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 6EB9113AD11; Mon, 6 Jan 2025 15:53:26 +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=1736178806; cv=none; b=tC4O2vxfHKfqMTzbPgl1SG/F/WWB6clgM0GmRq9KUr7Rv2U9/mjdLuer0GNibpr5QExh6+4o6k9vkFmgZm9P6O0BF30Usg9nf//bJi4XNOTuYI0Xg7+QkE0ZlklwH2B+06lv/K+vkIoDl0ojSEjt0k5Fq+ZIsH/QtHBmHW8y1pA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736178806; c=relaxed/simple; bh=zvX/N77nNMchI2DoUwbEKz/Rys6AivIX7Bbu4MruDME=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=auDcmeSCfaqSj8HCmRNjdqo++eOKjO3v5MNjjjvM50xJ3m+jkTmLRDTi0BW1UfRqARqeA+jebaZOyRz49F8z9EE3g0O/CUH21tzG7PvG0womRCyqN4k2mCRoJgKR7ICQZ4kLCgps9TMTwWgJFNOhnUkNukcgnLUDg8yc18lmZ5E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=EVNoW06C; 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="EVNoW06C" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8BD33C4CED2; Mon, 6 Jan 2025 15:53:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1736178805; bh=zvX/N77nNMchI2DoUwbEKz/Rys6AivIX7Bbu4MruDME=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=EVNoW06CvVE1nprfsiH0mL/nqos1MmDWNl8hO2O+wH67l1QbWBbYUlJgmPfHuiQ1z N6woEGb8/5gqbbYSuAiGZ3PvQl+ICMrJWX6B/Nvb/Zwx7Gd5dF6iSaqQfGVwClI/Pt Oi/gy9VhVsgfB5D+mrOHhJr8wgAB4k/f6LUhJHrE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Alexandre Ghiti , Palmer Dabbelt , Sasha Levin Subject: [PATCH 5.15 097/168] riscv: Fix IPIs usage in kfence_protect_page() Date: Mon, 6 Jan 2025 16:16:45 +0100 Message-ID: <20250106151142.127570645@linuxfoundation.org> X-Mailer: git-send-email 2.47.1 In-Reply-To: <20250106151138.451846855@linuxfoundation.org> References: <20250106151138.451846855@linuxfoundation.org> User-Agent: quilt/0.68 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 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Alexandre Ghiti [ Upstream commit b3431a8bb336cece8adc452437befa7d4534b2fd ] 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: Sasha Levin --- arch/riscv/include/asm/kfence.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/arch/riscv/include/asm/kfence.h b/arch/riscv/include/asm/kfence.h index d887a54042aa..5d013dc52c0b 100644 --- a/arch/riscv/include/asm/kfence.h +++ b/arch/riscv/include/asm/kfence.h @@ -55,7 +55,9 @@ static inline bool kfence_protect_page(unsigned long addr, bool protect) else set_pte(pte, __pte(pte_val(*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; } -- 2.39.5