Messages in this thread | | | Date | Mon, 4 Feb 2019 10:55:35 -0500 | From | "Theodore Y. Ts'o" <> | Subject | Re: [PATCH v2] x86, random: Fix get_random_bytes() warning in x86 start_kernel |
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On Sun, Feb 03, 2019 at 08:09:37AM -0500, Prarit Bhargava wrote: > Ted, the bug I'm trying to fix is the warning: > > random: get_random_bytes called from start_kernel+0x8e/0x587 with crng_init=0 > > during early boot. Even with the kernel parameter the warning appears.
Sometimes the warnings are real, and shouldn't be suppressed. A Debian maintainer once tried to suppress a compile-time warning, and it was disastrous for security. :-)
What line number is that corresponding to? It sounds like something is trying to use get_random_bytes() before the random driver was initialized, and so the first question is does it really need to call get_random_bytes() then or can it be moved?
> > Also, relying on the TSC for entropy is not something we should be > > recommending. > > The current code uses the TSC. It is not something new I'm introducing.
But we don't *rely* on it. That's a big difference.
- Ted
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