[gnutls-devel] gnutls 3.4.10 testsuite error on amd64 (SSSE3 cipher tests failed)

[Nikos Mavrogiannopoulos]

On Wed, Mar 16, 2016 at 5:44 PM, Andreas Metzler <ametzler at bebt.de> wrote:
> On 2016-03-16 Nikos Mavrogiannopoulos <nmav at gnutls.org> wrote:
>> On Tue, Mar 15, 2016 at 7:44 PM, Andreas Metzler <ametzler at bebt.de> wrote:
>>> ./test-hash-large failed on one of Debian's autobuilders (AMD Opteron
>>> 23xx):
>>> (sid_amd64-dchroot)ametzler at barriere:~/GNUTLS/gnutls28-3.4.10/tests/slow$ ./test-hash-large --verbose --debug  7777
>>> Illegal instruction
>>> SSSE3 cipher tests failed
>
>> Thanks. It seems that the CPU has no SSSE3 and the test overrides the
>> cpuid to force SSSE3 usage. I'm wondering whether it is better to
>> change the test to detect cpu capabilities via /proc/cpuinfo, or
>> remove the ability to override a CPU flag if the CPU doesn't support
>> it.
>
> Hello,
>
> I thought that GNUTLS_CPUID_OVERRIDE was not supposed to enable
> unavailable features: "Note that CPU detection cannot be overriden,
> i.e., VIA options cannot be enabled on an Intel CPU."

Correct, and the statement is in a way precise :) Only VIA options
cannot be enabled on an Intel CPU. Let's fix that then. Does the
attached patch solves the issue in the system without ssse3?

regards,
Nikos
-------------- next part --------------
diff --git a/lib/accelerated/x86/x86-common.c b/lib/accelerated/x86/x86-common.c
index 18e3710..5cc8c00 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) { /* ecx */
+			_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) { /* edx */
+			_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];
 }