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@xxxxxxxxxxxxx>
AuthorDate: Thu, 12 Jan 2023 20:44:05 +01:00
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
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@xxxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20230112195542.458034262@xxxxxxxxxxxxx
---
kernel/context_tracking.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)
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);
}
}
}
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