Re: Getting empty callchain from perf_callchain_kernel()
From: Josh Poimboeuf
Date: Fri May 24 2019 - 09:09:02 EST
On Fri, May 24, 2019 at 10:53:19AM +0200, Peter Zijlstra wrote:
> On Thu, May 23, 2019 at 10:24:13AM -0500, Josh Poimboeuf wrote:
> > Here's the latest version which should fix it in all cases (based on
> > tip/master):
> > https://git.kernel.org/pub/scm/linux/kernel/git/jpoimboe/linux.git/commit/?h=bpf-orc-fix
> That patch suffers an inconsitency, the comment states:
> 'if they have "jump_table" in the name'
> while the actual code implements:
> 'if the name starts with "jump_table"'
> Other than that, I suppose that works just fine ;-)
The thing is, gcc converts a static local variable named "jump_table" to
an ELF symbol with a numbered suffix, something like "jump_table.12345".
But yeah I should at least clarify that in the comment.