This is the second of two big changes to clean up includes throughout
the project. Since I've started using clangd with Neovim and using
VSCode's intellisense, my former strategy of copying all header files
into place in `build/include` means that the real files don't show up in
`compile_commands.json` and so display many include errors when viewing
those header files in those tools.
That setup was mostly predicated on a desire to keep directory depths
small, but really I don't think paths like `src/libraries/j6/j6` are
much better than `src/libraries/j6/include/j6`, and the latter doesn't
have the aforementioned issues, and is clearer to the casual observer as
well.
Some additional changes:
- Added a new module flag `copy_headers` for behavior similar to the old
style, but placing headers in `$module_dir/include` instead of the
global `build/include`. This was needed for external projects that
don't follow the same source/headers folder structure - in this case,
`zstd`.
- There is no longer an associated `headers.*.ninja` for each
`module.*.ninja` file, as only parsed headers need to be listed; this
functionality has been moved back into the module's ninja file.
These are some changes I made to debug tooling while tracking down the
bugfix in the previous commit.
Each `scripts/debug_*_alloc.gdb` script has gdb output a `*_allocs.txt`
file, which in turn can be parsed by the `scripts/parse_*_allocs.py`
script to find errors.
Now that the log ring buffer is at a fixed known address, and entries
persist even after being read, it's easy to add a command to see what's
in the buffer from GDB. Useful if there's some log messages that hadn't
yet been printed at the time of a panic.
Two minor debugging helpers:
- the GDB script was still referencing m_koid on objects, switched to
the replacement m_obj_id instead.
- finally gave in and made panic print 1-based CPU ids like GDB uses
instead of 0-based like the hardware and LITERALLY EVERYTHING ELSE
Adding pretty printers to aid in debugging:
* For the cap_table type so that `p g_cap_table` displays a neat table
* For node_sets of handles to easily see what handles a process owns
* For util::vector to include its contents in the output
Added profiler.h which defines classes and macros for defining profiler
objects. Also added gdb command j6prof for printing profile data. Added
the syscall_profiles profiler class and auto wrapping of syscalls with
profile objects.
Other changes in this commit:
- Made the gdb command `j6threads` argument for specifying a CPU
optional. Without an argument, it loops through all CPUs.
- Switched to -mcmodel=kernel for kernel code, which makes `call`
instructions easier to follow when debugging / looking at disassembly.
Added a list of currently-set flags on the thread's state. Also stopped
tracebacks and returned instead of erroring out when they threw
gdb.MemoryError.
The j6threads command shows the current thread, ready threads, and
blocked threads for a given CPU.
To support this, TCB structs gained a pointer to their thread (instead
of trying to do offset magic) and threads gained a pointer to their
creator. Also removed thread::from_tcb() now that the TCB has a pointer.
These commands had a number of issues. They weren't evaluating their
arguments (eg, you couldn't use a symbol name instead of a number), and
they weren't explicitly using hex when evaluating numbers, so they were
getting incorrect values when the default radix was not 10.
The j6tw (j6 table walk) command to debug page tables was throwing an
exception for an integer that was too big when the default radix was 16,
because it would interpret ints as hex even without the 0x prefix. Now
j6tw explicitly converts to hex and uses the prefix to be explicit.
When setting a radix other than 10, the j6stack command will start
adding the wrong values - make sure to specify a radix for the offset
explicitly.
Also show the frame pointer for each frame with the j6bt command, and
don't throw exceptions if the name of the block is unknown.
Added the command "j6tw <pml4> <addr>" which takes any arguments that
evaluate to addresses or integers. It displays the full breakdown of the
page table walk for the given address, with flags.
Improve the j6stack command in two ways: first, swap the order of the
arguments, as depth is much more likely to be changed. Second, on any
exception accessing memory in the stack, print the exception and
continue instead of failing the whole command.
GDB works far better now with QEMU's `-S` flag. No longer does it
complain about changing the target from 32 to 64 bits. Get rid of the
old `waiting` loop and `sleep` call in the GDB config for the kernel.
Tags: debugging
There are a lot of under the hood changes here:
- Move syscalls to be a dispatch table, defined by syscalls.inc
- Don't need a full process state (push_all) in syscalls now
- In push_all, define REGS instead of using offsets
- Save TWO stack pointers as well as current saved stack pointer in TCB:
- rsp0 is the base of the kernel stack for interrupts
- rsp3 is the saved user stack from cpu_data
- Update syscall numbers in nulldrv
- Some asm-debugging enhancements to the gdb script
- fork() still not working
