kbuild: fix NULL dereference in scripts/mod/modpost.c

[pandora-kernel.git] / scripts / mod / modpost.c

diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index 3b570b1..7e8079a 100644 (file)
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -191,7 +191,7 @@ static struct symbol *sym_add_exported(const char *name, struct module *mod)
                s = new_symbol(name, mod);
        } else {
                if (!s->preloaded) {
-                       warn("%s: duplicate symbol '%s' previous definition "
+                       warn("%s: '%s' exported twice. Previous export "
                             "was in %s%s\n", mod->name, name,
                             s->module->name,
                             is_vmlinux(s->module->name) ?"":".ko");
@@ -346,8 +346,8 @@ static void parse_elf_finish(struct elf_info *info)
        release_file(info->hdr, info->size);
 }
 
-#define CRC_PFX     "__crc_"
-#define KSYMTAB_PFX "__ksymtab_"
+#define CRC_PFX     MODULE_SYMBOL_PREFIX "__crc_"
+#define KSYMTAB_PFX MODULE_SYMBOL_PREFIX "__ksymtab_"
 
 static void handle_modversions(struct module *mod, struct elf_info *info,
                               Elf_Sym *sym, const char *symname)
@@ -558,7 +558,10 @@ static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf_Addr addr,
 }
 
 /*
- * Find symbols before or equal addr and after addr - in the section sec
+ * Find symbols before or equal addr and after addr - in the section sec.
+ * If we find two symbols with equal offset prefer one with a valid name.
+ * The ELF format may have a better way to detect what type of symbol
+ * it is, but this works for now.
  **/
 static void find_symbols_between(struct elf_info *elf, Elf_Addr addr,
                                 const char *sec,
@@ -587,6 +590,12 @@ static void find_symbols_between(struct elf_info *elf, Elf_Addr addr,
                                beforediff = addr - sym->st_value;
                                *before = sym;
                        }
+                       else if ((addr - sym->st_value) == beforediff) {
+                               /* equal offset, valid name? */
+                               const char *name = elf->strtab + sym->st_name;
+                               if (name && strlen(name))
+                                       *before = sym;
+                       }
                }
                else
                {
@@ -594,6 +603,12 @@ static void find_symbols_between(struct elf_info *elf, Elf_Addr addr,
                                afterdiff = sym->st_value - addr;
                                *after = sym;
                        }
+                       else if ((sym->st_value - addr) == afterdiff) {
+                               /* equal offset, valid name? */
+                               const char *name = elf->strtab + sym->st_name;
+                               if (name && strlen(name))
+                                       *after = sym;
+                       }
                }
        }
 }
@@ -643,7 +658,7 @@ static void warn_sec_mismatch(const char *modname, const char *fromsec,
                warn("%s - Section mismatch: reference to %s:%s from %s "
                     "before '%s' (at offset -0x%llx)\n",
                     modname, secname, refsymname, fromsec,
-                    elf->strtab + before->st_name,
+                    elf->strtab + after->st_name,
                     (long long)r.r_offset);
        } else {
                warn("%s - Section mismatch: reference to %s:%s from %s "
@@ -908,19 +923,14 @@ void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf,
 
        va_start(ap, fmt);
        len = vsnprintf(tmp, SZ, fmt, ap);
-       if (buf->size - buf->pos < len + 1) {
-               buf->size += 128;
-               buf->p = realloc(buf->p, buf->size);
-       }
-       strncpy(buf->p + buf->pos, tmp, len + 1);
-       buf->pos += len;
+       buf_write(buf, tmp, len);
        va_end(ap);
 }
 
 void buf_write(struct buffer *buf, const char *s, int len)
 {
        if (buf->size - buf->pos < len) {
-               buf->size += len;
+               buf->size += len + SZ;
                buf->p = realloc(buf->p, buf->size);
        }
        strncpy(buf->p + buf->pos, s, len);