Commit Graph

30 Commits

Author SHA1 Message Date
Andreas Kling
208147c77c Kernel: Rename Process::space() => Process::address_space()
We commonly talk about "a process's address space" so let's nudge the
code towards matching how we talk about it. :^)
2021-08-06 14:05:58 +02:00
Andreas Kling
cd5faf4e42 Kernel: Rename Range => VirtualRange
...and also RangeAllocator => VirtualRangeAllocator.

This clarifies that the ranges we're dealing with are *virtual* memory
ranges and not anything else.
2021-08-06 14:05:58 +02:00
Andreas Kling
93d98d4976 Kernel: Move Kernel/Memory/ code into Kernel::Memory namespace 2021-08-06 14:05:58 +02:00
Andreas Kling
a1d7ebf85a Kernel: Rename Kernel/VM/ to Kernel/Memory/
This directory isn't just about virtual memory, it's about all kinds
of memory management.
2021-08-06 14:05:58 +02:00
Brian Gianforcaro
0fc853f5ba Kernel: Remove ThreadTracer.h include from Process.h / Thread.h
This isn't needed for Process / Thread as they only reference it
by pointer and it's already part of Kernel/Forward.h. So just include
it where the implementation needs to call it.
2021-08-01 08:10:16 +02:00
Brian Gianforcaro
9201a06027 Kernel: Annotate all syscalls with VERIFY_PROCESS_BIG_LOCK_ACQUIRED
Before we start disabling acquisition of the big process lock for
specific syscalls, make sure to document and assert that all the
lock is held during all syscalls.
2021-07-20 03:21:14 +02:00
Andreas Kling
9457d83986 Kernel: Rename Locker => MutexLocker 2021-07-18 01:53:04 +02:00
Andreas Kling
88d490566f Kernel: Rename various *VMObject::create*() => try_create()
try_*() implies that it can fail (and they all return RefPtr with
nullptr signalling failure.)
2021-07-11 17:55:29 +02:00
Gunnar Beutner
2a78bf8596 Kernel: Fix the return type for syscalls
The Process::Handler type has KResultOr<FlatPtr> as its return type.
Using a different return type with an equally-sized template parameter
sort of works but breaks once that condition is no longer true, e.g.
for KResultOr<int> on x86_64.

Ideally the syscall handlers would also take FlatPtrs as their args
so we can get rid of the reinterpret_cast for the function pointer
but I didn't quite feel like cleaning that up as well.
2021-06-28 22:29:28 +02:00
Brian Gianforcaro
65d5f81afc Kernel: Make PrivateInodeVMObject factory APIs OOM safe 2021-05-29 09:04:05 +02:00
Brian Gianforcaro
956314f0a1 Kernel: Make Process::start_tracing_from API OOM safe
Modify the API so it's possible to propagate error on OOM failure.
NonnullOwnPtr<T> is not appropriate for the ThreadTracer::create() API,
so switch to OwnPtr<T>, use adopt_own_if_nonnull() to handle creation.
2021-05-13 16:21:53 +02:00
Brian Gianforcaro
1682f0b760 Everything: Move to SPDX license identifiers in all files.
SPDX License Identifiers are a more compact / standardized
way of representing file license information.

See: https://spdx.dev/resources/use/#identifiers

This was done with the `ambr` search and replace tool.

 ambr --no-parent-ignore --key-from-file --rep-from-file key.txt rep.txt *
2021-04-22 11:22:27 +02:00
FalseHonesty
3123ffb19d Kernel: Add ptrace commands for reading/writing the debug registers
This adds PT_PEEKDEBUG and PT_POKEDEBUG to allow for reading/writing
the debug registers, and updates the Kernel's debug handler to read the
new information from the debug status register.
2021-04-18 17:02:40 +02:00
Andreas Kling
ac71775de5 Kernel: Make all syscall functions return KResultOr<T>
This makes it a lot easier to return errors since we no longer have to
worry about negating EFOO errors and can just return them flat.
2021-03-01 13:54:32 +01:00
Andreas Kling
5d180d1f99 Everywhere: Rename ASSERT => VERIFY
(...and ASSERT_NOT_REACHED => VERIFY_NOT_REACHED)

Since all of these checks are done in release builds as well,
let's rename them to VERIFY to prevent confusion, as everyone is
used to assertions being compiled out in release.

We can introduce a new ASSERT macro that is specifically for debug
checks, but I'm doing this wholesale conversion first since we've
accumulated thousands of these already, and it's not immediately
obvious which ones are suitable for ASSERT.
2021-02-23 20:56:54 +01:00
Andreas Kling
4ff0f971f7 Kernel: Prevent execve/ptrace race
Add a per-process ptrace lock and use it to prevent ptrace access to a
process after it decides to commit to a new executable in sys$execve().

