intel/tools: make sure the binary file is properly read

1. tools/i965_disasm.c:58:4: warning:
     ignoring return value of ‘fread’,
     declared with attribute warn_unused_result
     fread(assembly, *end, 1, fp);

v2: Fixed incorrect return value check.
       ( Eric Engestrom <eric.engestrom@intel.com> )

v3: Zero size file check placed before fread with exit()
       ( Eric Engestrom <eric.engestrom@intel.com> )

v4: - Title is changed.
    - The 'size' variable was moved to top of a function scope.
    - The assertion was replaced by the proper error handling.
    - The error message on a caller side was fixed.
       ( Eric Engestrom <eric.engestrom@intel.com> )

Signed-off-by: Andrii Simiklit <andrii.simiklit@globallogic.com>
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: Eric Engestrom <eric.engestrom@intel.com>

diff --git a/src/intel/tools/i965_disasm.c b/src/intel/tools/i965_disasm.c
index 73a6760fc131d36117704f9091454698a87238b2..79434e6462af6a563d8497a410ab17fada413bd0 100644 (file)
--- a/src/intel/tools/i965_disasm.c
+++ b/src/intel/tools/i965_disasm.c
@@ -47,17 +47,23 @@ i965_disasm_get_file_size(FILE *fp)
 static void *
 i965_disasm_read_binary(FILE *fp, size_t *end)
 {
+   size_t size;
    void *assembly;
 
    *end = i965_disasm_get_file_size(fp);
+   if (!*end)
+      return NULL;
 
    assembly = malloc(*end + 1);
    if (assembly == NULL)
       return NULL;
 
-   fread(assembly, *end, 1, fp);
+   size = fread(assembly, *end, 1, fp);
    fclose(fp);
-
+   if (!size) {
+      free(assembly);
+      return NULL;
+   }
    return assembly;
 }
 
@@ -167,7 +173,11 @@ int main(int argc, char *argv[])
 
    assembly = i965_disasm_read_binary(fp, &end);
    if (!assembly) {
-      fprintf(stderr, "Unable to allocate buffer to read binary file\n");
+      if (end)
+        fprintf(stderr, "Unable to allocate buffer to read binary file\n");
+      else
+        fprintf(stderr, "Input file is empty\n");
+
       exit(EXIT_FAILURE);
    }