From patchwork Wed Jan 8 20:05:02 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ilya Leoshkevich X-Patchwork-Id: 13931510 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 lists.gnu.org (lists.gnu.org [209.51.188.17]) (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 C3C30E77188 for ; Wed, 8 Jan 2025 20:27:28 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1tVcdm-0007Gp-IZ; Wed, 08 Jan 2025 15:26:58 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1tVcdb-0007Dx-Um for qemu-devel@nongnu.org; Wed, 08 Jan 2025 15:26:50 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1tVcda-0006sF-7N for qemu-devel@nongnu.org; Wed, 08 Jan 2025 15:26:47 -0500 Received: from pps.filterd (m0353725.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 508E6JMj032725; Wed, 8 Jan 2025 20:26:35 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=cc :content-transfer-encoding:date:from:in-reply-to:message-id :mime-version:references:subject:to; s=pp1; bh=0HYadt2Bci6R3ZhHv Ykb4RWPdq1pPEoIeLGOO4wuU6k=; b=F53sFiMFKyZoAs8qjifmGtDizs96kzsTc pXR2nwkx3BhBBNB8AfcSe/d96ZVYCxvp9gq3eRqionvqKKB9JGj4/l64Es6Gea63 a/qeZiubOjBt/ocH8GFjX9J5kDgA624dWdh5Q4AY+tfWUvBPBg5roL6W97It9waH xQFqTu4aDP0gDxbD3HGY22HvaZq0/w439m6oVBh7oukwbBmNmjhmo/HobTmJ9O8b idc+DRBtMEpyfWs8/TlVKP+Oz2x0p2bpOmJfWo/jAKackO0qAkFACpXyVeomLezK 0QGkQ5SODFazZr/87jIbKzD6FnxnX78ATPxs1H9e3cXMewyTDc2Fw== Received: from ppma21.wdc07v.mail.ibm.com (5b.69.3da9.ip4.static.sl-reverse.com [169.61.105.91]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 441tu5hmmk-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 08 Jan 2025 20:26:35 +0000 (GMT) Received: from pps.filterd (ppma21.wdc07v.mail.ibm.com [127.0.0.1]) by ppma21.wdc07v.mail.ibm.com (8.18.1.2/8.18.1.2) with ESMTP id 508GoeMi013663; Wed, 8 Jan 2025 20:26:34 GMT Received: from smtprelay04.fra02v.mail.ibm.com ([9.218.2.228]) by ppma21.wdc07v.mail.ibm.com (PPS) with ESMTPS id 43ygap1jr2-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 08 Jan 2025 20:26:34 +0000 Received: from smtpav02.fra02v.mail.ibm.com (smtpav02.fra02v.mail.ibm.com [10.20.54.101]) by smtprelay04.fra02v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 508KQWiD12452164 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 8 Jan 2025 20:26:32 GMT Received: from smtpav02.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 944EC2004B; Wed, 8 Jan 2025 20:26:32 +0000 (GMT) Received: from smtpav02.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id F2CE320040; Wed, 8 Jan 2025 20:26:31 +0000 (GMT) Received: from heavy.ibm.com (unknown [9.179.24.127]) by smtpav02.fra02v.mail.ibm.com (Postfix) with ESMTP; Wed, 8 Jan 2025 20:26:31 +0000 (GMT) From: Ilya Leoshkevich To: Warner Losh , Riku Voipio , Laurent Vivier , Paolo Bonzini , Richard Henderson , =?utf-8?q?Alex_Benn=C3=A9?= =?utf-8?q?e?= Cc: Kyle Evans , =?utf-8?q?Philippe_Mathieu-Daud=C3=A9?= , qemu-devel@nongnu.org, Ilya Leoshkevich Subject: [PATCH v4 7/9] gdbstub: Allow late attachment Date: Wed, 8 Jan 2025 21:05:02 +0100 Message-ID: <20250108202625.149869-8-iii@linux.ibm.com> X-Mailer: git-send-email 2.47.1 In-Reply-To: <20250108202625.149869-1-iii@linux.ibm.com> References: <20250108202625.149869-1-iii@linux.ibm.com> MIME-Version: 1.0 X-TM-AS-GCONF: 00 X-Proofpoint-GUID: MEiQeJe4u-uFAMiOFUVZOXOP3R7NaLc8 X-Proofpoint-ORIG-GUID: MEiQeJe4u-uFAMiOFUVZOXOP3R7NaLc8 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1051,Hydra:6.0.680,FMLib:17.12.62.30 definitions=2024-10-15_01,2024-10-11_01,2024-09-30_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 mlxscore=0 priorityscore=1501 mlxlogscore=861 adultscore=0 bulkscore=0 impostorscore=0 clxscore=1015 suspectscore=0 phishscore=0 malwarescore=0 spamscore=0 lowpriorityscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.19.0-2411120000 definitions=main-2501080163 Received-SPF: pass client-ip=148.163.158.5; envelope-from=iii@linux.ibm.com; helo=mx0b-001b2d01.pphosted.com X-Spam_score_int: -26 X-Spam_score: -2.7 X-Spam_bar: -- X-Spam_report: (-2.7 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H2=-0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Allow debugging individual processes in multi-process applications by starting them with export QEMU_GDB=/tmp/qemu-%d.sock,suspend=n. Currently one would have to attach to every process to ensure the app makes progress. In case suspend=n is not specified, the flow remains unchanged. If it is specified, then accepting the client connection is