From 3a4ee5951643ad1da28c8d36e89106f9c8c26309 Mon Sep 17 00:00:00 2001
From: Nikos Mavrogiannopoulos <nmav@redhat.com>
Date: Wed, 16 Mar 2016 10:00:17 +0100
Subject: x86-common: CPUID override will only work if CPU has already the
 capability present

This resolves test suite failure on CPUs with limited capabilities.
Reported by Andreas Metzler.
---
 lib/accelerated/x86/x86-common.c | 66 ++++++++++++++++++++++++++++++++++------
 1 file changed, 56 insertions(+), 10 deletions(-)

diff --git a/lib/accelerated/x86/x86-common.c b/lib/accelerated/x86/x86-common.c
index 18e3710362..6c0e7b66a2 100644
--- a/lib/accelerated/x86/x86-common.c
+++ b/lib/accelerated/x86/x86-common.c
@@ -76,18 +76,40 @@ unsigned int _gnutls_x86_cpuid_s[3];
 
 static void capabilities_to_intel_cpuid(unsigned capabilities)
 {
+	unsigned a,b,c,t;
+
 	memset(_gnutls_x86_cpuid_s, 0, sizeof(_gnutls_x86_cpuid_s));
+
 	if (capabilities & EMPTY_SET) {
 		return;
 	}
+
+	gnutls_cpuid(1, &t, &a, &b, &c);
+
 	if (capabilities & INTEL_AES_NI) {
-		_gnutls_x86_cpuid_s[1] |= bit_AES;
+		if (b & bit_AES) {
+			_gnutls_x86_cpuid_s[1] |= bit_AES;
+		} else {
+			_gnutls_debug_log
+			    ("AESNI acceleration requested but not available\n");
+		}
 	}
+
 	if (capabilities & INTEL_SSSE3) {
-		_gnutls_x86_cpuid_s[1] |= bit_SSSE3;
+		if (b & bit_SSSE3) {
+			_gnutls_x86_cpuid_s[1] |= bit_SSSE3;
+		} else {
+			_gnutls_debug_log
+			    ("SSSE3 acceleration requested but not available\n");
+		}
 	}
-	if (capabilities & INTEL_PCLMUL) { /* ecx */
-		_gnutls_x86_cpuid_s[1] |= bit_PCLMUL;
+	if (capabilities & INTEL_PCLMUL) {
+		if (b & bit_PCLMUL) {
+			_gnutls_x86_cpuid_s[1] |= bit_PCLMUL;
+		} else {
+			_gnutls_debug_log
+			    ("PCLMUL acceleration requested but not available\n");
+		}
 	}
 }
 
@@ -111,19 +133,43 @@ static unsigned check_pclmul(void)
 #ifdef ENABLE_PADLOCK
 static unsigned capabilities_to_via_edx(unsigned capabilities)
 {
+	unsigned a,b,c,t;
+
 	memset(_gnutls_x86_cpuid_s, 0, sizeof(_gnutls_x86_cpuid_s));
+
 	if (capabilities & EMPTY_SET) {
 		return 0;
 	}
-	if (capabilities & VIA_PADLOCK) { /* edx */
-		_gnutls_x86_cpuid_s[2] |= via_bit_PADLOCK;
+
+	gnutls_cpuid(1, &t, &a, &b, &c);
+
+	if (capabilities & VIA_PADLOCK) {
+		if (c & via_bit_PADLOCK) {
+			_gnutls_x86_cpuid_s[2] |= via_bit_PADLOCK;
+		} else {
+			_gnutls_debug_log
+			    ("Padlock acceleration requested but not available\n");
+		}
 	}
-	if (capabilities & VIA_PADLOCK_PHE) { /* edx */
-		_gnutls_x86_cpuid_s[2] |= via_bit_PADLOCK_PHE;
+
+	if (capabilities & VIA_PADLOCK_PHE) {
+		if (c & via_bit_PADLOCK_PHE) {
+			_gnutls_x86_cpuid_s[2] |= via_bit_PADLOCK_PHE;
+		} else {
+			_gnutls_debug_log
+			    ("Padlock-PHE acceleration requested but not available\n");
+		}
 	}
-	if (capabilities & VIA_PADLOCK_PHE_SHA512) { /* edx */
-		_gnutls_x86_cpuid_s[2] |= via_bit_PADLOCK_PHE_SHA512;
+
+	if (capabilities & VIA_PADLOCK_PHE_SHA512) {
+		if (c & via_bit_PADLOCK_PHE_SHA512) {
+			_gnutls_x86_cpuid_s[2] |= via_bit_PADLOCK_PHE_SHA512;
+		} else {
+			_gnutls_debug_log
+			    ("Padlock-PHE-SHA512 acceleration requested but not available\n");
+		}
 	}
+
 	return _gnutls_x86_cpuid_s[2];
 }
 
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