Commit graph

16 commits

Author SHA1 Message Date
Linus Groh
146903a3b5 Kernel: Require semicolon after VERIFY_{NO_,}PROCESS_BIG_LOCK_ACQUIRED
This matches out general macro use, and specifically other verification
macros like VERIFY(), VERIFY_NOT_REACHED(), VERIFY_INTERRUPTS_ENABLED(),
and VERIFY_INTERRUPTS_DISABLED().
2022-08-17 22:56:51 +02:00
sin-ack
fbc771efe9 Everywhere: Use default StringView constructor over nullptr
While null StringViews are just as bad, these prevent the removal of
StringView(char const*) as that constructor accepts a nullptr.

No functional changes.
2022-07-12 23:11:35 +02:00
Andreas Kling
79fa9765ca Kernel: Replace KResult and KResultOr<T> with Error and ErrorOr<T>
We now use AK::Error and AK::ErrorOr<T> in both kernel and userspace!
This was a slightly tedious refactoring that took a long time, so it's
not unlikely that some bugs crept in.

Nevertheless, it does pass basic functionality testing, and it's just
real nice to finally see the same pattern in all contexts. :^)
2021-11-08 01:10:53 +01:00
Andreas Kling
17933b193a Kernel: Use TRY() in sys$perf_register_string() 2021-09-05 18:15:05 +02:00
Andreas Kling
a29788e58a Kernel: Don't record sys$perf_event() if profiling is not enabled
If you want to record perf events, just enable profiling. This allows us
to add random perf events to programs without littering the file system
with perfcore files.
2021-08-12 00:03:40 +02:00
Andreas Kling
1e90a3a542 Kernel: Make sys$perf_register_string() generate the string ID's
Making userspace provide a global string ID was silly, and made the API
extremely difficult to use correctly in a global profiling context.

Instead, simply make the kernel do the string ID allocation for us.
This also allows us to convert the string storage to a Vector in the
kernel (and an array in the JSON profile data.)
2021-08-12 00:03:39 +02:00
Andreas Kling
4657c79143 Kernel+LibC: Add sys$perf_register_string()
This syscall allows userspace to register a keyed string that appears in
a new "strings" JSON object in profile output.

This will be used to add custom strings to profile signposts. :^)
2021-08-12 00:03:39 +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
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
Gunnar Beutner
4ab9d8736b Kernel: Make perf_event() work for global profiles
Previously calls to perf_event() would end up in a process-specific
perfcore file even though global profiling was enabled. This changes
the behavior for perf_event() so that these events are stored into
the global profile instead.
2021-05-15 16:28:18 +02:00
Gunnar Beutner
eb798d5538 Kernel+Profiler: Improve profiling subsystem
This turns the perfcore format into more a log than it was before,
which lets us properly log process, thread and region
creation/destruction. This also makes it unnecessary to dump the
process' regions every time it is scheduled like we did before.

Incidentally this also fixes 'profile -c' because we previously ended
up incorrectly dumping the parent's region map into the profile data.

Log-based mmap support enables profiling shared libraries which
are loaded at runtime, e.g. via dlopen().

This enables profiling both the parent and child process for
programs which use execve(). Previously we'd discard the profiling
data for the old process.

The Profiler tool has been updated to not treat thread IDs as
process IDs anymore. This enables support for processes with more
than one thread. Also, there's a new widget to filter which
process should be displayed.
2021-04-26 17:13:55 +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
Andreas Kling
b425c2602c Kernel: Better handling of allocation failure in profiling
If we can't allocate a PerformanceEventBuffer to store the profiling
events, we now fail sys$profiling_enable() and sys$perf_event()
with ENOMEM instead of carrying on with a broken buffer.
2021-03-02 22:38:06 +01:00
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
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
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