On Nov 24, 2015 1:38 PM, "Kees Cook" <keescook@xxxxxxxxxxxx> wrote: > > One of the easiest ways to protect the kernel from attack is to reduce > the internal attack surface exposed when a "write" flaw is available. By > making as much of the kernel read-only as possible, we reduce the > attack surface. > > Many things are written to only during __init, and never changed > again. These cannot be made "const" since the compiler will do the wrong > thing (we do actually need to write to them). Instead, move these items > into a memory region that will be made read-only during mark_rodata_ro() > which happens after all kernel __init code has finished. > > This introduces __read_only as a way to mark such memory, and adds some > documentation about the existing __read_mostly marking. Obligatory bikeshed: __ro_after_init, please. It's barely longer, and it directly explains what's going on. __read_only makes me think that it's really read-only and could, for example, actually be in ROM. --Andy -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
