Re: [PATCH v5 06/10] Uprobes: Support SDT markers having reference count (semaphore)

From: Oleg Nesterov
Date: Tue Jul 10 2018 - 11:25:37 EST


Hi Ravi,

On 07/04, Ravi Bangoria wrote:
>
> > Now I understand what did you mean by "for each consumer". So if we move this logic
> > into install/remove_breakpoint as I tried to suggest, we will also need another error
> > code for the case when verify_opcode() returns false.
>
> Ok so if we can use verify_opcode() inside install_breakpoint(), we can probably
> move implementation logic in install/remove_breakpoint(). Let me explore that more.

No, sorry for confusion, I meant another thing... But please forget. If we rely on
verify_opcode() I no longer think it would be more clean to move this logic into
install/remove_breakpoint.

However, I still think it would be better to avoid uprobe exporting and modifying
set_swbp/set_orig_insn. May be we can simply kill both set_swbp() and set_orig_insn(),
I'll re-check...

Oleg.