Re: [PATCH v8 5/6] trace_uprobe/sdt: Prevent multiple reference counter for same uprobe

From: Srikar Dronamraju
Date: Mon Aug 13 2018 - 04:48:50 EST


* Ravi Bangoria <ravi.bangoria@xxxxxxxxxxxxx> [2018-08-09 09:48:55]:

> We assume to have only one reference counter for one uprobe.
> Don't allow user to add multiple trace_uprobe entries having
> same inode+offset but different reference counter.
>
> Ex,
> # echo "p:sdt_tick/loop2 /home/ravi/tick:0x6e4(0x10036)" > uprobe_events
> # echo "p:sdt_tick/loop2_1 /home/ravi/tick:0x6e4(0xfffff)" >> uprobe_events
> bash: echo: write error: Invalid argument
>
> # dmesg
> trace_kprobe: Reference counter offset mismatch.
>
> There is one exception though:
> When user is trying to replace the old entry with the new
> one, we allow this if the new entry does not conflict with
> any other existing entries.
>
> Signed-off-by: Ravi Bangoria <ravi.bangoria@xxxxxxxxxxxxx>
> ---

Looks good to me.

Acked-by: Srikar Dronamraju <srikar@xxxxxxxxxxxxxxxxxx>