x86/speculation: Rework speculative_store_bypass_update()

commit 0270be3e34efb05a88bc4c422572ece038ef3608 upstream

The upcoming support for the virtual SPEC_CTRL MSR on AMD needs to reuse
speculative_store_bypass_update() to avoid code duplication. Add an
argument for supplying a thread info (TIF) value and create a wrapper
speculative_store_bypass_update_current() which is used at the existing
call site.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Srivatsa S. Bhat <srivatsa@csail.mit.edu>
Reviewed-by: Matt Helsley (VMware) <matt.helsley@gmail.com>
Reviewed-by: Alexey Makhalov <amakhalov@vmware.com>
Reviewed-by: Bo Gan <ganb@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/x86/include/asm/spec-ctrl.h b/arch/x86/include/asm/spec-ctrl.h
index 6e28740..82b6c5a 100644 (file)
--- a/arch/x86/include/asm/spec-ctrl.h
+++ b/arch/x86/include/asm/spec-ctrl.h
@@ -42,6 +42,11 @@ extern void speculative_store_bypass_ht_init(void);
 static inline void speculative_store_bypass_ht_init(void) { }
 #endif
 
-extern void speculative_store_bypass_update(void);
+extern void speculative_store_bypass_update(unsigned long tif);
+
+static inline void speculative_store_bypass_update_current(void)
+{
+       speculative_store_bypass_update(current_thread_info()->flags);
+}
 
 #endif

diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index 50ab206..1b29be9 100644 (file)
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -596,7 +596,7 @@ 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();
+               speculative_store_bypass_update_current();
 
        return 0;
 }

diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index eab9d0c..e18c879 100644 (file)
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -334,10 +334,10 @@ static __always_inline void __speculative_store_bypass_update(unsigned long tifn
                intel_set_ssb_state(tifn);
 }
 
-void speculative_store_bypass_update(void)
+void speculative_store_bypass_update(unsigned long tif)
 {
        preempt_disable();
-       __speculative_store_bypass_update(current_thread_info()->flags);
+       __speculative_store_bypass_update(tif);
        preempt_enable();
 }