diff mbox series

[v3,10/12] x86/vsyscall: Document the fact that vsyscall=emulate disables LASS

Message ID 20230609183632.48706-11-alexander.shishkin@linux.intel.com
State New
Headers
Series Enable Linear Address Space Separation support |

Commit Message

Alexander Shishkin June 9, 2023, 6:36 p.m. UTC 
  Since EMULATE mode of vsyscall disables LASS, because fixing the LASS
violations during the EMULATE mode would need complex instruction
decoding, document this fact in kernel-parameters.txt.

Cc: Andy Lutomirski <luto@kernel.org>
Suggested-by: Dave Hansen <dave.hansen@intel.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
---
 Documentation/admin-guide/kernel-parameters.txt | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 9e5bab29685f..efed9193107e 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -6850,7 +6850,9 @@ 
 
 			emulate     Vsyscalls turn into traps and are emulated
 			            reasonably safely.  The vsyscall page is
-				    readable.
+				    readable.  This also disables the LASS
+				    feature to allow userspace to poke around
+				    the vsyscall page.
 
 			xonly       [default] Vsyscalls turn into traps and are
 			            emulated reasonably safely.  The vsyscall