From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 16379C433F5 for ; Mon, 11 Oct 2021 14:05:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F41126103C for ; Mon, 11 Oct 2021 14:05:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236251AbhJKOH5 (ORCPT ); Mon, 11 Oct 2021 10:07:57 -0400 Received: from mail.kernel.org ([198.145.29.99]:56584 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238479AbhJKOF4 (ORCPT ); Mon, 11 Oct 2021 10:05:56 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id CED236103C; Mon, 11 Oct 2021 14:00:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1633960804; bh=O4t1blipEXtA6PklmgI0he90SEvJj0aWMpJhp/1WgSs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=LQTA9hetQxjtexaICumss6MFQHG2SP8LHJ+Uw8lU0FLT6Be+e2oYvKEIq/NiJ1a0l smv9UPRDheoKXx9/s3zHo7ogdtg2P71YWMuxIlFrfiivVeZGLAw1oCLYLiemZEJrIm pu3nGnY50fhG5Cyssei/riwJUJOUSb0TWfvJPsaQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Alexandre Ghiti , Palmer Dabbelt Subject: [PATCH 5.14 035/151] riscv: Flush current cpu icache before other cpus Date: Mon, 11 Oct 2021 15:45:07 +0200 Message-Id: <20211011134518.984567771@linuxfoundation.org> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20211011134517.833565002@linuxfoundation.org> References: <20211011134517.833565002@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Alexandre Ghiti commit bb8958d5dc79acbd071397abb57b8756375fe1ce upstream. On SiFive Unmatched, I recently fell onto the following BUG when booting: [ 0.000000] ftrace: allocating 36610 entries in 144 pages [ 0.000000] Oops - illegal instruction [#1] [ 0.000000] Modules linked in: [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 5.13.1+ #5 [ 0.000000] Hardware name: SiFive HiFive Unmatched A00 (DT) [ 0.000000] epc : riscv_cpuid_to_hartid_mask+0x6/0xae [ 0.000000] ra : __sbi_rfence_v02+0xc8/0x10a [ 0.000000] epc : ffffffff80007240 ra : ffffffff80009964 sp : ffffffff81803e10 [ 0.000000] gp : ffffffff81a1ea70 tp : ffffffff8180f500 t0 : ffffffe07fe30000 [ 0.000000] t1 : 0000000000000004 t2 : 0000000000000000 s0 : ffffffff81803e60 [ 0.000000] s1 : 0000000000000000 a0 : ffffffff81a22238 a1 : ffffffff81803e10 [ 0.000000] a2 : 0000000000000000 a3 : 0000000000000000 a4 : 0000000000000000 [ 0.000000] a5 : 0000000000000000 a6 : ffffffff8000989c a7 : 0000000052464e43 [ 0.000000] s2 : ffffffff81a220c8 s3 : 0000000000000000 s4 : 0000000000000000 [ 0.000000] s5 : 0000000000000000 s6 : 0000000200000100 s7 : 0000000000000001 [ 0.000000] s8 : ffffffe07fe04040 s9 : ffffffff81a22c80 s10: 0000000000001000 [ 0.000000] s11: 0000000000000004 t3 : 0000000000000001 t4 : 0000000000000008 [ 0.000000] t5 : ffffffcf04000808 t6 : ffffffe3ffddf188 [ 0.000000] status: 0000000200000100 badaddr: 0000000000000000 cause: 0000000000000002 [ 0.000000] [] riscv_cpuid_to_hartid_mask+0x6/0xae [ 0.000000] [] sbi_remote_fence_i+0x1e/0x26 [ 0.000000] [] flush_icache_all+0x12/0x1a [ 0.000000] [] patch_text_nosync+0x26/0x32 [ 0.000000] [] ftrace_init_nop+0x52/0x8c [ 0.000000] [] ftrace_process_locs.isra.0+0x29c/0x360 [ 0.000000] [] ftrace_init+0x80/0x130 [ 0.000000] [] start_kernel+0x5c4/0x8f6 [ 0.000000] ---[ end trace f67eb9af4d8d492b ]--- [ 0.000000] Kernel panic - not syncing: Attempted to kill the idle task! [ 0.000000] ---[ end Kernel panic - not syncing: Attempted to kill the idle task! ]--- While ftrace is looping over a list of addresses to patch, it always failed when patching the same function: riscv_cpuid_to_hartid_mask. Looking at the backtrace, the illegal instruction is encountered in this same function. However, patch_text_nosync, after patching the instructions, calls flush_icache_range. But looking at what happens in this function: flush_icache_range -> flush_icache_all -> sbi_remote_fence_i -> __sbi_rfence_v02 -> riscv_cpuid_to_hartid_mask The icache and dcache of the current cpu are never synchronized between the patching of riscv_cpuid_to_hartid_mask and calling this same function. So fix this by flushing the current cpu's icache before asking for the other cpus to do the same. Signed-off-by: Alexandre Ghiti Fixes: fab957c11efe ("RISC-V: Atomic and Locking Code") Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt Signed-off-by: Greg Kroah-Hartman --- arch/riscv/mm/cacheflush.c | 2 ++ 1 file changed, 2 insertions(+) --- a/arch/riscv/mm/cacheflush.c +++ b/arch/riscv/mm/cacheflush.c @@ -16,6 +16,8 @@ static void ipi_remote_fence_i(void *inf void flush_icache_all(void) { + local_flush_icache_all(); + if (IS_ENABLED(CONFIG_RISCV_SBI)) sbi_remote_fence_i(NULL); else