From: Josh Poimboeuf jpoimboe@kernel.org
[ Upstream commit f87d28673b71b35b248231a2086f9404afbb7f28 ]
__enter_from_user_mode() is triggering noinstr warnings with CONFIG_DEBUG_PREEMPT due to its call of preempt_count_add() via ct_state().
The preemption disable isn't needed as interrupts are already disabled. And the context_tracking_enabled() check in ct_state() also isn't needed as that's already being done by the CT_WARN_ON().
Just use __ct_state() instead.
Fixes the following warnings:
vmlinux.o: warning: objtool: enter_from_user_mode+0xba: call to preempt_count_add() leaves .noinstr.text section vmlinux.o: warning: objtool: syscall_enter_from_user_mode+0xf9: call to preempt_count_add() leaves .noinstr.text section vmlinux.o: warning: objtool: syscall_enter_from_user_mode_prepare+0xc7: call to preempt_count_add() leaves .noinstr.text section vmlinux.o: warning: objtool: irqentry_enter_from_user_mode+0xba: call to preempt_count_add() leaves .noinstr.text section
Fixes: 171476775d32 ("context_tracking: Convert state to atomic_t") Signed-off-by: Josh Poimboeuf jpoimboe@kernel.org Signed-off-by: Thomas Gleixner tglx@linutronix.de Link: https://lore.kernel.org/r/d8955fa6d68dc955dda19baf13ae014ae27926f5.167736969... Signed-off-by: Sasha Levin sashal@kernel.org --- include/linux/context_tracking.h | 1 + include/linux/context_tracking_state.h | 2 ++ kernel/entry/common.c | 2 +- 3 files changed, 4 insertions(+), 1 deletion(-)
diff --git a/include/linux/context_tracking.h b/include/linux/context_tracking.h index d4afa8508a806..3a7909ed54980 100644 --- a/include/linux/context_tracking.h +++ b/include/linux/context_tracking.h @@ -96,6 +96,7 @@ static inline void user_exit_irqoff(void) { } static inline int exception_enter(void) { return 0; } static inline void exception_exit(enum ctx_state prev_ctx) { } static inline int ct_state(void) { return -1; } +static inline int __ct_state(void) { return -1; } static __always_inline bool context_tracking_guest_enter(void) { return false; } static inline void context_tracking_guest_exit(void) { } #define CT_WARN_ON(cond) do { } while (0) diff --git a/include/linux/context_tracking_state.h b/include/linux/context_tracking_state.h index 4a4d56f771802..fdd537ea513ff 100644 --- a/include/linux/context_tracking_state.h +++ b/include/linux/context_tracking_state.h @@ -46,7 +46,9 @@ struct context_tracking {
#ifdef CONFIG_CONTEXT_TRACKING DECLARE_PER_CPU(struct context_tracking, context_tracking); +#endif
+#ifdef CONFIG_CONTEXT_TRACKING_USER static __always_inline int __ct_state(void) { return arch_atomic_read(this_cpu_ptr(&context_tracking.state)) & CT_STATE_MASK; diff --git a/kernel/entry/common.c b/kernel/entry/common.c index 846add8394c41..1314894d2efad 100644 --- a/kernel/entry/common.c +++ b/kernel/entry/common.c @@ -21,7 +21,7 @@ static __always_inline void __enter_from_user_mode(struct pt_regs *regs) arch_enter_from_user_mode(regs); lockdep_hardirqs_off(CALLER_ADDR0);
- CT_WARN_ON(ct_state() != CONTEXT_USER); + CT_WARN_ON(__ct_state() != CONTEXT_USER); user_exit_irqoff();
instrumentation_begin();