Messages in this thread | | | From | Thomas Gleixner <> | Subject | Re: [PATCH] x86/entry: Fix noinstr warning in __enter_from_user_mode() | Date | Tue, 21 Mar 2023 10:08:29 +0100 |
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On Sat, Feb 25 2023 at 16:01, Josh Poimboeuf wrote: > __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> > --- > include/linux/context_tracking.h | 1 + > kernel/entry/common.c | 2 +- > 2 files changed, 2 insertions(+), 1 deletion(-) > > diff --git a/include/linux/context_tracking.h b/include/linux/context_tracking.h > index d4afa8508a80..3a7909ed5498 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; }
This results in a redefinition warning due to CONFIG_CONTEXT_TRACKING=y and CONFIG_CONFIG_TRACKING_USER=n.
Those headers are a fricking mess.
Thanks,
tglx
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