Em Fri, Jan 28, 2011 at 02:11:33PM -0800, Arun Sharma escreveu:
> Symbolize binaries which don't have buildids and are stripped, but have a .dynsym.
> 
> Signed-off-by: Arun Sharma <asharma@fb.com>

Sorry for taking soooo long to look at this, as I mentioned some time
ago I wasn't on the CC list, so it fell thru the cracks.

Srikar just mentioned that to me and by coincidence I was working on
fixing bugs on cross analysis, collecting perf.data files on a ppc64
system to run report on my workstation, a x86_64 machine.o

But if we do as in your patch we will miss looking for the .dynsym on
the build id cache (DSO__ORIG_BUILD_ID_CACHE):

[acme@emilia ~]$ cat want_symtab.c 
#include <stdio.h>

int main(void)
{
	int origin, want_symtab;

	for (origin = 0, want_symtab = 1; origin < 5; ++origin) {
		printf("origin=%d, want_symtab=%d\n", origin,
want_symtab);
		if (origin == 4 && want_symtab) {
			want_symtab = 0;
			origin = 0;
			continue;
		}
	}
}
[acme@emilia ~]$ ./want_symtab 
origin=0, want_symtab=1
origin=1, want_symtab=1
origin=2, want_symtab=1
origin=3, want_symtab=1
origin=4, want_symtab=1
origin=1, want_symtab=0
origin=2, want_symtab=0
origin=3, want_symtab=0
origin=4, want_symtab=0
[acme@emilia ~]$

So I'm applying another patch I came up with that I'm attaching to this
message.

Please let me know if you guys are ok with it and if I can add a
Tested-by: you.

- Arnaldo

> diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
> index 15ccfba..a84db85 100644
> --- a/tools/perf/util/symbol.c
> +++ b/tools/perf/util/symbol.c
> @@ -1480,7 +1480,7 @@ int dso__load(struct dso *self, struct map *map, symbol_filter_t filter)
>  	 * Failing that, do a second pass where we accept .dynsym also
>  	 */
>  	for (self->origin = DSO__ORIG_BUILD_ID_CACHE, want_symtab = 1;
> -	     self->origin != DSO__ORIG_NOT_FOUND;
> +	     self->origin != DSO__ORIG_END;
>  	     self->origin++) {
>  		switch (self->origin) {
>  		case DSO__ORIG_BUILD_ID_CACHE:
> @@ -1530,6 +1530,7 @@ int dso__load(struct dso *self, struct map *map, symbol_filter_t filter)
>  				 self->long_name);
>  			break;
>  
> +		case DSO__ORIG_NOT_FOUND:
>  		default:
>  			/*
>  			 * If we wanted a full symtab but no image had one,
> @@ -1538,8 +1539,7 @@ int dso__load(struct dso *self, struct map *map, symbol_filter_t filter)
>  			if (want_symtab) {
>  				want_symtab = 0;
>  				self->origin = DSO__ORIG_BUILD_ID_CACHE;
> -			} else
> -				continue;
> +			}
>  		}
>  
>  		/* Name is now the name of the next image to try */
> diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h
> index 670cd1c..6b79ab9 100644
> --- a/tools/perf/util/symbol.h
> +++ b/tools/perf/util/symbol.h
> @@ -201,6 +201,7 @@ enum dso_origin {
>  	DSO__ORIG_GUEST_KMODULE,
>  	DSO__ORIG_KMODULE,
>  	DSO__ORIG_NOT_FOUND,
> +	DSO__ORIG_END,
>  };