Improved AESNI check

1 files changed, 15 insertions, 5 deletions

diff --git a/src/lib/third_party/src/gcrypt/aesni.c b/src/lib/third_party/src/gcrypt/aesni.c
index 5a32ae692..00f64aed0 100644
--- a/src/lib/third_party/src/gcrypt/aesni.c
+++ b/src/lib/third_party/src/gcrypt/aesni.c
@@ -45,6 +45,10 @@
 #include <intrin.h>
 #endif
 
+#if defined(linux) || defined(__linux__)
+static u_int8_t cached_has_aesni = 0. has_aesni_checked = 0;
+#endif
+
 /*
  * AES-NI support detection routine
  */
@@ -59,10 +63,10 @@ int mbedtls_aesni_has_support( unsigned int what )
 #if defined(linux) || defined(__linux__)
   unsigned int eax, ebx, ecx, edx;
 
-  {
+  if(has_aesni_checked == 0) {
     /*
       NOTE
-      
+
       This code is necessary as __get_cpuid() is not reliable
       Example with Intel(R) Celeron(R) CPU N2930 (that has NO AES-NI)
       the code based on __get_cpuid() reports that AES-NI is present
@@ -73,21 +77,27 @@ int mbedtls_aesni_has_support( unsigned int what )
     if(fd != NULL) {
       char *line = NULL;
       size_t len = 0;
-      int found = 0;
+      u_int8_t num_lines = 0;
 
       while(getline(&line, &len, fd) != -1) {
         if(strstr(line, "aes")) {
           /* printf("FOUND %s", line); */
-          found = 1;
+	  cached_has_aesni = 1;
           break;
         }
+
+	if(++num_lines > 99)
+	  break; /* We giveup */
       }
 
       free(line);
       fclose(fd);
+
+      has_aesni_checked = 1;
       return(found);
     }
-  }
+  } else
+    return(cached_has_aesni);
 
   if (__get_cpuid(1, &eax, &ebx, &ecx, &edx) == 0)
   {