Re: [PATCH v3] modprobe: add --show-exports

[Lucas De Marchi <lucas.de.marchi@gmail.com>]

On Tue, Nov 13, 2018 at 12:59 AM Yauheni Kaliuta
<yauheni.kaliuta@redhat.com> wrote:
>
> modprobe has --show-modversions switch, which dumps symbols with
> their modversion crcs from the __versions sections.
>
> At the moment the section contains information for the dependency
> symbols only, while exported symbols add to symtab entries with
> __crc_ prefix (the format may differ, see 1e48901166ef libkmod-elf:
> resolve CRC if module is built with MODULE_REL_CRCS).
>
> The patch makes it to show exported symbols as well.
>
> The function is basically cut'n'paste of show_modversions(),
> but 'version' family replaced with 'symbol' one.
>
> Signed-off-by: Yauheni Kaliuta <yauheni.kaliuta@redhat.com>
> ---

Applied, thanks

Lucas De Marchi

>  tools/modprobe.c | 36 ++++++++++++++++++++++++++++++++++++
>  1 file changed, 36 insertions(+)
> ---
> Changelog:
>
> v2 -> v3:
>
> - remove --dump-exports
> - amend help string to be like --show-depends
>
> v1 -> v2:
>
> - do not abstract show functions, because it requires API change
>
> diff --git a/tools/modprobe.c b/tools/modprobe.c
> index 43605ccaf0f0..a9e2331567af 100644
> --- a/tools/modprobe.c
> +++ b/tools/modprobe.c
> @@ -76,6 +76,7 @@ static const struct option cmdopts[] = {
>         {"show-config", no_argument, 0, 'c'},
>         {"show-modversions", no_argument, 0, 4},
>         {"dump-modversions", no_argument, 0, 4},
> +       {"show-exports", no_argument, 0, 6},
>
>         {"dry-run", no_argument, 0, 'n'},
>         {"show", no_argument, 0, 'n'},
> @@ -124,6 +125,7 @@ static void help(void)
>                 "\t-c, --show-config           Same as --showconfig\n"
>                 "\t    --show-modversions      Dump module symbol version and exit\n"
>                 "\t    --dump-modversions      Same as --show-modversions\n"
> +               "\t    --show-exports          Only print module exported symbol versions and exit\n"
>                 "\n"
>                 "General Options:\n"
>                 "\t-n, --dry-run               Do not execute operations, just print out\n"
> @@ -232,6 +234,34 @@ static int show_modversions(struct kmod_ctx *ctx, const char *filename)
>         return 0;
>  }
>
> +static int show_exports(struct kmod_ctx *ctx, const char *filename)
> +{
> +       struct kmod_list *l, *list = NULL;
> +       struct kmod_module *mod;
> +       int err = kmod_module_new_from_path(ctx, filename, &mod);
> +       if (err < 0) {
> +               LOG("Module %s not found.\n", filename);
> +               return err;
> +       }
> +
> +       err = kmod_module_get_symbols(mod, &list);
> +       if (err < 0) {
> +               LOG("could not get symbols of %s: %s\n",
> +                       filename, strerror(-err));
> +               kmod_module_unref(mod);
> +               return err;
> +       }
> +
> +       kmod_list_foreach(l, list) {
> +               const char *symbol = kmod_module_symbol_get_symbol(l);
> +               uint64_t crc = kmod_module_symbol_get_crc(l);
> +               printf("0x%08"PRIx64"\t%s\n", crc, symbol);
> +       }
> +       kmod_module_symbols_free_list(list);
> +       kmod_module_unref(mod);
> +       return 0;
> +}
> +
>  static int command_do(struct kmod_module *module, const char *type,
>                                 const char *command, const char *cmdline_opts)
>  {
> @@ -727,6 +757,7 @@ static int do_modprobe(int argc, char **orig_argv)
>         int do_remove = 0;
>         int do_show_config = 0;
>         int do_show_modversions = 0;
> +       int do_show_exports = 0;
>         int err;
>
>         argv = prepend_options_from_env(&argc, orig_argv);
> @@ -783,6 +814,9 @@ static int do_modprobe(int argc, char **orig_argv)
>                 case 4:
>                         do_show_modversions = 1;
>                         break;
> +               case 6:
> +                       do_show_exports = 1;
> +                       break;
>                 case 'n':
>                         dry_run = 1;
>                         break;
> @@ -886,6 +920,8 @@ static int do_modprobe(int argc, char **orig_argv)
>                 err = show_config(ctx);
>         else if (do_show_modversions)
>                 err = show_modversions(ctx, args[0]);
> +       else if (do_show_exports)
> +               err = show_exports(ctx, args[0]);
>         else if (do_remove)
>                 err = rmmod_all(ctx, args, nargs);
>         else if (use_all)
> --
> 2.19.1
>


-- 
Lucas De Marchi