Messages in this thread | | | Date | Fri, 28 Apr 2023 12:48:47 +0100 | From | Mark Rutland <> | Subject | Re: [PATCH v3 01/60] arm64: kernel: Disable latent_entropy GCC plugin in early C runtime |
| |
On Fri, Apr 28, 2023 at 11:54:16AM +0100, Ard Biesheuvel wrote: > On Fri, 28 Apr 2023 at 11:38, Mark Rutland <mark.rutland@arm.com> wrote: > > > > On Tue, Mar 07, 2023 at 03:04:23PM +0100, Ard Biesheuvel wrote: > > > Avoid build issues in the early C code related to the latent_entropy GCC > > > plugin, by incorporating the C flags fragment that disables it. > > > > > > Signed-off-by: Ard Biesheuvel <ardb@kernel.org> > > > > Just to check, are you seeing issues today? IIUC the plugin only instruments > > functions which are explicitly marked with __latent_entropy, and if we're > > seeing that happen unexpectedly (or due to that being applying to __meminit / > > __init), we might need to do likewise for other noinstr code. > > > > I don't quite remember, tbh, but it is unlikely that I would have > written or included this patch without having run into some actual > issue.
Sure.
Looking at the series, from patch 15 onwards you mark portions of the PI code as __init. As __init currently implies __latent_entropy (which I think is a bit crazy as of itself...), that's why this'll start to fail.
It would be nice if we could mention that in the commit message, e.g.
| In subsequent patches we'll mark portions of the early C code as __init. | Unfortunarely, __init implies __latent_entropy, and this would result in the | early C code being instrumented in an unsafe manner. | | Disable the latent entropy plugin for the early C code.
... though my ack stands regardless of whether we add such wording.
Mark.
> > Regardless, for this patch: > > > > Acked-by: Mark Rutland <mark.rutland@arm.com> > > > > Thanks,
| |