pwritev2 - attempts to write data to a file descriptor at a given position
pwritev2() is used to write data to a file descriptor at a given position. The data is written to the file descriptor in the form of an array of iovec structures, which allow for the writing of multiple buffers in a single call.
pwritev2() differs from the pwritev() system call in that it has optional
flags argument which controls the behavior of the syscall in more detail. The flag
PWRITEV_UPDATE_POSITION causes the file pointer to be adjusted to reflect the amount of data written to the file descriptor.
pwritev2() is useful for maximizing the performance of writing large amounts of data to a file descriptor, as it can allow for the writing of multiple buffers in a single call.
int- file descriptor of the opened file.
const struct iovec*- pointer to an array of iovec structures that specify the source buffers from which data is written to the file descriptor.
unsigned long- the number of elements in the iovec array.
unsigned long- lower 32 bits of 64-bit position data.
unsigned long- higher 32 bits of 64-bit position data.
int[OPT] - optional flags which control the behavior of the call.
- 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)
To capture the data passed to the pwritev2() syscall.
Example Use Case¶
pwritev2() can be used to write data to a file descriptor at a specific position in an optimized way. For example, it could be used in an application that needs to write large amounts of data to a file in an efficient way.
Due to the fact that pwritev2() writes data from multiple buffers, it can be vulnerable to race conditions. It is important to be aware of the possibility of race conditions when using the pwritev2() system call.
pwritev() - similar system call but with fewer optional flags parameter. preadv2(), writev(), preadv(), writev2() - other system calls related to writing data to or from file descriptors.
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.