Commit Graph

23 Commits

Author SHA1 Message Date
Andreas Kling
8129f3da52 Kernel: Move SMAP disabler RAII helper to its own file
Added this in a new directory called Kernel/Arch/x86/ where stuff
that applies to both i386 and x86_64 can live.
2021-02-25 17:25:34 +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
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
c10e0adaca Kernel: Move perf event backtrace capture out of Thread class
There's no need for this to be generic and support running from an
arbitrary thread context. Perf events are always generated from within
the thread being profiled, so take advantage of that to simplify the
code. Also use Vector capacity to avoid heap allocations.
2021-02-03 11:53:05 +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
647cfcb641 Kernel: Prune uninteresting kernel frames from profiling samples
Start capturing the sample stacks at the EIP/EBP of the pre-empted
thread instead of capturing EBP in the sampling function itself.
2021-01-17 14:36:53 +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
Andreas Kling
5dafb72370 Kernel+Profiler: Make profiling per-process and without core dumps
This patch merges the profiling functionality in the kernel with the
performance events mechanism. A profiler sample is now just another
perf event, rather than a dedicated thing.

Since perf events were already per-process, this now makes profiling
per-process as well.

Processes with perf events would already write out a perfcore.PID file
to the current directory on death, but since we may want to profile
a process and then let it continue running, recorded perf events can
now be accessed at any time via /proc/PID/perf_events.

This patch also adds information about process memory regions to the
perfcore JSON format. This removes the need to supply a core dump to
the Profiler app for symbolication, and so the "profiler coredump"
mechanism is removed entirely.

There's still a hard limit of 4MB worth of perf events per process,
so this is by no means a perfect final design, but it's a nice step
forward for both simplicity and stability.

Fixes #4848
Fixes #4849
2021-01-11 11:36:00 +01:00
Andreas Kling
d893498e57 Kernel: Use fallible KBuffer API in PerformanceEventBuffer 2020-12-19 10:23:12 +01:00
Andreas Kling
8e79bde2b7 Kernel: Move KBufferBuilder to the fallible KBuffer API
KBufferBuilder::build() now returns an OwnPtr<KBuffer> and can fail.
Clients of the API have been updated to handle that situation.
2020-12-18 19:22:26 +01:00
Tom
6cb640eeba Kernel: Move some time related code from Scheduler into TimeManagement
Use the TimerQueue to expire blocking operations, which is one less thing
the Scheduler needs to check on every iteration.

Also, add a BlockTimeout class that will automatically handle relative or
absolute timeouts as well as overriding timeouts (e.g. socket timeouts)
more consistently.

Also, rework the TimerQueue class to be able to fire events from
any processor, which requires Timer to be RefCounted. Also allow
creating id-less timers for use by blocking operations.
2020-11-30 13:17:02 +01:00
Andreas Kling
d5d54da0ea Kernel: Don't use copy_from_user() for kernelspace read in perf events
Fixes #3182.
2020-08-17 09:57:18 +02:00
Nico Weber
430b265cd4 AK: Rename KB, MB, GB to KiB, MiB, GiB
The SI prefixes "k", "M", "G" mean "10^3", "10^6", "10^9".
The IEC prefixes "Ki", "Mi", "Gi" mean "2^10", "2^20", "2^30".

Let's use the correct name, at least in code.

Only changes the name of the constants, no other behavior change.
2020-08-16 16:33:28 +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
Tom
16783bd14d Kernel: Turn Thread::current and Process::current into functions
This allows us to query the current thread and process on a
per processor basis
2020-07-01 12:07:01 +02:00
Andreas Kling
b7ff3b5ad1 Kernel: Include the current instruction pointer in profile samples
We were missing the innermost instruction pointer when sampling.
This makes the instruction-level profile info a lot cooler! :^)
2020-04-11 21:04:45 +02:00
Shannon Booth
81adefef27 Kernel: Run clang-format on files
Let's rip off the band-aid
2020-03-22 01:22:32 +01:00
Andreas Kling
b1058b33fb AK: Add global FlatPtr typedef. It's u32 or u64, based on sizeof(void*)
Use this instead of uintptr_t throughout the codebase. This makes it
possible to pass a FlatPtr to something that has u32 and u64 overloads.
2020-03-08 13:06:51 +01:00
Andreas Kling
7e6c2068bf Kernel: Fix suspicious local shadowing in PerformanceEventBuffer 2020-03-01 21:08:04 +01:00
Andreas Kling
983b4bd9f2 Kernel+ProfileViewer: Move symbolication to userspace for time profiles
This makes the time profiles look like the memory profiles so we can
use the userspace symbolication code in ProfileViewer.
2020-02-22 10:09:54 +01:00
Andreas Kling
48f7c28a5c Kernel: Replace "current" with Thread::current and Process::current
Suggested by Sergey. The currently running Thread and Process are now
Thread::current and Process::current respectively. :^)
2020-02-17 15:04:27 +01:00
Andreas Kling
a356e48150 Kernel: Move all code into the Kernel namespace 2020-02-16 01:27:42 +01:00
Andreas Kling
3879e5b9d4 Kernel: Start working on a syscall for logging performance events
This patch introduces sys$perf_event() with two event types:

- PERF_EVENT_MALLOC
- PERF_EVENT_FREE

After the first call to sys$perf_event(), a process will begin keeping
these events in a buffer. When the process dies, that buffer will be
written out to "perfcore" in the current directory unless that filename
is already taken.

This is probably not the best way to do this, but it's a start and will
make it possible to start doing memory allocation profiling. :^)
2020-02-02 20:26:27 +01:00