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 91CA2C25B06 for ; Sun, 14 Aug 2022 16:29:24 +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=SRMrUaL07mRpQOyZc1w7ErgvbuJCPuAp8Fh21G2Elx0=; b=n4XqEtkGUg6wlw 5eeTrXd0uflugTj81HwixHIWa9i2MHlHATI4VxI1FV3g1LOz+F6fyOAnPjgdZBebVMArQBNNSaLwI iE9X0bg2WUCwqiF6LRrqwrs2VzsGbJO4lx1QxgY8+nxJZ+YEeHr40mIlEC307HAxgMMA7fpWUk8hh jp+oizfVGPZ6Vj+LFzerQwsfyTXyGD3Yhut1kD8UHYoWeHEV4zsXOV1JUagPOUZEs4Hqkz7tqcseg C6BNDPWCj9tdPJUUom8h01EYHIIbU2CK/N2V0Gp6meLDZRQD94TcHFin0DYanOn+CnqSoRSwRlyWR SLXKA0t8Ph1B57+7pONw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1oNGU4-007vLz-Qc; Sun, 14 Aug 2022 16:29:05 +0000 Received: from dfw.source.kernel.org ([2604:1380:4641:c500::1]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1oNGTt-007vAZ-JW for linux-riscv@lists.infradead.org; Sun, 14 Aug 2022 16:28:55 +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 dfw.source.kernel.org (Postfix) with ESMTPS id 2668160F97; Sun, 14 Aug 2022 16:28:53 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id DE376C433D6; Sun, 14 Aug 2022 16:28:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1660494532; bh=IRbIsN0AupDAgZNVGkixlOAzpjRVaFRHazxcux/MI2k=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=iT/+2JiG43Kh5DxcpEo586FKdv58a3AmkL2dgLXjS62rMaZgBJ45wPLAwAL1iAjEH wTQKG8NFb4o6wDFYz8/zNRV+QZdZdkQ4V+FcrNIuiAQUbOSeL1x3q0zB3uB5Nf5vX5 OZV7sjSBVy2KlfbERGICZtjJYw4+TRgYaz8YuKIDfBYCo+cGqvdakbvAo6KyEWw6jE hZPBN5yVu+11/l6YIwkqlor5BgoMINbxO8MSpKWSFSybM3X8IUQhwNkz2vBz2CN/ly QoCbMDkxlAm5yjIDsWypxDBZbmnJZfCu07nCOIpkxSHmAiCAv4S1c6LwKkfSLJDfWV bqwIDb1q3SCuA== 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, ebiederm@xmission.com, akpm@linux-foundation.org, wangkefeng.wang@huawei.com, linux-riscv@lists.infradead.org Subject: [PATCH AUTOSEL 5.4 07/16] RISC-V: Add fast call path of crash_kexec() Date: Sun, 14 Aug 2022 12:28:22 -0400 Message-Id: <20220814162833.2398478-7-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220814162833.2398478-1-sashal@kernel.org> References: <20220814162833.2398478-1-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_092853_852743_78B51B12 X-CRM114-Status: GOOD ( 10.12 ) 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 473de3ae8bb7..ae462037910b 100644 --- a/arch/riscv/kernel/traps.c +++ b/arch/riscv/kernel/traps.c @@ -15,6 +15,7 @@ #include #include #include +#include #include #include @@ -43,6 +44,9 @@ void die(struct pt_regs *regs, const char *str) ret = notify_die(DIE_OOPS, str, regs, 0, regs->scause, 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