[PATCH 3.16 39/86] x86/speculation: Rename SSBD update functions

Ben Hutchings
2019-05-16T16:01:21Z

From: Thomas Gleixner <tglx@linutronix.de>

commit 26c4d75b234040c11728a8acb796b3a85ba7507c upstream.

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>
Link: https://lkml.kernel.org/r/20181125185004.058866968@linutronix.de
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
arch/x86/include/asm/spec-ctrl.h | 6 +++---
arch/x86/kernel/cpu/bugs.c | 4 ++--
arch/x86/kernel/process.c | 12 ++++++------
3 files changed, 11 insertions(+), 11 deletions(-)

--- 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_
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
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -255,7 +255,7 @@ x86_virt_spec_ctrl(u64 guest_spec_ctrl,
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);
@@ -692,7 +692,7 @@ static int ssb_prctl_set(struct task_str
* mitigation until it is next scheduled.
*/
if (task == current && update)
- speculative_store_bypass_update_current();
+ speculation_ctrl_update_current();

return 0;
}
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -335,27 +335,27 @@ static __always_inline void amd_set_ssb_
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();
}

@@ -393,7 +393,7 @@ void __switch_to_xtra(struct task_struct
}

if ((tifp ^ tifn) & _TIF_SSBD)
- __speculative_store_bypass_update(tifn);
+ __speculation_ctrl_update(tifn);
}

/*