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 6FD03C25B06 for ; Sun, 14 Aug 2022 16:24:48 +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:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version: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=vBonlxv0XPhSHZGATybtesfRZz5xxDqdI8NXbqIKy94=; b=AVu0D4y0qnwaNs QfNu/1sk+lC0JqaoVgp085TTP9dwiiIsmKsufCvco/bP79CrHjdbjT3ldked1V7i7NGkkkmb/t0jO n1y70CUMuvDMvZd83kiAwwA6VVLg835ScaozHFTW3K18vwuGYjDH9RL29yu6ggrnztR23Cs9R0OEG 9mebVkmP1nEtR5/Mcx9/wxyr0cgmbQyBNfR68iwZIqkHvvfEmoh/06duFP3u7XQm93OzF1k5EaNKn dPcV/6poJ9XnSXRDMef0C79MHHDehMbzIJ3DFZkQf7Rk2x13JHmBxtdPWjxVEISX38Bs57NrCIVu9 4S6uV4w9vRw9zbklGZSA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1oNGPm-007s4U-FW; Sun, 14 Aug 2022 16:24:38 +0000 Received: from ams.source.kernel.org ([145.40.68.75]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1oNGPU-007roH-NH for linux-riscv@lists.infradead.org; Sun, 14 Aug 2022 16:24:22 +0000 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 70E4EB80AEE; Sun, 14 Aug 2022 16:24:19 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D5F22C433D7; Sun, 14 Aug 2022 16:24:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1660494258; bh=yG70TElzY3pqwf+P+DefanwjD3PKIULBwNjRqXQjbtg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=iDWJ7idB1pVhU2nZzpKciKKxRPNmeaTl0eN5kEw3kS+bHg8TxjBs3WyM0yOMBYHxt K+po3LEk987S0P76fGwTZfZXW7NMOOknRnS4HeVf93kn8GURfa7ojz7ZU4c/MgAwW4 M2z8P0IhuljlDJAZS/Z2UimmHUAup5JI8t8vGLS/q2QkxnYxJUSWN97pWlfWQySLCP H7jAoLQbNv3Kv8bPXnsUm7q+HFyhvn/1jB4ZADdJfLt+gDtHdq2LSFQiPvCXeNKL1l lszyg8+Fe5T2UPrapT63FDXFm65V+PzlIVjtYZJ9Um/K3rGcPBSQjx47DL+iCTTpdY DmwmvlZdnNUvA== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Xianting Tian , Guo Ren , Palmer Dabbelt , Sasha Levin , paul.walmsley@sifive.com, palmer@dabbelt.com, aou@eecs.berkeley.edu, heiko@sntech.de, wangkefeng.wang@huawei.com, ebiederm@xmission.com, linux-riscv@lists.infradead.org Subject: [PATCH AUTOSEL 5.18 15/39] RISC-V: Add fast call path of crash_kexec() Date: Sun, 14 Aug 2022 12:23:04 -0400 Message-Id: <20220814162332.2396012-15-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220814162332.2396012-1-sashal@kernel.org> References: <20220814162332.2396012-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220814_092421_460272_F9E60C86 X-CRM114-Status: GOOD ( 10.51 ) 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: , 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 From: Xianting Tian [ Upstream commit 3f1901110a89b0e2e13adb2ac8d1a7102879ea98 ] 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; Reviewed-by: Guo Ren Tested-by: Xianting Tian Signed-off-by: Xianting Tian Link: https://lore.kernel.org/r/20220606082308.2883458-1-xianting.tian@linux.alibaba.com Signed-off-by: Palmer Dabbelt Signed-off-by: Sasha Levin --- 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 fe92e119e6a3..e666ebfa2a64 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); -- 2.35.1 _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv