Messages in this thread | | | Subject | Re: [PATCH v3] Allow user probes on versioned symbols | From | Paul Clarke <> | Date | Fri, 31 Mar 2017 14:38:11 -0500 |
| |
On 03/31/2017 12:31 PM, Arnaldo Carvalho de Melo wrote: > Em Fri, Mar 31, 2017 at 11:06:16AM -0500, Paul Clarke escreveu: >> Symbol versioning, as in glibc, results in symbols being defined as: >> <real symbol>@[@]<version> >> (Note that "@@" identifies a default symbol, if the symbol name >> is repeated.) >> >> perf is currently unable to deal with this, and is unable to create >> user probes at such symbols: > > On top of what tree/branch should I try to apply this?
I worked from torvalds/linux.
> Trying on acme/perf/core:
Pardon my ignorance, but where can I find that tree?
> [acme@jouet linux]$ patch -p1 < /wb/1.patch > patching file tools/perf/util/auxtrace.c > Hunk #1 FAILED at 1875. [...]
> Apart from that, you are not checking the return of strndup, that > however unlikely, can fail, so must be checked.
It's in the middle of strcmp-type function, so all return values are valid. Shall I emit a message and call exit()?
> On the style front you sometimes add a space after commas, sometimes > not, please make sure you add one.
Ack.
> But apart from those problems, I think that one should be able to ask > for a versioned symbol, to probe just apps using that specific version,
I agree, but wasn't trying to tackle that at the moment. I can look into it, though.
> for instance, we should consider the whole name as two functions, which > in fact, they are, no?
I'm not sure I understand what you mean here. Do you mean we should set a probe at every version of a given symbol name? For example, if there are symbols: a@@V2 a@V1.1 a@V1
...for a request to set a probe at "a", we'd actually set a probe at all 3?
> Additionaly, I can't reproduce your problem here, on x86_64:
I just cloned from acme/linux, and will rebase to there, if that's the best tree.
PC
| |