Function report

Linux Kernel

v5.5.9

Brick Technologies Co., Ltd

Source Code:kernel\trace\trace_events.c Create Date:2022-07-28 12:19:52
Last Modify:2020-03-12 14:18:49 Copyright©Brick
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Annotation kernel can get tool activityDownload SCCTChinese

Name:subsystem_filter_read

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

Type:ssize_t

Parameter:

TypeParameterName
struct file *filp
char __user *ubuf
size_tcnt
loff_t *ppos
1512  dir = needed for tty driver, and maybe others
1513  system = subsystem
1517  If ppos Then Return 0
1520  s = Allocation memory
1521  If Not s Then Return -ENOMEM
1524  trace_seq_init(s)
1526  print_subsystem_event_filter(system, s)
1527  r = 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  Return r