函数逻辑报告

Linux Kernel

v5.5.9

Brick Technologies Co., Ltd

Source Code:kernel\trace\trace_events.c Create Date:2022-07-27 13:26:54
Last Modify:2020-03-12 14:18:49 Copyright©Brick
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函数名称：subsystem_filter_read

函数原型：static ssize_t subsystem_filter_read(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos)

返回类型：ssize_t

参数：

类型参数名称
struct file *filp
char __user *ubuf
size_tcnt
loff_t *ppos
1512  dir等于 needed for tty driver, and maybe others
1513  system等于subsystem
1517  如果ppos则返回:0
1520  s等于开辟内存
1521  如果非s则返回:负ENOMEM
1524  trace_seq_init(s)
1526  print_subsystem_event_filter(system, s)
1527  r等于simple_read_from_buffer(ubuf, cnt, ppos, buffer, race_seq_used - amount of actual data written to buffer*@s: trace sequence descriptor* Returns the amount of data written to the buffer.* IMPORTANT!* Use this instead of @s->seq.len if you need to pass the amount)
1530  kfree(s)
1532  返回:r