Anhad Singh
5ccd2414af
The `AddrSpaceWrapper::r#move` is used by `mremap` to move, expand or
shrink existing mappings.
`src_span.count`: Size of old region in pages
`new_page_count`: Size of new region in pages
Fixes the following panic when running `cargo`:
```
KERNEL PANIC: panicked at src/context/memory.rs:1969:9:
assertion failed: self.info.can_extract(false)
FP ffff80000cbbf2c0: PC ffffffff8004ced5
FFFFFFFF8004CD50+0185
kernel::panic::panic_handler_inner
FP ffff80000cbbf3a0: PC ffffffff8004ac99
FP ffff80000cbbf3b0: PC ffffffff800a34df
FP ffff80000cbbf3e0: PC ffffffff800a34b4
FP ffff80000cbbf430: PC ffffffff8001c029
FFFFFFFF8001BF10+0119
kernel::context::memory::Grant::extract
FP ffff80000cbbf4a0: PC ffffffff800181ac
FFFFFFFF80016D30+147C
kernel::context::memory::AddrSpaceWrapper::move
FP ffff80000cbbfd30: PC ffffffff80037c08
FFFFFFFF80035660+25A8
kernel::syscall::syscall
FP ffff80000cbbfe90: PC ffffffff8008efbf
FFFFFFFF8008EF10+00AF
__inner_syscall_instruction
FP ffff80000cbbff50: PC ffffffff80085d33
FFFFFFFF80085CF0+0043
kernel::arch::x86_64::interrupt::syscall::syscall_instruction
0000000000004455: GUARD PAGE
CPU #2, CID 0xffffff7f80133690
NAME: /scheme/initfs/bin/redoxfs, DEBUG ID: 43
SYSCALL: mremap(0x2177F000, 0x8000, 0x0, 0xC7000, 0x60000)
HALT
```
```
mremap_flags = MremapFlags(
0x0,
)
prot_flags = MapFlags(
PROT_WRITE | PROT_READ,
)
```
Signed-off-by: Anhad Singh <andypython@protonmail.com>
Kernel
Redox OS Microkernel
Requirements
nasmneeds to be available on the PATH at build time.
Building The Documentation
Use this command:
cargo doc --open --target x86_64-unknown-none
Debugging
QEMU
Running QEMU with the -s flag will set up QEMU to listen on port 1234 for a GDB client to connect to it. To debug the redox kernel run.
make qemu gdb=yes
This will start a virtual machine with and listen on port 1234 for a GDB or LLDB client.
GDB
If you are going to use GDB, run these commands to load debug symbols and connect to your running kernel:
(gdb) symbol-file build/kernel.sym
(gdb) target remote localhost:1234
LLDB
If you are going to use LLDB, run these commands to start debugging:
(lldb) target create -s build/kernel.sym build/kernel
(lldb) gdb-remote localhost:1234
After connecting to your kernel you can set some interesting breakpoints and continue
the process. See your debuggers man page for more information on useful commands to run.
Notes
-
Always use
foo.get(n)instead offoo[n]and try to cover for the possibility ofOption::None. Doing the regular way may work fine for applications, but never in the kernel. No possible panics should ever exist in kernel space, because then the whole OS would just stop working. -
If you receive a kernel panic in QEMU, use
pkill qemu-systemto kill the frozen QEMU process.
How To Contribute
To learn how to contribute to this system component you need to read the following document:
Development
To learn how to do development with this system component inside the Redox build system you need to read the Build System and Coding and Building pages.
How To Build
To build this system component you need to download the Redox build system, you can learn how to do it on the Building Redox page.
This is necessary because they only work with cross-compilation to a Redox virtual machine, but you can do some testing from Linux.
Funding - Unix-style Signals and Process Management
This project is funded through NGI Zero Core, a fund established by NLnet with financial support from the European Commission's Next Generation Internet program. Learn more at the NLnet project page.
