函数逻辑报告

Linux Kernel

v5.5.9

Brick Technologies Co., Ltd

Source Code:kernel\bpf\cpumap.c Create Date:2022-07-27 14:41:58
Last Modify:2020-03-12 14:18:49 Copyright©Brick
首页 函数Tree
注解内核,赢得工具下载SCCTEnglish

函数名称：cpu_map_update_elem

函数原型：static int cpu_map_update_elem(struct bpf_map *map, void *key, void *value, u64 map_flags)

返回类型：int

参数：

类型参数名称
struct bpf_map *map
void *key
void *value
u64map_flags
471  cmap等于container_of - cast a member of a structure out to the containing structure*@ptr: the pointer to the member.*@type: the type of the container struct this is embedded in.*@member: the name of the member within the struct.(map, structbpf_cpu_map, map)
475  key_cpu等于key
477  qsize等于value
479  如果此条件成立可能性小(为编译器优化)(map_flags > update existing element )则返回:负EINVAL
481  如果此条件成立可能性小(为编译器优化)(key_cpu >= max_entries)则返回:负E2BIG
483  如果此条件成立可能性小(为编译器优化)(map_flags == create new element if it didn't exist )则返回:负EEXIST
485  如果此条件成立可能性小(为编译器优化)(qsize > 16384)则返回:负EOVERFLOW
489  如果非cpu_possible(key_cpu)则返回:负ENODEV
492  如果qsize恒等于0则
493  rcpu = NULL
494  否则
496  rcpu等于__cpu_map_entry_alloc(qsize, key_cpu, id)
497  如果非rcpu则返回:负ENOMEM
499  cmap等于cmap
501  _read_lock() - mark the beginning of an RCU read-side critical section* When synchronize_rcu() is invoked on one CPU while other CPUs* are within RCU read-side critical sections, then the* synchronize_rcu() is guaranteed to block until after all the other
502  After xchg pointer to bpf_cpu_map_entry, use the call_rcu() to* ensure any driver rcu critical sections have completed, but this* does not guarantee a flush has happened yet. Because driver side* rcu_read_lock/unlock only protects the running XDP program
503  _read_unlock() - marks the end of an RCU read-side critical section.* In most situations, rcu_read_unlock() is immune from deadlock.* However, in kernels built with CONFIG_RCU_BOOST, rcu_read_unlock()
504  返回:0