From patchwork Tue Aug 22 13:57:09 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Brown X-Patchwork-Id: 13360959 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 9FD04EE49AA for ; Tue, 22 Aug 2023 14:08:05 +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:Cc:To:In-Reply-To:References:Message-Id :MIME-Version:Subject:Date:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=+VzLzt6T2jHlHCwNpKFTk0aCAFPoSS4HkEce9AQMRq8=; b=iJvlhaRHKxQ/5/ RloGat2i++OHd/UD0SqMRK6JQ8GUIZwUjDVMM/QyS3FKxqNkS/c7kkIxAo02FJXSAQ47ICFxGewKy bku1Twe0x/9pWAPyNuNjCV3jzVXvW6/G4+SSWVkwpeGflAazVD1rDMSms/ff5sjxOcU04uO0wUaAg fkc21BKd9SKn4lN5KXiiGwuDthy6Fc7YkWp3f1aW6PoYnMTBwNjh6wI8zIOaLE86moS9likT3sMYl V41ePgvtxJ94xDNZx/pxhL0oZUVCRJiw9nj4VfUKkbjO0xUKZOVbO36lbVZsoILdsvCj7uxPWNg7I m+0/BQ6J6LhiSpeN/YXw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qYS36-00GAMA-2O; Tue, 22 Aug 2023 14:08:00 +0000 Received: from dfw.source.kernel.org ([139.178.84.217]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qYS22-00G9RI-1T; Tue, 22 Aug 2023 14:06:58 +0000 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id CB39F6548F; Tue, 22 Aug 2023 14:06:53 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 59F92C433C9; Tue, 22 Aug 2023 14:06:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1692713213; bh=lG3KgbVIo1r1OqYBn7opAKflBQLCvcGKxyXVF2NNf4w=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=CiQow4BjmfJmqzleMD+b9npvUMHjtcmzuNGuiQWARTf7ifueMyM/kIW6MB/j5DDjR ADPg//W7yeuahu1IxHQ1UCGd7YRRFZnibJtuzaSHDkpUt4oci5TNuRHZxIZx80kTfH u2D2UZIyl2i0u+QOg92n/n+/sKswnujTRA604P5N/bfjYWbo/acm44YP5brFdnaPP2 ZsazFqU5Vx6d97auFrB/X0Xw7sZs9H3gkrtTEM9BIgmyAtglU9WXITeWAyhwPVnP1R YmAFAFrJbXDW5paKsKCzKiff8DEGJumvLnmmN3W60Af7w/hJkJoB0g0KDglwEDM0fq NqxyYTwCfFVyA== From: Mark Brown Date: Tue, 22 Aug 2023 14:57:09 +0100 Subject: [PATCH v5 36/37] kselftest/arm64: Add a GCS stress test MIME-Version: 1.0 Message-Id: <20230822-arm64-gcs-v5-36-9ef181dd6324@kernel.org> References: <20230822-arm64-gcs-v5-0-9ef181dd6324@kernel.org> In-Reply-To: <20230822-arm64-gcs-v5-0-9ef181dd6324@kernel.org> To: Catalin Marinas , Will Deacon , Jonathan Corbet , Andrew Morton , Marc Zyngier , Oliver Upton , James Morse , Suzuki K Poulose , Arnd Bergmann , Oleg Nesterov , Eric Biederman , Kees Cook , Shuah Khan , "Rick P. Edgecombe" , Deepak Gupta , Ard Biesheuvel , Szabolcs Nagy Cc: "H.J. Lu" , Paul Walmsley , Palmer Dabbelt , Albert Ou , linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org, kvmarm@lists.linux.dev, linux-fsdevel@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org, Mark Brown X-Mailer: b4 0.13-dev-034f2 X-Developer-Signature: v=1; a=openpgp-sha256; l=21150; i=broonie@kernel.org; h=from:subject:message-id; bh=lG3KgbVIo1r1OqYBn7opAKflBQLCvcGKxyXVF2NNf4w=; b=owEBbQGS/pANAwAKASTWi3JdVIfQAcsmYgBk5MAMD9eTv7ZbDnXFHzBcOgPugi2QBotu5VZR8VDV 1jQnzT+JATMEAAEKAB0WIQSt5miqZ1cYtZ/in+ok1otyXVSH0AUCZOTADAAKCRAk1otyXVSH0LjHB/ 4+XJM+/z0FIm4iRmWfobp2p1YsKSiNDkMMxjZyQOl3E9dYd33xM/zgtXE3wbx0TE6745taRCnp64dy SSs4DLETfpA3MNwmP9s+rwSAJnQ+o+6psiOOeuSu1PaemPjgT609MQaL0XOgyQ2/IR2tpNq+wCpQkT l0RG3uRGNmGdqib1yu5fsbVPKPhWi4V/ExyYkscNR8cadjTlcdcwbThSR/8vk11kkqSnoJijoVU1nz Yv4tepADfQTiF3DtOa0pCEes9Aklj1amxCgZMh+SliJ+igTgucEwMZKdBufrgcXvAIVCpBuMWVvXfz Ivm5vuZYsjF0GAwAq8GecwZ8cuy8HL