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McKenney" Subject: [linux-next:master 3520/4317] arch/powerpc/kernel/interrupt.c:542:55: warning: suggest braces around empty body in an 'if' statement Message-ID: <202206190314.0EFTboD0-lkp@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline ARC-Authentication-Results: i=1; imf28.hostedemail.com; dkim=pass header.d=intel.com header.s=Intel header.b=N8sPKsIm; dmarc=pass (policy=none) header.from=intel.com; spf=none (imf28.hostedemail.com: domain of lkp@intel.com has no SPF policy when checking 192.55.52.120) smtp.mailfrom=lkp@intel.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1655580638; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding:in-reply-to: references:dkim-signature; bh=Z0x7w858xjKCkC/SDCybF3B4C1Q6nLz8dUR/hY6vJ+w=; b=MP09fdIp6o4+9oX7EEaC5P7OYaIv3XKovl7rJuXIMOSx9EcymCzkRzQCY5g4rQA+dobsSp bRIyZx5mbtk6WtoTlACM7UZU9W7/i9c9N5kPCTTKQE5I18L96dK03wf/eIeMeH0b2Eq0f7 HKA+PuVg/Rqpgw+cxXoDiUXdJYYVC4I= ARC-Seal: i=1; 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| ^ vim +/if +542 arch/powerpc/kernel/interrupt.c 6cc0c16d82f889 arch/powerpc/kernel/syscall_64.c Nicholas Piggin 2020-02-26 527 bf9155f1970c4d arch/powerpc/kernel/interrupt.c Nicholas Piggin 2021-06-18 528 notrace unsigned long interrupt_exit_kernel_prepare(struct pt_regs *regs) 6cc0c16d82f889 arch/powerpc/kernel/syscall_64.c Nicholas Piggin 2020-02-26 529 { 6cc0c16d82f889 arch/powerpc/kernel/syscall_64.c Nicholas Piggin 2020-02-26 530 unsigned long flags; 6cc0c16d82f889 arch/powerpc/kernel/syscall_64.c Nicholas Piggin 2020-02-26 531 unsigned long ret = 0; ad2d2344771dab arch/powerpc/kernel/interrupt.c Christophe Leroy 2021-03-12 532 unsigned long kuap; 985faa78687de6 arch/powerpc/kernel/interrupt.c Mark Rutland 2021-11-29 533 bool stack_store = read_thread_flags() & _TIF_EMULATE_STACK_STORE; 6cc0c16d82f889 arch/powerpc/kernel/syscall_64.c Nicholas Piggin 2020-02-26 534 806c0e6e7e97ad arch/powerpc/kernel/interrupt.c Christophe Leroy 2021-08-23 535 if (regs_is_unrecoverable(regs)) 6cc0c16d82f889 arch/powerpc/kernel/syscall_64.c Nicholas Piggin 2020-02-26 536 unrecoverable_exception(regs); f821bc97dee4f3 arch/powerpc/kernel/syscall_64.c Nicholas Piggin 2021-01-30 537 /* f821bc97dee4f3 arch/powerpc/kernel/syscall_64.c Nicholas Piggin 2021-01-30 538 * CT_WARN_ON comes here via program_check_exception, f821bc97dee4f3 arch/powerpc/kernel/syscall_64.c Nicholas Piggin 2021-01-30 539 * so avoid recursion. f821bc97dee4f3 arch/powerpc/kernel/syscall_64.c Nicholas Piggin 2021-01-30 540 */ 7153d4bf0b3734 arch/powerpc/kernel/interrupt.c Xiongwei Song 2021-04-14 541 if (TRAP(regs) != INTERRUPT_PROGRAM) f821bc97dee4f3 arch/powerpc/kernel/syscall_64.c Nicholas Piggin 2021-01-30 @542 CT_WARN_ON(ct_state() == CONTEXT_USER); 6cc0c16d82f889 arch/powerpc/kernel/syscall_64.c Nicholas Piggin 2020-02-26 543 ad2d2344771dab arch/powerpc/kernel/interrupt.c Christophe Leroy 2021-03-12 544 kuap = kuap_get_and_assert_locked(); c0d7dcf89e5151 arch/powerpc/kernel/syscall_64.c Nicholas Piggin 2020-04-29 545 6cc0c16d82f889 arch/powerpc/kernel/syscall_64.c Nicholas Piggin 2020-02-26 546 local_irq_save(flags); 6cc0c16d82f889 arch/powerpc/kernel/syscall_64.c Nicholas Piggin 2020-02-26 547 344bb20b159dd0 arch/powerpc/kernel/interrupt.c Christophe Leroy 2021-02-08 548 if (!arch_irq_disabled_regs(regs)) { 6cc0c16d82f889 arch/powerpc/kernel/syscall_64.c Nicholas Piggin 2020-02-26 549 /* Returning to a kernel context with local irqs enabled. */ 6cc0c16d82f889 arch/powerpc/kernel/syscall_64.c Nicholas Piggin 2020-02-26 550 WARN_ON_ONCE(!