This implements bits and pieces to get the debugging functionality to
build. No testing has been done to check whether it actually works
because GCC doesn't currently work.
GCC and Clang allow us to inject a call to a function named
__sanitizer_cov_trace_pc on every edge. This function has to be defined
by us. By noting down the caller in that function we can trace the code
we have encountered during execution. Such information is used by
coverage guided fuzzers like AFL and LibFuzzer to determine if a new
input resulted in a new code path. This makes fuzzing much more
effective.
Additionally this adds a basic KCOV implementation. KCOV is an API that
allows user space to request the kernel to start collecting coverage
information for a given user space thread. Furthermore KCOV then exposes
the collected program counters to user space via a BlockDevice which can
be mmaped from user space.
This work is required to add effective support for fuzzing SerenityOS to
the Syzkaller syscall fuzzer. :^) :^)
This patch changes the semantics of purgeable memory.
- AnonymousVMObject now has a "purgeable" flag. It can only be set when
constructing the object. (Previously, all anonymous memory was
effectively purgeable.)
- AnonymousVMObject now has a "volatile" flag. It covers the entire
range of physical pages. (Previously, we tracked ranges of volatile
pages, effectively making it a page-level concept.)
- Non-volatile objects maintain a physical page reservation via the
committed pages mechanism, to ensure full coverage for page faults.
- When an object is made volatile, it relinquishes any unused committed
pages immediately. If later made non-volatile again, we then attempt
to make a new committed pages reservation. If this fails, we return
ENOMEM to userspace.
mmap() now creates purgeable objects if passed the MAP_PURGEABLE option
together with MAP_ANONYMOUS. anon_create() memory is always purgeable.
As we've opted to make these inline functions and not macros, let's at
least make sure that the users don't *observe* multiple definitions of
these functions.
This implementation features a fast path for pthread_cond_signal() and
pthread_cond_broadcast() for the case there's no thread waiting, and
does not exhibit the "thundering herd" issue in
pthread_cond_broadcast().
Fixes https://github.com/SerenityOS/serenity/issues/8432
Depending on the driver, the second buffer may not be located right
after the first, e.g. it may be page aligned. This removes this
assumption and queries the driver for the appropriate offset.
Some devices may require DMA transfers to flush the updated buffer
areas prior to flipping. For those devices we track the areas that
require flushing prior to the next flip. For devices that do not
support flipping, but require flushing, we'll simply flush after
updating the front buffer.
This also adds a small optimization that skips these steps entirely for
a screen that doesn't have any updates that need to be rendered.
We regularily need to flush many rectangles, so instead of making many
expensive ioctl() calls to the framebuffer driver, collect the
rectangles and only make one call. And if we have too many rectangles
then it may be cheaper to just update the entire region, in which case
we simply convert them all into a union and just flush that one
rectangle instead.
wint_t is also not supposed to be defined by sys/types.h, but should
be defined in wchar.h instead. Since we require it for our definition of
btowc, let's move it to the correct place.
Unlike accept() the new accept4() system call lets the caller specify
flags for the newly accepted socket file descriptor, such as
SOCK_CLOEXEC and SOCK_NONBLOCK.
This commit adds support for the various ECHO* lflags and fixes some
POSIX conformance issues around newline handling. Also included are
error messages when setting not implemented settings.
This non-POSIX header is used in Linux/BSD systems for storing the
default termios settings. This lets us setup new TTYs' `m_termios.c_cc`
in a nicer way than using a magic string.
The function fstatat can do the same thing as the stat and lstat
functions. However, it can be passed the file descriptor of a directory
which will be used when as the starting point for relative paths. This
is contrary to stat and lstat which use the current working directory as
the starting for relative paths.
It's technically not specified by POSIX, but it appears most Unix-like
systems worth mentioning put those definitions there. Also, it's more
logical since the dev_t type is defined there.
This change implements the pthread user space spinlock API. The
stress-ng Port requires a functioning version to work correctly.
To facilitate the requirements of the posix specification for the API
we implement the spinlock so that the owning tid is the value stored
in the spinlock. This gives us the proper ownership semantics needed
to implement the proper error handling.
This commit will add MSG_PEEK support, which allows a package to be
seen without taking it from the buffer, so that a subsequent recv()
without the MSG_PEEK flag can pick it up.
- Reorganized some variables (alphabetically and based on their function) so that the new ones don't stick out.
- See: https://github.com/SerenityOS/serenity/issues/6068
Co-authored-by: Linus Groh <mail@linusgroh.de>
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 *
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.
This patch adds a few missing ioctls which were required by Wine.
SIOCGIFNETMASK, SIOCGIFBRDADDR and SIOCGIFMTU are fully implemented,
while SIOCGIFFLAGS and SIOCGIFCONF are stubs.
According to the Single UNIX Specification, Version 2 that's where
those macros should be defined. This fixes the libiconv port.
This also fixes some (but not all) build errors for the diffutils and nano ports.
Added a dummy TIOCSTI ioctl placeholder. This is a dangerous ioctl that
can be used to inject input into a tty. Added for compatibility. Always
fails with EIO.
