From 941c411dd0ad5c6a066363426093c0cce6429b4e Mon Sep 17 00:00:00 2001
From: "msvensson@pilot.blaudden" <>
Date: Wed, 11 Apr 2007 22:07:24 +0200
Subject: Bug#21765 Illegal Instruction crash on pre-pentium when using YASSL 
 - Import patch with different method of detecting if machine has    cpuid
 instruction

---
 extra/yassl/taocrypt/src/misc.cpp | 37 +++++++++++++++++++++----------------
 1 file changed, 21 insertions(+), 16 deletions(-)

(limited to 'extra')

diff --git a/extra/yassl/taocrypt/src/misc.cpp b/extra/yassl/taocrypt/src/misc.cpp
index 726d9e630e6..402645c93fd 100644
--- a/extra/yassl/taocrypt/src/misc.cpp
+++ b/extra/yassl/taocrypt/src/misc.cpp
@@ -192,27 +192,32 @@ bool HaveCpuId()
     }
     return true;
 #else
-    typedef void (*SigHandler)(int);
-
-    SigHandler oldHandler = signal(SIGILL, SigIllHandler);
-    if (oldHandler == SIG_ERR)
-        return false;
-
-    bool result = true;
-    if (setjmp(s_env))
-        result = false;
-    else 
+    word32 eax, ebx;
         __asm__ __volatile
         (
-            // save ebx in case -fPIC is being used
-            "push %%ebx; mov $0, %%eax; cpuid; pop %%ebx"
-            : 
+        /* Put EFLAGS in eax and ebx */
+        "pushf;"
+        "pushf;"
+        "pop %0;"
+        "movl %0,%1;"
+
+        /* Flip the cpuid bit and store back in EFLAGS */
+        "xorl $0x200000,%0;"
+        "push %0;"
+        "popf;"
+
+        /* Read EFLAGS again */
+        "pushf;"
+        "pop %0;"
+        "popf"
+        : "=r" (eax), "=r" (ebx)
             :
-            : "%eax", "%ecx", "%edx" 
+        : "cc"
         );
 
-    signal(SIGILL, oldHandler);
-    return result;
+    if (eax == ebx)
+        return false;
+    return true;
 #endif
 }
 
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