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authorPawan Gupta <pawan.kumar.gupta@linux.intel.com>2019-10-23 11:01:53 +0200
committerThomas Gleixner <tglx@linutronix.de>2019-10-28 08:36:58 +0100
commit95c5824f75f3ba4c9e8e5a4b1a623c95390ac266 (patch)
tree435c7815c83cb35214bb13686e47422b66b25ef7 /arch/x86/kernel/cpu/intel.c
parent286836a70433fb64131d2590f4bf512097c255e1 (diff)
x86/cpu: Add a "tsx=" cmdline option with TSX disabled by default
Add a kernel cmdline parameter "tsx" to control the Transactional Synchronization Extensions (TSX) feature. On CPUs that support TSX control, use "tsx=on|off" to enable or disable TSX. Not specifying this option is equivalent to "tsx=off". This is because on certain processors TSX may be used as a part of a speculative side channel attack. Carve out the TSX controlling functionality into a separate compilation unit because TSX is a CPU feature while the TSX async abort control machinery will go to cpu/bugs.c. [ bp: - Massage, shorten and clear the arg buffer. - Clarifications of the tsx= possible options - Josh. - Expand on TSX_CTRL availability - Pawan. ] Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Diffstat (limited to 'arch/x86/kernel/cpu/intel.c')
-rw-r--r--arch/x86/kernel/cpu/intel.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index c2fdc00df163..11d5c5950e2d 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -762,6 +762,11 @@ static void init_intel(struct cpuinfo_x86 *c)
detect_tme(c);
init_intel_misc_features(c);
+
+ if (tsx_ctrl_state == TSX_CTRL_ENABLE)
+ tsx_enable();
+ if (tsx_ctrl_state == TSX_CTRL_DISABLE)
+ tsx_disable();
}
#ifdef CONFIG_X86_32