From nobody Fri May 3 23:49:07 2024 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) client-ip=192.237.175.120; envelope-from=xen-devel-bounces@lists.xenproject.org; helo=lists.xenproject.org; Authentication-Results: mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org; dmarc=pass(p=quarantine dis=none) header.from=suse.com ARC-Seal: i=1; a=rsa-sha256; t=1607932605; cv=none; d=zohomail.com; s=zohoarc; b=E3sv2jhpy97/eiW+/RPKg2a/44mLMMaC5yu61HFNf79y8gR/Lcr/G0YECGONhyjzSpzjOETDeHNdsk/0h8zRlGsXoWixxL4A4Ph4nJaGsOsRlseSfcnEVd1SVB3aFPSZ1OxlWNA2ZbHqBCd1PflR/lYpRDYkUtYAkkhiqKElFCU= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1607932605; h=Content-Transfer-Encoding:Cc:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:To; bh=eg1c78s9LNkI41yc1G5ej9Fm++xiGV/QggtLqwnFVz8=; b=LJyumj9IRb6WhwhHHsNxZRCqpAmG571PQ6lXyQNkGjuBYlds82OTyLPi1QfimGWyDtCGRizpHzmp3LKzRQ8Tb0+uOitLvEP8kf51XgokyKUUT1R9a2023sbGHKdAaAJsYvE7WjrIgIhHYD2SlW9Nz8uJEEygw6aajyYsmfdIXiY= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org; dmarc=pass header.from= (p=quarantine dis=none) header.from= Return-Path: Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) by mx.zohomail.com with SMTPS id 1607932605460634.0502133582679; Sun, 13 Dec 2020 23:56:45 -0800 (PST) Received: from list by lists.xenproject.org with outflank-mailman.51924.90853 (Exim 4.92) (envelope-from ) id 1koiiX-000883-9n; Mon, 14 Dec 2020 07:56:25 +0000 Received: by outflank-mailman (output) from mailman id 51924.90853; Mon, 14 Dec 2020 07:56:25 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1koiiX-00087q-5y; Mon, 14 Dec 2020 07:56:25 +0000 Received: by outflank-mailman (input) for mailman id 51924; Mon, 14 Dec 2020 07:56:24 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1koiiW-00084u-0o for xen-devel@lists.xenproject.org; Mon, 14 Dec 2020 07:56:24 +0000 Received: from mx2.suse.de (unknown [195.135.220.15]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id 77c91e7b-82b9-4efa-a6bd-8a7d300e751c; Mon, 14 Dec 2020 07:56:18 +0000 (UTC) Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 7AE46ACA5; Mon, 14 Dec 2020 07:56:17 +0000 (UTC) X-Outflank-Mailman: Message body and most headers restored to incoming version X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 77c91e7b-82b9-4efa-a6bd-8a7d300e751c X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1607932577; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=eg1c78s9LNkI41yc1G5ej9Fm++xiGV/QggtLqwnFVz8=; b=XLkzyl+dE9NarKGUaMHvMul9Fl1T4yp6CCztRcmk0fsg+gGxEv4060P69tXZgIWyffoF64 HwVNiyJscfgeTkPTlp8o4VAF4T7NOyhjIr8aZTHB8PQ+4zjcIqEt0ryoicJDfG9z25V3vq MtnddzbiYNUnhLKx9KwfsE2eK29sxaw= From: Juergen Gross To: xen-devel@lists.xenproject.org Cc: Juergen Gross , Stefano Stabellini , Julien Grall , Volodymyr Babchuk , Andrew Cooper , George Dunlap , Ian Jackson , Jan Beulich , Wei Liu Subject: [PATCH v4 1/3] xen/arm: add support for run_in_exception_handler() Date: Mon, 14 Dec 2020 08:56:13 +0100 Message-Id: <20201214075615.25038-2-jgross@suse.com> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20201214075615.25038-1-jgross@suse.com> References: <20201214075615.25038-1-jgross@suse.