Fixes #5230.
2021-02-08 23:05:41 +01:00
Andreas Kling
f39c2b653e Kernel: Reorganize ptrace implementation a bit
The generic parts of ptrace now live in Kernel/Syscalls/ptrace.cpp
and the i386 specific parts are moved to Arch/i386/CPU.cpp
2021-02-08 19:34:41 +01:00
Andreas Kling
f1b5def8fd Kernel: Factor address space management out of the Process class
This patch adds Space, a class representing a process's address space.

- Each Process has a Space.
- The Space owns the PageDirectory and all Regions in the Process.

This allows us to reorganize sys$execve() so that it constructs and
populates a new Space fully before committing to it.

Previously, we would construct the new address space while still
running in the old one, and encountering an error meant we had to do
tedious and error-prone rollback.

Those problems are now gone, replaced by what's hopefully a set of much
smaller problems and missing cleanups. :^)
2021-02-08 18:27:28 +01:00
Andreas Kling
19d3f8cab7 Kernel+LibC: Turn errno codes into a strongly typed enum
..and allow implicit creation of KResult and KResultOr from ErrnoCode.
This means that kernel functions that return those types can finally
do "return EINVAL;" and it will just work.

There's a handful of functions that still deal with signed integers
that should be converted to return KResults.
2021-01-20 23:20:02 +01:00
Andreas Kling
f03800cee3 Kernel: Add dedicated "ptrace" pledge promise
The vast majority of programs don't ever need to use sys$ptrace(),
and it seems like a high-value system call to prevent a compromised
process from using.

This patch moves sys$ptrace() from the "proc" promise to its own,
new "ptrace" promise and updates the affected apps.
2021-01-11 22:32:59 +01:00
asynts
723effd051 Everywhere: Replace a bundle of dbg with dbgln.
These changes are arbitrarily divided into multiple commits to make it
easier to find potentially introduced bugs with git bisect.Everything:
2021-01-11 11:55:47 +01:00
Andreas Kling
8ff0afd829 Kernel: Defer switching the paging scope in ptrace(PT_POKE) a little
If we can fail with EFAULT early, might as well avoid switching the
paging scope.
2021-01-09 15:42:03 +01:00
Andreas Kling
02ef3f6343 Kernel: Ptrace should not assert on poke in non-mapped tracee memory 2020-12-20 18:49:24 +01:00
Tom
c455fc2030 Kernel: Change wait blocking to Process-only blocking
This prevents zombies created by multi-threaded applications and brings
our model back to closer to what other OSs do.

This also means that SIGSTOP needs to halt all threads, and SIGCONT needs
to resume those threads.
2020-12-12 21:28:12 +01:00
Ben Wiederhake
64cc3f51d0 Meta+Kernel: Make clang-format-10 clean 2020-09-25 21:18:17 +02:00
Tom
c8d9f1b9c9 Kernel: Make copy_to/from_user safe and remove unnecessary checks
Since the CPU already does almost all necessary validation steps
for us, we don't really need to attempt to do this. Doing it
ourselves doesn't really work very reliably, because we'd have to
account for other processors modifying virtual memory, and we'd
have to account for e.g. pages not being able to be allocated
due to insufficient resources.

So change the copy_to/from_user (and associated helper functions)
to use the new safe_memcpy, which will return whether it succeeded
or not. The only manual validation step needed (which the CPU
can't perform for us) is making sure the pointers provided by user
mode aren't pointing to kernel mappings.

To make it easier to read/write from/to either kernel or user mode
data add the UserOrKernelBuffer helper class, which will internally
either use copy_from/to_user or directly memcpy, or pass the data
through directly using a temporary buffer on the stack.

Last but not least we need to keep syscall params trivial as we
need to copy them from/to user mode using copy_from/to_user.
2020-09-13 21:19:15 +02:00
Ben Wiederhake
f5744a6f2f Kernel: PID/TID typing
This compiles, and contains exactly the same bugs as before.
The regex 'FIXME: PID/' should reveal all markers that I left behind, including:
- Incomplete conversion
- Issues or things that look fishy
- Actual bugs that will go wrong during runtime
2020-08-10 11:51:45 +02:00
Brian Gianforcaro
1209bf82c1 Kernel: Use Userspace<T> in ptrace syscall 2020-08-02 00:29:04 +02:00
Andreas Kling
be7add690d Kernel: Rename region_from_foo() => find_region_from_foo()
Let's emphasize that these functions actually go out and find regions.
2020-07-30 23:52:28 +02:00
Andreas Kling
949aef4aef Kernel: Move syscall implementations out of Process.cpp
This is something I've been meaning to do for a long time, and here we
finally go. This patch moves all sys$foo functions out of Process.cpp
and into files in Kernel/Syscalls/.

It's not exactly one syscall per file (although it could be, but I got
a bit tired of the repetitive work here..)

This makes hacking on individual syscalls a lot less painful since you
don't have to rebuild nearly as much code every time. I'm also hopeful
that this makes it easier to understand individual syscalls. :^)
2020-07-30 23:40:57 +02:00