delegated to a thread. In the future this machinery may be reused for handling reconnections and interruptions. On accepting a connection, the thread schedules gdb_handlesig() on the first CPU and wakes it up with host_interrupt_signal. Note that the result of this gdb_handlesig() invocation is handled, as opposed to many other existing call sites. These other call sites probably need to be fixed separately. Signed-off-by: Ilya Leoshkevich --- bsd-user/main.c | 1 - gdbstub/user.c | 118 ++++++++++++++++++++++++++++++++++++++++++---- linux-user/main.c | 1 - 3 files changed, 108 insertions(+), 12 deletions(-) diff --git a/bsd-user/main.c b/bsd-user/main.c index 0a5bc578365..478c2b65e7d 100644 --- a/bsd-user/main.c +++ b/bsd-user/main.c @@ -629,7 +629,6 @@ int main(int argc, char **argv) if (gdbstub) { gdbserver_start(gdbstub); - gdb_handlesig(cpu, 0, NULL, NULL, 0); } cpu_loop(env); /* never exits */ diff --git a/gdbstub/user.c b/gdbstub/user.c index 2c500eb1e23..23fe4104a92 100644 --- a/gdbstub/user.c +++ b/gdbstub/user.c @@ -22,6 +22,7 @@ #include "gdbstub/user.h" #include "gdbstub/enums.h" #include "hw/core/cpu.h" +#include "user/signal.h" #include "trace.h" #include "internals.h" @@ -401,11 +402,100 @@ static int gdbserver_open_port(int port) return fd; } -int gdbserver_start(const char *port_or_path) +static bool gdbserver_accept(int port, int gdb_fd, const char *path) { - int port = g_ascii_strtoull(port_or_path, NULL, 10); + bool ret; + + if (port > 0) { + ret = gdb_accept_tcp(gdb_fd); + } else { + ret = gdb_accept_socket(gdb_fd); + if (ret) { + gdbserver_user_state.socket_path = g_strdup(path); + } + } + + if (!ret) { + close(gdb_fd); + } + + return ret; +} + +struct { + int port; int gdb_fd; + char *path; +} gdbserver_args; + +static void do_gdb_handlesig(CPUState *cs, run_on_cpu_data arg) +{ + int sig; + sig = target_to_host_signal(gdb_handlesig(cs, 0, NULL, NULL, 0)); + if (sig >= 1 && sig < NSIG) { + qemu_kill_thread(gdb_get_cpu_index(cs), sig); + } +} + +static void *gdbserver_accept_thread(void *arg) +{ + if (gdbserver_accept(gdbserver_args.port, gdbserver_args.gdb_fd, + gdbserver_args.path)) { + CPUState *cs = first_cpu; + + async_safe_run_on_cpu(cs, do_gdb_handlesig, RUN_ON_CPU_NULL); + qemu_kill_thread(gdb_get_cpu_index(cs), host_interrupt_signal); + } + + g_free(gdbserver_args.path); + gdbserver_args.path = NULL; + + return NULL; +} + +__attribute__((__format__(__printf__, 1, 2))) +static void print_usage(const char *format, ...) +{ + va_list ap; + + va_start(ap, format); + vfprintf(stderr, format, ap); + va_end(ap); + fprintf(stderr, "Usage: -g {port|path}[,suspend={y|n}]\n"); +} + +int gdbserver_start(const char *args) +{ + g_auto(GStrv) argv = g_strsplit(args, ",", 0); + const char *port_or_path = NULL; + bool suspend = true; + int gdb_fd, port; + GStrv arg; + + for (arg = argv; *arg; arg++) { + g_auto(GStrv) tokens = g_strsplit(*arg, "=", 2); + Error *err = NULL; + + if (g_strcmp0(tokens[0], "suspend") == 0) { + if (!qapi_bool_parse(tokens[0], tokens[1], &suspend, &err)) { + warn_report_err(err); + return -1; + } + } else { + if (port_or_path) { + print_usage("Unknown option: %s\n", *arg); + return -1; + } + port_or_path = *arg; + } + } + if (!port_or_path) { + print_usage("Port or path not specified\n"); + return -1; + } + + port = g_ascii_strtoull(port_or_path, NULL, 10); if (port > 0) { gdb_fd = gdbserver_open_port(port); } else { @@ -416,16 +506,24 @@ int gdbserver_start(const char *port_or_path) return -1; } - if (port > 0 && gdb_accept_tcp(gdb_fd)) { - return 0; - } else if (gdb_accept_socket(gdb_fd)) { - gdbserver_user_state.socket_path = g_strdup(port_or_path); + if (suspend) { + if (gdbserver_accept(port, gdb_fd, port_or_path)) { + gdb_handlesig(first_cpu, 0, NULL, NULL, 0); + return 0; + } else { + return -1; + } + } else { + QemuThread thread; + + gdbserver_args.port = port; + gdbserver_args.gdb_fd = gdb_fd; + gdbserver_args.path = g_strdup(port_or_path); + qemu_thread_create(&thread, "gdb-accept", + &gdbserver_accept_thread, NULL, + QEMU_THREAD_DETACHED); return 0; } - - /* gone wrong */ - close(gdb_fd); - return -1; } void gdbserver_fork_start(void) diff --git a/linux-user/main.c b/linux-user/main.c index b97634a32dd..affec6863aa 100644 --- a/linux-user/main.c +++ b/linux-user/main.c @@ -1028,7 +1028,6 @@ int main(int argc, char **argv, char **envp) gdbstub); exit(EXIT_FAILURE); } - gdb_handlesig(cpu, 0, NULL, NULL, 0); } #ifdef CONFIG_SEMIHOSTING