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-ZohoMail-DKIM: pass (identity @suse.com) Content-Type: text/plain; charset="utf-8" Add support to run a function in an exception handler for Arm. Do it the same way as on x86 via a bug_frame. Unfortunately inline assembly on Arm seems to be less capable than on x86, leading to functions called via run_in_exception_handler() having to be globally visible. Signed-off-by: Juergen Gross --- V4: - new patch I have verified the created bugframe is correct by inspecting the created binary. Signed-off-by: Juergen Gross --- xen/arch/arm/traps.c | 10 +++++++++- xen/drivers/char/ns16550.c | 3 ++- xen/include/asm-arm/bug.h | 32 +++++++++++++++++++++----------- 3 files changed, 32 insertions(+), 13 deletions(-) diff --git a/xen/arch/arm/traps.c b/xen/arch/arm/traps.c index 22bd1bd4c6..6e677affe2 100644 --- a/xen/arch/arm/traps.c +++ b/xen/arch/arm/traps.c @@ -1236,8 +1236,16 @@ int do_bug_frame(const struct cpu_user_regs *regs, v= addr_t pc) if ( !bug ) return -ENOENT; =20 + if ( id =3D=3D BUGFRAME_run_fn ) + { + void (*fn)(const struct cpu_user_regs *) =3D bug_ptr(bug); + + fn(regs); + return 0; + } + /* WARN, BUG or ASSERT: decode the filename pointer and line number. */ - filename =3D bug_file(bug); + filename =3D bug_ptr(bug); if ( !is_kernel(filename) ) return -EINVAL; fixup =3D strlen(filename); diff --git a/xen/drivers/char/ns16550.c b/xen/drivers/char/ns16550.c index 9235d854fe..dd6500acc8 100644 --- a/xen/drivers/char/ns16550.c +++ b/xen/drivers/char/ns16550.c @@ -192,7 +192,8 @@ static void ns16550_interrupt( /* Safe: ns16550_poll() runs as softirq so not reentrant on a given CPU. */ static DEFINE_PER_CPU(struct serial_port *, poll_port); =20 -static void __ns16550_poll(struct cpu_user_regs *regs) +/* run_in_exception_handler() on Arm requires globally visible symbol. */ +void __ns16550_poll(struct cpu_user_regs *regs) { struct serial_port *port =3D this_cpu(poll_port); struct ns16550 *uart =3D port->uart; diff --git a/xen/include/asm-arm/bug.h b/xen/include/asm-arm/bug.h index 36c803357c..a7da2c306f 100644 --- a/xen/include/asm-arm/bug.h +++ b/xen/include/asm-arm/bug.h @@ -15,34 +15,38 @@ =20 struct bug_frame { signed int loc_disp; /* Relative address to the bug address */ - signed int file_disp; /* Relative address to the filename */ + signed int ptr_disp; /* Relative address to the filename or functio= n */ signed int msg_disp; /* Relative address to the predicate (for ASSE= RT) */ uint16_t line; /* Line number */ uint32_t pad0:16; /* Padding for 8-bytes align */ }; =20 #define bug_loc(b) ((const void *)(b) + (b)->loc_disp) -#define bug_file(b) ((const void *)(b) + (b)->file_disp); +#define bug_ptr(b) ((const void *)(b) + (b)->ptr_disp); #define bug_line(b) ((b)->line) #define bug_msg(b) ((const char *)(b) + (b)->msg_disp) =20 -#define BUGFRAME_warn 0 -#define BUGFRAME_bug 1 -#define BUGFRAME_assert 2 +#define BUGFRAME_run_fn 0 +#define BUGFRAME_warn 1 +#define BUGFRAME_bug 2 +#define BUGFRAME_assert 3 =20 -#define BUGFRAME_NR 3 +#define BUGFRAME_NR 4 =20 /* Many versions of GCC doesn't support the asm %c parameter which would * be preferable to this unpleasantness. We use mergeable string * sections to avoid multiple copies of the string appearing in the * Xen image. */ -#define BUG_FRAME(type, line, file, has_msg, msg) do { = \ +#define BUG_FRAME(type, line, ptr, ptr_is_file, has_msg, msg) do { = \ BUILD_BUG_ON((line) >> 16); = \ BUILD_BUG_ON((type) >=3D BUGFRAME_NR); = \ asm ("1:"BUG_INSTR"\n" = \ ".pushsection .rodata.str, \"aMS\", %progbits, 1\n" = \ - "2:\t.asciz " __stringify(file) "\n" = \ + "2:\n" = \ + ".if " #ptr_is_file "\n" = \ + "\t.asciz " __stringify(ptr) "\n" = \ + ".endif\n" = \ "3:\n" = \ ".if " #has_msg "\n" = \ "\t.asciz " #msg "\n" = \ @@ -52,21 +56,27 @@ struct bug_frame { "4:\n" = \ ".p2align 2\n" = \ ".long (1b - 4b)\n" = \ + ".if " #ptr_is_file "\n" = \ ".long (2b - 4b)\n" = \ + ".else\n" = \ + ".long (" #ptr " - 4b)\n" = \ + ".endif\n" = \ ".long (3b - 4b)\n" = \ ".hword " __stringify(line) ", 0\n" = \ ".popsection"); = \ } while (0) =20 -#define WARN() BUG_FRAME(BUGFRAME_warn, __LINE__, __FILE__, 0, "") +#define run_in_exception_handler(fn) BUG_FRAME(BUGFRAME_run_fn, 0, fn, 0, = 0, "") + +#define WARN() BUG_FRAME(BUGFRAME_warn, __LINE__, __FILE__, 1, 0, "") =20 #define BUG() do { \ - BUG_FRAME(BUGFRAME_bug, __LINE__, __FILE__, 0, ""); \ + BUG_FRAME(BUGFRAME_bug, __LINE__, __FILE__, 1, 0, ""); \ unreachable(); \ } while (0) =20 #define assert_failed(msg) do { \ - BUG_FRAME(BUGFRAME_assert, __LINE__, __FILE__, 1, msg); \ + BUG_FRAME(BUGFRAME_assert, __LINE__, __FILE__, 1, 1, msg); \ unreachable(); \ } while (0) =20 --=20 2.26.2 From nobody Fri May 3 23:49:07 2024 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) client-ip=192.237.175.120; envelope-from=xen-devel-bounces@lists.xenproject.org; helo=lists.xenproject.org; Authentication-Results: mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org; dmarc=pass(p=quarantine dis=none) header.from=suse.com ARC-Seal: i=1; a=rsa-sha256; t=1607932605; cv=none; d=zohomail.com; s=zohoarc; b=bNjsHdY3JYhErKIlgc5a+UV2myAQYhVW0RB+OP90GAK7wYovssSqL40eruiGt8zVpFl5Dt72SP7T9gUNQEy/n7gGj9jIr1zd5+RhTbMz1HuqFiW7uCwNS1Pj+DNN0VWf7TGBUCXHp2OYZmzGCvTUUTJAHRTpXaDvjeUg8x1LFDs= ARC-Message-Signature: i=1; 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Mon, 14 Dec 2020 07:56:22 +0000 Received: by outflank-mailman (output) from mailman id 51923.90841; Mon, 14 Dec 2020 07:56:21 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1koiiT-00085w-TL; Mon, 14 Dec 2020 07:56:21 +0000 Received: by outflank-mailman (input) for mailman id 51923; Mon, 14 Dec 2020 07:56:20 +0000 Received: from all-amaz-eas1.inumbo.com ([34.197.232.57] helo=us1-amaz-eas2.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1koiiS-00084z-9R for xen-devel@lists.xenproject.org; Mon, 14 Dec 2020 07:56:20 +0000 Received: from mx2.suse.de (unknown [195.135.220.15]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTPS id 9baafd8a-bc33-4ffc-8299-c22e92bc3d06; Mon, 14 Dec 2020 07:56:18 +0000 (UTC) Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id B1377AD4D; Mon, 14 Dec 2020 07:56:17 +0000 (UTC) X-Outflank-Mailman: Message body and most headers restored to incoming version X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 9baafd8a-bc33-4ffc-8299-c22e92bc3d06 X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1607932577; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=KnYqlf/P+S7NcIzAGFzhLoCYbM4Ex5RUcFQo+09bQv0=; b=JMIzCIoqvl+4Kk85zJ96fL3dk1LmsPf7Eh90am/VZ8i3hIbfNMeKcneb9ggiJJlXwZqy9a 5mdT6doWSYcEioBQeFwH+n+Ukf3MXE53xbmkeT+fHY/gn7OI/soD0d+F3La1R9/3W1sM5N tAjNq8oW73Uxicw76ymhKMK82ifFKZE= From: Juergen Gross To: xen-devel@lists.xenproject.org Cc: Juergen Gross , Andrew Cooper , George Dunlap , Ian Jackson , Jan Beulich , Julien Grall , Stefano Stabellini , Wei Liu Subject: [PATCH v4 2/3] xen: enable keyhandlers to work without register set specified Date: Mon, 14 Dec 2020 08:56:14 +0100 Message-Id: <20201214075615.25038-3-jgross@suse.com> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20201214075615.25038-1-jgross@suse.com> References: <20201214075615.25038-1-jgross@suse.