From f87d28673b71b35b248231a2086f9404afbb7f28 Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Sat, 25 Feb 2023 16:01:36 -0800 Subject: entry: Fix noinstr warning in __enter_from_user_mode() __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 Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/d8955fa6d68dc955dda19baf13ae014ae27926f5.1677369694.git.jpoimboe@kernel.org --- include/linux/context_tracking.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/context_tracking.h') 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; } 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) -- cgit v1.2.3-70-g09d2 From e8deb00c0c4808654d1bf96a8f79cf1deb59b631 Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Wed, 12 Apr 2023 10:24:06 -0700 Subject: context_tracking: Fix KCSAN noinstr violation With KCSAN enabled, even empty inline stubs can be out-of-lined. Force the context_tracking_guest_exit() stub inline. Fixes the following warnings: vmlinux.o: warning: objtool: vmx_vcpu_enter_exit+0x1be: call to context_tracking_guest_exit() leaves .noinstr.text section vmlinux.o: warning: objtool: svm_vcpu_enter_exit+0x85: call to context_tracking_guest_exit() leaves .noinstr.text section Signed-off-by: Josh Poimboeuf Signed-off-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/r/dc93f45abdec90c171108b4b590b7fff5790963c.1681320026.git.jpoimboe@kernel.org --- include/linux/context_tracking.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux/context_tracking.h') diff --git a/include/linux/context_tracking.h b/include/linux/context_tracking.h index d4afa8508a80..5ae3abd767b4 100644 --- a/include/linux/context_tracking.h +++ b/include/linux/context_tracking.h @@ -97,7 +97,7 @@ 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 __always_inline bool context_tracking_guest_enter(void) { return false; } -static inline void context_tracking_guest_exit(void) { } +static __always_inline void context_tracking_guest_exit(void) { } #define CT_WARN_ON(cond) do { } while (0) #endif /* !CONFIG_CONTEXT_TRACKING_USER */ -- cgit v1.2.3-70-g09d2