X-Developer-Key: i=broonie@kernel.org; a=openpgp; fpr=3F2568AAC26998F9E813A1C5C3F436CA30F5D8EB X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230822_070654_601423_6F79DF30 X-CRM114-Status: GOOD ( 28.51 ) 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: , Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org Add a stress test which runs one more process than we have CPUs spinning through a very recursive function with frequent syscalls immediately prior to return and signals being injected every 100ms. The goal is to flag up any scheduling related issues, for example failure to ensure that barriers are inserted when moving a GCS using task to another CPU. The test runs for a configurable amount of time, defaulting to 10 seconds. Signed-off-by: Mark Brown --- tools/testing/selftests/arm64/gcs/.gitignore | 2 + tools/testing/selftests/arm64/gcs/Makefile | 6 +- tools/testing/selftests/arm64/gcs/asm-offsets.h | 0 .../selftests/arm64/gcs/gcs-stress-thread.S | 311 ++++++++++++ tools/testing/selftests/arm64/gcs/gcs-stress.c | 532 +++++++++++++++++++++ 5 files changed, 850 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/arm64/gcs/.gitignore b/tools/testing/selftests/arm64/gcs/.gitignore index 0c86f53f68ad..1e8d1f6b27f2 100644 --- a/tools/testing/selftests/arm64/gcs/.gitignore +++ b/tools/testing/selftests/arm64/gcs/.gitignore @@ -1,3 +1,5 @@ basic-gcs libc-gcs gcs-locking +gcs-stress +gcs-stress-thread diff --git a/tools/testing/selftests/arm64/gcs/Makefile b/tools/testing/selftests/arm64/gcs/Makefile index 2173d6275956..d8b06ca51e22 100644 --- a/tools/testing/selftests/arm64/gcs/Makefile +++ b/tools/testing/selftests/arm64/gcs/Makefile @@ -6,7 +6,8 @@ # nolibc. # -TEST_GEN_PROGS := basic-gcs libc-gcs gcs-locking +TEST_GEN_PROGS := basic-gcs libc-gcs gcs-locking gcs-stress +TEST_GEN_PROGS_EXTENDED := gcs-stress-thread LDLIBS+=-lpthread @@ -18,3 +19,6 @@ $(OUTPUT)/basic-gcs: basic-gcs.c -I../../../../../usr/include \ -std=gnu99 -I../.. -g \ -ffreestanding -Wall $^ -o $@ -lgcc + +$(OUTPUT)/gcs-stress-thread: gcs-stress-thread.S + $(CC) -nostdlib $^ -o $@ diff --git a/tools/testing/selftests/arm64/gcs/asm-offsets.h b/tools/testing/selftests/arm64/gcs/asm-offsets.h new file mode 100644 index 000000000000..e69de29bb2d1 diff --git a/tools/testing/selftests/arm64/gcs/gcs-stress-thread.S b/tools/testing/selftests/arm64/gcs/gcs-stress-thread.S new file mode 100644 index 000000000000..4fe8695333e5 --- /dev/null +++ b/tools/testing/selftests/arm64/gcs/gcs-stress-thread.S @@ -0,0 +1,311 @@ +// Program that loops for ever doing lots of recursions and system calls, +// intended to be used as part of a stress test for GCS context switching. +// +// Copyright 2015-2023 Arm Ltd + +#include + +#define sa_sz 32 +#define sa_flags 8 +#define sa_handler 0 +#define sa_mask_sz 8 + +#define si_code 8 + +#define SIGINT 2 +#define SIGABRT 6 +#define SIGUSR1 10 +#define SIGSEGV 11 +#define SIGUSR2 12 +#define SIGTERM 15 +#define SEGV_CPERR 10 + +#define SA_NODEFER 1073741824 +#define SA_SIGINFO 4 +#define ucontext_regs 184 + +#define PR_SET_SHADOW_STACK_STATUS 72 +# define PR_SHADOW_STACK_ENABLE (1UL << 0) + +#define GCSPR_EL0 S3_3_C2_C5_1 + +.macro function name + .macro endfunction + .type \name, @function + .purgem endfunction + .endm +\name: +.endm + +// Print a single character x0 to stdout +// Clobbers x0-x2,x8 +function putc + str x0, [sp, #-16]! + + mov x0, #1 // STDOUT_FILENO + mov x1, sp + mov x2, #1 + mov x8, #__NR_write + svc #0 + + add sp, sp, #16 + ret +endfunction +.globl putc + +// Print a NUL-terminated string starting at address x0 to stdout +// Clobbers x0-x3,x8 +function puts + mov x1, x0 + + mov x2, #0 +0: ldrb w3, [x0], #1 + cbz w3, 1f + add x2, x2, #1 + b 0b + +1: mov w0, #1 // STDOUT_FILENO + mov x8, #__NR_write + svc #0 + + ret +endfunction +.globl puts + +// Utility macro to print a literal string +// Clobbers x0-x4,x8 +.macro puts string + .pushsection .rodata.str1.1, "aMS", @progbits, 1 +.L__puts_literal\@: .string "\string" + .popsection + + ldr x0, =.L__puts_literal\@ + bl puts +.endm + +// Print an unsigned decimal number x0 to stdout +// Clobbers x0-x4,x8 +function putdec + mov x1, sp + str x30, [sp, #-32]! // Result can't be > 20 digits + + mov x2, #0 + strb w2, [x1, #-1]! // Write the NUL terminator + + mov x2, #10 +0: udiv x3, x0, x2 // div-mod loop to generate the digits + msub x0, x3, x2, x0 + add w0, w0, #'0' + strb w0, [x1, #-1]! + mov x0, x3 + cbnz x3, 0b + + ldrb w0, [x1] + cbnz w0, 1f + mov w0, #'0' // Print "0" for 0, not "" + strb w0, [x1, #-1]! + +1: mov x0, x1 + bl puts + + ldr x30, [sp], #32 + ret +endfunction +.globl putdec + +// Print an unsigned decimal number x0 to stdout, followed by a newline +// Clobbers x0-x5,x8 +function putdecn + mov x5, x30 + + bl putdec + mov x0, #'\n' + bl putc + + ret x5 +endfunction +.globl putdecn + +// Fill x1 bytes starting at x0 with 0. +// Clobbers x1, x2. +function memclr + mov w2, #0 +endfunction +.globl memclr + // fall through to memfill + +// Trivial memory fill: fill x1 bytes starting at address x0 with byte w2 +// Clobbers x1 +function memfill + cmp x1, #0 + b.eq 1f + +0: strb w2, [x0], #1 + subs x1, x1, #1 + b.ne 0b + +1: ret +endfunction +.globl memfill + +// w0: signal number +// x1: sa_action +// w2: sa_flags +// Clobbers x0-x6,x8 +function setsignal + str x30, [sp, #-((sa_sz + 15) / 16 * 16 + 16)]! + + mov w4, w0 + mov x5, x1 + mov w6, w2 + + add x0, sp, #16 + mov x1, #sa_sz + bl memclr + + mov w0, w4 + add x1, sp, #16 + str w6, [x1, #sa_flags] + str x5, [x1, #sa_handler] + mov x2, #0 + mov x3, #sa_mask_sz + mov x8, #__NR_rt_sigaction + svc #0 + + cbz w0, 1f + + puts "sigaction failure\n" + b abort + +1: ldr x30, [sp], #((sa_sz + 15) / 16 * 16 + 16) + ret +endfunction + + +function tickle_handler + // Perhaps collect GCSPR_EL0 here in future? + ret +endfunction + +function terminate_handler + mov w21, w0 + mov x20, x2 + + puts "Terminated by signal " + mov w0, w21 + bl putdec + puts ", no error\n" + + mov x0, #0 + mov x8, #__NR_exit + svc #0 +endfunction + +function segv_handler + // stash the siginfo_t * + mov x20, x1 + + // Disable GCS, we don't want additional faults logging things + mov x0, PR_SET_SHADOW_STACK_STATUS + mov x1, xzr + mov x2, xzr + mov x3, xzr + mov x4, xzr + mov x5, xzr + mov x8, #__NR_prctl + svc #0 + + puts "Got SIGSEGV code " + + ldr x21, [x20, #si_code] + mov x0, x21 + bl putdec + + // GCS faults should have si_code SEGV_CPERR + cmp x21, #SEGV_CPERR + bne 1f + + puts " (GCS violation)" +1: + mov x0, '\n' + bl putc + b abort +endfunction + +// Recurse x20 times +.macro recurse id +function recurse\id + stp x29, x30, [sp, #-16]! + mov x29, sp + + cmp x20, 0 + beq 1f + sub x20, x20, 1 + bl recurse\id + +1: + ldp x29, x30, [sp], #16 + + // Do a syscall immediately prior to returning to try to provoke + // scheduling and migration at a point where coherency issues + // might trigger. + mov x8, #__NR_getpid + svc #0 + + ret +endfunction +.endmacro + +// Generate and use two copies so we're changing the GCS contents +recurse 1 +recurse 2 + +.globl _start +function _start + // Run with GCS + mov x0, PR_SET_SHADOW_STACK_STATUS + mov x1, PR_SHADOW_STACK_ENABLE + mov x2, xzr + mov x3, xzr + mov x4, xzr + mov x5, xzr + mov x8, #__NR_prctl + svc #0 + cbz x0, 1f + puts "Failed to enable GCS\n" + b abort +1: + + mov w0, #SIGTERM + adr x1, terminate_handler + mov w2, #SA_SIGINFO + bl setsignal + + mov w0, #SIGUSR1 + adr x1, tickle_handler + mov w2, #SA_SIGINFO + orr w2, w2, #SA_NODEFER + bl setsignal + + mov w0, #SIGSEGV + adr x1, segv_handler + mov w2, #SA_SIGINFO + orr w2, w2, #SA_NODEFER + bl setsignal + + puts "Running\n" + +loop: + // Small recursion depth so we're frequently flipping between + // the two recursors and changing what's on the stack + mov x20, #5 + bl recurse1 + mov x20, #5 + bl recurse2 + b loop +endfunction + +abort: + mov x0, #255 + mov x8, #__NR_exit + svc #0 diff --git a/tools/testing/selftests/arm64/gcs/gcs-stress.c b/tools/testing/selftests/arm64/gcs/gcs-stress.c new file mode 100644 index 000000000000..23fd8ec37bdc --- /dev/null +++ b/tools/testing/selftests/arm64/gcs/gcs-stress.c @@ -0,0 +1,532 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2022-3 ARM Limited. + */ + +#define _GNU_SOURCE +#define _POSIX_C_SOURCE 199309L + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "../../kselftest.h" + +struct child_data { + char *name, *output; + pid_t pid; + int stdout; + bool output_seen; + bool exited; + int exit_status; + int exit_signal; +}; + +static int epoll_fd; +static struct child_data *children; +static struct epoll_event *evs; +static int tests; +static int num_children; +static bool terminate; + +static int startup_pipe[2]; + +static int num_processors(void) +{ + long nproc = sysconf(_SC_NPROCESSORS_CONF); + if (nproc < 0) { + perror("Unable to read number of processors\n"); + exit(EXIT_FAILURE); + } + + return nproc; +} + +static void start_thread(struct child_data *child) +{ + int ret, pipefd[2], i; + struct epoll_event ev; + + ret = pipe(pipefd); + if (ret != 0) + ksft_exit_fail_msg("Failed to create stdout pipe: %s (%d)\n", + strerror(errno), errno); + + child->pid = fork(); + if (child->pid == -1) + ksft_exit_fail_msg("fork() failed: %s (%d)\n", + strerror(errno), errno); + + if (!child->pid) { + /* + * In child, replace stdout with the pipe, errors to + * stderr from here as kselftest prints to stdout. + */ + ret = dup2(pipefd[1], 1); + if (ret == -1) { + fprintf(stderr, "dup2() %d\n", errno); + exit(EXIT_FAILURE); + } + + /* + * Duplicate the read side of the startup pipe to + * FD 3 so we can close everything else. + */ + ret = dup2(startup_pipe[0], 3); + if (ret == -1) { + fprintf(stderr, "dup2() %d\n", errno); + exit(EXIT_FAILURE); + } + + /* + * Very