Zig 0.17.0-dev (Split by item)

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expandStackSize

start.expandStackSize

fn expandStackSize(phdrs: []elf.Phdr) void

File

lib/std/start.zig:648

Code

fn expandStackSize(phdrs: []elf.Phdr) void {
    @disableInstrumentation();
    for (phdrs) |*phdr| {
        switch (phdr.p_type) {
            elf.PT_GNU_STACK => {
                if (phdr.p_memsz == 0) break;
                assert(phdr.p_memsz % std.heap.page_size_min == 0);

                // Silently fail if we are unable to get limits.
                const limits = std.posix.getrlimit(.STACK) catch break;

                // Clamp to limits.max .
                const wanted_stack_size = @min(phdr.p_memsz, limits.max);

                if (wanted_stack_size > limits.cur) {
                    std.posix.setrlimit(.STACK, .{
                        .cur = wanted_stack_size,
                        .max = limits.max,
                    }) catch {
                        // Because we could not increase the stack size to the upper bound,
                        // depending on what happens at runtime, a stack overflow may occur.
                        // However it would cause a segmentation fault, thanks to stack probing,
                        // so we do not have a memory safety issue here.
                        // This is intentional silent failure.
                        // This logic should be revisited when the following issues are addressed:
                        // https://github.com/ziglang/zig/issues/157
                        // https://github.com/ziglang/zig/issues/1006
                    };
                }
                break;
            },
            else => {},
        }
    }
}