Subject: Re: [PATCH 1/2] uprobes: Pass probed vaddr to arch_uprobe_analyze_insn()

From: Oleg Nesterov <[email-masked]>
Date: Wed, 6 Jun 2012 17:08:48 +0200

On 06/06, Ananth N Mavinakayanahalli wrote:
>
> From: Ananth N Mavinakayanahalli <[email-masked]>
>
> On RISC architectures like powerpc, instructions are fixed size.
> Instruction analysis on such platforms is just a matter of (insn % 4).
> Pass the vaddr at which the uprobe is to be inserted so that
> arch_uprobe_analyze_insn() can flag misaligned registration requests.

And the next patch checks "vaddr & 0x03".

But why do you need this new arg? arch_uprobe_analyze_insn() could
check "container_of(auprobe, struct uprobe, arch)->offset & 0x3" with
the same effect, no? vm_start/vm_pgoff are obviously page-aligned.

Oleg.