The following commit has been merged into the x86/urgent branch of tip:
Commit-ID: a664ec9158eeddd75121d39c9a0758016097fa96 Gitweb: https://git.kernel.org/tip/a664ec9158eeddd75121d39c9a0758016097fa96 Author: Rodrigo Branco bsdaemon@google.com AuthorDate: Tue, 03 Jan 2023 14:17:51 -06:00 Committer: Ingo Molnar mingo@kernel.org CommitterDate: Wed, 04 Jan 2023 11:25:32 +01:00
x86/bugs: Flush IBP in ib_prctl_set()
We missed the window between the TIF flag update and the next reschedule.
Signed-off-by: Rodrigo Branco bsdaemon@google.com Reviewed-by: Borislav Petkov (AMD) bp@alien8.de Signed-off-by: Ingo Molnar mingo@kernel.org Cc: stable@vger.kernel.org --- arch/x86/kernel/cpu/bugs.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index d970ddb..bca0bd8 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -1981,6 +1981,8 @@ static int ib_prctl_set(struct task_struct *task, unsigned long ctrl) if (ctrl == PR_SPEC_FORCE_DISABLE) task_set_spec_ib_force_disable(task); task_update_spec_tif(task); + if (task == current) + indirect_branch_prediction_barrier(); break; default: return -ERANGE;