Thread (4 messages) 4 messages, 2 authors, 2018-11-13

Re: [PATCH v2] modprobe: add --show-exports

From: Lucas De Marchi <hidden>
Date: 2018-11-12 23:15:24

On Mon, Nov 12, 2018 at 7:48 AM Yauheni Kaliuta
[off-list ref] wrote:
quoted hunk ↗ jump to hunk
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 <redacted>
---
 tools/modprobe.c | 38 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 38 insertions(+)
diff --git a/tools/modprobe.c b/tools/modprobe.c
index 43605ccaf0f0..ca161d09940c 100644
--- a/tools/modprobe.c
+++ b/tools/modprobe.c
@@ -76,6 +76,8 @@ 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},
+       {"dump-exports", no_argument, 0, 6},

        {"dry-run", no_argument, 0, 'n'},
        {"show", no_argument, 0, 'n'},
@@ -124,6 +126,8 @@ 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          Dump module exported symbol versions and exit\n"
+               "\t    --dump-exports          Same as --show-exports\n"
all the others are show-*. The dump-* and show* should be considered
aliases for compatibility. So I don't think we need that on a new one.

Lucas De Marchi
quoted hunk ↗ jump to hunk
                "\n"
                "General Options:\n"
                "\t-n, --dry-run               Do not execute operations, just print out\n"
@@ -232,6 +236,34 @@ 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 +759,7 @@ 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 +816,9 @@ 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 +922,8 @@ 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
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