This change boosts SSL handshake performance from 2,627 to ~10,000 per
second which is the same level of performance as NGINX at establishing
secure connections. That's impressive if we consider that redbean is a
forking frontend application server. This was accomplished by:
1. Enabling either SSL session caching or SSL tickets. We choose to
use tickets since they reduce network round trips too and that's
a more important metric than wrk'ing localhost.
2. Fixing mbedtls_mpi_sub_abs() which is the most frequently called
function. It's called about 12,000 times during an SSL handshake
since it's the basis of most arithmetic operations like addition
and for some strange reason it was designed to make two needless
copies in addition to calling malloc and free. That's now fixed.
3. Improving TLS output buffering during the SSL handshake only, so
that only a single is write and read system call is needed until
blocking on the ping pong.
redbean will now do a better job wiping sensitive memory from a child
process as soon as it's not needed. The nice thing about fork is it's
much faster than reverse proxying so the goal is to use the different
address spaces along with setuid() to minimize the risk that a server
key will be compromised in the event that application code is hacked.
The following Lua APIs have been added:
- IsDaemon() → bool
- ProgramPidPath(str)
The following Lua hooks have been added:
- OnClientConnection(ip:int,port:int,serverip:int,serverport:int) → bool
- OnProcessCreate(pid:int,ip:int,port:int,serverip:int,serverport:int)
- OnProcessDestroy(pid:int)
- OnServerStart()
- OnServerStop()
- OnWorkerStart()
- OnWorkerStop()
redbean now does a better job at applying gzip on the fly from the local
filesystem, using a streaming chunked api with constant memory, which is
useful for doing things like serving a 4gb text file off NFS, and having
it start transmitting in milliseconds. redbean will also compute entropy
on the beginnings of files to determine if compression is profitable.
This change pays off technical debts relating to memory, such as relying
on exit() to free() allocations. That's now mostly fixed so it should be
easier now to spot memory leaks in malloc traces.
This change also fixes bugs and makes improvements to our SSL support.
Uniprocess mode failed handshakes are no longer an issue. Token Alpn is
offered so curl -v looks less weird. Hybrid SSL certificate loading is
now smarter about naming conflicts. Self-signed CA root anchors will no
longer be delivered to the client during the handshake.
The implementations of the getproto* functions follow from the getserv*
functions: same static name allocation, same type of internal function
that opens a file to search, aliases are not written to the struct, same
type of error handling/returns.
This changes also fixes a getaddrinfo AI_PASSIVE memory error. When
getaddrinfo is passed name = NULL and AI_PASSIVE in hints->ai_flags, it was
setting the s_addr value to INADDR_ANY but *not* returning the addrinfo
pointer via *res = ai. This caused a free(NULL) memory error when the caller
tried to free res, because the caller expects res to be a valid pointer to a
struct addrinfo.
Our non-standard API parseport() has been updated to use strtoimax.
strtoimax has an extra parameter endptr to store where the parsing was
terminated. endptr is used in parseport to check if the provided string
was valid.
- Fix Content-Type inference when file extension has number
- Remove shoddy Class A granular IP classiifcation
- Have setuid() and setgid() take effect w/o daemonization
- Make GetParams() return empty table instead of nil
- Change SetLogLevel(int) to only apply to one message
- Make SetLogLevel(int) good enough to be access_log off
- Introduce ProgramUid(int) which is same as -U INT
- Introduce ProgramGid(int) which is same as -G INT
- Introduce ProgramLogPath(str) which is same as -L PATH
- Introduce ProgramDirectory(str) which is same as -D PATH
- Introduce ProgramLogBodies(bool) which is same as -b
- Introduce ProgramLogMessages(bool) which is same as -m
You can now say the following in your redbean Lua code:
status,headers,payload = Fetch("https://foo.example")
The following Lua APIs have been introduced:
- Fetch(str) → str,{str:str},str
- GetHttpReason(int) → str
- GetHttpReason(int) → str
- ProgramSslFetchVerify(bool)
- ProgramSslClientVerify(bool)
The following flags have been introduced:
- `-j` enables client SSL verification
- `-k` disables Fetch() SSL verification
- `-t INT` may now be passed a negative value for keepalive
Lua exceptions now invoke Cosmopolitan's garbage collector when
unwinding the stack. So it's now safe to use _gc() w/ Lua 𝔱𝔥𝔯𝔬𝔴
See #97
Things are a little better. The LLD that comes with Linux seems to work.
