Read¶

Intro¶

read - Read from a file descriptor

Description¶

The read syscall is used to read from an open file descriptor. It takes as input three arguments: fd, buf, and count, and returns a result in the form of the number of bytes read.

The fd argument is an integer that represents a file descriptor, which can be retrieved using the open syscall. The buf argument is a pointer to the buffer used to store the read bytes, which should have size at least count. The count argument represents the maximum number of bytes to be read.

The read syscall usually blocks the calling process until the requested data has been read. This can cause issues if the process was expected to remain responsive while waiting for the data. If this is an issue, one possible solution would be to use the poll syscall to check when data is available.

Arguments¶

fd:int[K] - The file descriptor representing the file or device to read from.
buf:void*[KU] - Pointer to the buffer to which the data should be written.
count:size_t[K] - The maximum number of bytes to be read.

Available Tags¶

K - Originated from kernel-space.
U - Originated from user space (for example, pointer to user space memory used to get it)
TOCTOU - Vulnerable to TOCTOU (time of check, time of use)
OPT - Optional argument - might not always be available (passed with null value)

Hooks¶

sys_read¶

Type¶

Kprobe

Purpose¶

To trace syscall execution in order to record useful data like time, arguments, and return codes.

Example Use Case¶

The read syscall can be used to read data from a file in the system, such as the contents of log files or configuration files. It may be useful for profiling the system by monitoring which files are read and when.

Issues¶

None.

write, poll, open

This document was automatically generated by OpenAI and needs review. It might not be accurate and might contain errors. The authors of Tracee recommend that the user reads the "events.go" source file to understand the events and their arguments better.