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 752518615A; Tue, 17 Dec 2024 17:25:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734456336; cv=none; b=RnzPgbebKU2PRzWbarde9XhyfKrNz+xQCOTZqnZY04S+IdbW0rLw6333HSgMg1v5VSWAJYYb5EgrMWQgzn9qeOhcz8CzPjrXADuV3uBI5D0Hnnp8KZvLiT27Ocm3zP+SNoHxCIvcaV00+LwpC/4V0oq1BbaaUt6k5dzhhJ6HlEk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734456336; c=relaxed/simple; bh=ANM/uXaCPB25FpZ2Sq7CwdmRg/aQ0kmlC1B+N2Iu4UM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=C5NQsOwhVoElTZkhSPw3Xhiq3nr03tJFn0jhlgb88esEtdKkCffL6eiBqInPjk5E1nsdRseiJO2kBpw1XD3oYyofQljmTkt8+v49n0WQmzyLoKhyARBRIH2v3VMGXht/2CpKg13WJF44DGAzibv71iuKeAi30W4SroEbhIbI874= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=b990+oRe; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="b990+oRe" Received: by smtp.kernel.org (Postfix) with ESMTPSA id AC820C4CED3; Tue, 17 Dec 2024 17:25:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1734456336; bh=ANM/uXaCPB25FpZ2Sq7CwdmRg/aQ0kmlC1B+N2Iu4UM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=b990+oReTw8ydomMjayAUXAtBghQY0AJvrsW7r2grcs3caESuPiiKS+cYI7PGGAbk 37G5MddEBHpG9Y2lOH1N2rowaiHHURx3lz7/MtEmQTSXscTWhzYK6/qLAJst6B4ZIo 7qxghMUkkMMVswLPROJUgEBB2rES8cMLIxCSShRI= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Alexandre Ghiti , Palmer Dabbelt Subject: [PATCH 6.12 027/172] riscv: Fix IPIs usage in kfence_protect_page() Date: Tue, 17 Dec 2024 18:06:23 +0100 Message-ID: <20241217170547.391519511@linuxfoundation.org> X-Mailer: git-send-email 2.47.1 In-Reply-To: <20241217170546.209657098@linuxfoundation.org> References: <20241217170546.209657098@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Alexandre Ghiti commit b3431a8bb336cece8adc452437befa7d4534b2fd upstream. flush_tlb_kernel_range() may use IPIs to flush the TLBs of all the cores, which triggers the following warning when the irqs are disabled: [ 3.455330] WARNING: CPU: 1 PID: 0 at kernel/smp.c:815 smp_call_function_many_cond+0x452/0x520 [ 3.456647] Modules linked in: [ 3.457218] CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted 6.12.0-rc7-00010-g91d3de7240b8 #1 [ 3.457416] Hardware name: QEMU QEMU Virtual Machine, BIOS [ 3.457633] epc : smp_call_function_many_cond+0x452/0x520 [ 3.457736] ra : on_each_cpu_cond_mask+0x1e/0x30 [ 3.457786] epc : ffffffff800b669a ra : ffffffff800b67c2 sp : ff2000000000bb50 [ 3.457824] gp : ffffffff815212b8 tp : ff6000008014f080 t0 : 000000000000003f [ 3.457859] t1 : ffffffff815221e0 t2 : 000000000000000f s0 : ff2000000000bc10 [ 3.457920] s1 : 0000000000000040 a0 : ffffffff815221e0 a1 : 0000000000000001 [ 3.457953] a2 : 0000000000010000 a3 : 0000000000000003 a4 : 0000000000000000 [ 3.458006] a5 : 0000000000000000 a6 : ffffffffffffffff a7 : 0000000000000000 [ 3.458042] s2 : ffffffff815223be s3 : 00fffffffffff000 s4 : ff600001ffe38fc0 [ 3.458076] s5 : ff600001ff950d00 s6 : 0000000200000120 s7 : 0000000000000001 [ 3.458109] s8 : 0000000000000001 s9 : ff60000080841ef0 s10: 0000000000000001 [ 3.458141] s11: ffffffff81524812 t3 : 0000000000000001 t4 : ff60000080092bc0 [ 3.458172] t5 : 0000000000000000 t6 : ff200000000236d0 [ 3.458203] status: 0000000200000100 badaddr: ffffffff800b669a cause: 0000000000000003 [ 3.458373] [] smp_call_function_many_cond+0x452/0x520 [ 3.458593] [] on_each_cpu_cond_mask+0x1e/0x30 [ 3.458625] [] __flush_tlb_range+0x118/0x1ca [ 3.458656] [] flush_tlb_kernel_range+0x1e/0x26 [ 3.458683] [] kfence_protect+0xc0/0xce [ 3.458717] [] kfence_guarded_free+0xc6/0x1c0 [ 3.458742] [] __kfence_free+0x62/0xc6 [ 3.458764] [] kfree+0x106/0x32c [ 3.458786] [] detach_buf_split+0x188/0x1a8 [ 3.458816] [] virtqueue_get_buf_ctx+0xb6/0x1f6 [ 3.458839] [] virtqueue_get_buf+0xe/0x16 [ 3.458880] [] virtblk_done+0x5c/0xe2 [ 3.458908] [] vring_interrupt+0x6a/0x74 [ 3.458930] [] __handle_irq_event_percpu+0x7c/0xe2 [ 3.458956] [] handle_irq_event+0x3c/0x86 [ 3.458978] [] handle_simple_irq+0x9e/0xbe [ 3.459004] [] generic_handle_domain_irq+0x1c/0x2a [ 3.459027] [] imsic_handle_irq+0xba/0x120 [ 3.459056] [] generic_handle_domain_irq+0x1c/0x2a [ 3.459080] [] riscv_intc_aia_irq+0x24/0x34 [ 3.459103] [] handle_riscv_irq+0x2e/0x4c [ 3.459133] [] call_on_irq_stack+0x32/0x40 So only flush the local TLB and let the lazy kfence page fault handling deal with the faults which could happen when a core has an old protected pte version cached in its TLB. That leads to potential inaccuracies which can be tolerated when using kfence. Fixes: 47513f243b45 ("riscv: Enable KFENCE for riscv64") Signed-off-by: Alexandre Ghiti Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20241209074125.52322-1-alexghiti@rivosinc.com Signed-off-by: Palmer Dabbelt Signed-off-by: Greg Kroah-Hartman --- arch/riscv/include/asm/kfence.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/arch/riscv/include/asm/kfence.h +++ b/arch/riscv/include/asm/kfence.h @@ -22,7 +22,9 @@ static inline bool kfence_protect_page(u else set_pte(pte, __pte(pte_val(ptep_get(pte)) | _PAGE_PRESENT)); - flush_tlb_kernel_range(addr, addr + PAGE_SIZE); + preempt_disable(); + local_flush_tlb_kernel_range(addr, addr + PAGE_SIZE); + preempt_enable(); return true; }