This increases risk of fork bomb but is needed to support the NixOS.
Upstream dependencies of APE (uname, mkdir, dd, chmod, gzip, and mv)
will be removed from releases, and deleted from the cosmo.zip server
See #12
* Remove -f from loader usage
-f was removed in 1.5. As there is now only one flag, a couple more
bytes can be shaved off as well.
* Further loader golf
Shaves off a few bytes, paying for the cost of `RealPath` and then some
on x86_64 and offsetting some of the cost to aarch64.
* Shave off a few more bytes
Removes `-h` and flags from usage. Keeps flag-parsing logic the same,
i.e. still accepts `-h` / `--help`. Only difference is what fd and rc
the usage uses.
Still over 1k north of 8192.
* Reorder Launch arguments, pass aarch64 os
Third and fourth arguments are now identical between cosmo and Launch.
By passing sp as argument 4, we save a bit of register juggling.
Fourth argument (os) is now always passed by the loader on aarch64. It
is not yet processed by cosmo. Pushing this change separately, as the
cosmo side turns out to be somewhat more involved.
* cosmo2 receives os from loader
FreeBSD aarch64 now traps early rather than pretending to be Linux.
o/aarch64/examples/env.com still works on Linux and Xnu.
This implements proposals 1 and 2a from this gist:
https://gist.github.com/mrdomino/2222cab61715fd527e82e036ba4156b1
The only reason to use realpath from the loader was to try to prevent a
TOCTOU between the loader and the binary. But this is only a real issue
in set-id contexts, and in those cases there is already a canonical way
to do it: `/dev/fd`, passed by the kernel to the loader, so all we have
to do is pass that along to the binary.
Aside from realpath, there is no reason to absolutize the path we supply
to the binary, since it can call `getcwd` as well as we can, and on non-
M1 the binary is in a much better position to make that call.
Since we no longer absolutize the path, the binary does need to do this,
so we make its argv-parsing code generic and apply that to the different
possible places the path could come from. This means that `_` is finally
usable as a relative path, as a nice side benefit.
The M1 realpath code had a significant bug - it uses the wrong offset to
truncate the `.ape` in the `$prog.ape` case.
This PR also fixes a regression in `ape $progname` out of `$PATH` on the
two BSDs (Free and Net) that did not implement `RealPath`.
Somehow or another, I previously had missed `BUILD.mk` files.
In the process I found a few straggler cases where the modeline was
different from the file, including one very involved manual fix where a
file had been treated like it was ts=2 and ts=8 on separate occasions.
The commit history in the PR shows the gory details; the BUILD.mk was
automated, everything else was mostly manual.
The ape loader now passes the program executable name directly as a
register. `x2` is used on aarch64, `%rdx` on x86_64. This is passed
as the third argument to `cosmo()` (M1) or `Launch` (non-M1) and is
assigned to the global `__program_executable_name`.
`GetProgramExecutableName` now returns this global's value, setting
it if it is initially null. `InitProgramExecutableName` first tries
exotic, secure methods: `KERN_PROC_PATHNAME` on FreeBSD/NetBSD, and
`/proc` on Linux. If those produce a reasonable response (i.e., not
`"/usr/bin/ape"`, which happens with the loader before this change),
that is used. Otherwise, if `issetugid()`, the empty string is used.
Otherwise, the old argv/envp parsing code is run.
The value returned from the loader is always the full absolute path
of the binary to be executed, having passed through `realpath`. For
the non-M1 loader, this necessitated writing `RealPath`, which uses
`readlinkat` of `"/proc/self/fd/[progfd]"` on Linux, `F_GETPATH` on
Xnu, and the `__realpath` syscall on OpenBSD. On FreeBSD/NetBSD, it
punts to `GetProgramExecutableName`, which is secure on those OSes.
With the loader, all platforms now have a secure program executable
name. With no loader or an old loader, everything still works as it
did, but setuid/setgid is not supported if the insecure pathfinding
code would have been needed.
Fixes#991.
At least in neovim, `│vi:` is not recognized as a modeline because it
has no preceding whitespace. After fixing this, opening a file yields
an error because `net` is not an option. (`noet`, however, is.)
* Introduce env.com
Handy tool for debugging environment issues.
* Inject path as COSMOPOLITAN_PROGRAM_EXECUTABLE
`argv[0]` was previously being used as a communication channel between
the loader and the binary, giving the binary its full path for use e.g.
in `GetProgramExecutableName`. But `argv[0]` is not a good channel for
this; much of what made 2a3813c6 so gross is due to that.
This change fixes the issue by preserving `argv[0]` and establishing a
new communication channel: `COSMOPOLITAN_PROGRAM_EXECUTABLE`.
The M1 loader will always set this as the first variable. Linux should
soon follow. On the other side, `GetProgramExecutableName` checks that
variable first. If it sees it, it trusts it as-is.
A lot of the churn in `ape/ape-m1.c` in this change is actually backing
out hacks introduced in 2a3813c6; the best comparison is:
git diff 2a3813c6^..
