On Mon, Dec 4, 2017 at 1:22 PM, Tobin C. Harding <me@xxxxxxxx> wrote: > Advice about what to use as a unique identifier is no longer valid since > patch series was merged to hash pointers printed with %p. We can use > this as a unique identifier now. > > Signed-off-by: Tobin C. Harding <me@xxxxxxxx> I don't agree: %p should still not be encouraged. Exposing an identifier to userspace needs careful consideration, and atomics, idrs, etc, continue to be a good recommendation here, as far as I'm concerned. -Kees > --- > Documentation/security/self-protection.rst | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/Documentation/security/self-protection.rst b/Documentation/security/self-protection.rst > index 60c8bd8b77bf..f10f47cad825 100644 > --- a/Documentation/security/self-protection.rst > +++ b/Documentation/security/self-protection.rst > @@ -274,8 +274,8 @@ Unique identifiers > ------------------ > > Kernel memory addresses must never be used as identifiers exposed to > -userspace. Instead, use an atomic counter, an idr, or similar unique > -identifier. > +userspace. Printk specifier %p hashes addresses by default now and can be > +used as a unique identifier. > > Memory initialization > --------------------- > -- > 2.7.4 > -- Kees Cook Pixel Security -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
