Function initStatic [src]

Computes the layout of the static TLS area, allocates the area, initializes all of its fields, and assigns the architecture-specific value to the TP register.

Prototype

pub fn initStatic(phdrs: []elf.Phdr) void

Parameters

phdrs: []elf.Phdr

Source

  pub fn initStatic(phdrs: []elf.Phdr) void {
    @setRuntimeSafety(false);
    @disableInstrumentation();

    computeAreaDesc(phdrs);

    const area = blk: {
        // Fast path for the common case where the TLS data is really small, avoid an allocation and
        // use our local buffer.
        if (area_desc.alignment <= page_size_min and area_desc.size <= main_thread_area_buffer.len) {
            break :blk main_thread_area_buffer[0..area_desc.size];
        }

        const begin_addr = mmap(
            null,
            area_desc.size + area_desc.alignment - 1,
            posix.PROT.READ | posix.PROT.WRITE,
            .{ .TYPE = .PRIVATE, .ANONYMOUS = true },
            -1,
            0,
        );
        if (@as(isize, @bitCast(begin_addr)) < 0) @trap();

        const area_ptr: [*]align(page_size_min) u8 = @ptrFromInt(begin_addr);

        // Make sure the slice is correctly aligned.
        const begin_aligned_addr = alignForward(begin_addr, area_desc.alignment);
        const start = begin_aligned_addr - begin_addr;
        break :blk area_ptr[start..][0..area_desc.size];
    };

    const tp_value = prepareArea(area);
    setThreadPointer(tp_value);
}  