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-ZohoMail-DKIM: pass (identity @suse.com) Content-Type: text/plain; charset="utf-8" There are only two keyhandlers which make use of the cpu_user_regs struct passed to them. In order to be able to call any keyhandler in non-interrupt contexts, too, modify those two handlers to copy with a NULL regs pointer by using run_in_exception_handler() in that case. Suggested-by: Julien Grall Signed-off-by: Juergen Gross --- V4: - new patch --- xen/common/keyhandler.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) diff --git a/xen/common/keyhandler.c b/xen/common/keyhandler.c index 68364e987d..de120fa092 100644 --- a/xen/common/keyhandler.c +++ b/xen/common/keyhandler.c @@ -181,7 +181,10 @@ static void dump_registers(unsigned char key, struct c= pu_user_regs *regs) cpumask_copy(&dump_execstate_mask, &cpu_online_map); =20 /* Get local execution state out immediately, in case we get stuck. */ - dump_execstate(regs); + if ( regs ) + dump_execstate(regs); + else + run_in_exception_handler(dump_execstate); =20 /* Alt. handling: remaining CPUs are dumped asynchronously one-by-one.= */ if ( alt_key_handling ) @@ -481,15 +484,24 @@ static void run_all_keyhandlers(unsigned char key, st= ruct cpu_user_regs *regs) tasklet_schedule(&run_all_keyhandlers_tasklet); } =20 -static void do_debug_key(unsigned char key, struct cpu_user_regs *regs) +/* run_in_exception_handler() on Arm requires globally visible symbol. */ +void do_debugger_trap_fatal(struct cpu_user_regs *regs) { - printk("'%c' pressed -> trapping into debugger\n", key); (void)debugger_trap_fatal(0xf001, regs); =20 /* Prevent tail call optimisation, which confuses xendbg. */ barrier(); } =20 +static void do_debug_key(unsigned char key, struct cpu_user_regs *regs) +{ + printk("'%c' pressed -> trapping into debugger\n", key); + if ( regs ) + do_debugger_trap_fatal(regs); + else + run_in_exception_handler(do_debugger_trap_fatal); +} + static void do_toggle_alt_key(unsigned char key, struct cpu_user_regs *reg= s) { alt_key_handling =3D !alt_key_handling; --=20 2.26.2 From nobody Fri May 3 23:49:07 2024 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) client-ip=192.237.175.120; envelope-from=xen-devel-bounces@lists.xenproject.org; helo=lists.xenproject.org; Authentication-Results: mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org; 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Mon, 14 Dec 2020 07:56:18 +0000 (UTC) Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id ED18CADE1; Mon, 14 Dec 2020 07:56:17 +0000 (UTC) X-Outflank-Mailman: Message body and most headers restored to incoming version X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: cc7a59b2-24d4-49b6-bf31-c7e39c17db19 X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1607932578; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=suR4RG6T/UXhQCsJzrD78qjsYpHI44RyxZHYiYIhyhw=; b=ZtZ4p22y1wIsbwX5UkkNEa8JLGpdr1YGd8rGp9CFD2oinxfY/TU+5H5Hx5w23+vQYkcrRY P7dM1MX9lxk3rDH6NP1hUB+tsFy03al58u66BlH5dufaxtLvrkSF/dNmeC62k+Pm5Mxr0t iGtCsuCU2EyLHcugQwD3yMiBOtkr3nk= From: Juergen Gross To: xen-devel@lists.xenproject.org Cc: Juergen Gross , Andrew Cooper , George Dunlap , Ian Jackson , Jan Beulich , Julien Grall , Stefano Stabellini , Wei Liu Subject: [PATCH v4 3/3] xen: add support for automatic debug key actions in case of crash Date: Mon, 14 Dec 2020 08:56:15 +0100 Message-Id: <20201214075615.25038-4-jgross@suse.com> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20201214075615.25038-1-jgross@suse.com> References: <20201214075615.25038-1-jgross@suse.