modutils-24: use xasprintf and xzalloc where appropriate,

 remove unreachanble code
build system: correct some dependencies in config system
init: convert one #if into if() - for Rob.

function                                             old     new   delta
obj_string_patch                                     136     129      -7
bb_init_module_24                                   4759    4615    -144
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/2 up/down: 0/-151)           Total: -151 bytes

2 files changed, 53 insertions, 80 deletions

diff --git a/modutils/Config.in b/modutils/Config.in
index e7b839db9..ce3bce1d8 100644
--- a/modutils/Config.in
+++ b/modutils/Config.in
@@ -5,20 +5,6 @@
 
 menu "Linux Module Utilities"
 
-config DEFAULT_MODULES_DIR
-        string "Default directory containing modules"
-        default "/lib/modules"
-        help
-          Directory that contains kernel modules.
-          Defaults to "/lib/modules"
-
-config DEFAULT_DEPMOD_FILE
-        string "Default name of modules.dep"
-        default "modules.dep"
-        help
-          Filename that contains kernel modules dependencies.
-          Defaults to "modules.dep"
-
 config MODPROBE_SMALL
         bool "Simplified modutils"
         default n
@@ -193,7 +179,7 @@ config FEATURE_INSMOD_LOAD_MAP_FULL
 config FEATURE_CHECK_TAINTED_MODULE
         bool "Support tainted module checking with new kernels"
         default y
-        depends on !MODPROBE_SMALL
+        depends on (LSMOD || FEATURE_2_4_MODULES) && !MODPROBE_SMALL
         help
           Support checking for tainted modules. These are usually binary
           only modules that will make the linux-kernel list ignore your
@@ -227,4 +213,20 @@ config FEATURE_MODUTILS_SYMBOLS
 
           Say Y if unsure.
 
+config DEFAULT_MODULES_DIR
+        string "Default directory containing modules"
+        default "/lib/modules"
+        depends on DEPMOD || MODPROBE || MODPROBE_SMALL
+        help
+          Directory that contains kernel modules.
+          Defaults to "/lib/modules"
+
+config DEFAULT_DEPMOD_FILE
+        string "Default name of modules.dep"
+        default "modules.dep"
+        depends on DEPMOD || MODPROBE || MODPROBE_SMALL
+        help
+          Filename that contains kernel modules dependencies.
+          Defaults to "modules.dep"
+
 endmenu
diff --git a/modutils/modutils-24.c b/modutils/modutils-24.c
index 7c7568639..4e112a06f 100644
--- a/modutils/modutils-24.c
+++ b/modutils/modutils-24.c
@@ -646,7 +646,7 @@ static enum obj_reloc arch_apply_relocation(struct obj_file *f,
 static void arch_create_got(struct obj_file *f);
 #if ENABLE_FEATURE_CHECK_TAINTED_MODULE
 static int obj_gpl_license(struct obj_file *f, const char **license);
-#endif /* FEATURE_CHECK_TAINTED_MODULE */
+#endif
 #endif /* obj.h */
 //----------------------------------------------------------------------------
 //--------end of modutils obj.h
@@ -1687,11 +1687,11 @@ static int arch_list_add(ElfW(RelM) *rel, struct arch_list_entry **list,
         }
 
         if (pe == NULL) {
-                pe = xmalloc(sizeof(struct arch_list_entry));
+                pe = xzalloc(sizeof(struct arch_list_entry));
                 pe->next = *list;
                 pe->addend = rel->r_addend;
                 pe->offset = offset;
-                pe->inited = 0;
+                /*pe->inited = 0;*/
                 *list = pe;
                 return size;
         }
@@ -2255,7 +2255,7 @@ add_symbols_from( struct obj_file *f,
                 strcpy(name_buf, SYMBOL_PREFIX);
                 strcpy(name_buf + extra - 1, name);
                 name = name_buf;
-#endif /* SYMBOL_PREFIX */
+#endif
 
                 sym = obj_find_symbol(f, name);
                 if (sym && !(ELF_ST_BIND(sym->info) == STB_LOCAL)) {
@@ -2618,7 +2618,8 @@ static void new_get_kernel_symbols(void)
 
         /* Collect the kernel's symbols.  */
 
-        syms = xmalloc(bufsize = 16 * 1024);
+        bufsize = 16 * 1024;
+        syms = xmalloc(bufsize);
  retry_kern_sym_load:
         if (query_module(NULL, QM_SYMBOLS, syms, bufsize, &ret)) {
                 if (errno == ENOSPC && bufsize < ret) {
@@ -2802,10 +2803,8 @@ new_init_module(const char *m_name, struct obj_file *f, unsigned long m_size)
                 module->ndeps = n_ext_modules_used;
         }
 
