[PATCH 4.4 091/107] x86/speculation: Rework speculative_store_bypass_update()
From: Greg Kroah-Hartman
Date: Mon Jul 23 2018 - 08:49:51 EST
4.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
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@xxxxxxxxxxxxx>
Reviewed-by: Borislav Petkov <bp@xxxxxxx>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Signed-off-by: David Woodhouse <dwmw@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Srivatsa S. Bhat <srivatsa@xxxxxxxxxxxxx>
Reviewed-by: Matt Helsley (VMware) <matt.helsley@xxxxxxxxx>
Reviewed-by: Alexey Makhalov <amakhalov@xxxxxxxxxx>
Reviewed-by: Bo Gan <ganb@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/include/asm/spec-ctrl.h | 7 ++++++-
arch/x86/kernel/cpu/bugs.c | 2 +-
arch/x86/kernel/process.c | 4 ++--
3 files changed, 9 insertions(+), 4 deletions(-)
--- 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_
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
--- 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_str
* mitigation until it is next scheduled.
*/
if (task == current && update)
- speculative_store_bypass_update();
+ speculative_store_bypass_update_current();
return 0;
}
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -334,10 +334,10 @@ static __always_inline void __speculativ
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();
}