states;
- unsigned long cpus[0];
+ unsigned long cpus[];
};
#ifdef CONFIG_ENERGY_MODEL
compat_u64 data;
struct compat_ethtool_rx_flow_spec fs;
u32 rule_cnt;
- u32 rule_locs[0];
+ u32 rule_locs[];
};
#endif /* CONFIG_COMPAT */
struct ethtool_rx_flow_rule {
struct flow_rule *rule;
- unsigned long priv[0];
+ unsigned long priv[];
};
struct ethtool_rx_flow_spec_input {
void *owner; /* private data to retrieve at alloc time */
unsigned long start_addr; /* start address of memory chunk */
unsigned long end_addr; /* end address of memory chunk (inclusive) */
- unsigned long bits[0]; /* bitmap for allocating memory chunk */
+ unsigned long bits[]; /* bitmap for allocating memory chunk */
};
/*
unsigned int sl_max;
unsigned int sl_count;
struct rcu_head rcu;
- __be32 sl_addr[0];
+ __be32 sl_addr[];
};
#define IP_SFLSIZE(count) (sizeof(struct ip_sf_socklist) + \
struct ihex_binrec {
__be32 addr;
__be16 len;
- uint8_t data[0];
+ uint8_t data[];
} __attribute__((packed));
static inline uint16_t ihex_binrec_size(const struct ihex_binrec *p)
unsigned long unused;
struct irq_domain *domain;
struct list_head list;
- struct irq_chip_type chip_types[0];
+ struct irq_chip_type chip_types[];
};
/**
unsigned int irq_flags_to_clear;
unsigned int irq_flags_to_set;
enum irq_gc_flags gc_flags;
- struct irq_chip_generic *gc[0];
+ struct irq_chip_generic *gc[];
};
/* Generic chip callback functions */
struct list_lru_memcg {
struct rcu_head rcu;
/* array of per cgroup lists, indexed by memcg_cache_id */
- struct list_lru_one *lru[0];
+ struct list_lru_one *lru[];
};
struct list_lru_node {
*/
struct memcg_shrinker_map {
struct rcu_head rcu;
- unsigned long map[0];
+ unsigned long map[];
};
/*
/* Size of entries[] */
unsigned int size;
/* Array of thresholds */
- struct mem_cgroup_threshold entries[0];
+ struct mem_cgroup_threshold entries[];
};
struct mem_cgroup_thresholds {
u16 result;
u16 data_size;
u8 reserved[2];
- u8 data[0];
+ u8 data[];
} __packed;
/**
refcount_t a_refcount;
struct rcu_head a_rcu;
unsigned int a_count;
- struct posix_acl_entry a_entries[0];
+ struct posix_acl_entry a_entries[];
};
#define FOREACH_ACL_ENTRY(pa, acl, pe) \
u32 port_ok;
struct rio_switch_ops *ops;
spinlock_t lock;
- struct rio_dev *nextdev[0];
+ struct rio_dev *nextdev[];
};
/**
u8 hopcount;
struct rio_dev *prev;
atomic_t state;
- struct rio_switch rswitch[0]; /* RIO switch info */
+ struct rio_switch rswitch[]; /* RIO switch info */
};
#define rio_dev_g(n) list_entry(n, struct rio_dev, global_list)
*/
struct rs_control {
struct rs_codec *codec;
- uint16_t buffers[0];
+ uint16_t buffers[];
};
/* General purpose RS codec, 8-bit data width, symbol width 1-15 bit */
* by attaching extra space to the end of the structure,
* depending on how many CPUs the kernel has booted up with)
*/
- unsigned long span[0];
+ unsigned long span[];
};
static inline struct cpumask *sched_domain_span(struct sched_domain *sd)
refcount_t refcnt;
u8 offset[SKB_EXT_NUM]; /* in chunks of 8 bytes */
u8 chunks; /* same */
- char data[0] __aligned(8);
+ char data[] __aligned(8);
};
struct skb_ext *__skb_ext_alloc(void);
*/
struct work_struct discard_work; /* discard worker */
struct swap_cluster_list discard_clusters; /* discard clusters list */
- struct plist_node avail_lists[0]; /*
+ struct plist_node avail_lists[]; /*
* entries in swap_avail_heads, one
* entry per node.
* Must be last as the number of the
u32 magic;
u32 version;
u8 future[24];
- u8 actions[0];
+ u8 actions[];
} __attribute__ ((packed));
/**
struct bts_action {
u16 type;
u16 size;
- u8 data[0];
+ u8 data[];
} __attribute__ ((packed));
struct bts_action_send {
struct bts_action_wait {
u32 msec;
u32 size;
- u8 data[0];
+ u8 data[];
} __attribute__ ((packed));
struct bts_action_delay {
u32 event_type;
u8 pcr_value[20]; /* SHA1 */
u32 event_size;
- u8 event_data[0];
+ u8 event_data[];
};
enum tcpa_event_types {
struct tcpa_pc_event {
u32 event_id;
u32 event_size;
- u8 event_data[0];
+ u8 event_data[];
};
enum tcpa_pc_event_ids {
struct tcg_event_field {
u32 event_size;
- u8 event[0];
+ u8 event[];
} __packed;
struct tcg_pcr_event2_head {
struct list_head list;
char *name;
size_t size;
- char value[0];
+ char value[];
};
/*
void __user *bastaddr;
struct dlm_lksb __user *lksb;
char lvb[DLM_USER_LVB_LEN];
- char name[0];
+ char name[];
};
struct dlm_lspace_params {
__u32 flags;
__u32 minor;
- char name[0];
+ char name[];
};
struct dlm_purge_params {
__u32 fm_mapped_extents;/* number of extents that were 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) */
};
#define FIEMAP_MAX_OFFSET (~0ULL)