This adds a new header <sys/internals.h>, which provides access to LibC internals.
This is in the interest of type-checking LibC itself, as well as enabling less-hacky
access for uses like LinkDemo.
And, of course, this progresses LibC towards building cleanly with -Wmissing-declarations.
These new syscalls allow you to send and receive file descriptors over
a local domain socket. This will enable various privilege separation
techniques and other good stuff. :^)
pselect() is similar() to select(), but it takes its timeout
as timespec instead of as timeval, and it takes an additional
sigmask parameter.
Change the sys$select parameters to match pselect() and implement
select() in terms of pselect().
And rewrite the timeval functions as inline functions.
Also add the non-standard but fairly common and useful
TIMEVAL_TO_TIMESPEC / TIMESPEC_TO_TIMEVAL functions.
This fixes terminal UI resizing in the vim port. The problem was that
vim had "#ifdef TIOCGWINSZ" around the code that figures out the size
of the terminal.
Since all of our ioctl() requests were enum values, this code was not
compiled into vim at all. This patch fixes that. :^)
.. and make travis run it.
I renamed check-license-headers.sh to check-style.sh and expanded it so
that it now also checks for the presence of "#pragma once" in .h files.
It also checks the presence of a (single) blank line above and below the
"#pragma once" line.
I also added "#pragma once" to all the files that need it: even the ones
we are not check.
I also added/removed blank lines in order to make the script not fail.
I also ran clang-format on the files I modified.
While the compiler provides __SIZE_TYPE__ for declaring size_t,
there's unfortunately no __SSIZE_TYPE__ for ssize_t.
However, we can trick the preprocessor into doing what we want anyway
by doing "#define unsigned signed" before using __SIZE_TYPE__ again.
In f4302b58fb, the kernel-side syscalls (e.g Process::sys$getsockname)
were updated to use SC_get{sock,peer}name_params, but the libc
functions were not updated.
The syscall wrapper for ptrace needs to return the peeked value when
using PT_PEEK.
Because of this, the user has to check errno to detect an error in
PT_PEEK.
This commit changes the actual syscall's interface (only for PT_PEEK) to
allow the syscall wrapper to detect an error and change errno.
PT_SETTREGS sets the regsiters of the traced thread. It can only be
used when the tracee is stopped.
Also, refactor ptrace.
The implementation was getting long and cluttered the alraedy large
Process.cpp file.
This commit moves the bulk of the implementation to Kernel/Ptrace.cpp,
and factors out peek & poke to separate methods of the Process class.
PT_POKE writes a single word to the tracee's address space.
Some caveats:
- If the user requests to write to an address in a read-only region, we
temporarily change the page's protections to allow it.
- If the user requests to write to a region that's backed by a
SharedInodeVMObject, we replace the vmobject with a PrivateIndoeVMObject.
This patch adds a way for a socket to ask to be routed through a
specific interface.
Currently, this option only applies to sending, however, it should also
apply to receiving...somehow :^)
This commit adds a basic implementation of
the ptrace syscall, which allows one process
(the tracer) to control another process (the tracee).
While a process is being traced, it is stopped whenever a signal is
received (other than SIGCONT).
The tracer can start tracing another thread with PT_ATTACH,
which causes the tracee to stop.
From there, the tracer can use PT_CONTINUE
to continue the execution of the tracee,
or use other request codes (which haven't been implemented yet)
to modify the state of the tracee.
Additional request codes are PT_SYSCALL, which causes the tracee to
continue exection but stop at the next entry or exit from a syscall,
and PT_GETREGS which fethces the last saved register set of the tracee
(can be used to inspect syscall arguments and return value).
A special request code is PT_TRACE_ME, which is issued by the tracee
and causes it to stop when it calls execve and wait for the
tracer to attach.
A new IP address or a new network mask can be specified in the command
line arguments of ifconfig to replace the old values of a given network
adapter. Additionally, more information is being printed for each adapter.
Calling shutdown prevents further reads and/or writes on a socket.
We should do a few more things based on the type of socket, but this
initial implementation just puts the basic mechanism in place.
Work towards #428.
sys$waitid() takes an explicit description of whether it's waiting for a single
process with the given PID, all of the children, a group, etc., and returns its
info as a siginfo_t.
It also doesn't automatically imply WEXITED, which clears up the confusion in
the kernel.
As suggested by Joshua, this commit adds the 2-clause BSD license as a
comment block to the top of every source file.
For the first pass, I've just added myself for simplicity. I encourage
everyone to add themselves as copyright holders of any file they've
added or modified in some significant way. If I've added myself in
error somewhere, feel free to replace it with the appropriate copyright
holder instead.
Going forward, all new source files should include a license header.
While I was updating syscalls to stop passing null-terminated strings,
I added some helpful struct types:
- StringArgument { const char*; size_t; }
- ImmutableBuffer<Data, Size> { const Data*; Size; }
- MutableBuffer<Data, Size> { Data*; Size; }
The Process class has some convenience functions for validating and
optionally extracting the contents from these structs:
- get_syscall_path_argument(StringArgument)
- validate_and_copy_string_from_user(StringArgument)
- validate(ImmutableBuffer)
- validate(MutableBuffer)
There's still so much code around this and I'm wondering if we should
generate most of it instead. Possible nice little project.
This patch implements a simple version of the futex (fast userspace
mutex) API in the kernel and uses it to make the pthread_cond_t API's
block instead of busily sched_yield().
An arbitrary userspace address is passed to the kernel as a "token"
that identifies the futex and you can then FUTEX_WAIT and FUTEX_WAKE
that specific userspace address.
FUTEX_WAIT corresponds to pthread_cond_wait() and FUTEX_WAKE is used
for pthread_cond_signal() and pthread_cond_broadcast().
I'm pretty sure I'm missing something in this implementation, but it's
hopefully okay for a start. :^)
