mirror of
https://github.com/RGBCube/serenity
synced 2025-05-18 16:45:09 +00:00
38f93ef13b
It's still possible to read the TSC via the read_tsc() syscall, but we will now clear some of the bottom bits for unprivileged users.
45 lines
1.5 KiB
Markdown
45 lines
1.5 KiB
Markdown
## Name
|
|
|
|
crash - intentionally perform an illegal operation
|
|
|
|
## Synopsis
|
|
|
|
```**sh
|
|
$ crash [options]
|
|
```
|
|
|
|
## Description
|
|
|
|
This program is used to test how the Serenity kernel handles
|
|
userspace crashes, and can be used to simulate many different
|
|
kinds of crashes.
|
|
|
|
## Options
|
|
|
|
* `-A`: Test that all of the following crashes crash as intended.
|
|
* `-s`: Perform a segmentation violation by dereferencing an invalid pointer.
|
|
* `-d`: Perform a division by zero.
|
|
* `-i`: Execute an illegal CPU instruction.
|
|
* `-a`: Call `abort()`.
|
|
* `-m`: Read a pointer from uninitialized memory, then read from it.
|
|
* `-f`: Read a pointer from memory freed using `free()`, then read from it.
|
|
* `-M`: Read a pointer from uninitialized memory, then write to it.
|
|
* `-F`: Read a pointer from memory freed using `free()`, then write to it.
|
|
* `-r`: Write to read-only memory.
|
|
* `-T`: Make a syscall while using an invalid stack pointer.
|
|
* `-t`: Trigger a page fault while using an invalid stack pointer.
|
|
* `-S`: Make a syscall from writeable memory.
|
|
* `-x`: Read from recently freed memory. (Tests an opportunistic malloc guard.)
|
|
* `-y`: Write to recently freed memory. (Tests an opportunistic malloc guard.)
|
|
* `-X`: Attempt to execute non-executable memory. (Not mapped with PROT\_EXEC.)
|
|
* `-U`: Attempt to trigger an x86 User Mode Instruction Prevention fault.
|
|
* `-I`: Use an x86 I/O instruction in userspace.
|
|
* `-c`: Read the x86 TSC (Time Stamp Counter) directly.
|
|
|
|
## Examples
|
|
|
|
```sh
|
|
$ crash -F
|
|
Testing: "Write to freed memory"
|
|
Shell: crash(33) exitied due to signal "Segmentation violation"
|
|
```
|