* ape loader: $prog.ape + login shell support
If the ape loader is invoked with `$0 = $prog.ape`, then it searches for
a `$prog` in the same directory as it and loads that. In particular, the
loader searches the `PATH` for an executable named `$prog.ape`, then for
an executable named `$prog` in the same directory. If the former but not
the latter is found, the search terminates with an error.
It also handles the special case of getting started as `-$SHELL`, which
getty uses to indicate that the shell is a login shell. The path is not
searched in this case, and the program location is read straight out of
the `SHELL` variable.
It is now possible to have `/usr/local/bin/zsh.ape` act as a login shell
for a `/usr/local/bin/zsh` αpε, insofar as the program will get started
with the 'correct' args. Unfortunately, many things break if `$0` is not
the actual full path of the executable being run; for example, backspace
does not update the display properly.
To work around the brokenness introduced by not having `$0` be the full
path of the binary, we cut the leading `-` out of `argv[0]` if present.
This gets the loader's behavior with `$prog.ape` up to par, but doesn't
tell login shells that they are login shells.
So we introduce a hack to accomplish that: if ape is run as `-$prog.ape`
and the shell is `$prog`, the binary that is loaded has a `-l` flag put
into its first argument.
As of this commit, αpε binaries can be used as login shells on OSX.
* if islogin, execfn = shell
Prior to this, execfn was not being properly set for login shells that
did not receive `$_`, which was the case for iTerm2 on Mac. There were
no observable consequences of this, but fixing it seems good anyway.
* Fix auxv location calculation
In the non-login-shell case, it was leaving a word of uninitialized
memory at `envp[i] + 1`. This reuses the previous calculation based
on `envp`.
- Introduce MAP_JIT which is zero on other platforms
- Invent __jit_begin() and __jit_end() which wrap Apple's APIs
- Runtime dispatch to sys_icache_invalidate() in __clear_cache()
We now have an `#include <cxxabi.h>` header which defines all the APIs
Cosmopolitan's implemented so far. The `cosmocc` README.md file is now
greatly expanded with documentation.
The `cosmocc` compiler is now being distributed as a self-contained
toolchain that's path-agnostic and it no longer requires you clone the
Cosmop repo to use it. The bin/ folder has been deleted from the mono
repo. The `fatcosmocc` command has been renamed to `cosmocc`. MacOS
support now works very well.
This change addresses a $PATH resolution issue where APE depends on
uname and uname is an APE program. So sorry to anyone this impacted
we'll get a release out soon.
Every program built using Cosmopolitan is statically-linked. However
there are some cases, e.g. GUIs and video drivers, where linking the
host platform libraries is desirable. So what we do in such cases is
launch a stub executable using the host platform's libc, and longjmp
back into this executable. The stub executable passes back to us the
platform-specific dlopen() implementation, which we shall then wrap.
Here's the list of platforms that are supported so far:
- x86-64 Linux w/ Glibc
- x86-64 Linux w/ Musl Libc
- x86-64 FreeBSD
- x86-64 Windows
- aarch64 Linux w/ Glibc
- aarch64 MacOS
What this means is your Cosmo programs can call foreign functions on
your host operating system. However, it's important to note that any
foreign library you link won't have the ability to call functions in
your Cosmopolitan program. For example it's now technically possible
that Lua can load a module, however that almost certainly won't work
since the Lua module won't have access to Cosmo's Lua API.
Kudos to @jacereda for figuring out how to do this.
- This change fixes a bug that allowed unbuffered printf() output (to
streams like stderr) to be truncated. This regression was introduced
some time between now and the last release.
- POSIX specifies all functions as thread safe by default. This change
works towards cleaning up our use of the @threadsafe / @threadunsafe
documentation annotations to reflect that. The goal is (1) to use
@threadunsafe to document functions which POSIX say needn't be thread
safe, and (2) use @threadsafe to document functions that we chose to
implement as thread safe even though POSIX didn't mandate it.
- Tidy up the clock_gettime() implementation. We're now trying out a
cleaner approach to system call support that aims to maintain the
Linux errno convention as long as possible. This also fixes bugs that
existed previously, where the vDSO errno wasn't being translated
properly. The gettimeofday() system call is now a wrapper for
clock_gettime(), which reduces bloat in apps that use both.
- The recently-introduced improvements to the execute bit on Windows has
had bugs fixed. access(X_OK) on a directory on Windows now succeeds.
fstat() will now perform the MZ/#! ReadFile() operation correctly.
- Windows.h is no longer included in libc/isystem/, because it confused
PCRE's build system into thinking Cosmopolitan is a WIN32 platform.
Cosmo's Windows.h polyfill was never even really that good, since it
only defines a subset of the subset of WIN32 APIs that Cosmo defines.
- The setlongerjmp() / longerjmp() APIs are removed. While they're nice
APIs that are superior to the standardized setjmp / longjmp functions,
they weren't superior enough to not be dead code in the monorepo. If
you use these APIs, please file an issue and they'll be restored.
- The .com appending magic has now been removed from APE Loader.
