Commit graph

32 commits

Author SHA1 Message Date
Andreas Kling
ef1e5db1d0 Everywhere: Remove klog(), dbg() and purge all LogStream usage :^)
Good-bye LogStream. Long live AK::Format!
2021-03-12 17:29:37 +01:00
Andreas Kling
839d2d70a4 Kernel: Add non-const KBuffer::impl() getter 2021-03-10 22:30:02 +01:00
Brian Gianforcaro
eaef57443c Kernel: Make MemoryManager API type-safe for Region::Access enum
Increase type-safety moving the MemoryManager APIs which take a
Region::Access to actually use that type instead of a `u8`.

Eventually the actually m_access can be moved there as well, but
I hit some weird bug where it wasn't using the correct operators
in `set_access_bit(..)` even though it's declared (and tested).
Something to fix-up later.
2021-03-08 18:47:40 +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
Brian Gianforcaro
69df3cfae7 Kernel: Mark KBuffer and its getters as [[nodiscard]]
There is no reason to call a getter without observing the result, doing
so indicates an error in the code. Mark these methods as [[nodiscard]]
to find these cases.
2021-02-15 09:34:52 +01:00
Andreas Kling
09b1b09c19 Kernel: Assert if rounding-up-to-page-size would wrap around to 0
If we try to align a number above 0xfffff000 to the next multiple of
the page size (4 KiB), it would wrap around to 0. This is most likely
never what we want, so let's assert if that happens.
2021-02-14 10:01:50 +01:00
Andreas Kling
8415866c03 Kernel: Remove user/kernel flags from Region
Now that we no longer need to support the signal trampolines being
user-accessible inside the kernel memory range, we can get rid of the
"kernel" and "user-accessible" flags on Region and simply use the
address of the region to determine whether it's kernel or user.

This also tightens the page table mapping code, since it can now set
user-accessibility based solely on the virtual address of a page.
2021-02-14 01:34:23 +01:00
Lenny Maiorani
e6f907a155 AK: Simplify constructors and conversions from nullptr_t
Problem:
- Many constructors are defined as `{}` rather than using the ` =
  default` compiler-provided constructor.
- Some types provide an implicit conversion operator from `nullptr_t`
  instead of requiring the caller to default construct. This violates
  the C++ Core Guidelines suggestion to declare single-argument
  constructors explicit
  (https://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines#c46-by-default-declare-single-argument-constructors-explicit).

Solution:
- Change default constructors to use the compiler-provided default
  constructor.
- Remove implicit conversion operators from `nullptr_t` and change
  usage to enforce type consistency without conversion.
2021-01-12 09:11:45 +01:00
Tom
f98ca35b83 Kernel: Improve ProcFS behavior in low memory conditions
When ProcFS could no longer allocate KBuffer objects to serve calls to
read, it would just return 0, indicating EOF. This then triggered
parsing errors because code assumed it read the file.

Because read isn't supposed to return ENOMEM, change ProcFS to populate
the file data upon file open or seek to the beginning. This also means
that calls to open can now return ENOMEM if needed. This allows the
caller to either be able to successfully open the file and read it, or
fail to open it in the first place.
2021-01-03 22:12:19 +01:00
Tom
60f5f48dd1 Kernel: Allocate profiling memory upfront
We need to allocate all pages for the profiler right away so that
we don't trigger page faults in the timer interrupt handler to
allocate them.

Fixes #4734
2021-01-02 11:36:48 +01:00
Tom
476f17b3f1 Kernel: Merge PurgeableVMObject into AnonymousVMObject
This implements memory commitments and lazy-allocation of committed
memory.
2021-01-01 23:43:44 +01:00
Andreas Kling
c77dda6827 Kernel: Make KBuffer::try_create_with_bytes() actually copy the bytes
KBuffers created with this API were actually just zero-filled instead
of being populated with the provided bytes.

Fixes #4493.
2020-12-23 00:40:11 +01:00
Andreas Kling
d936d86332 Kernel: Add KBuffer::try_create_with_bytes()
Here's another fallible KBuffer construction API that creates a KBuffer
and populates it with a range of bytes.
2020-12-18 19:22:26 +01:00
Andreas Kling
8cde8ba511 Kernel: Add KBuffer::try_create_with_size()
We need to stop assuming that KBuffer allocation always succeeds.
This patch adds the following API:

- static OwnPtr<KBuffer> KBuffer::create_with_size(size_t);

