Commit graph

4 commits

Author SHA1 Message Date
Justine Tunney
b77cae2d57 Fix some regressions with execution 2022-08-07 22:10:18 -07:00
Justine Tunney
4e9662cbc7 Write tests for new APE loader and fix bugs
- Add FreeBSD-specific mmap() flags
- Reduce size of the APE loader from 8kb to 4kb
- Work towards fixing the Makefile build on WSL
- Automate testing of APE no-modify-self behaviors
- Make the ape.S shell script code cleaner and tinier
- Improve the APE sanity check to test behavior better
- Fixed issue with ShowCrashReports() sigaltstack() on BSDs
- Delete symbols for S_MODE magnums which wasted compile time

If you checked out yesterday's APE commit, please run:

    rm -f /usr/bin/ape o/tmp/ape /tmp/ape "${TMPDIR:-/tmp}/ape"

Because this change fixes certain aspects of the new ABI. We don't have
automated migrations for APE loader versions yet. Thanks! You can also
download prebuilt binaries here:

- https://justine.lol/ape.elf    (Linux/FreeBSD/NetBSD/OpenBSD)
- https://justine.lol/ape.macho  (Apple)

Install the appropriate one as `/usr/bin/ape`.
2022-05-22 05:45:38 -07:00
Justine Tunney
db0d8dd806 Support Linux binfmt_misc and APE loading on Apple
The "no modify self" variant of Actually Portable Executable is now
supported on all platforms. If you use `$(APE_NO_MODIFY_SELF)` then
ld.bfd will embed a 4096 byte ELF binary and a 4096 byte Macho file
which are installed on the fly to ${TMPDIR:-/tmp}, which enables us
launch the executable, without needing to copy the whole executable

To prevent it from copying a tiny executable to your temp directory
you need to install the `ape` command (renamed from ape-loader), to
a system path. For example:

    # FreeBSD / NetBSD / OpenBSD
    make -j8 o//ape/ape
    cp o//ape/ape /usr/bin/ape

    # Mac OS
    # make -j8 o//ape/ape.macho
    curl https://justine.lol/ape.macho >/usr/bin/ape
    chmod +x /usr/bin/ape

On Linux you can get even more performance with the new binfmt_misc
support which makes launching non-modifying APE binaries as fast as
launching ELF executables. Running the following command:

    # Linux
    ape/apeinstall.sh

Will copy APE loader to /usr/bin/ape and register with binfmt_misc
Lastly, this change also fixes a really interesting race condition
with OpenBSD thread joining.
2022-05-21 09:28:25 -07:00
Justine Tunney
f213556366 Add binfmt_misc workaround detector to builds
This is a recently introduced Linux Kernel feature that gives people
like Debian package mantainers the power to arbitrarily redefine how
executables are interpreted by the kernel. If your system gets tuned
this way and you're not able to disable it, then you need to restore
default behavior for the APE MZqFpD prefix as follows:

    sudo sh -c "echo ':APE:M::MZqFpD::/bin/sh:' >/proc/sys/fs/binfmt_misc/register"

This prefix will cover all .com executables built with this tooling.
Please don't run the above command unless you're certain you need it.
See #2 for additional context.
2020-08-31 20:09:23 -07:00