(regs->msr & MSR_EE)); 6cc0c16d82f889 arch/powerpc/kernel/syscall_64.c Nicholas Piggin 2020-02-26 551 again: 6cc0c16d82f889 arch/powerpc/kernel/syscall_64.c Nicholas Piggin 2020-02-26 552 if (IS_ENABLED(CONFIG_PREEMPT)) { 6cc0c16d82f889 arch/powerpc/kernel/syscall_64.c Nicholas Piggin 2020-02-26 553 /* Return to preemptible kernel context */ 985faa78687de6 arch/powerpc/kernel/interrupt.c Mark Rutland 2021-11-29 554 if (unlikely(read_thread_flags() & _TIF_NEED_RESCHED)) { 6cc0c16d82f889 arch/powerpc/kernel/syscall_64.c Nicholas Piggin 2020-02-26 555 if (preempt_count() == 0) 6cc0c16d82f889 arch/powerpc/kernel/syscall_64.c Nicholas Piggin 2020-02-26 556 preempt_schedule_irq(); 6cc0c16d82f889 arch/powerpc/kernel/syscall_64.c Nicholas Piggin 2020-02-26 557 } 6cc0c16d82f889 arch/powerpc/kernel/syscall_64.c Nicholas Piggin 2020-02-26 558 } 6cc0c16d82f889 arch/powerpc/kernel/syscall_64.c Nicholas Piggin 2020-02-26 559 6eaaf9de359986 arch/powerpc/kernel/interrupt.c Nicholas Piggin 2021-06-22 560 check_return_regs_valid(regs); 6eaaf9de359986 arch/powerpc/kernel/interrupt.c Nicholas Piggin 2021-06-22 561 13799748b957bc arch/powerpc/kernel/interrupt.c Nicholas Piggin 2021-06-18 562 /* 13799748b957bc arch/powerpc/kernel/interrupt.c Nicholas Piggin 2021-06-18 563 * Stack store exit can't be restarted because the interrupt 13799748b957bc arch/powerpc/kernel/interrupt.c Nicholas Piggin 2021-06-18 564 * stack frame might have been clobbered. 13799748b957bc arch/powerpc/kernel/interrupt.c Nicholas Piggin 2021-06-18 565 */ 61eece2d170779 arch/powerpc/kernel/interrupt.c Christophe Leroy 2021-06-18 566 if (!prep_irq_for_enabled_exit(unlikely(stack_store))) { 13799748b957bc arch/powerpc/kernel/interrupt.c Nicholas Piggin 2021-06-18 567 /* 13799748b957bc arch/powerpc/kernel/interrupt.c Nicholas Piggin 2021-06-18 568 * Replay pending soft-masked interrupts now. Don't 13799748b957bc arch/powerpc/kernel/interrupt.c Nicholas Piggin 2021-06-18 569 * just local_irq_enabe(); local_irq_disable(); because 13799748b957bc arch/powerpc/kernel/interrupt.c Nicholas Piggin 2021-06-18 570 * if we are returning from an asynchronous interrupt 13799748b957bc arch/powerpc/kernel/interrupt.c Nicholas Piggin 2021-06-18 571 * here, another one might hit after irqs are enabled, 13799748b957bc arch/powerpc/kernel/interrupt.c Nicholas Piggin 2021-06-18 572 * and it would exit via this same path allowing 13799748b957bc arch/powerpc/kernel/interrupt.c Nicholas Piggin 2021-06-18 573 * another to fire, and so on unbounded. 13799748b957bc arch/powerpc/kernel/interrupt.c Nicholas Piggin 2021-06-18 574 */ 13799748b957bc arch/powerpc/kernel/interrupt.c Nicholas Piggin 2021-06-18 575 hard_irq_disable(); 13799748b957bc arch/powerpc/kernel/interrupt.c Nicholas Piggin 2021-06-18 576 replay_soft_interrupts(); 13799748b957bc arch/powerpc/kernel/interrupt.c Nicholas Piggin 2021-06-18 577 /* Took an interrupt, may have more exit work to do. */ 6cc0c16d82f889 arch/powerpc/kernel/syscall_64.c Nicholas Piggin 2020-02-26 578 goto again; 13799748b957bc arch/powerpc/kernel/interrupt.c Nicholas Piggin 2021-06-18 579 } 13799748b957bc arch/powerpc/kernel/interrupt.c Nicholas Piggin 2021-06-18 580 #ifdef CONFIG_PPC64 13799748b957bc arch/powerpc/kernel/interrupt.c Nicholas Piggin 2021-06-18 581 /* 13799748b957bc arch/powerpc/kernel/interrupt.c Nicholas Piggin 2021-06-18 582 * An interrupt may clear MSR[EE] and set this concurrently, 13799748b957bc arch/powerpc/kernel/interrupt.c Nicholas Piggin 2021-06-18 583 * but it will be marked pending and the exit will be retried. 