-        module->init =
-                obj_symbol_final_value(f, obj_find_symbol(f, SPFX "init_module"));
-        module->cleanup =
-                obj_symbol_final_value(f, obj_find_symbol(f, SPFX "cleanup_module"));
+        module->init = obj_symbol_final_value(f, obj_find_symbol(f, SPFX "init_module"));
+        module->cleanup = obj_symbol_final_value(f, obj_find_symbol(f, SPFX "cleanup_module"));
 
         sec = obj_find_section(f, "__ex_table");
         if (sec) {
@@ -2863,7 +2862,7 @@ obj_string_patch(struct obj_file *f, int secidx, ElfW(Addr) offset,
         size_t len = strlen(string) + 1;
         char *loc;
 
-        p = xmalloc(sizeof(*p));
+        p = xzalloc(sizeof(*p));
         p->next = f->string_patches;
         p->reloc_secidx = secidx;
         p->reloc_offset = offset;
@@ -2872,7 +2871,7 @@ obj_string_patch(struct obj_file *f, int secidx, ElfW(Addr) offset,
         strsec = obj_find_section(f, ".kstrtab");
         if (strsec == NULL) {
                 strsec = obj_create_alloced_section(f, ".kstrtab", 1, len);
-                p->string_offset = 0;
+                /*p->string_offset = 0;*/
                 loc = strsec->contents;
         } else {
                 p->string_offset = strsec->header.sh_size;
@@ -2925,38 +2924,37 @@ static void obj_allocate_commons(struct obj_file *f)
 
         for (i = 0; i < HASH_BUCKETS; ++i) {
                 struct obj_symbol *sym;
-                for (sym = f->symtab[i]; sym; sym = sym->next)
+                for (sym = f->symtab[i]; sym; sym = sym->next) {
                         if (sym->secidx == SHN_COMMON) {
                                 /* Collect all COMMON symbols and sort them by size so as to
                                    minimize space wasted by alignment requirements.  */
-                                {
-                                        struct common_entry **p, *n;
-                                        for (p = &common_head; *p; p = &(*p)->next)
-                                                if (sym->size <= (*p)->sym->size)
-                                                        break;
-
-                                        n = alloca(sizeof(*n));
-                                        n->next = *p;
-                                        n->sym = sym;
-                                        *p = n;
-                                }
+                                struct common_entry **p, *n;
+                                for (p = &common_head; *p; p = &(*p)->next)
+                                        if (sym->size <= (*p)->sym->size)
+                                                break;
+                                n = alloca(sizeof(*n));
+                                n->next = *p;
+                                n->sym = sym;
+                                *p = n;
                         }
+                }
         }
 
         for (i = 1; i < f->local_symtab_size; ++i) {
                 struct obj_symbol *sym = f->local_symtab[i];
                 if (sym && sym->secidx == SHN_COMMON) {
                         struct common_entry **p, *n;
-                        for (p = &common_head; *p; p = &(*p)->next)
+                        for (p = &common_head; *p; p = &(*p)->next) {
                                 if (sym == (*p)->sym)
                                         break;
-                                else if (sym->size < (*p)->sym->size) {
+                                if (sym->size < (*p)->sym->size) {
                                         n = alloca(sizeof(*n));
                                         n->next = *p;
                                         n->sym = sym;
                                         *p = n;
                                         break;
                                 }
+                        }
                 }
         }
 
@@ -3546,16 +3544,13 @@ static void check_tainted_module(struct obj_file *f, const char *m_name)
                 case 1:
                         set_tainted(fd, m_name, kernel_has_tainted, TAINT_PROPRIETORY_MODULE, "no license", "");
                         break;
-                case 2:
+                default: /* case 2: */
                         /* The module has a non-GPL license so we pretend that the
                          * kernel always has a taint flag to get a warning even on
                          * kernels without the proc flag.
                          */
                         set_tainted(fd, m_name, 1, TAINT_PROPRIETORY_MODULE, "non-GPL license - ", ptr);
                         break;
-                default:
-                        set_tainted(fd, m_name, 1, TAINT_PROPRIETORY_MODULE, "Unexpected return from obj_gpl_license", "");
-                        break;
         }
 
         if (flag_force_load)
@@ -3564,9 +3559,9 @@ static void check_tainted_module(struct obj_file *f, const char *m_name)
         if (fd >= 0)
                 close(fd);
 }
-#else /* FEATURE_CHECK_TAINTED_MODULE */
+#else /* !FEATURE_CHECK_TAINTED_MODULE */
 #define check_tainted_module(x, y) do { } while (0);
-#endif /* FEATURE_CHECK_TAINTED_MODULE */
+#endif
 
 #if ENABLE_FEATURE_INSMOD_KSYMOOPS_SYMBOLS
 /* add module source, timestamp, kernel version and a symbol for the
@@ -3581,10 +3576,10 @@ get_module_version(struct obj_file *f, char str[STRVERSIONLEN])
 {
 #if ENABLE_FEATURE_INSMOD_VERSION_CHECKING
         return new_get_module_version(f, str);
-#else  /* FEATURE_INSMOD_VERSION_CHECKING */
+#else
         strncpy(str, "???", sizeof(str));
         return -1;
-#endif /* FEATURE_INSMOD_VERSION_CHECKING */
+#endif
 }
 
