Do a uname version check before using statx on Android.
#312
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Some Android versions disallow these even on Linux kernel versions which otherwise would support them, and they crash the process rather than returning `ENOSYS` so there's no way to detect this. So disallow using `statx` and `openat2` on Android altogether.
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It appears there's no reliable way to test for syscall availability on Android, so this PR now disabled the use of |
| // On Android, seccomp kills processes that execute unrecognized system | ||
| // calls, so we do an explicit version check rather than relying on | ||
| // getting an `ENOSYS`. | ||
| #[cfg(target_os = "android")] | ||
| { | ||
| static CHECKED: AtomicBool = AtomicBool::new(false); | ||
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| if !CHECKED.load(Relaxed) { | ||
| if !openat2_supported() { | ||
| INVALID.store(true, Relaxed); | ||
| return Err(rustix::io::Errno::NOSYS.into()); | ||
| } | ||
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| CHECKED.store(true, Relaxed); | ||
| } | ||
| } |
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AFACIT removing this is wrong, you need to always return NONSYS instead.
That's because there are other callers of this function, e.g.:
cap-std/cap-primitives/src/rustix/linux/fs/stat_impl.rs
Lines 11 to 23 in 1317c28
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Here's what I just tried, locally:
pub(crate) fn open_beneath(
start: &fs::File,
path: &Path,
options: &OpenOptions,
) -> io::Result<fs::File> {
#[cfg(target_os = "android")]
{
return Err(rustix::io::Errno::NOSYS.into());
}And that definitely works (tested on an actual Android impl that hit both openat2 and statx issues before now - an Oculus Quest 2, which makes this an extremely side-tracked thing for me so I will very likely not be opening a PR myself).
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Thanks for the report! Confirmed that this what's happening. I've now filed #316 to fix this, and disable openat2 on Android entirely with a cfg.
Disable the `openat2` code entirely on Android with a `cfg`, and adjust other code to avoid calling it. This fixes some `openat2` calls that remained after #312.
Disable the `openat2` code entirely on Android with a `cfg`, and adjust other code to avoid calling it. This fixes some `openat2` calls that remained after #312.
Similar to #197, do a
unameversion check before usingstatxon Android, since Android's seccomp configuration kills the process if any unrecognized system calls are used.Fixes #311.