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-ZohoMail-DKIM: pass (identity @suse.com) Content-Type: text/plain; charset="utf-8" When the host crashes it would sometimes be nice to have additional debug data available which could be produced via debug keys, but halting the server for manual intervention might be impossible due to the need to reboot/kexec rather sooner than later. Add support for automatic debug key actions in case of crashes which can be activated via boot- or runtime-parameter. Depending on the type of crash the desired data might be different, so support different settings for the possible types of crashes. The parameter is "crash-debug" with the following syntax: crash-debug-=3D with being one of: panic, hwdom, watchdog, kexeccmd, debugkey and a sequence of debug key characters with '+' having the special semantics of a 10 millisecond pause. So "crash-debug-watchdog=3D0+0qr" would result in special output in case of watchdog triggered crash (dom0 state, 10 ms pause, dom0 state, domain info, run queues). Signed-off-by: Juergen Gross Reviewed-by: Jan Beulich --- V2: - switched special character '.' to '+' (Jan Beulich) - 10 ms instead of 1 s pause (Jan Beulich) - added more text to the boot parameter description (Jan Beulich) V3: - added const (Jan Beulich) - thorough test of crash reason parameter (Jan Beulich) - kexeccmd case should depend on CONFIG_KEXEC (Jan Beulich) - added dummy get_irq_regs() helper on Arm V4: - call keyhandlers with NULL for regs - use ARRAY_SIZE() (Jan Beulich) - don't activate handlers in early boot (Jan Beulich) - avoid recursion - extend documentation a bit Signed-off-by: Juergen Gross --- docs/misc/xen-command-line.pandoc | 41 +++++++++++++++++++++++ xen/common/kexec.c | 8 +++-- xen/common/keyhandler.c | 55 +++++++++++++++++++++++++++++++ xen/common/shutdown.c | 4 +-- xen/drivers/char/console.c | 2 +- xen/include/xen/kexec.h | 10 ++++-- xen/include/xen/keyhandler.h | 10 ++++++ 7 files changed, 122 insertions(+), 8 deletions(-) diff --git a/docs/misc/xen-command-line.pandoc b/docs/misc/xen-command-line= .pandoc index b4a0d60c11..e4c0a144fc 100644 --- a/docs/misc/xen-command-line.pandoc +++ b/docs/misc/xen-command-line.pandoc @@ -574,6 +574,47 @@ reduction of features at Xen's disposal to manage gues= ts. ### cpuinfo (x86) > `=3D ` =20 +### crash-debug-debugkey +### crash-debug-hwdom +### crash-debug-kexeccmd +### crash-debug-panic +### crash-debug-watchdog +> `=3D ` + +> Can be modified at runtime + +Specify debug-key actions in cases of crashes. Each of the parameters appl= ies +to a different crash reason. The `` is a sequence of debug key +characters, with `+` having the special meaning of a 10 millisecond pause. + +`crash-debug-debugkey` will be used for crashes induced by the `C` debug +key (i.e. manually induced crash). + +`crash-debug-hwdom` denotes a crash of dom0. + +`crash-debug-kexeccmd` is an explicit request of dom0 to continue with the +kdump kernel via kexec. Only available on