Old versions like LLVM 8 haven't been supported since Cosmopolitan v0.2.
Running Clang on Windows with --target=x86_64-pc-linux-gnu doesn't seem
to work. It has something to do with the recently added .zip section in
the linker script. But even if that's removed, LLD on Windows thinks it
is building an EFI application for some reason. Linker scripts are such
a brittle house of cards, even for just ld.bfd alone..
We should just find a way to run our one true musl-cross-make linux gcc
toolchain under Blinkenlights on non-Linux because GCC and Clang are so
nondeterministic, inconsistent, and unreproducible when built for other
operating systems. We need an actually portable compiler/linker that'll
always behave the same way no matter what.
See #180
- Use nullness checks when calling weakly linked functions.
- Avoid typedef for reasons described in Linux Kernel style guide.
- Avoid enum in in Windows headers. Earlier in Cosmo's history all one
hundred files in libc/nt/enum/ used to be enums and it resulted in
gigabytes of DWARF data almost as large as everything else in the
codebase combined.
- Bitfields aren't our friends. They have frequent ABI breakages,
inconsistent arithmetic across compilers, and different endianness
between cpus. Compiler authors also haven't invested much roi into
making bit fields go fast so they produce poor assembly.
- Use memccpy() instead of strncpy() or snprintf() for length-bounded
copying of C strings. strncpy() is a misunderstood function and
snprintf() is awesome but memccpy() deserves more love.
Your redbean can now interoperate with clients that require TLS crypto.
This is accomplished using a protocol polyglot that lets us distinguish
between HTTP and HTTPS regardless of the port number. Certificates will
be generated automatically, if none are supplied by the user. Footprint
increases by only a few hundred kb so redbean in MODY=tiny is now 1.0mb
- Add lseek() polyfills for ZIP executable
- Automatically polyfill /tmp/FOO paths on NT
- Fix readdir() / ftw() / nftw() bugs on Windows
- Introduce -B flag for slower SSL that's stronger
- Remove mbedtls features Cosmopolitan doesn't need
- Have base64 decoder support the uri-safe alternative
- Remove Truncated HMAC because it's forbidden by the IETF
- Add all the mbedtls test suites and make them go 3x faster
- Support opendir() / readdir() / closedir() on ZIP executable
- Use Everest for ECDHE-ECDSA because it's so good it's so good
- Add tinier implementation of sha1 since it's not worth the rom
- Add chi-square monte-carlo mean correlation tests for getrandom()
- Source entropy on Windows from the proper interface everyone uses
We're continuing to outperform NGINX and other servers on raw message
throughput. Using SSL means that instead of 1,000,000 qps you can get
around 300,000 qps. However redbean isn't as fast as NGINX yet at SSL
handshakes, since redbean can do 2,627 per second and NGINX does 4.3k
Right now, the SSL UX story works best if you give your redbean a key
signing key since that can be easily generated by openssl using a one
liner then redbean will do all the things that are impossibly hard to
do like signing ecdsa and rsa certificates that'll work in chrome. We
should integrate the let's encrypt acme protocol in the future.
Live Demo: https://redbean.justine.lol/
Root Cert: https://redbean.justine.lol/redbean1.crt
The getnameinfo implementation requires an address -> name lookup on the
hosts file (ie struct HostsTxt) and the previous implementation used
flags to check whether HostsTxt was sorted according to address or name,
and then re-sorted it if necessary. Now getnameinfo lookup does not
require sorting, it does a simple linear lookup, and so the related code
was simplified
See #172 for discussion.
This change gets redbean SQLite working in write mode on Windows.
Warnings have been added to the appropriate and responsible places.
Hacking proprietary PC systems into production-worthy servers isn't
terribly high on the list of priorities. Consider BSD or Linux when
building online systems that service requests from multiple people.
Fixes#193
Added necessary constants (DNS_TYPE_PTR, NI_NUMERICHOST etc.).
Implementation of getnameinfo is similar to getaddrinfo, with internal
functions:
* ResolveDnsReverse: performs rDNS query and parses the PTR record
* ResolveHostsReverse: reads /etc/hosts to map hostname to
address
Earlier, the HOSTS.txt would only need to be sorted at loading time,
because the only kind of lookup was name -> address. Now since address
-> name lookups are also possible, so the HostsTxt struct, the sorting
method (and the related tests) was changed to reflect this.
