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

From: Arun Sharma
Date: Mon May 07 2012 - 19:47:11 EST


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
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