13799748b957bc arch/powerpc/kernel/interrupt.c Nicholas Piggin 2021-06-18 584 * This leaves a racy window where MSR[EE]=0 and HARD_DIS is 13799748b957bc arch/powerpc/kernel/interrupt.c Nicholas Piggin 2021-06-18 585 * clear, until interrupt_exit_kernel_restart() calls 13799748b957bc arch/powerpc/kernel/interrupt.c Nicholas Piggin 2021-06-18 586 * hard_irq_disable(), which will set HARD_DIS again. 13799748b957bc arch/powerpc/kernel/interrupt.c Nicholas Piggin 2021-06-18 587 */ 13799748b957bc arch/powerpc/kernel/interrupt.c Nicholas Piggin 2021-06-18 588 local_paca->irq_happened &= ~PACA_IRQ_HARD_DIS; 13799748b957bc arch/powerpc/kernel/interrupt.c Nicholas Piggin 2021-06-18 589 6cc0c16d82f889 arch/powerpc/kernel/syscall_64.c Nicholas Piggin 2020-02-26 590 } else { 6eaaf9de359986 arch/powerpc/kernel/interrupt.c Nicholas Piggin 2021-06-22 591 check_return_regs_valid(regs); 6eaaf9de359986 arch/powerpc/kernel/interrupt.c Nicholas Piggin 2021-06-22 592 13799748b957bc arch/powerpc/kernel/interrupt.c Nicholas Piggin 2021-06-18 593 if (unlikely(stack_store)) 6cc0c16d82f889 arch/powerpc/kernel/syscall_64.c Nicholas Piggin 2020-02-26 594 __hard_EE_RI_disable(); 13799748b957bc arch/powerpc/kernel/interrupt.c Nicholas Piggin 2021-06-18 595 /* 13799748b957bc arch/powerpc/kernel/interrupt.c Nicholas Piggin 2021-06-18 596 * Returning to a kernel context with local irqs disabled. 13799748b957bc arch/powerpc/kernel/interrupt.c Nicholas Piggin 2021-06-18 597 * Here, if EE was enabled in the interrupted context, enable 13799748b957bc arch/powerpc/kernel/interrupt.c Nicholas Piggin 2021-06-18 598 * it on return as well. A problem exists here where a soft 13799748b957bc arch/powerpc/kernel/interrupt.c Nicholas Piggin 2021-06-18 599 * masked interrupt may have cleared MSR[EE] and set HARD_DIS 13799748b957bc arch/powerpc/kernel/interrupt.c Nicholas Piggin 2021-06-18 600 * here, and it will still exist on return to the caller. This 13799748b957bc arch/powerpc/kernel/interrupt.c Nicholas Piggin 2021-06-18 601 * will be resolved by the masked interrupt firing again. 13799748b957bc arch/powerpc/kernel/interrupt.c Nicholas Piggin 2021-06-18 602 */ 6cc0c16d82f889 arch/powerpc/kernel/syscall_64.c Nicholas Piggin 2020-02-26 603 if (regs->msr & MSR_EE) 6cc0c16d82f889 arch/powerpc/kernel/syscall_64.c Nicholas Piggin 2020-02-26 604 local_paca->irq_happened &= ~PACA_IRQ_HARD_DIS; 13799748b957bc arch/powerpc/kernel/interrupt.c Nicholas Piggin 2021-06-18 605 #endif /* CONFIG_PPC64 */ 6cc0c16d82f889 arch/powerpc/kernel/syscall_64.c Nicholas Piggin 2020-02-26 606 } 6cc0c16d82f889 arch/powerpc/kernel/syscall_64.c Nicholas Piggin 2020-02-26 607 13799748b957bc arch/powerpc/kernel/interrupt.c Nicholas Piggin 2021-06-18 608 if (unlikely(stack_store)) { 13799748b957bc arch/powerpc/kernel/interrupt.c Nicholas Piggin 2021-06-18 609 clear_bits(_TIF_EMULATE_STACK_STORE, ¤t_thread_info()->flags); 13799748b957bc arch/powerpc/kernel/interrupt.c Nicholas Piggin 2021-06-18 610 ret = 1; 13799748b957bc arch/powerpc/kernel/interrupt.c Nicholas Piggin 2021-06-18 611 } 6cc0c16d82f889 arch/powerpc/kernel/syscall_64.c Nicholas Piggin 2020-02-26 612 :::::: The code at line 542 was first introduced by commit :::::: f821bc97dee4f3ee92c3668d495af49dfd720fe0 powerpc/64s: move context tracking exit to interrupt exit path :::::: TO: Nicholas Piggin :::::: CC: Michael Ellerman -- 0-DAY CI Kernel Test Service https://01.org/lkp