Re: [PATCH] scripts: add script for translating stack dump function offsets

From: Vegard Nossum
Date: Sat Sep 17 2016 - 05:11:58 EST

On 16 September 2016 at 21:17, Josh Poimboeuf <jpoimboe@xxxxxxxxxx> wrote:
> On Fri, Sep 16, 2016 at 11:12:10AM -0700, Linus Torvalds wrote:
>> Side note: I find addr2line almost completely useless in many cases
>> not because of address space randomization, but because of how complex
>> the inlining often is. I just had something where I decided to use
>> addr2line and it just pointed me to the __read_once_size_nocheck()
>> line in <linux/compiler.h>. That was not very useful.
>> I ended up actually looking at the instructions *around* it, to find
>> where that one instruction had been inlined from.
>> So I'm wondering if this kind of helper script could be extended to
>> have that "look around it" thing to help.
> I think that issue is solved by addr2line's '--inline' option, which the
> script uses:

Another small gotcha is that stack trace addresses are _return
addresses_, not callsites. So you'll sometimes want to pass 'addr - 1'
instead of just addr, as the next address (the return address) may
belong to a completely unrelated deeply inlined function.