insmod: mix xmalloc with xrealloc_vector more carefully

diff --git a/modutils/insmod.c b/modutils/insmod.c
index 120feabf386d113b1c04d01b2025e8cb466161f2..09e7d6811306d8edb7270cde8e38a8ddd5cb08ce 100644 (file)
--- a/modutils/insmod.c
+++ b/modutils/insmod.c
@@ -1059,8 +1059,9 @@ arch_apply_relocation(struct obj_file *f,
 
                case R_68K_PC8:
                        v -= dot;
-                       if ((ElfW(Sword))v > 0x7f ||
-                                       (ElfW(Sword))v < -(ElfW(Sword))0x80) {
+                       if ((ElfW(Sword))v > 0x7f
+                        || (ElfW(Sword))v < -(ElfW(Sword))0x80
+                       ) {
                                ret = obj_reloc_overflow;
                        }
                        *(char *)loc = v;
@@ -1068,8 +1069,9 @@ arch_apply_relocation(struct obj_file *f,
 
                case R_68K_PC16:
                        v -= dot;
-                       if ((ElfW(Sword))v > 0x7fff ||
-                                       (ElfW(Sword))v < -(ElfW(Sword))0x8000) {
+                       if ((ElfW(Sword))v > 0x7fff
+                        || (ElfW(Sword))v < -(ElfW(Sword))0x8000
+                       ) {
                                ret = obj_reloc_overflow;
                        }
                        *(short *)loc = v;
@@ -1208,8 +1210,9 @@ arch_apply_relocation(struct obj_file *f,
                        {
                                Elf32_Addr word;
 
-                               if ((Elf32_Sword)v > 0x7fff ||
-                                   (Elf32_Sword)v < -(Elf32_Sword)0x8000) {
+                               if ((Elf32_Sword)v > 0x7fff
+                                || (Elf32_Sword)v < -(Elf32_Sword)0x8000
+                               ) {
                                        ret = obj_reloc_overflow;
                                }
 
@@ -1238,8 +1241,9 @@ arch_apply_relocation(struct obj_file *f,
                                Elf32_Addr word;
 
                                v -= dot + 4;
-                               if ((Elf32_Sword)v > 0x7fff ||
-                                   (Elf32_Sword)v < -(Elf32_Sword)0x8000) {
+                               if ((Elf32_Sword)v > 0x7fff
+                                || (Elf32_Sword)v < -(Elf32_Sword)0x8000
+                               ) {
                                        ret = obj_reloc_overflow;
                                }
 
@@ -1253,9 +1257,10 @@ arch_apply_relocation(struct obj_file *f,
                                Elf32_Addr word, gp;
                                /* get _gp */
                                gp = obj_symbol_final_value(f, obj_find_symbol(f, SPFX "_gp"));
-                               v-=gp;
-                               if ((Elf32_Sword)v > 0x7fff ||
-                                               (Elf32_Sword)v < -(Elf32_Sword)0x8000) {
+                               v -= gp;
+                               if ((Elf32_Sword)v > 0x7fff
+                                || (Elf32_Sword)v < -(Elf32_Sword)0x8000
+                               ) {
                                        ret = obj_reloc_overflow;
                                }
 
@@ -2132,7 +2137,6 @@ obj_find_symbol(struct obj_file *f, const char *name)
        for (sym = f->symtab[hash]; sym; sym = sym->next)
                if (f->symbol_cmp(sym->name, name) == 0)
                        return sym;
-
        return NULL;
 }
 
@@ -2141,12 +2145,10 @@ static ElfW(Addr) obj_symbol_final_value(struct obj_file * f, struct obj_symbol
        if (sym) {
                if (sym->secidx >= SHN_LORESERVE)
                        return sym->value;
-
                return sym->value + f->sections[sym->secidx]->header.sh_addr;
-       } else {
-               /* As a special case, a NULL sym has value zero.  */
-               return 0;
        }
+       /* As a special case, a NULL sym has value zero.  */
+       return 0;
 }
 
 static struct obj_section *obj_find_section(struct obj_file *f, const char *name)
@@ -2156,7 +2158,6 @@ static struct obj_section *obj_find_section(struct obj_file *f, const char *name
        for (i = 0; i < n; ++i)
                if (strcmp(f->sections[i]->name, name) == 0)
                        return f->sections[i];
-
        return NULL;
 }
 
@@ -2167,9 +2168,11 @@ static int obj_load_order_prio(struct obj_section *a)
        af = a->header.sh_flags;
 
        ac = 0;
-       if (a->name[0] != '.' || strlen(a->name) != 10 ||
-                       strcmp(a->name + 5, ".init"))
+       if (a->name[0] != '.' || strlen(a->name) != 10
+        || strcmp(a->name + 5, ".init") != 0
+       ) {
                ac |= 32;
+       }
        if (af & SHF_ALLOC)
                ac |= 16;
        if (!(af & SHF_WRITE))
@@ -2856,18 +2859,19 @@ static int new_create_module_ksymtab(struct obj_file *f)
                /* We don't want to export symbols residing in sections that
                   aren't loaded.  There are a number of these created so that
                   we make sure certain module options don't appear twice.  */
-
-               loaded = alloca(sizeof(int) * (i = f->header.e_shnum));
+               i = f->header.e_shnum;
+               loaded = alloca(sizeof(int) * i);
                while (--i >= 0)
                        loaded[i] = (f->sections[i]->header.sh_flags & SHF_ALLOC) != 0;
 
                for (nsyms = 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 (ELF_ST_BIND(sym->info) != STB_LOCAL
                                                && sym->secidx <= SHN_HIRESERVE
                                                && (sym->secidx >= SHN_LORESERVE
-                                                       || loaded[sym->secidx])) {
+                                                       || loaded[sym->secidx])
+                               ) {
                                        ElfW(Addr) ofs = nsyms * 2 * tgt_sizeof_void_p;
 
