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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.
This commit is contained in:
Andrew Senkevich 2016-12-19 13:20:31 +03:00
parent 7051390094
commit 2702856bf4
2 changed files with 29 additions and 6 deletions
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6
ChangeLog
View File

@ -1,3 +1,9 @@
2016-12-19 Andrew Senkevich <andrew.senkevich@intel.com>
* sysdeps/x86/cpu-features.c (get_common_indeces): Add
stepping identification.
(init_cpu_features): Add handle of Haswell.
2016-11-25 Jim Meyering <meyering@fb.com>
[BZ #20386]

29
sysdeps/x86/cpu-features.c
View File

@ -22,7 +22,7 @@
static void
get_common_indeces (struct cpu_features *cpu_features,
unsigned int *family, unsigned int *model,
unsigned int *extended_model)
unsigned int *extended_model, unsigned int *stepping)
{
if (family)
{
@ -34,6 +34,7 @@ get_common_indeces (struct cpu_features *cpu_features,
*family = (eax >> 8) & 0x0f;
*model = (eax >> 4) & 0x0f;
*extended_model = (eax >> 12) & 0xf0;
*stepping = eax & 0x0f;
if (*family == 0x0f)
{
*family += (eax >> 20) & 0xff;
@ -116,11 +117,12 @@ init_cpu_features (struct cpu_features *cpu_features)
/* This spells out "GenuineIntel". */
if (ebx == 0x756e6547 && ecx == 0x6c65746e && edx == 0x49656e69)
{
unsigned int extended_model;
unsigned int extended_model, stepping;
kind = arch_kind_intel;
get_common_indeces (cpu_features, &family, &model, &extended_model);
get_common_indeces (cpu_features, &family, &model, &extended_model,
&stepping);
if (family == 0x06)
{
@ -201,6 +203,20 @@ init_cpu_features (struct cpu_features *cpu_features)
| bit_arch_Fast_Unaligned_Copy
| bit_arch_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_cpu_RTM);
break;
}
}
@ -227,11 +243,12 @@ init_cpu_features (struct cpu_features *cpu_features)
/* This spells out "AuthenticAMD". */
else if (ebx == 0x68747541 && ecx == 0x444d4163 && edx == 0x69746e65)
{
unsigned int extended_model;
unsigned int extended_model, stepping;
kind = arch_kind_amd;
get_common_indeces (cpu_features, &family, &model, &extended_model);
get_common_indeces (cpu_features, &family, &model, &extended_model,
&stepping);
ecx = cpu_features->cpuid[COMMON_CPUID_INDEX_1].ecx;
@ -268,7 +285,7 @@ init_cpu_features (struct cpu_features *cpu_features)
else
{
kind = arch_kind_other;
get_common_indeces (cpu_features, NULL, NULL, NULL);
get_common_indeces (cpu_features, NULL, NULL, NULL, NULL);
}
/* Support i586 if CX8 is available. */