On Tue, Mar 16, 2021 at 09:59:18AM -0700, Nick Desaulniers wrote:
From: Ard Biesheuvel ardb@kernel.org
commit 3cce9d44321e460e7c88cdec4e4537a6e9ad7c0d upstream.
Commit f77ac2e378be9dd6 ("ARM: 9030/1: entry: omit FP emulation for UND exceptions taken in kernel mode") failed to take into account that there is in fact a case where we relied on this code path: during boot, the VFP detection code issues a read of FPSID, which will trigger an undef exception on cores that lack VFP support.
So let's reinstate this logic using an undef hook which is registered only for the duration of the initcall to vpf_init(), and which sets VFP_arch to a non-zero value - as before - if no VFP support is present.
Fixes: f77ac2e378be9dd6 ("ARM: 9030/1: entry: omit FP emulation for UND ...") Reported-by: "kernelci.org bot" bot@kernelci.org Signed-off-by: Ard Biesheuvel ardb@kernel.org Signed-off-by: Russell King rmk+kernel@armlinux.org.uk Signed-off-by: Nick Desaulniers ndesaulniers@google.com
This is meant to be applied on top of https://lore.kernel.org/stable/20210315231952.1482097-1-ndesaulniers@google..... If it's preferrable to send an .mbox file or a series with cover letter, I'm happy to resend it as such, just let me know.
Please resend it that way, makes it easier to figure out what is going on here...
thanks,
greg k-h