[tip:,sched/core] context_tracking: Fix noinstr vs KASAN

Message ID 167361306437.4906.1206766567988276870.tip-bot2@tip-bot2
State New
Headers
Series [tip:,sched/core] context_tracking: Fix noinstr vs KASAN |

Commit Message

tip-bot2 for Thomas Gleixner Jan. 13, 2023, 12:31 p.m. UTC
  The following commit has been merged into the sched/core branch of tip:

Commit-ID:     0e26e1de0032779e43929174339429c16307a299
Gitweb:        https://git.kernel.org/tip/0e26e1de0032779e43929174339429c16307a299
Author:        Peter Zijlstra <peterz@infradead.org>
AuthorDate:    Thu, 12 Jan 2023 20:44:05 +01:00
Committer:     Ingo Molnar <mingo@kernel.org>
CommitterDate: Fri, 13 Jan 2023 11:48:18 +01:00

context_tracking: Fix noinstr vs KASAN

Low level noinstr context-tracking code is calling out to instrumented
code on KASAN:

  vmlinux.o: warning: objtool: __ct_user_enter+0x72: call to __kasan_check_write() leaves .noinstr.text section
  vmlinux.o: warning: objtool: __ct_user_exit+0x47: call to __kasan_check_write() leaves .noinstr.text section

Use even lower level atomic methods to avoid the instrumentation.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20230112195542.458034262@infradead.org
---
 kernel/context_tracking.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)
  

Patch

diff --git a/kernel/context_tracking.c b/kernel/context_tracking.c
index 77978e3..a09f1c1 100644
--- a/kernel/context_tracking.c
+++ b/kernel/context_tracking.c
@@ -510,7 +510,7 @@  void noinstr __ct_user_enter(enum ctx_state state)
 			 * In this we case we don't care about any concurrency/ordering.
 			 */
 			if (!IS_ENABLED(CONFIG_CONTEXT_TRACKING_IDLE))
-				atomic_set(&ct->state, state);
+				arch_atomic_set(&ct->state, state);
 		} else {
 			/*
 			 * Even if context tracking is disabled on this CPU, because it's outside
@@ -527,7 +527,7 @@  void noinstr __ct_user_enter(enum ctx_state state)
 			 */
 			if (!IS_ENABLED(CONFIG_CONTEXT_TRACKING_IDLE)) {
 				/* Tracking for vtime only, no concurrent RCU EQS accounting */
-				atomic_set(&ct->state, state);
+				arch_atomic_set(&ct->state, state);
 			} else {
 				/*
 				 * Tracking for vtime and RCU EQS. Make sure we don't race
@@ -535,7 +535,7 @@  void noinstr __ct_user_enter(enum ctx_state state)
 				 * RCU only requires RCU_DYNTICKS_IDX increments to be fully
 				 * ordered.
 				 */
-				atomic_add(state, &ct->state);
+				arch_atomic_add(state, &ct->state);
 			}
 		}
 	}
@@ -630,12 +630,12 @@  void noinstr __ct_user_exit(enum ctx_state state)
 			 * In this we case we don't care about any concurrency/ordering.
 			 */
 			if (!IS_ENABLED(CONFIG_CONTEXT_TRACKING_IDLE))
-				atomic_set(&ct->state, CONTEXT_KERNEL);
+				arch_atomic_set(&ct->state, CONTEXT_KERNEL);
 
 		} else {
 			if (!IS_ENABLED(CONFIG_CONTEXT_TRACKING_IDLE)) {
 				/* Tracking for vtime only, no concurrent RCU EQS accounting */
-				atomic_set(&ct->state, CONTEXT_KERNEL);
+				arch_atomic_set(&ct->state, CONTEXT_KERNEL);
 			} else {
 				/*
 				 * Tracking for vtime and RCU EQS. Make sure we don't race
@@ -643,7 +643,7 @@  void noinstr __ct_user_exit(enum ctx_state state)
 				 * RCU only requires RCU_DYNTICKS_IDX increments to be fully
 				 * ordered.
 				 */
-				atomic_sub(state, &ct->state);
+				arch_atomic_sub(state, &ct->state);
 			}
 		}
 	}