- Better UBSAN error messages
- POSIX Advisory Locks polyfills
- Move redbean manual to /.help.txt
- System call memory safety in ASAN mode
- Character classification now does UNICODE
This change brings page faults for precompressed static asset serving
down from 27 to 20 (or fewer) after fork. This is more of an art than
science. Hopefully Blinkenlights can visualize page faults soon.
ASAN and vfork() don't appear to play well together. Maybe in later
versions of GCC it'll be better. But vfork() is flirting with danger
after all and that probably doesn't make sense in ASAN mode anyway.
- Fix regression with `%lu`
- Added some more headers witnessed in the wild
- Added `-M INT` option to redbean to tune max payload size
- Work around InfoZIP 256 character limit on comment line size
redbean improvements:
- Explicitly disable corking
- Simulate Python regex API for Lua
- Send warmup requests in main process on startup
- Add Class-A granular IPv4 network classification
- Add /statusz page so you can monitor your redbean's health
- Fix regressions on OpenBSD/NetBSD caused by recent changes
- Plug Authorization header into Lua GetUser and GetPass APIs
- Recognize X-Forwarded-{For,Host} from local reverse proxies
- Add many additional functions to redbean Lua server page API
- Report resource usage of child processes on `/` listing page
- Introduce `-a` flag for logging child process resource usage
- Introduce `-t MILLIS` flag and `ProgramTimeout(ms)` init API
- Introduce `-H "Header: value"` flag and `ProgramHeader(k,v)` API
Cosmopolitan Libc improvements:
- Make strerror() simpler
- Make inet_pton() not depend on sscanf()
- Fix OpenExecutable() which broke .data section earlier
- Fix stdio in cases where it overflows kernel tty buffer
- Fix bugs in crash reporting w/o .com.dbg binary present
- Add polyfills for SO_LINGER, SO_RCVTIMEO, and SO_SNDTIMEO
- Polyfill TCP_CORK on BSD and XNU using TCP_NOPUSH magnums
New netcat clone in examples/nc.c:
While testing some of the failure conditions for redbean, I noticed that
BusyBox's `nc` command is pretty busted, if you use it as an interactive
tool, rather than having it be part of a pipeline. Unfortunately this'll
only work on UNIX since Windows doesn't let us poll on stdio and sockets
at the same time because I don't think they want tools like this running
on their platform. So if you want forbidden fruit, it's here so enjoy it
- POSIX regular expressions for Lua
- Improved protocol parsing and encoding
- Additional APIs for ZIP storage retrieval
- Fix st_mode issue on NT for regular files
- Generalized APIs for URL and Host handling
- Worked out the kinks in resource resolution
- Allow for custom error pages like /404.html
The most exciting improvement is dynamic pages will soon be able to use
the executable itself as an object store. it required a heroic technique
for overcoming ETXTBSY restrictions which lets us open the executable in
read/write mode, which means (1) wa can restore the APE header, and (2)
we can potentially containerize redbean extension code so that modules
you download for your redbean online will only impact your redbean.
Here's a list of breaking changes to redbean:
- Remove /tool/net/ prefix from magic ZIP paths
- GetHeader() now returns NIL if header is absent
Here's a list of fixes and enhancements to redbean:
- Support 64-bit ZIP archives
- Record User-Agent header in logs
- Add twelve error handlers to accept()
- Display octal st_mode on listing page
- Show ZIP file comments on listing page
- Restore APE MZ header on redbean startup
- Track request count on redbean index page
- Report server uptime on redbean index page
- Don't bind server socket using SO_REUSEPORT
- Fix#151 where Lua LoadAsset() could free twice
- Report rusage accounting when workers exit w/ -vv
- Use ZIP iattr field as text/plain vs. binary hint
- Add ParseUrl() API for parsing things like a.href
- Add ParseParams() API for parsing HTTP POST bodies
- Add IsAcceptablePath() API for checking dots, etc.
- Add IsValidHttpToken() API for validating sane ASCII
- Add IsAcceptableHostPort() for validating HOST[:PORT]
- Send 400 response to HTTP/1.1 requests without a Host
- Send 403 response if ZIP or file isn't other readable
- Add virtual hosting that tries prepending Host to path
- Route requests based on Host in Request-URI if present
- Host routing will attempt to remove or add the www. prefix
- Sign-extend UNIX timestamps and don't adjust FileTime zone
Here's some of the improvements made to Cosmopolitan Libc:
- Fix ape.S indentation
- Improve consts.sh magnums
- Write pretty good URL parser
- Improve rusage accounting apis
- Bring mremap() closer to working
- Added ZIP APIs which will change
- Check for overflow in reallocarray()
- Remove overly fancy linkage in strerror()
- Fix GDB attach on crash w/ OpenBSD msyscall()
- Make sigqueue() portable to most UNIX distros
- Make integer serialization macros more elegant
- Bring back 34x tprecode8to16() performance boost
- Make malloc() more resilient to absurdly large sizes
This isn't working as intended in the Travis CI build environment.
