2012-05-07 23:47:15

by Arun Sharma

[permalink] [raw]
Subject: Re: [PATCH 1/4] perf, x86: Allow multiple stacks

On 4/20/12 3:41 PM, Arun Sharma wrote:
> Without this patch, applications with two different stack
> regions (eg: native stack vs JIT stack) get truncated
> callchains even when RBP chaining is present. GDB shows proper
> stack traces and the frame pointer chaining is intact.
>
> This patch disables the (fp< RSP) check, hoping that other checks
> in the code save the day for us. In our limited testing, this
> didn't seem to break anything.
>
> In the long term, we could potentially have userspace advise
> the kernel on the range of valid stack addresses, so we don't
> spend a lot of time unwinding from bogus addresses.

Ingo/Peter: Did you get a chance to look at this patch series (Support
multiple stacks v3)?

-Arun