Re: [PATCH] perf: Properly align symbol_conf.priv_size

[Arnaldo Carvalho de Melo <acme@ghostprotocols.net>]

Em Mon, Mar 28, 2011 at 05:58:49PM -0700, David Miller escreveu:
> 
> If symbol_conf.priv_size is not a multiple of "sizeof(u64)" we'll bus
> error on sparc64 in symbol__new because the "struct symbol *" pointer
> is computed by adding symbol_conf.priv_size to the memory allocated.
> 
> We cannot isloate the fix to symbol__new and symbol__delete since the
> private area is computed by subtracting the priv_size value from a
> "struct symbol" pointer, so then the private area can still be
> potentially unaligned.

That is a clever area, aka something that needs some sanitization,
container_of use possibilities...
attempt-possible-to-become-some-sort-of-progress. :-\

Rusty willing, vowel-optmz+=blts words to trow at that...
 
> So, simply align the symbol_conf.priv_size value in symbol__init()
> 
> Signed-off-by: David S. Miller <davem@davemloft.net>
> 
> diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
> index 17df793..76c09099 100644
> --- a/tools/perf/util/symbol.c
> +++ b/tools/perf/util/symbol.c
> @@ -2403,6 +2403,8 @@ int symbol__init(void)
>  	if (symbol_conf.initialized)
>  		return 0;
>  
> +	symbol_conf.priv_size = ALIGN(symbol_conf.priv_size, sizeof(u64));
> +
>  	elf_version(EV_CURRENT);
>  	if (symbol_conf.sort_by_name)
>  		symbol_conf.priv_size += (sizeof(struct symbol_name_rb_node) -