Re: [PATCH] perf: unwind: fix segbase for libunwind.

From: Ingo Molnar
Date: Wed Apr 01 2015 - 10:48:49 EST

* Wang Nan <wangnan0@xxxxxxxxxx> wrote:

> Perf passes incorrect segbase and table_data to libunwind when
> map->pgoff != 0, causes unwind failure. This patch fixes this
> problem.
> segbase is an absolute offset from the head of object file, directly
> read from ELF file. Original code computes corresponding virtual
> address using map->start + segbase, doesn't consider map->pgoff.
> Which causes libunwind read from incorrect offset.

What's the effect of this bug in practice?

Is there any before/after output you can show that demonstrates the


To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at