base/SOURCES/glibc-rh841653-17.patch

commit 2702856bf45c82cf8e69f2064f5aa15c0ceb6359
Author: Andrew Senkevich <andrew.senkevich@intel.com>
Date:   Mon Dec 19 13:20:31 2016 +0300

    Disable TSX on some Haswell processors.
    
    Patch disables Intel TSX on some Haswell processors to avoid TSX
    on kernels that weren't updated with the latest microcode package
    (which disables broken feature by default).
    
        * sysdeps/x86/cpu-features.c (get_common_indeces): Add
        stepping identification.
        (init_cpu_features): Add handle of Haswell.

Index: glibc-2.17-c758a686/sysdeps/x86/cpu-features.c
===================================================================
--- glibc-2.17-c758a686.orig/sysdeps/x86/cpu-features.c
+++ glibc-2.17-c758a686/sysdeps/x86/cpu-features.c
@@ -21,7 +21,8 @@
 
 static inline void
 get_common_indeces (struct cpu_features *cpu_features,
-		    unsigned int *family, unsigned int *model)
+		    unsigned int *family, unsigned int *model,
+		    unsigned int *stepping)
 {
   unsigned int eax;
   __cpuid (1, eax, cpu_features->cpuid[COMMON_CPUID_INDEX_1].ebx,
@@ -30,6 +31,7 @@ get_common_indeces (struct cpu_features
   GLRO(dl_x86_cpu_features).cpuid[COMMON_CPUID_INDEX_1].eax = eax;
   *family = (eax >> 8) & 0x0f;
   *model = (eax >> 4) & 0x0f;
+  *stepping = eax & 0x0f;
 }
 
 static inline void
@@ -45,9 +47,11 @@ init_cpu_features (struct cpu_features *
   /* This spells out "GenuineIntel".  */
   if (ebx == 0x756e6547 && ecx == 0x6c65746e && edx == 0x49656e69)
     {
+      unsigned int stepping;
+
       kind = arch_kind_intel;
 
-      get_common_indeces (cpu_features, &family, &model);
+      get_common_indeces (cpu_features, &family, &model, &stepping);
 
       /* Intel processors prefer SSE instruction for memory/string
         routines if they are available.  */
@@ -128,6 +132,20 @@ init_cpu_features (struct cpu_features *
 		    | bit_Fast_Unaligned_Load
 		    | bit_Prefer_PMINUB_for_stringop);
 	      break;
+
+	    case 0x3f:
+	      /* Xeon E7 v3 with stepping >= 4 has working TSX.  */
+	      if (stepping >= 4)
+		break;
+	    case 0x3c:
+	    case 0x45:
+	    case 0x46:
+	      /* Disable Intel TSX on Haswell processors (except Xeon E7 v3
+		 with stepping >= 4) to avoid TSX on kernels that weren't
+		 updated with the latest microcode package (which disables
+		 broken feature by default).  */
+	      cpu_features->cpuid[COMMON_CPUID_INDEX_7].ebx &= ~(bit_RTM);
+	      break;
 	    }
 	}
 
@@ -148,9 +166,11 @@ init_cpu_features (struct cpu_features *
   /* This spells out "AuthenticAMD".  */
   else if (ebx == 0x68747541 && ecx == 0x444d4163 && edx == 0x69746e65)
     {
+      unsigned int stepping;
+
       kind = arch_kind_amd;
 
-      get_common_indeces (cpu_features, &family, &model);
+      get_common_indeces (cpu_features, &family, &model, &stepping);
 
       ecx = cpu_features->cpuid[COMMON_CPUID_INDEX_1].ecx;