hypervisors built with CONFIG_KE= XEC. + +`crash-debug-panic` is a crash of the hypervisor. + +`crash-debug-watchdog` is a crash due to the watchdog timer expiring. + +It should be noted that dumping diagnosis data to the console can fail in +multiple ways (missing data, hanging system, ...) depending on the reason +of the crash, which might have left the hypervisor in a bad state. In case +a debug-key action leads to another crash recursion will be avoided, so no +additional debug-key actions will be performed in this case. A crash in the +early boot phase will not result in any debug-key action, as the system +might not yet be in a state where the handlers can work. + +So e.g. `crash-debug-watchdog=3D0+0r` would dump dom0 state twice with 10 +milliseconds between the two state dumps, followed by the run queues of the +hypervisor, if the system crashes due to a watchdog timeout. + +Depending on the reason of the system crash it might happen that triggering +some debug key action will result in a hang instead of dumping data and th= en +doing a reboot or crash dump. + ### crashinfo_maxaddr > `=3D ` =20 diff --git a/xen/common/kexec.c b/xen/common/kexec.c index 52cdc4ebc3..ebeee6405a 100644 --- a/xen/common/kexec.c +++ b/xen/common/kexec.c @@ -373,10 +373,12 @@ static int kexec_common_shutdown(void) return 0; } =20 -void kexec_crash(void) +void kexec_crash(enum crash_reason reason) { int pos; =20 + keyhandler_crash_action(reason); + pos =3D (test_bit(KEXEC_FLAG_CRASH_POS, &kexec_flags) !=3D 0); if ( !test_bit(KEXEC_IMAGE_CRASH_BASE + pos, &kexec_flags) ) return; @@ -409,7 +411,7 @@ static long kexec_reboot(void *_image) static void do_crashdump_trigger(unsigned char key) { printk("'%c' pressed -> triggering crashdump\n", key); - kexec_crash(); + kexec_crash(CRASHREASON_DEBUGKEY); printk(" * no crash kernel loaded!\n"); } =20 @@ -840,7 +842,7 @@ static int kexec_exec(XEN_GUEST_HANDLE_PARAM(void) uarg) ret =3D continue_hypercall_on_cpu(0, kexec_reboot, image); break; case KEXEC_TYPE_CRASH: - kexec_crash(); /* Does not return */ + kexec_crash(CRASHREASON_KEXECCMD); /* Does not return */ break; } =20 diff --git a/xen/common/keyhandler.c b/xen/common/keyhandler.c index de120fa092..806355ed8b 100644 --- a/xen/common/keyhandler.c +++ b/xen/common/keyhandler.c @@ -3,7 +3,9 @@ */ =20 #include +#include #include +#include #include #include #include @@ -519,6 +521,59 @@ void __init initialize_keytable(void) } } =20 +#define CRASHACTION_SIZE 32 +static char crash_debug_panic[CRASHACTION_SIZE]; +string_runtime_param("crash-debug-panic", crash_debug_panic); +static char crash_debug_hwdom[CRASHACTION_SIZE]; +string_runtime_param("crash-debug-hwdom", crash_debug_hwdom); +static char crash_debug_watchdog[CRASHACTION_SIZE]; +string_runtime_param("crash-debug-watchdog", crash_debug_watchdog); +#ifdef CONFIG_KEXEC +static char crash_debug_kexeccmd[CRASHACTION_SIZE]; +string_runtime_param("crash-debug-kexeccmd", crash_debug_kexeccmd); +#else +#define crash_debug_kexeccmd NULL +#endif +static char crash_debug_debugkey[CRASHACTION_SIZE]; +string_runtime_param("crash-debug-debugkey", crash_debug_debugkey); + +void keyhandler_crash_action(enum crash_reason reason) +{ + static const char *const crash_action[] =3D { + [CRASHREASON_PANIC] =3D crash_debug_panic, + [CRASHREASON_HWDOM] =3D crash_debug_hwdom, + [CRASHREASON_WATCHDOG] =3D