stackoverflow.zig

const std = @import("std");

extern fn sigaltstack(ss: *const stack_t, oss: *stack_t) c_int;

const stack_t = extern struct {
    sp: ?*anyopaque,
    flags: c_int,
    size: usize,
};

var newstack: [4096]usize = undefined;

pub fn enable() void {
    const new = stack_t{ .sp = &newstack, .flags = 0, .size = @sizeOf(@TypeOf(newstack)) };
    var old = stack_t{ .sp = null, .flags = 0, .size = 0 };
    std.debug.assert(sigaltstack(&new, &old) == 0);

    _ = std.os.linux.sigaction(std.os.linux.SIG.SEGV, &.{
        .handler = .{ .handler = handle },
        .mask = std.mem.zeroes(std.os.linux.sigset_t),
        .flags = std.os.linux.SA.NODEFER | std.os.linux.SA.ONSTACK,
    }, null);
}

fn handle(s: c_int) callconv(.C) void {
    std.debug.print("\n", .{});
    _ = s;
    std.log.err("caught stack overflow", .{});
    std.debug.dumpCurrentStackTrace(@returnAddress());
    std.os.abort();
}