From patchwork Wed Oct 2 14:50:42 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Noah Goldstein X-Patchwork-Id: 13819878 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 CFC6CCF6D2C for ; Wed, 2 Oct 2024 14:51:32 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1sw0gz-0003l0-OD; Wed, 02 Oct 2024 10:51:05 -0400 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 1sw0gr-0003kr-Uv for qemu-devel@nongnu.org; Wed, 02 Oct 2024 10:50:57 -0400 Received: from mail-oi1-x234.google.com ([2607:f8b0:4864:20::234]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1sw0gq-0001bZ-6X for qemu-devel@nongnu.org; Wed, 02 Oct 2024 10:50:57 -0400 Received: by mail-oi1-x234.google.com with SMTP id 5614622812f47-3e04801bb65so3718460b6e.0 for ; Wed, 02 Oct 2024 07:50:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1727880654; x=1728485454; darn=nongnu.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=09KvACH4arAXjV+oT9t8w/5nQn5cnKAOwRFPFd/Tva0=; b=F+x0cKEi6JJkp5H4ErT0ac5Io1yQewWbt8f04A29LOa+0by5sinvOS5aa2Tfj6gmtl QIfESr0/j5LK/rWao/vJavNWxRP8U5FNVM8pM3HlVnLxljIXN31avQijS6SU4aqU3XZG RNcmPoQVzG/IB/SPeQ+Qi2EXckw1fI++JSOViBpzsOkxRAUpdQZm8fArmG4pYyAvICet DCU9KbOr9uVkdegq7Wsi6nhuqplJr4CxXwWl7+PD0nYXYtIzt5oEqiRnyZ0BcXhetCGi rg2oSJ7IbWQxEOO1losNix1TSeURNTaveJOl5kRmSi8E7Q3wnrP619ujLRJv/2jT8Vgv UBaw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1727880654; x=1728485454; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=09KvACH4arAXjV+oT9t8w/5nQn5cnKAOwRFPFd/Tva0=; b=CvYnQh9KXkU3lODZ+E0SNR0+55xCXXSpOs/gCXe2lJSSQAhQarMQ72HuxGYqMD6vws ATEX0T5f0mZCmb9k+hcSRkzD7DNqoakEIMbtQdV/n8GqF9fv6lS4y1Hdm3B5z3FJFSo5 LsjRFnYpMrrEwgZCoD2G168czqihNcYEX53u6tp+kfC6CR79U0TVG/QZ0q9Z1j0q/1G6 b81hpZ8jLDQ8jI94emqA1JKEvim+EABd60TNvov9f42C/JmgvLAFV/qmX8XLlByw3/FJ ATvncmLa91CF3ItNiDeFq3AGUcMjopT/NMbwuID/54++bnhm0WV8osQi8ToYbAUyEgmN +8VA== X-Gm-Message-State: AOJu0YxDd+T1HnJEGMKNnXh58cPvcPzAl0k1nF9kmBG9fY1kh7ujbsFZ UnJJjPOmU+jx1WpXz1uIriCqL3YlgNCnT6ADyxhMfRh8MQYQJIG9Vz/H4lYz X-Google-Smtp-Source: AGHT+IH93Ombi39Q51Lm3dHDUZW2b6QuVOB8cAxWoUZ9y2YUhOhh49rkiJm2N7r8yrKOTGyVpJ++EQ== X-Received: by 2002:a05:6808:f04:b0:3e0:4674:79c7 with SMTP id 5614622812f47-3e3b4176a47mr2705556b6e.39.1727880654493; Wed, 02 Oct 2024 07:50:54 -0700 (PDT) Received: from localhost.localdomain.lan ([2603:8080:1600:131:df30:868d:97ce:27b]) by smtp.gmail.com with ESMTPSA id 5614622812f47-3e393597da1sm3704368b6e.25.2024.10.02.07.50.53 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 02 Oct 2024 07:50:54 -0700 (PDT) From: Noah Goldstein To: qemu-devel@nongnu.org Cc: goldstein.w.n@gmail.com, iii@linux.ibm.com, laurent@vivier.eu Subject: [PATCH v2] linux-user: Add option to run `execve`d programs through QEMU Date: Wed, 2 Oct 2024 09:50:42 -0500 Message-ID: <20241002145042.1142194-1-goldstein.w.n@gmail.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240830223601.2796327-1-goldstein.w.n@gmail.com> References: <20240830223601.2796327-1-goldstein.w.n@gmail.com> MIME-Version: 1.0 Received-SPF: pass client-ip=2607:f8b0:4864:20::234; envelope-from=goldstein.w.n@gmail.com; helo=mail-oi1-x234.google.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_FROM=0.001, RCVD_IN_DNSWL_NONE=-0.0001, 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 The new option '-qemu-children' makes it so that on `execve` the child process will be launch by the same `qemu` executable that is currently running along with its current commandline arguments. The motivation for the change is to make it so that plugins running through `qemu` can continue to run on children. Why not just `binfmt`?: Plugins can be desirable regardless of system/architecture emulation, and can sometimes be useful for elf files that can run natively. Enabling `binfmt` for all natively runnable elf files may not be desirable. Signed-off-by: Noah Goldstein --- linux-user/main.c | 21 +++++++++++++++++++++ linux-user/syscall.c | 21 ++++++++++++++++----- linux-user/user-internals.h | 4 ++++ 3 files changed, 41 insertions(+), 5 deletions(-) diff --git a/linux-user/main.c b/linux-user/main.c index 8143a0d4b0..5e3d41dc2b 100644 --- a/linux-user/main.c +++ b/linux-user/main.c @@ -81,6 +81,10 @@ unsigned long mmap_min_addr; uintptr_t guest_base; bool have_guest_base; +bool qemu_dup_for_children; +int qemu_argc; +char **qemu_argv; + /* * Used to implement backwards-compatibility for the `-strace`, and * QEMU_STRACE options. Without this, the QEMU_LOG can be overwritten by @@ -451,6 +455,11 @@ static void handle_arg_jitdump(const char *arg) perf_enable_jitdump(); } +static void handle_arg_qemu_children(const char *arg) +{ + qemu_dup_for_children = true; +} + static QemuPluginList plugins = QTAILQ_HEAD_INITIALIZER(plugins); #ifdef CONFIG_PLUGIN @@ -526,6 +535,10 @@ static const struct qemu_argument arg_table[] = { "", "Generate a /tmp/perf-${pid}.map file for perf"}, {"jitdump", "QEMU_JITDUMP", false, handle_arg_jitdump, "", "Generate a jit-${pid}.dump file for perf"}, + {"qemu-children", + "QEMU_CHILDREN", false, handle_arg_qemu_children, + "", "Run child processes (created with execve) with qemu " + "(as instantiated for the parent)"}, {NULL, NULL, false, NULL, NULL, NULL} }; @@ -729,6 +742,14 @@ int main(int argc, char **argv, char **envp) optind = parse_args(argc, argv); + if (qemu_dup_for_children) { + qemu_argc = optind; + qemu_argv = g_new0(char *, qemu_argc); + for (i = 0; i < optind; ++i) { + qemu_argv[i] = strdup(argv[i]); + } + } + qemu_set_log_filename_flags(last_log_filename, last_log_mask | (enable_strace * LOG_STRACE), &error_fatal); diff --git a/linux-user/syscall.c b/linux-user/syscall.c index a666986189..79019c0db0 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -8457,13 +8457,14 @@ static int do_execv(CPUArchState *cpu_env, int dirfd, abi_long pathname, abi_long guest_argp, abi_long guest_envp, int flags, bool is_execveat) { - int ret; + int ret, argp_offset; char **argp, **envp; int argc, envc; abi_ulong gp; abi_ulong addr; char **q; void *p; + bool through_qemu = dirfd == AT_FDCWD && qemu_dup_for_children; argc = 0; @@ -8487,10 +8488,12 @@ static int do_execv(CPUArchState *cpu_env, int dirfd, envc++; } - argp = g_new0(char *, argc + 1); + argp_offset = through_qemu ? qemu_argc : 0; + argp = g_new0(char *, argc + argp_offset + 1); envp = g_new0(char *, envc + 1); - for (gp = guest_argp, q = argp; gp; gp += sizeof(abi_ulong), q++) { + for (gp = guest_argp, q = argp + argp_offset; + gp; gp += sizeof(abi_ulong), q++) { if (get_user_ual(addr, gp)) { goto execve_efault; } @@ -8535,9 +8538,16 @@ static int do_execv(CPUArchState *cpu_env, int dirfd, } const char *exe = p; - if (is_proc_myself(p, "exe")) { + if (through_qemu) { + int i; + for (i = 0; i < argp_offset; ++i) { + argp[i] = qemu_argv[i]; + } + exe = qemu_argv[0]; + } else if (is_proc_myself(p, "exe")) { exe = exec_path; } + ret = is_execveat ? safe_execveat(dirfd, exe, argp, envp, flags) : safe_execve(exe, argp, envp); @@ -8551,7 +8561,8 @@ execve_efault: ret = -TARGET_EFAULT; execve_end: - for (gp = guest_argp, q = argp; *q; gp += sizeof(abi_ulong), q++) { + for (gp = guest_argp, q = argp + argp_offset; + *q; gp += sizeof(abi_ulong), q++) { if (get_user_ual(addr, gp) || !addr) { break; } diff --git a/linux-user/user-internals.h b/linux-user/user-internals.h index 5c7f173ceb..a4615eee54 100644 --- a/linux-user/user-internals.h +++ b/linux-user/user-internals.h @@ -30,6 +30,10 @@ void stop_all_tasks(void); extern const char *qemu_uname_release; extern unsigned long mmap_min_addr; +extern bool qemu_dup_for_children; +extern int qemu_argc; +extern char **qemu_argv; + typedef struct IOCTLEntry IOCTLEntry; typedef abi_long do_ioctl_fn(const IOCTLEntry *ie, uint8_t *buf_temp,