cosmopolitan/libc/sysv
Justine Tunney 00611e9b06 Improve ZIP filesystem and change its prefix
The ZIP filesystem has a breaking change. You now need to use /zip/ to
open() / opendir() / etc. assets within the ZIP structure of your APE
binary, instead of the previous convention of using zip: or zip! URIs.
This is needed because Python likes to use absolute paths, and having
ZIP paths encoded like URIs simply broke too many things.

Many more system calls have been updated to be able to operate on ZIP
files and file descriptors. In particular fcntl() and ioctl() since
Python would do things like ask if a ZIP file is a terminal and get
confused when the old implementation mistakenly said yes, because the
fastest way to guarantee native file descriptors is to dup(2). This
change also improves the async signal safety of zipos and ensures it
doesn't maintain any open file descriptors beyond that which the user
has opened.

This change makes a lot of progress towards adding magic numbers that
are specific to platforms other than Linux. The philosophy here is that,
if you use an operating system like FreeBSD, then you should be able to
take advantage of FreeBSD exclusive features, even if we don't polyfill
them on other platforms. For example, you can now open() a file with the
O_VERIFY flag. If your program runs on other platforms, then Cosmo will
automatically set O_VERIFY to zero. This lets you safely use it without
the need for #ifdef or ifstatements which detract from readability.

One of the blindspots of the ASAN memory hardening we use to offer Rust
like assurances has always been that memory passed to the kernel via
system calls (e.g. writev) can't be checked automatically since the
kernel wasn't built with MODE=asan. This change makes more progress
ensuring that each system call will verify the soundness of memory
before it's passed to the kernel. The code for doing these checks is
fast, particularly for buffers, where it can verify 64 bytes a cycle.

- Correct O_LOOP definition on NT
- Introduce program_executable_name
- Add ASAN guards to more system calls
- Improve termios compatibility with BSDs
- Fix bug in Windows auxiliary value encoding
- Add BSD and XNU specific errnos and open flags
- Add check to ensure build doesn't talk to internet
2021-08-22 01:11:53 -07:00
..
calls Improve Libc by making Python work even better 2021-08-18 22:16:23 -07:00
consts Improve ZIP filesystem and change its prefix 2021-08-22 01:11:53 -07:00
errfuns Remove more nonstandard stuff from cosmopolitan.h 2021-03-01 00:18:23 -08:00
machcalls Get codebase completely working with LLVM 2021-02-09 02:57:32 -08:00
consts.sh Improve ZIP filesystem and change its prefix 2021-08-22 01:11:53 -07:00
errfuns.h Make ANSI mode closer to being ANSI 2021-02-03 17:14:17 -08:00
errfuns.sh Change license 2020-12-27 17:18:44 -08:00
g_syscount.S Remove more nonstandard stuff from cosmopolitan.h 2021-03-01 00:18:23 -08:00
gen.sh Remove more nonstandard stuff from cosmopolitan.h 2021-03-01 00:18:23 -08:00
machcalls.sh Change license 2020-12-27 17:18:44 -08:00
macros.internal.h Make improvements 2020-12-01 03:43:40 -08:00
README.md Initial import 2020-06-15 07:18:57 -07:00
restorert.S Remove more nonstandard stuff from cosmopolitan.h 2021-03-01 00:18:23 -08:00
syscall.S Remove more nonstandard stuff from cosmopolitan.h 2021-03-01 00:18:23 -08:00
syscalls.sh Improve Libc by making Python work even better 2021-08-18 22:16:23 -07:00
systemfive.S Make redbean StoreAsset() work better 2021-05-14 05:44:37 -07:00
sysv.mk Remove more nonstandard stuff from cosmopolitan.h 2021-03-01 00:18:23 -08:00

SYNOPSIS

System Five Import Libraries

OVERVIEW

Bell System Five is the umbrella term we use to describe Linux, FreeBSD, OpenBSD, and Mac OS X which all have nearly-identical application binary interfaces that stood the test of time, having definitions nearly the same as those of AT&T back in the 1980's.

Cosmopolitan aims to help you build apps that can endure over the course of decades, just like these systems have: without needing to lift a finger for maintenance churn, broken builds, broken hearts.

The challenge to System V binary compatibility basically boils down to numbers. All these systems agree on what services are provided, but tend to grant them wildly different numbers.

We address this by putting all the numbers in a couple big shell scripts, ask the GNU Assembler to encode them into binaries using an efficient LEB128 encoding, unpacked by _init(), and ref'd via extern const. It gives us good debuggability, and any costs are gained back by fewer branches in wrapper functions.z