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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id CFE63C43334 for ; Sun, 17 Jul 2022 10:13:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:List-Subscribe:List-Help: List-Post:List-Archive:List-Unsubscribe:List-Id:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=2cgVW7rTQsKCEDNvOxermtmBG3MzXTOXJqlMiS0yWDQ=; b=cBRFBbPEG03Exk Nonk5B52qhXKUcIW3nCQY5/q6l4ZJMndR6ouj8jtnlw/zgbBOA6COVYZtD3/pTh9WjJ8c9augbmkE ftieyAH8xic7zF3LYHv2Ml+w7Y+uu4is99aYSZcNlUkAXkLl8eaKTh7QwR25XtkTk5xdesauAbo6o 7K5jlM0/JQ5XPkbT8cuDRpUltNDFcpu00+izixpikQMoTx1/pogEgnDqHwYlbtOF8jK+lqfTXGMGW 8ZTscvu5q8Y3I+fRkhu0Rxo0bu9rYtgywXgqeu65c0DeHPJJ3pORXVC0exhDdQLt6Tn/2uibITLiI FC4XKGIXOdVdvsh8MfwQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1oD1HO-006Ipp-3Q; Sun, 17 Jul 2022 10:13:38 +0000 Received: from out30-133.freemail.mail.aliyun.com ([115.124.30.133]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1oD1HJ-006Imt-52 for linux-riscv@lists.infradead.org; Sun, 17 Jul 2022 10:13:34 +0000 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R151e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018046049;MF=xianting.tian@linux.alibaba.com;NM=1;PH=DS;RN=16;SR=0;TI=SMTPD_---0VJXih1g_1658052806; Received: from localhost(mailfrom:xianting.tian@linux.alibaba.com fp:SMTPD_---0VJXih1g_1658052806) by smtp.aliyun-inc.com; Sun, 17 Jul 2022 18:13:27 +0800 From: Xianting Tian To: paul.walmsley@sifive.com, palmer@dabbelt.com, aou@eecs.berkeley.edu, anup@brainfault.org, heiko@sntech.de, guoren@kernel.org, mick@ics.forth.gr, alexandre.ghiti@canonical.com Cc: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, crash-utility@redhat.com, huanyi.xj@alibaba-inc.com, heinrich.schuchardt@canonical.com, k-hagio-ab@nec.com, hschauhan@nulltrace.org, Xianting Tian Subject: [PATCH 1/5] RISC-V: Fixup fast call of crash_kexec() Date: Sun, 17 Jul 2022 18:13:19 +0800 Message-Id: <20220717101323.370245-2-xianting.tian@linux.alibaba.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20220717101323.370245-1-xianting.tian@linux.alibaba.com> References: <20220717101323.370245-1-xianting.tian@linux.alibaba.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220717_031333_415412_7F19F3B6 X-CRM114-Status: UNSURE ( 6.92 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org Currently, almost all archs (x86, arm64, mips...) support fast call of crash_kexec() when "regs && kexec_should_crash()" is true. But RISC-V not, it can only enter crash system via panic(). However panic() doesn't pass the regs of the real accident scene to crash_kexec(), it caused we can't get accurate backtrace via gdb, $ riscv64-linux-gnu-gdb vmlinux vmcore Reading symbols from vmlinux... [New LWP 95] #0 console_unlock () at kernel/printk/printk.c:2557 2557 if (do_cond_resched) (gdb) bt #0 console_unlock () at kernel/printk/printk.c:2557 #1 0x0000000000000000 in ?? () With the patch we can get the accurate backtrace, $ riscv64-linux-gnu-gdb vmlinux vmcore Reading symbols from vmlinux... [New LWP 95] #0 0xffffffe00063a4e0 in test_thread (data=) at drivers/test_crash.c:81 81 *(int *)p = 0xdead; (gdb) (gdb) bt #0 0xffffffe00064d5c0 in test_thread (data=) at drivers/test_crash.c:81 #1 0x0000000000000000 in ?? () Test code to produce NULL address dereference in test_crash.c, void *p = NULL; *(int *)p = 0xdead; Fixes: 76d2a0493a17 ("RISC-V: Init and Halt Code") Reviewed-by: Guo Ren Reviewed-by: Kefeng Wang Signed-off-by: Xianting Tian --- arch/riscv/kernel/traps.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/riscv/kernel/traps.c b/arch/riscv/kernel/traps.c index b40426509244..39d0f8bba4b4 100644 --- a/arch/riscv/kernel/traps.c +++ b/arch/riscv/kernel/traps.c @@ -16,6 +16,7 @@ #include #include #include +#include #include #include @@ -44,6 +45,9 @@ void die(struct pt_regs *regs, const char *str) ret = notify_die(DIE_OOPS, str, regs, 0, regs->cause, SIGSEGV); + if (regs && kexec_should_crash(current)) + crash_kexec(regs); + bust_spinlocks(0); add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE); spin_unlock_irq(&die_lock); -- 2.17.1 _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv