Re: [PATCH dwarves] dwarf_loader: handle subprogram ret type with abstract_origin properly

[Jiri Olsa <jolsa@redhat.com>]

On Fri, Apr 02, 2021 at 03:08:27PM -0300, Arnaldo wrote:
> 
> 
> On April 2, 2021 2:42:21 PM GMT-03:00, Yonghong Song <yhs@fb.com> wrote:
> >On 4/2/21 10:23 AM, Yonghong Song wrote:
> :> Thanks. I checked out the branch and did some testing with latest
> >clang 
> >> trunk (just pulled in).
> >> 
> >> With kernel LTO note support, I tested gcc non-lto, and llvm-lto
> >mode, 
> >> it works fine.
> >> 
> >> Without kernel LTO note support, I tested
> >>    gcc non-lto  <=== ok
> >>    llvm non-lto  <=== not ok
> >>    llvm lto     <=== ok
> >> 
> >> Surprisingly llvm non-lto vmlinux had the same "tcp_slow_start"
> >issue.
> >> Some previous version of clang does not have this issue.
> >> I double checked the dwarfdump and it is indeed has the same reason
> >> for lto vmlinux. I checked abbrev section and there is no cross-cu
> >> references.
> >> 
> >> That means we need to adapt this patch
> >>    dwarf_loader: Handle subprogram ret type with abstract_origin
> >properly
> >> for non merging case as well.
> >> The previous patch fixed lto subprogram abstract_origin issue,
> >> I will submit a followup patch for this.
> >
> >Actually, the change is pretty simple,
> >
> >diff --git a/dwarf_loader.c b/dwarf_loader.c
> >index 5dea837..82d7131 100644
> >--- a/dwarf_loader.c
> >+++ b/dwarf_loader.c
> >@@ -2323,7 +2323,11 @@ static int die__process_and_recode(Dwarf_Die 
> >*die, struct cu *cu)
> >         int ret = die__process(die, cu);
> >         if (ret != 0)
> >                 return ret;
> >-       return cu__recode_dwarf_types(cu);
> >+       ret = cu__recode_dwarf_types(cu);
> >+       if (ret != 0)
> >+               return ret;
> >+
> >+       return cu__resolve_func_ret_types(cu);
> >  }
> >
> >Arnaldo, do you just want to fold into previous patches, or
> >you want me to submit a new one?
> 
> I can take care of that.
> 
> And I think it's time for to look at Jiri's test suite... :-)
> 
> It's a holiday here, so I'll take some time to get to this, hopefully I'll tag 1.21 tomorrow tho.

heya,
I did not follow this change, but if you put the latest change
into some branch I can run it on top of that

jirka