There's likely some kind of microarchitectural issue. This change
gets us back into the green for the time being.
Cosmopolitan's QuickJS is now equally conformant and performant, with
the exception of Atomics, which have been disabled since Cosmopolitan
currently doesn't support pthreads.
QuickJS memory usage -- BigNum 2021-03-27 version, 64-bit, malloc limit: -1
NAME COUNT SIZE
memory allocated 937 131764 (140.6 per block)
memory used 938 116103 (8 overhead, 16.7 average slack)
atoms 513 21408 (41.7 per atom)
objects 170 12279 (72.2 per object)
properties 864 15531 (5.1 per object)
shapes 58 12995 (224.1 per shape)
bytecode functions 13 1512
bytecode 13 867 (66.7 per function)
C functions 99
arrays 1
fast arrays 1
elements 1 16 (1.0 per fast array)
Result: 35/74740 errors, 1279 excluded, 485 skipped, 19 new, 2 fixed
real 2m40.828s
user 2m29.764s
sys 0m10.939s
This change introduces ape-no-modify-self.o to the amalgamated release
binaries, which may be used as an alternative to ape.o to make it easier
to use APE in cases where the self-modifying behavior isn't acceptable.
Please note that this alternative copying behavior isn't necessarily
better. It introduces a whole bunch of questions of its own, which are
documented in the ape.S source comment and should be considered by both
the program author as well as the end-user of programs linked this way.
For example, build environments that use read-only file systems and
would prefer to not have a launcher wrapper (like we use in our build)
can use ape-no-modify-self.o instead of ape.o and then set the $TMPDIR
environment variable to point to a sane read-write-exec location.
Fixes#146
See #82
You can now pass `-D directory` to redbean which will serve assets from
the local filesystem. This is useful for development since it allows us
to skip needing to shut down the server and run InfoZIP when testing an
iteration of a lua server page script.
See #97
If we keep making changes like this, redbean might not be a toy anymore.
Additional steps are also being taken now to prevent ANSI control codes
sent by the client from slipping into logs.
Buffering now has optimal performance, bugs have been fixed, and some
missing apis have been introduced. This implementation is also now more
production worthy since it's less brittle now in terms of system errors.
That's going to help redbean since lua i/o is all based on stdio.
See #97
- removed unneeded share parameter from pipe on nt
- socktpair(type | SOCK_CLOEXEC) is now polyfilled
- use textwindows for linker micro-optimization
- apologies for auto clang-format diff noise :(
- improve socketpair docstring
See #122
You can now do epic things like this:
puts(_gc(xasprintf("%d", 123)));
The _gc() API is shorthand for _defer() which works like Go's keyword:
const char *s = xasprintf("%d", 123);
_defer(free, s);
puts(s);
Be sure to always use -fno-omit-frame-pointer which makes code fast too.
Enjoy! See also #114
- Polyfill open() w/ O_CLOEXEC on RHEL5
- Remove old workaround from rmdir() on the New Technology
- preadv() and pwritev() are now smarter about demodernization
- preadv() and pwritev() are now available on the New Technology
We can put this back the moment someone requests it. Pain-free garbage
collection for the C language is pretty cool. All it does is overwrite
the return address with a trampoline that calls free(). It's not clear
what it should be named if it's made a public API.
Here's why we got those `Killed: 11` failures on MacOS after modifying
the contentns of the redbean.com executable. If you were inserting a
small file, such as a HelloWorld.html file, then InfoZIP might have
decreased the size of the executable to less than what the Mach-O
section had been expecting.
That's because when zipobj.com put things like time zone data in the
executable, it aligned each zip file entry on a 64-byte boundary, simply
for the sake of readability in binary dumps. But when InfoZIP edited the
file it would rewrite every entry using ZIP's usual 2-byte alignment.
Thus causing shrinkage.
The solution was to reconfigure the linker script so that zip file bits
that get put into the executable at link-time, such as timezone data,
aren't officially part of the executable image, i.e. we don't want the
operating system to load that part.