                                        obj_symbol_patch(f, sec->idx, ofs, sym);
@@ -2876,6 +2880,7 @@ static int new_create_module_ksymtab(struct obj_file *f)
 
                                        nsyms++;
                                }
+                       }
                }
 
                obj_extend_section(sec, nsyms * 2 * tgt_sizeof_char_p);
@@ -2934,9 +2939,11 @@ new_init_module(const char *m_name, struct obj_file *f, unsigned long m_size)
        }
        sec = obj_find_section(f, ".data.init");
        if (sec) {
-               if (!module->runsize ||
-                               module->runsize > sec->header.sh_addr - m_addr)
+               if (!module->runsize
+                || module->runsize > sec->header.sh_addr - m_addr
+               ) {
                        module->runsize = sec->header.sh_addr - m_addr;
+               }
        }
        sec = obj_find_section(f, ARCHDATA_SEC_NAME);
        if (sec && sec->header.sh_size) {
@@ -3219,8 +3226,8 @@ static int obj_relocate(struct obj_file *f, ElfW(Addr) base)
 #if SHT_RELM == SHT_RELA
 #if defined(__alpha__) && defined(AXP_BROKEN_GAS)
                        /* Work around a nasty GAS bug, that is fixed as of 2.7.0.9.  */
-                       if (!extsym || !extsym->st_name ||
-                                       ELF_ST_BIND(extsym->st_info) != STB_LOCAL)
+                       if (!extsym || !extsym->st_name
+                        || ELF_ST_BIND(extsym->st_info) != STB_LOCAL)
 #endif
                                value += rel->r_addend;
 #endif
@@ -3326,16 +3333,17 @@ static struct obj_file *obj_load(FILE *fp, int loadprogbits UNUSED_PARAM)
        }
 
        if (f->header.e_ident[EI_MAG0] != ELFMAG0
-                       || f->header.e_ident[EI_MAG1] != ELFMAG1
-                       || f->header.e_ident[EI_MAG2] != ELFMAG2
-                       || f->header.e_ident[EI_MAG3] != ELFMAG3) {
+        || f->header.e_ident[EI_MAG1] != ELFMAG1
+        || f->header.e_ident[EI_MAG2] != ELFMAG2
+        || f->header.e_ident[EI_MAG3] != ELFMAG3
+       ) {
                bb_error_msg_and_die("not an ELF file");
        }
        if (f->header.e_ident[EI_CLASS] != ELFCLASSM
-                       || f->header.e_ident[EI_DATA] != (BB_BIG_ENDIAN
-                               ? ELFDATA2MSB : ELFDATA2LSB)
-                       || f->header.e_ident[EI_VERSION] != EV_CURRENT
-                       || !MATCH_MACHINE(f->header.e_machine)) {
+        || f->header.e_ident[EI_DATA] != (BB_BIG_ENDIAN ? ELFDATA2MSB : ELFDATA2LSB)
+        || f->header.e_ident[EI_VERSION] != EV_CURRENT
+        || !MATCH_MACHINE(f->header.e_machine)
+       ) {
                bb_error_msg_and_die("ELF file not for this architecture");
        }
        if (f->header.e_type != ET_REL) {
@@ -3351,7 +3359,10 @@ static struct obj_file *obj_load(FILE *fp, int loadprogbits UNUSED_PARAM)
        }
 
        shnum = f->header.e_shnum;
-       f->sections = xzalloc(sizeof(struct obj_section *) * shnum);
+       /* Growth of ->sections vector will be done by
+        * xrealloc_vector(..., 2, ...), therefore we must allocate
+        * at least 2^2 = 4 extra elements here. */
+       f->sections = xzalloc(sizeof(f->sections[0]) * (shnum + 4));
 
        section_headers = alloca(sizeof(ElfW(Shdr)) * shnum);
        fseek(fp, f->header.e_shoff, SEEK_SET);
@@ -3855,16 +3866,20 @@ static void print_load_map(struct obj_file *f)
        for (nsyms = i = 0; i < HASH_BUCKETS; ++i)
                for (sym = f->symtab[i]; sym; sym = sym->next)
                        if (sym->secidx <= SHN_HIRESERVE
-                                       && (sym->secidx >= SHN_LORESERVE || loaded[sym->secidx]))
+                        && (sym->secidx >= SHN_LORESERVE || loaded[sym->secidx])
+                       ) {
                                ++nsyms;
+                       }
 
        all = alloca(nsyms * sizeof(struct obj_symbol *));
 
        for (i = 0, p = all; i < HASH_BUCKETS; ++i)
                for (sym = f->symtab[i]; sym; sym = sym->next)
                        if (sym->secidx <= SHN_HIRESERVE
-                                       && (sym->secidx >= SHN_LORESERVE || loaded[sym->secidx]))
+                        && (sym->secidx >= SHN_LORESERVE || loaded[sym->secidx])
+                       ) {
                                *p++ = sym;
+                       }
 
        /* And list them.  */
        printf("\nSymbols:\n");