diff mbox series

[tip:,x86/urgent] x86/bugs: Flush IBP in ib_prctl_set()

Message ID 167283353750.4906.14334038214138785293.tip-bot2@tip-bot2
State New
Headers
Series [tip:,x86/urgent] x86/bugs: Flush IBP in ib_prctl_set() |

Commit Message

tip-bot2 for Thomas Gleixner Jan. 4, 2023, 11:58 a.m. UTC 
  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 mbox series

Patch

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;