The original decision to put the linked zip files into the .data section
was mostly made so that when the executable was run in its .com.dbg form
it would still have the zip entries be accessible, even though there was
tons of GNU debug data following the central directory. We're not going
to be able to do that. The .com executable should be the canonical
executable. We have really good tools for automatically attaching and
configuring GDB correctly with debug symbols even when the .com is run.
We'll have to rely on those in cases where zip embedding is used.
See #53
See #54
See #68
- Polyfill ucontext_t on FreeBSD/OpenBSD/NetBSD
- Add tests confirming signals can edit CPU state
- Work towards supporting ZIP filesystem on bare metal
- Add more tinymath unit tests for POSIX conformance
- Add X87 and SSE status flags to crash report
- Fix some bugs in blinkenlights
- Fix llvm build breakage
Your Actually Portable Executables now contains a simple virtual memory
that works similarly to the Linux Kernel in the sense that it maps your
physical memory to negative addresses. This is needed to support mmap()
and malloc(). This functionality has zero code size impact. For example
the MODE=tiny LIFE.COM executable is still only 12KB in size.
The APE bootloader code has also been simplified to improve readibility
and further elevate the elegance by which we're able to support so many
platforms thereby enhancing verifiability so that we may engender trust
in this bootloading process.
- Reduce full build latency from ~20s to ~18s
- Bring back silent mode if `make V=0` is passed
- Demodernize utimes() polyfill so it works RHEL5
- Delete some old shell scripts that are no longer needed
- Truncate long lines when outputting builds to Emacs buffers
You can now build Cosmopolitan with Clang:
make -j8 MODE=llvm
o/llvm/examples/hello.com
The assembler and linker code is now friendly to LLVM too.
So it's not needed to configure Clang to use binutils under
the hood. If you love LLVM then you can now use pure LLVM.
You can now use cosmopolitan.h with an ANSI C89 compiler like MSVC. The
Cosmopolitan codebase itself won't support being compiled that way. But
you can build objects that link against Cosmopolitan using any compiler
and you can furthermore use tools like IntelliSense that can't even GNU
See also #40
- Get ASAN working on Windows.
- Deleting directories and then recreating them with the same name in a
short period of time appears to be a no-no on Windows.
- There's no reason to call FlushFileBuffers on close() for pipes, and
it's harmful since it might block indefinitely for no good reason.
- Support deterministic stacks on OpenBSD
- Support OpenBSD system call origin verification
- Fix overrun by one in chibicc string token allocator
- Get all chibicc tests passing under Address Sanitizer
We now have an integration test that runs the amalgamated sources
through a C++ compiler, to prevent the recurrence of such issues.
Fixes#38
Thanks @gbbnfhb for the report!
This change enables Address Sanitizer systemically w/ `make MODE=dbg`.
Our version of Rust's `unsafe` keyword is named `noasan` which is used
for two functions that do aligned memory chunking, like `strcpy.c` and
we need to fix the tiny DEFLATE code, but that's it everything else is
fabulous you can have all the fischer price security blankets you need
Best of all is we're now able to use the ASAN data in Blinkenlights to
colorize the memory dumps. See the screenshot below of a test program:
https://justine.lol/blinkenlights/asan.png
Which is operating on float arrays stored on the stack, with red areas
indicating poisoned memory, and the green areas indicate valid memory.
The libm code from musl wasn't being used since most of these functions
are implemented using x87 which goes faster than a library intended for
risc machines.
We always favor calling functions like openat(), fstatat(), etc. because
Linux, XNU, FreeBSD, and OpenBSD all elected to support them, while some
systems like Android love them so much, that they stopped supporting the
old interfaces.
This change ensures that when dirfd is actually a dirfd and not AT_FDCWD
we'll do the right thing on Windows NT. We use an API that's been around
since Vista to accomplish that.
This change also adds exponential backoff to chdir() on Windows since it
seems almost as flaky on Windows 7 as the rmdir() function.
For the first time ever, all tests in this codebase now pass, when
run automatically on macos, freebsd, openbsd, rhel5, rhel7, alpine
and windows via the network using the runit and runitd build tools
- Fix vfork exec path etc.