- Improved async signal safety of read() particularly for longjmp()
- Started adding cancel cleanup handlers for locks / etc on Windows
- Make /dev/tty work better particularly for uses like `foo | less`
- Eagerly read console input into a linked list, so poll can signal
- Fix some libc definitional bugs, which configure scripts detected
- Every unit test now passes on Apple Silicon. The final piece of this
puzzle was porting our POSIX threads cancelation support, since that
works differently on ARM64 XNU vs. AMD64. Our semaphore support on
Apple Silicon is also superior now compared to AMD64, thanks to the
grand central dispatch library which lets *NSYNC locks go faster.
- The Cosmopolitan runtime is now more stable, particularly on Windows.
To do this, thread local storage is mandatory at all runtime levels,
and the innermost packages of the C library is no longer being built
using ASAN. TLS is being bootstrapped with a 128-byte TIB during the
process startup phase, and then later on the runtime re-allocates it
either statically or dynamically to support code using _Thread_local.
fork() and execve() now do a better job cooperating with threads. We
can now check how much stack memory is left in the process or thread
when functions like kprintf() / execve() etc. call alloca(), so that
ENOMEM can be raised, reduce a buffer size, or just print a warning.
- POSIX signal emulation is now implemented the same way kernels do it
with pthread_kill() and raise(). Any thread can interrupt any other
thread, regardless of what it's doing. If it's blocked on read/write
then the killer thread will cancel its i/o operation so that EINTR can
be returned in the mark thread immediately. If it's doing a tight CPU
bound operation, then that's also interrupted by the signal delivery.
Signal delivery works now by suspending a thread and pushing context
data structures onto its stack, and redirecting its execution to a
trampoline function, which calls SetThreadContext(GetCurrentThread())
when it's done.
- We're now doing a better job managing locks and handles. On NetBSD we
now close semaphore file descriptors in forked children. Semaphores on
Windows can now be canceled immediately, which means mutexes/condition
variables will now go faster. Apple Silicon semaphores can be canceled
too. We're now using Apple's pthread_yield() funciton. Apple _nocancel
syscalls are now used on XNU when appropriate to ensure pthread_cancel
requests aren't lost. The MbedTLS library has been updated to support
POSIX thread cancelations. See tool/build/runitd.c for an example of
how it can be used for production multi-threaded tls servers. Handles
on Windows now leak less often across processes. All i/o operations on
Windows are now overlapped, which means file pointers can no longer be
inherited across dup() and fork() for the time being.
- We now spawn a thread on Windows to deliver SIGCHLD and wakeup wait4()
which means, for example, that posix_spawn() now goes 3x faster. POSIX
spawn is also now more correct. Like Musl, it's now able to report the
failure code of execve() via a pipe although our approach favors using
shared memory to do that on systems that have a true vfork() function.
- We now spawn a thread to deliver SIGALRM to threads when setitimer()
is used. This enables the most precise wakeups the OS makes possible.
- The Cosmopolitan runtime now uses less memory. On NetBSD for example,
it turned out the kernel would actually commit the PT_GNU_STACK size
which caused RSS to be 6mb for every process. Now it's down to ~4kb.
On Apple Silicon, we reduce the mandatory upstream thread size to the
smallest possible size to reduce the memory overhead of Cosmo threads.
The examples directory has a program called greenbean which can spawn
a web server on Linux with 10,000 worker threads and have the memory
usage of the process be ~77mb. The 1024 byte overhead of POSIX-style
thread-local storage is now optional; it won't be allocated until the
pthread_setspecific/getspecific functions are called. On Windows, the
threads that get spawned which are internal to the libc implementation
use reserve rather than commit memory, which shaves a few hundred kb.
- sigaltstack() is now supported on Windows, however it's currently not
able to be used to handle stack overflows, since crash signals are
still generated by WIN32. However the crash handler will still switch
to the alt stack, which is helpful in environments with tiny threads.
- Test binaries are now smaller. Many of the mandatory dependencies of
the test runner have been removed. This ensures many programs can do a
better job only linking the the thing they're testing. This caused the
test binaries for LIBC_FMT for example, to decrease from 200kb to 50kb
- long double is no longer used in the implementation details of libc,
except in the APIs that define it. The old code that used long double
for time (instead of struct timespec) has now been thoroughly removed.
- ShowCrashReports() is now much tinier in MODE=tiny. Instead of doing
backtraces itself, it'll just print a command you can run on the shell
using our new `cosmoaddr2line` program to view the backtrace.
- Crash report signal handling now works in a much better way. Instead
of terminating the process, it now relies on SA_RESETHAND so that the
default SIG_IGN behavior can terminate the process if necessary.
- Our pledge() functionality has now been fully ported to AARCH64 Linux.
This changes *NSYNC to allocate waiters on the stack so our locks don't
need to depend on dynamic memory. This make our runtiem simpler, and it
also fixes bugs with thread cancellation support.
This change fixes bugs in the APE loader. The execve() unit tests are
now enabled for MODE=aarch64. See the README for how you need to have
binfmt_misc configured with Qemu to run them. Apple Silicon bugs have
been fixed too, e.g. tkill() now works.
This change reduces the memory requirements of your APE Loader by 10x,
in terms of virtual memory size, thanks to the help of alloca(). We're
also now creating argument blocks with the same layout across systems.
