insmod: mix xmalloc with xrealloc_vector more carefully

1 files changed, 52 insertions, 37 deletions

diff --git a/modutils/insmod.c b/modutils/insmod.c
index 120feabf3..09e7d6811 100644
--- 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");