- Add XNU opendir() support
- Add OpenBSD opendir() support
- Add Linux history to syscalls.sh
- Use copy_file_range on FreeBSD 13+
- Fix system calls with 7+ arguments
- Fix Windows with greater than 16 FDs
- Fix RUNIT.COM and RUNITD.COM flakiness
- Fix OpenBSD munmap() when files are mapped
- Fix long double so it's actually long on Windows
- Fix OpenBSD truncate() and ftruncate() thunk typo
- Let Windows fcntl() be used on socket files descriptors
- Fix Windows fstat() which had an accidental printf statement
- Fix RHEL5 CLOCK_MONOTONIC by not aliasing to CLOCK_MONOTONIC_RAW
This is wonderful. I never could have dreamed it would be possible
to get it working so well on so many platforms with tiny binaries.
Fixes#31Fixes#25Fixes#14
Multiple users have reported that this test fails, for reasons that
are currently unknown. It's possible that, some type of environment
variable configuration, e.g. PATH, CC, etc. is causing the failure.
Once the root cause is identified and addressed we'll re-enable it.
Anyone who is able to help us do that, please comment on the issue.
It turned out that the linker was doing the wrong with the amalgamation
library concerning weak stubs. A regression test has been added and new
binaries have been uploaded to https://justine.lol/cosmopolitan/
Ideally this should be fixed by building a tool that turns multiple .a
files into a single .a file with deduplication. As a workaround for now
the cosmopolitan.a build is restructured to not include LIBC_STUBS which
meant technical debt needed to be paid off where non-stub interfaces
were moved to LIBC_INTRIN and LIBC_NEXGEN32E.
Thank @PerfectProductions in #31 for the report!
This program popped up on Hacker News recently. It's the only modern
compiler I've ever seen that doesn't have dependencies and is easily
modified. So I added all of the missing GNU extensions I like to use
which means it might be possible soon to build on non-Linux and have
third party not vendor gcc binaries.
A new rollup tool now exists for flattening out the headers in a way
that works better for our purposes than cpp. A lot of the API clutter
has been removed. APIs that aren't a sure thing in terms of general
recommendation are now marked internal.
There's now a smoke test for the amalgamation archive and gigantic
header file. So we can now guarantee you can use this project on the
easiest difficulty setting without the gigantic repository.
A website is being created, which is currently a work in progress:
https://justine.storage.googleapis.com/cosmopolitan/index.html
This is done without using Microsoft's internal APIs. MAP_PRIVATE
mappings are copied to the subprocess via a pipe, since Microsoft
doesn't want us to have proper COW pages. MAP_SHARED mappings are
remapped without needing to do any copying. Global variables need
copying along with the stack and the whole heap of anonymous mem.
This actually improves the reliability of the redbean http server
although one shouldn't expect 10k+ connections on a home computer
that isn't running software built to serve like Linux or FreeBSD.
blinkenlights now does a pretty good job emulating what happens when
binaries boot from BIOS into long mode. So it's been much easier to
debug the bare metal process and wrinkle out many issues.
This change includes many bug fixes, for the NT polyfills, strings,
memory, boot, and math libraries which were discovered by adding more
tools for recreational programming, such as PC emulation. Lemon has also
been vendored because it works so well at parsing languages.
- Emulator can now test the αcτµαlly pδrταblε εxεcµταblε bootloader
- Whipped up a webserver named redbean. It services 150k requests per
second on a single core. Bundling assets inside zip enables extremely
fast serving for two reasons. The first is that zip central directory
lookups go faster than stat() system calls. The second is that both
zip and gzip content-encoding use DEFLATE, therefore, compressed
responses can be served via the sendfile() system call which does an
in-kernel copy directly from the zip executable structure. Also note
that red bean zip executables can be deployed easily to all platforms,
since these native executables work on Linux, Mac, BSD, and Windows.
- Address sanitizer now works very well
I wanted a tiny scriptable meltdown proof way to run userspace programs
and visualize how program execution impacts memory. It helps to explain
how things like Actually Portable Executable works. It can show you how
the GCC generated code is going about manipulating matrices and more. I
didn't feel fully comfortable with Qemu and Bochs because I'm not smart
enough to understand them. I wanted something like gVisor but with much
stronger levels of assurances. I wanted a single binary that'll run, on
all major operating systems with an embedded GPL barrier ZIP filesystem
that is tiny enough to transpile to JavaScript and run in browsers too.
https://justine.storage.googleapis.com/emulator625.mp4
One of the benefits of implementing system call support from scratch is
that we're able to have embedded zip filesystem support which trickles
into libraries such as stdio, without unportable symbolic interposition.
It's also be great if we could say open("gs://bucket/object", O_RDONLY)
for seamless GCS, similar to Java NIO, but abstracted by the C library.