dumb mechanism to clean open FDs other than + * stdio. We don't want O_CLOEXEC for the pipes... + */ + for (i = 4; i < 8192; i++) + close(i); + + /* + * Read from the startup pipe, there should be no data + * and we should block until it is closed. We just + * carry on on error since this isn't super critical. + */ + ret = read(3, &i, sizeof(i)); + if (ret < 0) + fprintf(stderr, "read(startp pipe) failed: %s (%d)\n", + strerror(errno), errno); + if (ret > 0) + fprintf(stderr, "%d bytes of data on startup pipe\n", + ret); + close(3); + + ret = execl("gcs-stress-thread", "gcs-stress-thread", NULL); + fprintf(stderr, "execl(gcs-stress-thread) failed: %d (%s)\n", + errno, strerror(errno)); + + exit(EXIT_FAILURE); + } else { + /* + * In parent, remember the child and close our copy of the + * write side of stdout. + */ + close(pipefd[1]); + child->stdout = pipefd[0]; + child->output = NULL; + child->exited = false; + child->output_seen = false; + + ev.events = EPOLLIN | EPOLLHUP; + ev.data.ptr = child; + + ret = asprintf(&child->name, "Thread-%d", child->pid); + if (ret == -1) + ksft_exit_fail_msg("asprintf() failed\n"); + + ret = epoll_ctl(epoll_fd, EPOLL_CTL_ADD, child->stdout, &ev); + if (ret < 0) { + ksft_exit_fail_msg("%s EPOLL_CTL_ADD failed: %s (%d)\n", + child->name, strerror(errno), errno); + } + } + + ksft_print_msg("Started %s\n", child->name); + num_children++; +} + +static bool child_output_read(struct child_data *child) +{ + char read_data[1024]; + char work[1024]; + int ret, len, cur_work, cur_read; + + ret = read(child->stdout, read_data, sizeof(read_data)); + if (ret < 0) { + if (errno == EINTR) + return true; + + ksft_print_msg("%s: read() failed: %s (%d)\n", + child->name, strerror(errno), + errno); + return false; + } + len = ret; + + child->output_seen = true; + + /* Pick up any partial read */ + if (child->output) { + strncpy(work, child->output, sizeof(work) - 1); + cur_work = strnlen(work, sizeof(work)); + free(child->output); + child->output = NULL; + } else { + cur_work = 0; + } + + cur_read = 0; + while (cur_read < len) { + work[cur_work] = read_data[cur_read++]; + + if (work[cur_work] == '\n') { + work[cur_work] = '\0'; + ksft_print_msg("%s: %s\n", child->name, work); + cur_work = 0; + } else { + cur_work++; + } + } + + if (cur_work) { + work[cur_work] = '\0'; + ret = asprintf(&child->output, "%s", work); + if (ret == -1) + ksft_exit_fail_msg("Out of memory\n"); + } + + return false; +} + +static void child_output(struct child_data *child, uint32_t events, + bool flush) +{ + bool read_more; + + if (events & EPOLLIN) { + do { + read_more = child_output_read(child); + } while (read_more); + } + + if (events & EPOLLHUP) { + close(child->stdout); + child->stdout = -1; + flush = true; + } + + if (flush && child->output) { + ksft_print_msg("%s: %s\n", child->name, child->output); + free(child->output); + child->output = NULL; + } +} + +static void child_tickle(struct child_data *child) +{ + if (child->output_seen && !child->exited) + kill(child->pid, SIGUSR1); +} + +static void child_stop(struct child_data *child) +{ + if (!child->exited) + kill(child->pid, SIGTERM); +} + +static void child_cleanup(struct child_data *child) +{ + pid_t ret; + int status; + bool fail = false; + + if (!child->exited) { + do { + ret = waitpid(child->pid, &status, 0); + if (ret == -1 && errno == EINTR) + continue; + + if (ret == -1) { + ksft_print_msg("waitpid(%d) failed: %s (%d)\n", + child->pid, strerror(errno), + errno); + fail = true; + break; + } + + if (WIFEXITED(status)) { + child->exit_status = WEXITSTATUS(status); + child->exited = true; + } + + if (WIFSIGNALED(status)) { + child->exit_signal = WTERMSIG(status); + ksft_print_msg("%s: Exited due to signal %d\n", + child->name); + fail = true; + child->exited = true; + } + } while (!child->exited); + } + + if (!child->output_seen) { + ksft_print_msg("%s no output seen\n", child->name); + fail = true; + } + + if (child->exit_status != 0) { + ksft_print_msg("%s exited with error code %d\n", + child->name, child->exit_status); + fail = true; + } + + ksft_test_result(!fail, "%s\n", child->name); +} + +static void handle_child_signal(int sig, siginfo_t *info, void *context) +{ + int i; + bool found = false; + + for (i = 0; i < num_children; i++) { + if (children[i].pid == info->si_pid) { + children[i].exited = true; + children[i].exit_status = info->si_status; + found = true; + break; + } + } + + if (!found) + ksft_print_msg("SIGCHLD for unknown PID %d with status %d\n", + info->si_pid, info->si_status); +} + +static void handle_exit_signal(int sig, siginfo_t *info, void *context) +{ + int i; + + /* If we're already exiting then don't signal again */ + if (terminate) + return; + + ksft_print_msg("Got signal, exiting...\n"); + + terminate = true; + + /* + * This should be redundant, the main loop should clean up + * after us, but for safety stop everything we can here. + */ + for (i = 0; i < num_children; i++) + child_stop(&children[i]); +} + +/* Handle any pending output without blocking */ +static void drain_output(bool flush) +{ + int ret = 1; + int i; + + while (ret > 0) { + ret = epoll_wait(epoll_fd, evs, tests, 0); + if (ret < 0) { + if (errno == EINTR) + continue; + ksft_print_msg("epoll_wait() failed: %s (%d)\n", + strerror(errno), errno); + } + + for (i = 0; i < ret; i++) + child_output(evs[i].data.ptr, evs[i].events, flush); + } +} + +static const struct option options[] = { + { "timeout", required_argument, NULL, 't' }, + { } +}; + +int main(int argc, char **argv) +{ + int seen_children; + bool all_children_started = false; + int gcs_threads; + int timeout = 10; + int ret, cpus, i, c; + struct sigaction sa; + + while ((c = getopt_long(argc, argv, "t:", options, NULL)) != -1) { + switch (c) { + case 't': + ret = sscanf(optarg, "%d", &timeout); + if (ret != 1) + ksft_exit_fail_msg("Failed to parse timeout %s\n", + optarg); + break; + default: + ksft_exit_fail_msg("Unknown argument\n"); + } + } + + cpus = num_processors(); + tests = 0; + + if (getauxval(AT_HWCAP2) & HWCAP2_GCS) { + /* One extra thread, trying to trigger migrations */ + gcs_threads = cpus + 1; + tests += gcs_threads; + } else { + gcs_threads = 0; + } + + ksft_print_header(); + ksft_set_plan(tests); + + ksft_print_msg("%d CPUs, %d GCS threads\n", + cpus, gcs_threads); + + if (!tests) + ksft_exit_skip("No tests scheduled\n"); + + if (timeout > 0) + ksft_print_msg("Will run for %ds\n", timeout); + else + ksft_print_msg("Will run until terminated\n"); + + children = calloc(sizeof(*children), tests); + if (!children) + ksft_exit_fail_msg("Unable to allocate child data\n"); + + ret = epoll_create1(EPOLL_CLOEXEC); + if (ret < 0) + ksft_exit_fail_msg("epoll_create1() failed: %s (%d)\n", + strerror(errno), ret); + epoll_fd = ret; + + /* Create a pipe which children will block on before execing */ + ret = pipe(startup_pipe); + if (ret != 0) + ksft_exit_fail_msg("Failed to create startup pipe: %s (%d)\n", + strerror(errno), errno); + + /* Get signal handers ready before we start any children */ + memset(&sa, 0, sizeof(sa)); + sa.sa_sigaction = handle_exit_signal; + sa.sa_flags = SA_RESTART | SA_SIGINFO; + sigemptyset(&sa.sa_mask); + ret = sigaction(SIGINT, &sa, NULL); + if (ret < 0) + ksft_print_msg("Failed to install SIGINT handler: %s (%d)\n", + strerror(errno), errno); + ret = sigaction(SIGTERM, &sa, NULL); + if (ret < 0) + ksft_print_msg("Failed to install SIGTERM handler: %s (%d)\n", + strerror(errno), errno); + sa.sa_sigaction = handle_child_signal; + ret = sigaction(SIGCHLD, &sa, NULL); + if (ret < 0) + ksft_print_msg("Failed to install SIGCHLD handler: %s (%d)\n", + strerror(errno), errno); + + evs = calloc(tests, sizeof(*evs)); + if (!evs) + ksft_exit_fail_msg("Failed to allocated %d epoll events\n", + tests); + + for (i = 0; i < gcs_threads; i++) + start_thread(&children[i]); + + /* + * All children started, close the startup pipe and let them + * run. + */ + close(startup_pipe[0]); + close(startup_pipe[1]); + + timeout *= 10; + for (;;) { + /* Did we get a signal asking us to exit? */ + if (terminate) + break; + + /* + * Timeout is counted in 100ms with no output, the + * tests print during startup then are silent when + * running so this should ensure they all ran enough + * to install the signal handler, this is especially + * useful in emulation where we will both be slow and + * likely to have a large set of VLs. + */ + ret = epoll_wait(epoll_fd, evs, tests, 100); + if (ret < 0) { + if (errno == EINTR) + continue; + ksft_exit_fail_msg("epoll_wait() failed: %s (%d)\n", + strerror(errno), errno); + } + + /* Output? */ + if (ret > 0) { + for (i = 0; i < ret; i++) { + child_output(evs[i].data.ptr, evs[i].events, + false); + } + continue; + } + + /* Otherwise epoll_wait() timed out */ + + /* + * If the child processes have not produced output they + * aren't actually running the tests yet. + */ + if (!all_children_started) { + seen_children = 0; + + for (i = 0; i < num_children; i++) + if (children[i].output_seen || + children[i].exited) + seen_children++; + + if (seen_children != num_children) { + ksft_print_msg("Waiting for %d children\n", + num_children - seen_children); + continue; + } + + all_children_started = true; + } + + ksft_print_msg("Sending signals, timeout remaining: %d00ms\n", + timeout); + + for (i = 0; i < num_children; i++) + child_tickle(&children[i]); + + /* Negative timeout means run indefinitely */ + if (timeout < 0) + continue; + if (--timeout == 0) + break; + } + + ksft_print_msg("Finishing up...\n"); + terminate = true; + + for (i = 0; i < tests; i++) + child_stop(&children[i]); + + drain_output(false); + + for (i = 0; i < tests; i++) + child_cleanup(&children[i]); + + drain_output(true); + + ksft_print_cnts(); + + return 0; +}