Re: [PATCH 11/16] perf symbol: introduce symsrc structure.

[Namhyung Kim <namhyung@kernel.org>]

2012-08-10 (금), 15:22 -0700, Cody P Schafer:
> Factors opening of certain sections & tracking certain elf info into an
> external structure.
> 
> The goal here is to keep multiple elfs (and their looked up
> sections/indexes) around during the symbol generation process (in
> dso__load()).
> 
> We need this to properly resolve symbols on PPC due to the
> use of function descriptors & the .opd section (ie: symbols which are
> functions don't point to their actual location, they point to their
> function descriptor in .opd which contains their actual location.
> 
> It would be possible to just keep the (Elf *) around, but then we'd end
> up with duplicate code for looking up the same sections and checking for
> the existence of an important section wouldn't be as clean (and we need
> to keep the Elf stuff confined to symtab-elf.c).
> 
> Utilized by the later patch
> "perf symbol: use both runtime and debug images"
> 
> Signed-off-by: Cody P Schafer <cody@linux.vnet.ibm.com>
> ---
>  tools/perf/util/symbol-elf.c     | 119 +++++++++++++++++++++++++++++----------
>  tools/perf/util/symbol-minimal.c |  30 +++++++++-
>  tools/perf/util/symbol.c         |  22 ++++----
>  tools/perf/util/symbol.h         |  36 +++++++++++-
>  4 files changed, 163 insertions(+), 44 deletions(-)
> 
[SNIP]
> diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h
> index 37f1ea1..5e55f98 100644
> --- a/tools/perf/util/symbol.h
> +++ b/tools/perf/util/symbol.h
> @@ -11,6 +11,12 @@
>  #include <stdio.h>
>  #include <byteswap.h>
>  
> +#ifndef NO_LIBELF

Should be NO_LIBELF_SUPPORT.


> +#include <libelf.h>
> +#include <gelf.h>
> +#include <elf.h>
> +#endif
> +
>  #ifdef HAVE_CPLUS_DEMANGLE
>  extern char *cplus_demangle(const char *, int);
>  
> @@ -219,6 +225,34 @@ struct dso {
>  	char		 name[0];
>  };
>  
> +struct symsrc {
> +	char *name;
> +	int fd;
> +	enum dso_binary_type type;
> +
> +#ifndef NO_LIBELF

Ditto.

Thanks,
Namhyung


> +	Elf *elf;
> +	GElf_Ehdr ehdr;
> +
> +	Elf_Scn *opdsec;
> +	size_t opdidx;
> +	GElf_Shdr opdshdr;
> +
> +	Elf_Scn *symtab;
> +	GElf_Shdr symshdr;
> +
> +	Elf_Scn *dynsym;
> +	size_t dynsym_idx;
> +	GElf_Shdr dynshdr;
> +
> +	bool adjust_symbols;
> +#endif
> +};
> +
> +void symsrc__destroy(struct symsrc *ss);
> +int symsrc__init(struct symsrc *ss, struct dso *dso, const char *name,
> +		 enum dso_binary_type type);
> +
>  #define DSO__SWAP(dso, type, val)			\
>  ({							\
>  	type ____r = val;				\
> @@ -334,7 +368,7 @@ ssize_t dso__data_read_addr(struct dso *dso, struct map *map,
>  			    struct machine *machine, u64 addr,
>  			    u8 *data, ssize_t size);
>  int dso__test_data(void);
> -int dso__load_sym(struct dso *dso, struct map *map, const char *name, int fd,
> +int dso__load_sym(struct dso *dso, struct map *map, struct symsrc *ss,
>  		  symbol_filter_t filter, int kmodule, int want_symtab);
>  int dso__synthesize_plt_symbols(struct dso *dso, char *name, struct map *map,
>  				symbol_filter_t filter);