linux-kernel - [PATCH RFC] x86: fix confusing name of /proc/cpuinfo "ht" flag

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:	Wed, 11 Nov 2009 21:34:34 +0100
From:	Bartlomiej Zolnierkiewicz <bzolnier@...il.com>
To:	x86@...nel.org
Cc:	linux-kernel@...r.kernel.org, Dave Jones <davej@...emonkey.org.uk>
Subject: [PATCH RFC] x86: fix confusing name of /proc/cpuinfo "ht" flag


"ht" flag indicates only ability to detect siblings not HT presence itself.

Inspired by:
http://www.codemonkey.org.uk/2009/11/10/common-hyperthreading-misconception/

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@...il.com>
---
It could be that there are some user-space programs depending on "ht"
flag so the patch is marked as RFC..

 arch/x86/include/asm/cpufeature.h |    4 ++--
 arch/x86/kernel/cpu/capflags.c    |    2 +-
 arch/x86/kernel/cpu/common.c      |    2 +-
 3 files changed, 4 insertions(+), 4 deletions(-)

Index: b/arch/x86/include/asm/cpufeature.h
===================================================================
--- a/arch/x86/include/asm/cpufeature.h
+++ b/arch/x86/include/asm/cpufeature.h
@@ -42,7 +42,7 @@
 #define X86_FEATURE_XMM		(0*32+25) /* "sse" */
 #define X86_FEATURE_XMM2	(0*32+26) /* "sse2" */
 #define X86_FEATURE_SELFSNOOP	(0*32+27) /* "ss" CPU self snoop */
-#define X86_FEATURE_HT		(0*32+28) /* Hyper-Threading */
+#define X86_FEATURE_HT_DETECTION (0*32+28) /* Hyper-Threading detection */
 #define X86_FEATURE_ACC		(0*32+29) /* "tm" Automatic clock control */
 #define X86_FEATURE_IA64	(0*32+30) /* IA-64 processor */
 #define X86_FEATURE_PBE		(0*32+31) /* Pending Break Enable */
@@ -220,7 +220,7 @@ extern const char * const x86_power_flag
 #define cpu_has_xmm2		boot_cpu_has(X86_FEATURE_XMM2)
 #define cpu_has_xmm3		boot_cpu_has(X86_FEATURE_XMM3)
 #define cpu_has_aes		boot_cpu_has(X86_FEATURE_AES)
-#define cpu_has_ht		boot_cpu_has(X86_FEATURE_HT)
+#define cpu_has_ht_detection	boot_cpu_has(X86_FEATURE_HT_DETECTION)
 #define cpu_has_mp		boot_cpu_has(X86_FEATURE_MP)
 #define cpu_has_nx		boot_cpu_has(X86_FEATURE_NX)
 #define cpu_has_k6_mtrr		boot_cpu_has(X86_FEATURE_K6_MTRR)
Index: b/arch/x86/kernel/cpu/capflags.c
===================================================================
--- a/arch/x86/kernel/cpu/capflags.c
+++ b/arch/x86/kernel/cpu/capflags.c
@@ -27,7 +27,7 @@ const char * const x86_cap_flags[NCAPINT
 	[X86_FEATURE_XMM]                = "sse",
 	[X86_FEATURE_XMM2]               = "sse2",
 	[X86_FEATURE_SELFSNOOP]          = "ss",
-	[X86_FEATURE_HT]                 = "ht",
+	[X86_FEATURE_HT_DETECTION]       = "ht_detection",
 	[X86_FEATURE_ACC]                = "tm",
 	[X86_FEATURE_IA64]               = "ia64",
 	[X86_FEATURE_PBE]                = "pbe",
Index: b/arch/x86/kernel/cpu/common.c
===================================================================
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -433,7 +433,7 @@ void __cpuinit detect_ht(struct cpuinfo_
 	u32 eax, ebx, ecx, edx;
 	int index_msb, core_bits;
 
-	if (!cpu_has(c, X86_FEATURE_HT))
+	if (!cpu_has(c, X86_FEATURE_HT_DETECTION))
 		return;
 
 	if (cpu_has(c, X86_FEATURE_CMP_LEGACY))
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/