 /* add module source, timestamp, kernel version and a symbol for the
@@ -3609,7 +3604,7 @@ add_ksymoops_symbols(struct obj_file *f, const char *filename,
         char *name, *absolute_filename;
         char str[STRVERSIONLEN];
         unsigned i;
-        int l, lm_name, lfilename, use_ksymtab, version;
+        int lm_name, lfilename, use_ksymtab, version;
         struct stat statbuf;
 
         /* WARNING: was using realpath, but replaced by readlink to stop using
@@ -3634,20 +3629,10 @@ add_ksymoops_symbols(struct obj_file *f, const char *filename,
                  * is 0xffffff, decimal 16777215.  putting all three fields in
                  * one symbol is less readable but saves kernel space.
                  */
-                l = sizeof(symprefix) +                 /* "__insmod_" */
-                        lm_name +                       /* module name */
-                        2 +                             /* "_O" */
-                        lfilename +                     /* object filename */
-                        2 +                             /* "_M" */
-                        2 * sizeof(statbuf.st_mtime) +  /* mtime in hex */
-                        2 +                             /* "_V" */
-                        8 +                             /* version in dec */
-                        1;                              /* nul */
-                name = xmalloc(l);
                 if (stat(absolute_filename, &statbuf) != 0)
                         statbuf.st_mtime = 0;
                 version = get_module_version(f, str);   /* -1 if not found */
-                snprintf(name, l, "%s%s_O%s_M%0*lX_V%d",
+                name = xasprintf("%s%s_O%s_M%0*lX_V%d",
                                 symprefix, m_name, absolute_filename,
                                 (int)(2 * sizeof(statbuf.st_mtime)), statbuf.st_mtime,
                                 version);
@@ -3662,34 +3647,20 @@ add_ksymoops_symbols(struct obj_file *f, const char *filename,
         /* record where the persistent data is going, same address as previous symbol */
 
         if (f->persist) {
-                l = sizeof(symprefix) +         /* "__insmod_" */
-                        lm_name +               /* module name */
-                        2 +                     /* "_P" */
-                        strlen(f->persist) +    /* data store */
-                        1;                      /* nul */
-                name = xmalloc(l);
-                snprintf(name, l, "%s%s_P%s",
+                name = xasprintf("%s%s_P%s",
                                 symprefix, m_name, f->persist);
                 sym = obj_add_symbol(f, name, -1, ELF_ST_INFO(STB_GLOBAL, STT_NOTYPE),
                                 sec->idx, sec->header.sh_addr, 0);
                 if (use_ksymtab)
                         new_add_ksymtab(f, sym);
         }
-#endif /* _NOT_SUPPORTED_ */
+#endif
         /* tag the desired sections if size is non-zero */
 
         for (i = 0; i < ARRAY_SIZE(section_names); ++i) {
                 sec = obj_find_section(f, section_names[i]);
                 if (sec && sec->header.sh_size) {
-                        l = sizeof(symprefix) +         /* "__insmod_" */
-                                lm_name +               /* module name */
-                                2 +                     /* "_S" */
-                                strlen(sec->name) +     /* section name */
-                                2 +                     /* "_L" */
-                                8 +                     /* length in dec */
-                                1;                      /* nul */
-                        name = xmalloc(l);
-                        snprintf(name, l, "%s%s_S%s_L%ld",
+                        name = xasprintf("%s%s_S%s_L%ld",
                                         symprefix, m_name, sec->name,
                                         (long)sec->header.sh_size);
                         sym = obj_add_symbol(f, name, -1, ELF_ST_INFO(STB_GLOBAL, STT_NOTYPE),
@@ -3855,7 +3826,7 @@ int FAST_FUNC bb_init_module_24(const char *m_filename, const char *options)
                 }
         }
         k_crcs = 0;
-#endif /* FEATURE_INSMOD_VERSION_CHECKING */
+#endif
 
         if (query_module(NULL, 0, NULL, 0, NULL))
                 bb_error_msg_and_die("not configured to support old kernels");
@@ -3869,7 +3840,7 @@ int FAST_FUNC bb_init_module_24(const char *m_filename, const char *options)
 
         if (m_crcs != k_crcs)
                 obj_set_symbol_compare(f, ncv_strcmp, ncv_symbol_hash);
-#endif /* FEATURE_INSMOD_VERSION_CHECKING */
+#endif
 
         /* Let the module know about the kernel symbols.  */
         add_kernel_symbols(f);
@@ -3889,7 +3860,7 @@ int FAST_FUNC bb_init_module_24(const char *m_filename, const char *options)
 
 #if ENABLE_FEATURE_INSMOD_KSYMOOPS_SYMBOLS
         add_ksymoops_symbols(f, m_filename, m_name);
-#endif /* FEATURE_INSMOD_KSYMOOPS_SYMBOLS */
+#endif
 
         new_create_module_ksymtab(f);