x86/speculation: Rename SSBD update functions

During context switch, the SSBD bit in SPEC_CTRL MSR is updated according
to changes of the TIF_SSBD flag in the current and next running task.

Currently, only the bit controlling speculative store bypass disable in
SPEC_CTRL MSR is updated and the related update functions all have
"speculative_store" or "ssb" in their names.

For enhanced mitigation control other bits in SPEC_CTRL MSR need to be
updated as well, which makes the SSB names inadequate.

Rename the "speculative_store*" functions to a more generic name. No
functional change.

Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Casey Schaufler <casey.schaufler@intel.com>
Cc: Asit Mallick <asit.k.mallick@intel.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Jon Masters <jcm@redhat.com>
Cc: Waiman Long <longman9394@gmail.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Dave Stewart <david.c.stewart@intel.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20181125185004.058866968@linutronix.de
CVE-2017-5715

(cherry picked from commit 26c4d75b234040c11728a8acb796b3a85ba7507c)
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Acked-by: Juerg Haefliger <juergh@canonical.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

diff --git a/arch/x86/include/asm/spec-ctrl.h b/arch/x86/include/asm/spec-ctrl.h
index ae7c2c5cd7f0e2e9f2becb438a1366461f5725c6..8e2f8411c7a761db4c22b534ae603543e5285fe6 100644 (file)
--- a/arch/x86/include/asm/spec-ctrl.h
+++ b/arch/x86/include/asm/spec-ctrl.h
@@ -70,11 +70,11 @@ extern void speculative_store_bypass_ht_init(void);
 static inline void speculative_store_bypass_ht_init(void) { }
 #endif
 
-extern void speculative_store_bypass_update(unsigned long tif);
+extern void speculation_ctrl_update(unsigned long tif);
 
-static inline void speculative_store_bypass_update_current(void)
+static inline void speculation_ctrl_update_current(void)
 {
-       speculative_store_bypass_update(current_thread_info()->flags);
+       speculation_ctrl_update(current_thread_info()->flags);
 }
 
 #endif

diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index feaf50c33001cd6db63d2aa9838e18fece98a387..d68feca917e9a5efdcf66760102601e3e1d6f2fd 100644 (file)
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -199,7 +199,7 @@ x86_virt_spec_ctrl(u64 guest_spec_ctrl, u64 guest_virt_spec_ctrl, bool setguest)
                tif = setguest ? ssbd_spec_ctrl_to_tif(guestval) :
                                 ssbd_spec_ctrl_to_tif(hostval);
 
-               speculative_store_bypass_update(tif);
+               speculation_ctrl_update(tif);
        }
 }
 EXPORT_SYMBOL_GPL(x86_virt_spec_ctrl);
@@ -629,7 +629,7 @@ static int ssb_prctl_set(struct task_struct *task, unsigned long ctrl)
         * mitigation until it is next scheduled.
         */
        if (task == current && update)
-               speculative_store_bypass_update_current();
+               speculation_ctrl_update_current();
 
        return 0;
 }

diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index a412ca16175c75a3d694124f0a0e52843c931010..e6025be040999b5e126aa020e9fdbc5edf9f2b7a 100644 (file)
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -398,27 +398,27 @@ static __always_inline void amd_set_ssb_virt_state(unsigned long tifn)
        wrmsrl(MSR_AMD64_VIRT_SPEC_CTRL, ssbd_tif_to_spec_ctrl(tifn));
 }
 
-static __always_inline void intel_set_ssb_state(unsigned long tifn)
+static __always_inline void spec_ctrl_update_msr(unsigned long tifn)
 {
        u64 msr = x86_spec_ctrl_base | ssbd_tif_to_spec_ctrl(tifn);
 
        wrmsrl(MSR_IA32_SPEC_CTRL, msr);
 }
 
-static __always_inline void __speculative_store_bypass_update(unsigned long tifn)
+static __always_inline void __speculation_ctrl_update(unsigned long tifn)
 {
        if (static_cpu_has(X86_FEATURE_VIRT_SSBD))
                amd_set_ssb_virt_state(tifn);
        else if (static_cpu_has(X86_FEATURE_LS_CFG_SSBD))
                amd_set_core_ssb_state(tifn);
        else
-               intel_set_ssb_state(tifn);
+               spec_ctrl_update_msr(tifn);
 }
 
-void speculative_store_bypass_update(unsigned long tif)
+void speculation_ctrl_update(unsigned long tif)
 {
        preempt_disable();
-       __speculative_store_bypass_update(tif);
+       __speculation_ctrl_update(tif);
        preempt_enable();
 }
 
@@ -455,7 +455,7 @@ void __switch_to_xtra(struct task_struct *prev_p, struct task_struct *next_p,
                set_cpuid_faulting(!!(tifn & _TIF_NOCPUID));
 
        if ((tifp ^ tifn) & _TIF_SSBD)
-               __speculative_store_bypass_update(tifn);
+               __speculation_ctrl_update(tifn);
 }
 
 /*