crash_debug_watchdog, + [CRASHREASON_KEXECCMD] =3D crash_debug_kexeccmd, + [CRASHREASON_DEBUGKEY] =3D crash_debug_debugkey, + }; + static bool ignore; + const char *action; + + /* Some handlers are not functional too early. */ + if ( system_state < SYS_STATE_smp_boot ) + return; + + /* Avoid recursion. */ + if ( ignore ) + return; + ignore =3D true; + + if ( (unsigned int)reason >=3D ARRAY_SIZE(crash_action) ) + return; + action =3D crash_action[reason]; + if ( !action ) + return; + + while ( *action ) + { + if ( *action =3D=3D '+' ) + mdelay(10); + else + handle_keypress(*action, NULL); + action++; + } +} + /* * Local variables: * mode: C diff --git a/xen/common/shutdown.c b/xen/common/shutdown.c index 912593915b..abde48aa4c 100644 --- a/xen/common/shutdown.c +++ b/xen/common/shutdown.c @@ -43,7 +43,7 @@ void hwdom_shutdown(u8 reason) case SHUTDOWN_crash: debugger_trap_immediate(); printk("Hardware Dom%u crashed: ", hardware_domain->domain_id); - kexec_crash(); + kexec_crash(CRASHREASON_HWDOM); maybe_reboot(); break; /* not reached */ =20 @@ -56,7 +56,7 @@ void hwdom_shutdown(u8 reason) case SHUTDOWN_watchdog: printk("Hardware Dom%u shutdown: watchdog rebooting machine\n", hardware_domain->domain_id); - kexec_crash(); + kexec_crash(CRASHREASON_WATCHDOG); machine_restart(0); break; /* not reached */ =20 diff --git a/xen/drivers/char/console.c b/xen/drivers/char/console.c index 861ad53a8f..acec277f5e 100644 --- a/xen/drivers/char/console.c +++ b/xen/drivers/char/console.c @@ -1271,7 +1271,7 @@ void panic(const char *fmt, ...) =20 debugger_trap_immediate(); =20 - kexec_crash(); + kexec_crash(CRASHREASON_PANIC); =20 if ( opt_noreboot ) machine_halt(); diff --git a/xen/include/xen/kexec.h b/xen/include/xen/kexec.h index e85ba16405..9f7a912e97 100644 --- a/xen/include/xen/kexec.h +++ b/xen/include/xen/kexec.h @@ -1,6 +1,8 @@ #ifndef __XEN_KEXEC_H__ #define __XEN_KEXEC_H__ =20 +#include + #ifdef CONFIG_KEXEC =20 #include @@ -48,7 +50,7 @@ void machine_kexec_unload(struct kexec_image *image); void machine_kexec_reserved(xen_kexec_reserve_t *reservation); void machine_reboot_kexec(struct kexec_image *image); void machine_kexec(struct kexec_image *image); -void kexec_crash(void); +void kexec_crash(enum crash_reason reason); void kexec_crash_save_cpu(void); struct crash_xen_info *kexec_crash_save_info(void); void machine_crash_shutdown(void); @@ -82,7 +84,11 @@ void vmcoreinfo_append_str(const char *fmt, ...) #define kexecing 0 =20 static inline void kexec_early_calculations(void) {} -static inline void kexec_crash(void) {} +static inline void kexec_crash(enum crash_reason reason) +{ + keyhandler_crash_action(reason); +} + static inline void kexec_crash_save_cpu(void) {} static inline void set_kexec_crash_area_size(u64 system_ram) {} =20 diff --git a/xen/include/xen/keyhandler.h b/xen/include/xen/keyhandler.h index 5131e86cbc..9c5830a037 100644 --- a/xen/include/xen/keyhandler.h +++ b/xen/include/xen/keyhandler.h @@ -48,4 +48,14 @@ void register_irq_keyhandler(unsigned char key, /* Inject a keypress into the key-handling subsystem. */ extern void handle_keypress(unsigned char key, struct cpu_user_regs *regs); =20 +enum crash_reason { + CRASHREASON_PANIC, + CRASHREASON_HWDOM, + CRASHREASON_WATCHDOG, + CRASHREASON_KEXECCMD, + CRASHREASON_DEBUGKEY, +}; + +void keyhandler_crash_action(enum crash_reason reason); + #endif /* __XEN_KEYHANDLER_H__ */ --=20 2.26.2