From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D3D9B2F39 for ; Tue, 7 Feb 2023 13:08:05 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 421C4C433D2; Tue, 7 Feb 2023 13:08:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1675775285; bh=9GJdinjANYFCzCmhoC+afbNe+2RjdAv0oZ3PI/E+JV8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=W9BHXzlofoQRly432gjj04s1i9XfQ4gF2dpahQj6IHQUgQtaCyi1exMkQSdDQzFk8 MJFvo1A+0BJ+sdaRblI2vPspOkbjCrTHQwHBBeEjmobmJolSHGR/9EPXTP3aF+IJHg x4oURyCKAQD5TktYJ0vfWQb8oohYJ2xLdWvsosrc= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Nicholas Piggin , Michael Ellerman Subject: [PATCH 6.1 198/208] powerpc/64s: Fix local irq disable when PMIs are disabled Date: Tue, 7 Feb 2023 13:57:32 +0100 Message-Id: <20230207125643.463143801@linuxfoundation.org> X-Mailer: git-send-email 2.39.1 In-Reply-To: <20230207125634.292109991@linuxfoundation.org> References: <20230207125634.292109991@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Nicholas Piggin commit bc88ef663265676419555df2dc469a471c0add31 upstream. When PMI interrupts are soft-masked, local_irq_save() will clear the PMI mask bit, allowing PMIs in and causing a race condition. This causes a deadlock in native_hpte_insert via hash_preload, which depends on PMIs being disabled since commit 8b91cee5eadd ("powerpc/64s/hash: Make hash faults work in NMI context"). native_hpte_insert calls local_irq_save(). It's possible the lpar hash code is also affected when tracing is enabled because __trace_hcall_entry() calls local_irq_save(). Fix this by making arch_local_irq_save() _or_ the IRQS_DISABLED bit into the mask. This was found with the stress_hpt option with a kbuild workload running together with `perf record -g`. Fixes: f442d004806e ("powerpc/64s: Add support to mask perf interrupts and replay them") Fixes: 8b91cee5eadd ("powerpc/64s/hash: Make hash faults work in NMI context") Signed-off-by: Nicholas Piggin [mpe: Just take the fix without the new warning] Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20230121095352.2823517-1-npiggin@gmail.com Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/include/asm/hw_irq.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/powerpc/include/asm/hw_irq.h b/arch/powerpc/include/asm/hw_irq.h index 77fa88c2aed0..0b7d01d408ac 100644 --- a/arch/powerpc/include/asm/hw_irq.h +++ b/arch/powerpc/include/asm/hw_irq.h @@ -192,7 +192,7 @@ static inline void arch_local_irq_enable(void) static inline unsigned long arch_local_irq_save(void) { - return irq_soft_mask_set_return(IRQS_DISABLED); + return irq_soft_mask_or_return(IRQS_DISABLED); } static inline bool arch_irqs_disabled_flags(unsigned long flags) -- 2.39.1