Segmentation Fault on aarch64 when linking with musl

[xoich]

Zig Version

0.10.0-dev.1448+b6203b89d

Steps to Reproduce

I run the following code with zig build-exe -target aarch64-linux-musl -lc sftest.zig; ./sftest.

const std = @import("std");

const Card = struct {
    a: u32 = 0,
    b: []u8 = undefined,
    c: []u8 = undefined,
    d: i8 = 0,
    e: i64 = 0,
    f: i64 = 0,
    g: f32 = 0,
    h: u32 = 0,
    i: i64 = 0,
    j: i64 = 0,
};

const Scheduler = struct {
    random: std.rand.Random,
    fn init() Scheduler {
        var prng = std.rand.DefaultPrng.init(0);
        const random = prng.random();
        return Scheduler{ .random = random };
    }
};

fn maybeCard() !Card {
    if (std.time.timestamp() < 0)
        return error.Hello;
    return Card{};
}

const Controller = struct {
    scheduler: *Scheduler,
    const Self = @This();
    pub fn createNewCard(self: *const Self, maybe: ?[]u64) !void {
        if (maybe) |t| {
            _ = t;
            var topic = try maybeCard();
            _ = topic;
        }
        _ = self.scheduler.random.intRangeLessThanBiased(i64, 0, 10);
    }
};

pub fn main() !void {
    var scheduler = Scheduler.init();
    var controller = Controller{ .scheduler = &scheduler };
    try controller.createNewCard(null);
}

Expected Behavior

The program runs without errors.

Actual Behavior

$ zig build-exe -target aarch64-linux-musl -lc sftest.zig
$ ./sftest
Segmentation fault at address 0x540000000ffbf2
/home/dn/sftest.zig:54:21: 0x2141c4 in main (sftest)
pub fn main() !void {
                    ^
Aborted

Notes

It does not happen on x86_64.

I think it might be a stack buffer overrun.

[xoich]

Building the same code without the -lc option result in this:

$ zig build-exe -target aarch64-linux-musl sftest.zig; ./sftest
Bus error at address 0x4c970dcf13cd5433
???:?:?: 0x4c970dcf13cd5433 in ??? (???)
Aborted

gdb:

Program received signal SIGBUS, Bus error.
0x4c970dcf13cd5433 in ?? ()
(gdb) bt
#0  0x4c970dcf13cd5433 in ?? ()
Backtrace stopped: previous frame identical to this frame (corrupt stack?)

[LemonBoy]

Not a bug (sadly), it's #9080 all over again.

[ominitay]

You can instead use an anytype field and hold the prng in there :)