All KBuffer clients should move towards using this (and handling any
failures with grace.)
2020-12-18 19:22:26 +01:00
Andreas Kling
62ec6e5fe0 Kernel: Make Inode::read_entire() return a KBuffer (not ByteBuffer)
ByteBuffer is backed by kmalloc heap memory which is a scarce resource.
This fixes an OOM panic when traversing a large directory.
2020-08-11 20:29:14 +02:00
Andreas Kling
7d862dd5fc AK: Reduce header dependency graph of String.h
String.h no longer pulls in StringView.h. We do this by moving a bunch
of String functions out-of-line.
2020-03-23 13:48:44 +01:00
Andreas Kling
fa9fba6901 Kernel: Add missing #includes now that <AK/StdLibExtras.h> is smaller 2020-03-08 13:06:51 +01:00
Andreas Kling
a70cc5ca1d Kernel: Commit the entire region up front in KBuffer::copy()
Since we know exactly how much physical memory we'll need, we might as
well commit it up front instead of letting page faults drive it.
2020-02-23 11:10:52 +01:00
Andreas Kling
8047ff8205 Kernel: Expose the underlying Region of a KBuffer 2020-02-21 15:49:35 +01:00
Andreas Kling
e28809a996 Kernel: Add forward declaration header 2020-02-16 01:50:32 +01:00
Andreas Kling
a356e48150 Kernel: Move all code into the Kernel namespace 2020-02-16 01:27:42 +01:00
Andreas Kling
0a282e0a02 Kernel: Allow naming KBuffers 2020-01-20 14:00:11 +01:00
Andreas Kling
94ca55cefd Meta: Add license header to source files
As suggested by Joshua, this commit adds the 2-clause BSD license as a
comment block to the top of every source file.

For the first pass, I've just added myself for simplicity. I encourage
everyone to add themselves as copyright holders of any file they've
added or modified in some significant way. If I've added myself in
error somewhere, feel free to replace it with the appropriate copyright
holder instead.

Going forward, all new source files should include a license header.
2020-01-18 09:45:54 +01:00
Andreas Kling
9e55bcb7da Kernel: Make kernel memory regions be non-executable by default
From now on, you'll have to request executable memory specifically
if you want some.
2019-12-25 22:41:34 +01:00
Andreas Kling
7f9a33dba1 Kernel: Make Region single-owner instead of ref-counted
This simplifies the ownership model and makes Region easier to reason
about. Userspace Regions are now primarily kept by Process::m_regions.

Kernel Regions are kept in various OwnPtr<Regions>'s.

Regions now only ever get unmapped when they are destroyed.
2019-09-27 14:25:42 +02:00
Andreas Kling
9bd68b189e KBuffer: capacity() should return internal capacity, not internal size
KBuffer is just meant to be a dumb wrapper around KBufferImpl.
With this change, we actually start to see KBuffers with different size
and capacity, which allows some reallocation-avoiding optimizations.
2019-08-24 18:33:22 +02:00
Andreas Kling
c973a51a23 Kernel: Make KBuffer lazily populated
KBuffers are now zero-filled on demand instead of up front. This means
that you can create a huge KBuffer and it will only take up VM, not
physical pages (until you access them.)
2019-08-06 15:06:31 +02:00
Andreas Kling
f58b0c245d KBuffer: Add set_size() and LogStream operator<<
It will be useful to be able to set the "public" size of a KBuffer.
It can still have a different amount of memory allocated internally.
2019-08-06 07:31:52 +02:00
Andreas Kling
79e22acb22 Kernel: Use KBuffers for ProcFS and SynthFS
Instead of generating ByteBuffers and keeping those lying around, have
these filesystems generate KBuffers instead. These are way less spooky
to leave around for a while.

Since FileDescription will keep a generated file buffer around until
userspace has read the whole thing, this prevents trivially exhausting
the kmalloc heap by opening many files in /proc for example.

The code responsible for generating each /proc file is not perfectly
efficient and many of them still use ByteBuffers internally but they
at least go away when we return now. :^)
2019-08-05 11:37:48 +02:00
Andreas Kling
6b6b86fbf3 Kernel: Add a little comment header about KBuffer 2019-08-05 11:11:00 +02:00
Andreas Kling
605975adb5 Kernel: Make KBuffer a value-type wrapper around a KBufferImpl
A KBuffer always contains a valid KBufferImpl. If you need a "null"
state buffer, use Optional<KBuffer>.

This makes KBuffer very easy to work with and pass around, just like
ByteBuffer before it.
2019-08-05 11:07:45 +02:00
Andreas Kling
609495882f Kernel: Add KBuffer, a simple byte buffer backed by kernel-only memory
This memory is not accessible to userspace and comes from the kernel
page allocator, not from the kmalloc heap. This makes it ideal for
larger allocations.
2019-08-04 21:07:20 +02:00