Re: [PATCH v3 2/2] Support interactive annotation of code without symbols

[Jin, Yao]

On 2/24/2020 10:04 PM, Ravi Bangoria wrote:
> On 2/24/20 7:21 PM, Jiri Olsa wrote:
> > On Mon, Feb 24, 2020 at 06:55:12PM +0530, Ravi Bangoria wrote:
> > > Hi Jin,
> > >
> > > On 2/24/20 7:52 AM, Jin Yao wrote:
> > > > For perf report on stripped binaries it is currently impossible to do
> > > > annotation. The annotation state is all tied to symbols, but there are
> > > > either no symbols, or symbols are not covering all the code.
> > > >
> > > > We should support the annotation functionality even without symbols.
> > > >
> > > > This patch fakes a symbol and the symbol name is the string of address.
> > > > After that, we just follow current annotation working flow.
> > > >
> > > > For example,
> > > >
> > > > 1. perf report
> > > >
> > > > Overhead Command Shared Object Symbol
> > > > ÂÂÂ 20.67%Â divÂÂÂÂÂ libc-2.27.soÂÂÂÂÂ [.] __random_r
> > > > ÂÂÂ 17.29%Â divÂÂÂÂÂ libc-2.27.soÂÂÂÂÂ [.] __random
> > > > ÂÂÂ 10.59%Â divÂÂÂÂÂ divÂÂÂÂÂÂÂÂÂÂÂÂÂÂ [.] 0x0000000000000628
> > > > ÂÂÂÂ 9.25%Â divÂÂÂÂÂ divÂÂÂÂÂÂÂÂÂÂÂÂÂÂ [.] 0x0000000000000612
> > > > ÂÂÂÂ 6.11%Â divÂÂÂÂÂ divÂÂÂÂÂÂÂÂÂÂÂÂÂÂ [.] 0x0000000000000645
> > > >
> > > > 2. Select the line of "10.59%Â divÂÂÂÂÂ divÂÂÂÂÂÂÂÂÂÂÂÂÂÂ [.] 
> > > > 0x0000000000000628" and ENTER.
> > > >
> > > > Annotate 0x0000000000000628
> > > > Zoom into div thread
> > > > Zoom into div DSO (use the 'k' hotkey to zoom directly into the kernel)
> > > > Browse map details
> > > > Run scripts for samples of symbol [0x0000000000000628]
> > > > Run scripts for all samples
> > > > Switch to another data file in PWD
> > > > Exit
> > > >
> > > > 3. Select the "Annotate 0x0000000000000628" and ENTER.
> > > >
> > > > Percentâ
> > > > ÂÂÂÂÂÂÂÂ â
> > > > ÂÂÂÂÂÂÂÂ â
> > > >  â Disassembly of section .text:
> > > > ÂÂÂÂÂÂÂÂ â
> > > >  â 0000000000000628 <.text+0x68>:
> > > >  â divsd %xmm4,%xmm0
> > > >  â divsd %xmm3,%xmm1
> > > >  â movsd (%rsp),%xmm2
> > > >  â addsd %xmm1,%xmm0
> > > >  â addsd %xmm2,%xmm0
> > > >  â movsd %xmm0,(%rsp)
> > > >
> > > > Now we can see the dump of object starting from 0x628.
> > >
> > > If I press 'a' on address, it's not annotating. But if I annotate
> > > by pressing enter, like you explained, it works. Is it intentional?
> >
> > I saw that too, but I thought it's unrelated issue,
> > because we played with that just recently
> >
> > if you go through the 'enter' way and back, then the
> > next time 'a' works ;-)
>
> Yes.
>
> I liked the series so I was trying out the patches. Just reporting 
> issues I found...
>
> jump/call arrows are also screwed up.. Like jump instruction is showing 
> call arrows.
> But these all are minor issues and can be fixed later on. I don't mind ;)
>
> Ravi

Some jumps will show arrow '->". For example,

â jne   120

Yes, we can check and fix that later.

Thanks
Jin Yao