depmod: fix builtin symbols resolution when the prefix symbol is set

When the prefix symbol is set, take it into account while adding symbols
from System.map file by skipping it before "__ksymtab_" comparison.

Also, prevent inserted fake symbols (like "__this_module") from being
wrongly truncated from beginning.

diff --git a/tools/depmod.c b/tools/depmod.c
index f7d71f852a84fc1dcc4ca8c938da255b8a4ff8ac..97f2dbe7ac9399a41c85311829ea20c13587ebea 100644 (file)
--- a/tools/depmod.c
+++ b/tools/depmod.c
@@ -1428,13 +1428,14 @@ corrupted:
 }
 
 static int depmod_symbol_add(struct depmod *depmod, const char *name,
-                                       uint64_t crc, const struct mod *owner)
+                                       bool prefix_skipped, uint64_t crc,
+                                       const struct mod *owner)
 {
        size_t namelen;
        int err;
        struct symbol *sym;
 
-       if (name[0] == depmod->cfg->sym_prefix)
+       if (!prefix_skipped && (name[0] == depmod->cfg->sym_prefix))
                name++;
 
        namelen = strlen(name) + 1;
@@ -1491,7 +1492,7 @@ static int depmod_load_modules(struct depmod *depmod)
                kmod_list_foreach(l, list) {
                        const char *name = kmod_module_symbol_get_symbol(l);
                        uint64_t crc = kmod_module_symbol_get_crc(l);
-                       depmod_symbol_add(depmod, name, crc, mod);
+                       depmod_symbol_add(depmod, name, false, crc, mod);
                }
                kmod_module_symbols_free_list(list);
 
@@ -2226,9 +2227,9 @@ static int depmod_output(struct depmod *depmod, FILE *out)
 static void depmod_add_fake_syms(struct depmod *depmod)
 {
        /* __this_module is magic inserted by kernel loader. */
-       depmod_symbol_add(depmod, "__this_module", 0, NULL);
+       depmod_symbol_add(depmod, "__this_module", true, 0, NULL);
        /* On S390, this is faked up too */
-       depmod_symbol_add(depmod, "_GLOBAL_OFFSET_TABLE_", 0, NULL);
+       depmod_symbol_add(depmod, "_GLOBAL_OFFSET_TABLE_", true, 0, NULL);
 }
 
 static int depmod_load_symvers(struct depmod *depmod, const char *filename)
@@ -2269,7 +2270,7 @@ static int depmod_load_symvers(struct depmod *depmod, const char *filename)
                        continue;
                }
 
-               depmod_symbol_add(depmod, sym, crc, NULL);
+               depmod_symbol_add(depmod, sym, false, crc, NULL);
        }
        depmod_add_fake_syms(depmod);
 
@@ -2310,6 +2311,10 @@ static int depmod_load_system_map(struct depmod *depmod, const char *filename)
                        goto invalid_syntax;
                p++;
 
+               /* skip prefix */
+               if (p[0] == depmod->cfg->sym_prefix)
+                       p++;
+
                /* Covers gpl-only and normal symbols. */
                if (strncmp(p, ksymstr, ksymstr_len) != 0)
                        continue;
@@ -2318,7 +2323,7 @@ static int depmod_load_system_map(struct depmod *depmod, const char *filename)
                if (end != NULL)
                        *end = '\0';
 
-               depmod_symbol_add(depmod, p + ksymstr_len, 0, NULL);
+               depmod_symbol_add(depmod, p + ksymstr_len, true, 0, NULL);
                continue;
 
        invalid_syntax: