[PATCH 7/7] arm64: uprobes - ARM32 instruction probing

[oleg@redhat.com (Oleg Nesterov)]

On 01/24, Maciej Slodczyk wrote:
>
> Detect what kind of instruction is being probed and depending on the result:
> - if an A64 instruction handle it the old way, using existing A64 instructions
> probing code,
> - if an A32 instruction decode it and handle using the new code, moved from
> 32 bit arm kernel tree.

how this connects to the change in prepare_uretprobe(),

> --- a/kernel/events/uprobes.c
> +++ b/kernel/events/uprobes.c
> @@ -1566,6 +1566,9 @@ static void prepare_uretprobe(struct uprobe *uprobe, struct pt_regs *regs)
>  	unsigned long orig_ret_vaddr, trampoline_vaddr;
>  	bool chained;
>
> +	if (!current->mm)
> +		return;
> +

?

and how it is possible to hit ->mm == NULL here?

Oleg.