The POSIX man-page states that inet_pton returns 0 if the input is not a
valid IPv4 dotted-decimal string or a valid IPv6 address string. This is
also how it is implemented in SerenityOS.
This means that we should treat a return value of 0 as an error to avoid
using an invalid address (or 0.0.0.0).
Take Kernel/UBSanitizer.cpp and make a copy in LibSanitizer.
We can use LibSanitizer to hold other sanitizers as people implement
them :^).
To enable UBSAN for LibC, DynamicLoader, and other low level system
libraries, LibUBSanitizer is built as a serenity_libc, and has a static
version for LibCStatic to use. The approach is the same as that taken in
Note that this means now UBSAN is enabled for code generators, Lagom,
Kernel, and Userspace with -DENABLE_UNDEFINED_SANTIZER=ON. In userspace
however, UBSAN is not deadly (yet).
Co-authored-by: ForLoveOfCats <ForLoveOfCats@vivaldi.net>
This implements the XSI-compliant version of strerror_r() - as opposed
to the GNU-specific variant.
The function explicitly saves errno so as to not accidentally change it
with one of the calls to other functions.
Previously each malloc size class would keep around a limited number of
unused blocks which were marked with MADV_SET_VOLATILE which could then
be reinitialized when additional blocks were needed.
This changes malloc() so that it also keeps around a number of blocks
without marking them with MADV_SET_VOLATILE. I termed these "hot"
blocks whereas blocks which were marked as MADV_SET_VOLATILE are called
"cold" blocks because they're more expensive to reinitialize.
In the worst case this could increase memory usage per process by
1MB when a program requests a bunch of memory and frees all of it.
Also, in order to make more efficient use of these unused blocks
they're now shared between size classes.
Problem:
- `static` variables consume memory and sometimes are less
optimizable.
- `static const` variables can be `constexpr`, usually.
- `static` function-local variables require an initialization check
every time the function is run.
Solution:
- If a global `static` variable is only used in a single function then
move it into the function and make it non-`static` and `constexpr`.
- Make all global `static` variables `constexpr` instead of `const`.
- Change function-local `static const[expr]` variables to be just
`constexpr`.
Hook the kernel page fault handler and capture page fault events when
the fault has a current thread attached in TLS. We capture the eip and
ebp so we can unwind the stack and locate which pieces of code are
generating the most page faults.
Co-authored-by: Gunnar Beutner <gbeutner@serenityos.org>
Problem:
- Function local `constexpr` variables do not need to be
`static`. This consumes memory which is unnecessary and can prevent
some optimizations.
Solution:
- Remove `static` keyword.
Problem:
- `size_classes` is a C-style array which makes it difficult to use in
algorithms.
- `all_of` algorithm is re-written for the specific implementation.
Solution:
- Change `size_classes` to be an `Array`.
- Directly use the generic `all_of` algorithm instead of
reimplementing.
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.
This implements the macOS API malloc_good_size() which returns the
true allocation size for a given requested allocation size. This
allows us to make use of all the available memory in a malloc chunk.
For example, for a malloc request of 35 bytes our malloc would
internally use a chunk of size 64, however the remaining 29 bytes
would be unused.
Knowing the true allocation size allows us to request more usable
memory that would otherwise be wasted and make that available for
Vector, HashTable and potentially other callers in the future.
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.
With the new InodeWatcher API, the old style of creating a watcher per
inode will no longer work. Therefore the FileWatcher API has been
updated to support multiple watches, and its users have also been
refactored to the new style. At the moment, all operations done on a
(Blocking)FileWatcher return Result objects, however, this may be
changed in the future if it becomes too obnoxious. :^)
Co-authored-by: Gunnar Beutner <gunnar@beutner.name>
The get_dir_entries syscall failed if the serialized form of all the
directory entries together was too large to fit in its temporary buffer.
Now the kernel uses a fixed size buffer, that is flushed to an output
buffer when it is full. If this flushing operation fails because there
is not enough space available, the syscall will return -EINVAL. That
error code is then used in userspace as a signal to allocate a larger
buffer and retry the syscall.
The LOCKER() macro appears to have been added to LibThread as a
userspace analog to the previous LOCKER() macro that existed in
the kernel. The kernel version used the macro to inject __FILE__ and
__LINE__ number into the lock acquisition for debugging. However
AK::SourceLocation was used to remove the need for the macro. So
the kernel version no longer exists. The LOCKER() in LibThread doesn't
appear to actually need to be a macro, using the type directly works
fine, and arguably is more readable as it removes an unnecessary
level of indirection.
Legally we could just return a null pointer, however returning a
pointer other than the null pointer is more compatible with
improperly written software that assumes that a null pointer means
allocation failure.
Only keep track of that (and eventually close() it) internally instead.
This argument is not present on other systems, so we were running into
compatibility issues with ports.
Also bring the implementation closer to Linux and OpenBSD by making sure
to close the slave pty fd in the fork()'d child as well as _exit()'ing
on login_tty() failure - it's non-POSIX, so those are our references
here. :^)
By default malloc manages memory internally in larger blocks. When
one of those blocks is added we initialize a free list by touching
each of the new block's pages, thereby committing all that memory
upfront.
This changes malloc to build the free list on demand which as a
bonus also distributes the latency hit for new blocks more evenly
because the page faults for the zero pages now don't happen all at
once.
An IP socket can now join a multicast group by using the
IP_ADD_MEMBERSHIP sockopt, which will cause it to start receiving
packets sent to the multicast address, even though this address does
not belong to this host.
When attempting to fix the dirent code I also changed
this to use strlcpy instead of the custom string copy
loop that was there before. Looking over strlcpy it
looked like it should work when using a non null terminated
string, I obviously misinterpreted the implementation
as it will read till it finds a null terminator.
Manually null terminate the string to address this.
Gunnar found this after he fixed UserspaceEmulator.
I reproduced it locally using his branch, and also
found the memory leak I had in the unit test for the
scandir that I added, so lets fix that as well.
Reported-by: Gunnar Beutner <gbeutner@serenityos.org>
