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authorThomas Gleixner <tglx@linutronix.de>2018-11-25 19:33:53 +0100
committerThomas Gleixner <tglx@linutronix.de>2018-11-28 11:57:13 +0100
commit9137bb27e60e554dab694eafa4cca241fa3a694f (patch)
tree210ca811947bb90452df9f8a3752402e6252a530 /Documentation/userspace-api
parent6893a959d7fdebbab5f5aa112c277d5a44435ba1 (diff)
downloadlinux-stericsson-9137bb27e60e554dab694eafa4cca241fa3a694f.tar.gz
x86/speculation: Add prctl() control for indirect branch speculation
Add the PR_SPEC_INDIRECT_BRANCH option for the PR_GET_SPECULATION_CTRL and PR_SET_SPECULATION_CTRL prctls to allow fine grained per task control of indirect branch speculation via STIBP and IBPB. Invocations: Check indirect branch speculation status with - prctl(PR_GET_SPECULATION_CTRL, PR_SPEC_INDIRECT_BRANCH, 0, 0, 0); Enable indirect branch speculation with - prctl(PR_SET_SPECULATION_CTRL, PR_SPEC_INDIRECT_BRANCH, PR_SPEC_ENABLE, 0, 0); Disable indirect branch speculation with - prctl(PR_SET_SPECULATION_CTRL, PR_SPEC_INDIRECT_BRANCH, PR_SPEC_DISABLE, 0, 0); Force disable indirect branch speculation with - prctl(PR_SET_SPECULATION_CTRL, PR_SPEC_INDIRECT_BRANCH, PR_SPEC_FORCE_DISABLE, 0, 0); See Documentation/userspace-api/spec_ctrl.rst. 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/20181125185005.866780996@linutronix.de
Diffstat (limited to 'Documentation/userspace-api')
-rw-r--r--Documentation/userspace-api/spec_ctrl.rst9
1 files changed, 9 insertions, 0 deletions
diff --git a/Documentation/userspace-api/spec_ctrl.rst b/Documentation/userspace-api/spec_ctrl.rst
index 32f3d55c54b7..c4dbe6f7cdae 100644
--- a/Documentation/userspace-api/spec_ctrl.rst
+++ b/Documentation/userspace-api/spec_ctrl.rst
@@ -92,3 +92,12 @@ Speculation misfeature controls
* prctl(PR_SET_SPECULATION_CTRL, PR_SPEC_STORE_BYPASS, PR_SPEC_ENABLE, 0, 0);
* prctl(PR_SET_SPECULATION_CTRL, PR_SPEC_STORE_BYPASS, PR_SPEC_DISABLE, 0, 0);
* prctl(PR_SET_SPECULATION_CTRL, PR_SPEC_STORE_BYPASS, PR_SPEC_FORCE_DISABLE, 0, 0);
+
+- PR_SPEC_INDIR_BRANCH: Indirect Branch Speculation in User Processes
+ (Mitigate Spectre V2 style attacks against user processes)
+
+ Invocations:
+ * prctl(PR_GET_SPECULATION_CTRL, PR_SPEC_INDIRECT_BRANCH, 0, 0, 0);
+ * prctl(PR_SET_SPECULATION_CTRL, PR_SPEC_INDIRECT_BRANCH, PR_SPEC_ENABLE, 0, 0);
+ * prctl(PR_SET_SPECULATION_CTRL, PR_SPEC_INDIRECT_BRANCH, PR_SPEC_DISABLE, 0, 0);
+ * prctl(PR_SET_SPECULATION_CTRL, PR_SPEC_INDIRECT_BRANCH, PR_SPEC_FORCE_DISABLE, 0, 0);