Commit graph

11 commits

Author SHA1 Message Date
Tom
7593418b77 Kernel: Fix futex race that could lead to thread waiting forever
There is a race condition where we would remove a FutexQueue from
our futex map and in the meanwhile another thread started to queue
itself into that very same futex, leading to that thread to wait
forever as no other wake operation could discover that removed
FutexQueue.

This fixes the problem by:
* Tracking imminent waits, which prevents a new FutexQueue from being
  deleted that a thread will wait on momentarily
* Atomically marking a FutexQueue as removed, which prevents a thread
  from waiting on it before it is actually removed from the futex map.
2021-07-07 10:05:55 +02:00
Linus Groh
649d2faeab Everywhere: Use "the SerenityOS developers." in copyright headers
We had some inconsistencies before:

- Sometimes "The", sometimes "the"
- Sometimes trailing ".", sometimes no trailing "."

I picked the most common one (lowecase "the", trailing ".") and applied
it to all copyright headers.

By using the exact same string everywhere we can ensure nothing gets
missed during a global search (and replace), and that these
inconsistencies are not spread any further (as copyright headers are
commonly copied to new files).
2021-04-29 00:59:26 +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
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
AnotherTest
09a43969ba Everywhere: Replace dbgln<flag>(...) with dbgln_if(flag, ...)
Replacement made by `find Kernel Userland -name '*.h' -o -name '*.cpp' | sed -i -Ee 's/dbgln\b<(\w+)>\(/dbgln_if(\1, /g'`
2021-02-08 18:08:55 +01:00
AnotherTest
53ce923e10 Everywhere: Fix obvious dbgln() bugs
This will allow compiletime dbgln() checks to pass
2021-02-08 18:08:55 +01:00
asynts
7cf0c7cc0d Meta: Split debug defines into multiple headers.
The following script was used to make these changes:

    #!/bin/bash
    set -e

    tmp=$(mktemp -d)

    echo "tmp=$tmp"

    find Kernel \( -name '*.cpp' -o -name '*.h' \) | sort > $tmp/Kernel.files
    find . \( -path ./Toolchain -prune -o -path ./Build -prune -o -path ./Kernel -prune \) -o \( -name '*.cpp' -o -name '*.h' \) -print | sort > $tmp/EverythingExceptKernel.files

    cat $tmp/Kernel.files | xargs grep -Eho '[A-Z0-9_]+_DEBUG' | sort | uniq > $tmp/Kernel.macros
    cat $tmp/EverythingExceptKernel.files | xargs grep -Eho '[A-Z0-9_]+_DEBUG' | sort | uniq > $tmp/EverythingExceptKernel.macros

    comm -23 $tmp/Kernel.macros $tmp/EverythingExceptKernel.macros > $tmp/Kernel.unique
    comm -1 $tmp/Kernel.macros $tmp/EverythingExceptKernel.macros > $tmp/EverythingExceptKernel.unique

    cat $tmp/Kernel.unique | awk '{ print "#cmakedefine01 "$1 }' > $tmp/Kernel.header
    cat $tmp/EverythingExceptKernel.unique | awk '{ print "#cmakedefine01 "$1 }' > $tmp/EverythingExceptKernel.header

    for macro in $(cat $tmp/Kernel.unique)
    do
        cat $tmp/Kernel.files | xargs grep -l $macro >> $tmp/Kernel.new-includes ||:
    done
    cat $tmp/Kernel.new-includes | sort > $tmp/Kernel.new-includes.sorted

    for macro in $(cat $tmp/EverythingExceptKernel.unique)
    do
        cat $tmp/Kernel.files | xargs grep -l $macro >> $tmp/Kernel.old-includes ||:
    done
    cat $tmp/Kernel.old-includes | sort > $tmp/Kernel.old-includes.sorted

    comm -23 $tmp/Kernel.new-includes.sorted $tmp/Kernel.old-includes.sorted > $tmp/Kernel.includes.new
    comm -13 $tmp/Kernel.new-includes.sorted $tmp/Kernel.old-includes.sorted > $tmp/Kernel.includes.old
    comm -12 $tmp/Kernel.new-includes.sorted $tmp/Kernel.old-includes.sorted > $tmp/Kernel.includes.mixed

    for file in $(cat $tmp/Kernel.includes.new)
    do
        sed -i -E 's/#include <AK\/Debug\.h>/#include <Kernel\/Debug\.h>/' $file
    done

    for file in $(cat $tmp/Kernel.includes.mixed)
    do
        echo "mixed include in $file, requires manual editing."
    done
2021-01-26 21:20:00 +01:00
asynts
8465683dcf Everywhere: Debug macros instead of constexpr.
This was done with the following script:

    find . \( -name '*.cpp' -o -name '*.h' -o -name '*.in' \) -not -path './Toolchain/*' -not -path './Build/*' -exec sed -i -E 's/dbgln<debug_([a-z_]+)>/dbgln<\U\1_DEBUG>/' {} \;

    find . \( -name '*.cpp' -o -name '*.h' -o -name '*.in' \) -not -path './Toolchain/*' -not -path './Build/*' -exec sed -i -E 's/if constexpr \(debug_([a-z0-9_]+)/if constexpr \(\U\1_DEBUG/' {} \;
2021-01-25 09:47:36 +01:00
asynts
1c1e577a5e Everywhere: Deprecate dbg(). 2021-01-23 16:46:26 +01:00
Linus Groh
421587c15c Everywhere: Fix typos 2021-01-22 18:41:29 +01:00
Tom
1d621ab172 Kernel: Some futex improvements
This adds support for FUTEX_WAKE_OP, FUTEX_WAIT_BITSET, FUTEX_WAKE_BITSET,
FUTEX_REQUEUE, and FUTEX_CMP_REQUEUE, as well well as global and private
futex and absolute/relative timeouts against the appropriate clock. This
also changes the implementation so that kernel resources are only used when
a thread is blocked on a futex.

Global futexes are implemented as offsets in VMObjects, so that different
processes can share a futex against the same VMObject despite potentially
being mapped at different virtual addresses.
2021-01-17 20:30:31 +01:00