Re: [PATCH] MIPS: kernel: Clear FPU states when setting up kernel threads

From: Thomas Bogendoerfer
Date: Tue Dec 05 2023 - 13:01:48 EST


On Thu, Nov 30, 2023 at 05:36:01PM +0100, Thomas Bogendoerfer wrote:
> io_uring sets up the io worker kernel thread via a syscall out of an
> user space prrocess. This process might have used FPU and since
> copy_thread() didn't clear FPU states for kernel threads a BUG()
> is triggered for using FPU inside kernel. Move code around
> to always clear FPU state for user and kernel threads.
>
> Cc: stable@xxxxxxxxxxxxxxx
> Reported-by: Aurelien Jarno <aurel32@xxxxxxxxxx>
> Closes: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1055021
> Signed-off-by: Thomas Bogendoerfer <tsbogend@xxxxxxxxxxxxxxxx>
> ---
> arch/mips/kernel/process.c | 25 +++++++++++++------------
> 1 file changed, 13 insertions(+), 12 deletions(-)

applied to mips-fixes.

Thomas.

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