Humble beginnings of quark-test(8 10000 ) #87
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init.c
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| execv(argv[0], argv); | ||
| /* NOTREACHED */ |
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What if argv[0] is not present?
| execv(argv[0], argv); | |
| /* NOTREACHED */ | |
| return execv(argv[0], argv); | |
| /* NOTREACHED */ |
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argc is checked above:
if (argc < 2) {
warnx("no binary to execute");
powerdown();
}
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Oh, I mean if the path doesn't exist. As in we forgot to add a binary to the initrd or something like that.
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you're absolutely right, I somehow had it right and then screwed up, I'll fix another case of the same mistake.
quark-test(8) is a testing binary, the idea is for all the tests to reside in one single binary that we can run selected tests or all. Currently we test that we can install the probes, it then forks and execs and checks if it got an event with all the required attributes. Changes were made to init.c to be able to properly run quark-test and halt after, we can run quark-test locally or in a qemu instance: ``` $ sudo ./quark-test t_probe @ ebpf: ok t_probe @ kprobe: ok t_fork_exec_exit @ ebpf: ok t_fork_exec_exit @ kprobe: ok failed tests 0 ``` or in qemu: ``` $ make initramfs.gz && qemu-system-x86_64 -initrd initramfs.gz \ -kernel /d/e/ebpf/kernel-images/debian/x86_64/linux-image-x86_64-5.10.46-5 \ -nographic --append "console=ttyS0 quark-test" .... .... .... [ 1.337177] Run /init as init process [ 2.052140] tsc: Refined TSC clocksource calibration: 2803.152 MHz [ 2.052956] clocksource: tsc: mask: 0xffffffffffffffff max_cycles: 0x2867e297e4e, max_idle_ns: 440795313952 ns [ 2.053860] clocksource: Switched to clocksource tsc [ 5.916017] random: fast init done t_probe @ ebpf: ok t_probe @ kprobe: ok t_fork_exec_exit @ ebpf: ok t_fork_exec_exit @ kprobe: ok failed tests 0 quark-test exited with 0 [ 7.701678] ACPI: Preparing to enter system sleep state S5 [ 7.702269] reboot: Power down ``` More importantly, spinning wheels! Party like it's the 90s!
| /* child */ | ||
| if (pid == 0) { | ||
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| if (mkdir("/proc", 0666) != 0) |
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Just curious, is there a reason these are done in the child?
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a tiny one, it's mostly so that I can call err(3) normally, since the parent (the actual init/pid=1) can't just err(1, "oh noes").
If we just exit in init, the kernel panics and the VM busyloops.
quark-test(8) is a testing binary, the idea is for all the tests to reside in one single binary that we can run selected tests or all.
Currently we test that we can install the probes, it then forks and execs and checks if it got an event with all the required attributes.
Changes were made to init.c to be able to properly run quark-test and halt after, we can run quark-test locally or in a qemu instance:
or in qemu:
More importantly, spinning wheels! Party like it's the 90s!
Screencast.from.2024-10-23.15-51-58.webm