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@xxxxxxxxxx> Suggested-by: Dave Hansen <dave.hansen@xxxxxxxxx> Signed-off-by: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx> --- Documentation/admin-guide/kernel-parameters.txt | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 27ec49af1bf2..f7f06049353c 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -7247,7 +7247,9 @@ 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 -- 2.43.0
