Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86/pti update from Thomas Gleixner:
 "Just a single change from the anti-performance departement:

   - Add a new PR_SPEC_DISABLE_NOEXEC option which allows to apply the
     speculation protections on a process without inheriting the state
     on exec.

     This remedies a situation where a Java-launcher has speculation
     protections enabled because that's the default for JVMs which
     causes the launched regular harmless processes to inherit the
     protection state which results in unintended performance
     degradation"

* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/speculation: Add PR_SPEC_DISABLE_NOEXEC

1 files changed, 5 insertions, 0 deletions

diff --git a/include/linux/sched.h b/include/linux/sched.h
index f9b43c989577..89ddece0b003 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1453,6 +1453,7 @@ static inline bool is_percpu_thread(void)
 #define PFA_SPEC_SSB_FORCE_DISABLE      4       /* Speculative Store Bypass force disabled*/
 #define PFA_SPEC_IB_DISABLE             5       /* Indirect branch speculation restricted */
 #define PFA_SPEC_IB_FORCE_DISABLE       6       /* Indirect branch speculation permanently restricted */
+#define PFA_SPEC_SSB_NOEXEC             7       /* Speculative Store Bypass clear on execve() */
 
 #define TASK_PFA_TEST(name, func)                                       \
         static inline bool task_##func(struct task_struct *p)           \
@@ -1481,6 +1482,10 @@ TASK_PFA_TEST(SPEC_SSB_DISABLE, spec_ssb_disable)
 TASK_PFA_SET(SPEC_SSB_DISABLE, spec_ssb_disable)
 TASK_PFA_CLEAR(SPEC_SSB_DISABLE, spec_ssb_disable)
 
+TASK_PFA_TEST(SPEC_SSB_NOEXEC, spec_ssb_noexec)
+TASK_PFA_SET(SPEC_SSB_NOEXEC, spec_ssb_noexec)
+TASK_PFA_CLEAR(SPEC_SSB_NOEXEC, spec_ssb_noexec)
+
 TASK_PFA_TEST(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable)
 TASK_PFA_SET(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable)