scftorture: Count single_rpc offline failures in statistics outputgrafted

scf_torture_stats_print() aggregates each invoker thread's counters
into a local scf_statistics structure before printing, but the
n_single_rpc_ofl field is missing from the aggregation loop.  As a
result, the "single_rpc_ofl" value printed in the statistics line is
always zero, even when smp_call_function_single() invocations for the
RPC test have failed due to offline CPUs and been counted by the
invoker threads.

Add the missing accumulation so that the printed value reflects the
actual counts.

Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

1 files changed, 358 insertions, 0 deletions

diff --git a/tools/lib/subcmd/run-command.c b/tools/lib/subcmd/run-command.c
new file mode 100644
index 000000000..bd21b8bfd
--- /dev/null
+++ b/tools/lib/subcmd/run-command.c
@@ -0,0 +1,358 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <ctype.h>
+#include <fcntl.h>
+#include <string.h>
+#include <linux/compiler.h>
+#include <linux/string.h>
+#include <errno.h>
+#include <sys/wait.h>
+#include "subcmd-util.h"
+#include "run-command.h"
+#include "exec-cmd.h"
+
+#define STRERR_BUFSIZE 128
+
+static inline void close_pair(int fd[2])
+{
+	close(fd[0]);
+	close(fd[1]);
+}
+
+static inline void dup_devnull(int to)
+{
+	int fd = open("/dev/null", O_RDWR);
+	dup2(fd, to);
+	close(fd);
+}
+
+int start_command(struct child_process *cmd)
+{
+	int need_in, need_out, need_err;
+	int fdin[2], fdout[2], fderr[2];
+	char sbuf[STRERR_BUFSIZE];
+
+	/*
+	 * In case of errors we must keep the promise to close FDs
+	 * that have been passed in via ->in and ->out.
+	 */
+
+	need_in = !cmd->no_stdin && cmd->in < 0;
+	if (need_in) {
+		if (pipe(fdin) < 0) {
+			if (cmd->out > 0)
+				close(cmd->out);
+			return -ERR_RUN_COMMAND_PIPE;
+		}
+		cmd->in = fdin[1];
+	}
+
+	need_out = !cmd->no_stdout
+		&& !cmd->stdout_to_stderr
+		&& cmd->out < 0;
+	if (need_out) {
+		if (pipe(fdout) < 0) {
+			if (need_in)
+				close_pair(fdin);
+			else if (cmd->in)
+				close(cmd->in);
+			return -ERR_RUN_COMMAND_PIPE;
+		}
+		cmd->out = fdout[0];
+	}
+
+	need_err = !cmd->no_stderr && cmd->err < 0;
+	if (need_err) {
+		if (pipe(fderr) < 0) {
+			if (need_in)
+				close_pair(fdin);
+			else if (cmd->in)
+				close(cmd->in);
+			if (need_out)
+				close_pair(fdout);
+			else if (cmd->out)
+				close(cmd->out);
+			return -ERR_RUN_COMMAND_PIPE;
+		}
+		cmd->err = fderr[0];
+	}
+
+	fflush(NULL);
+	cmd->pid = fork();
+	if (!cmd->pid) {
+		if (cmd->no_stdin)
+			dup_devnull(0);
+		else if (need_in) {
+			dup2(fdin[0], 0);
+			close_pair(fdin);
+		} else if (cmd->in) {
+			dup2(cmd->in, 0);
+			close(cmd->in);
+		}
+
+		if (cmd->no_stderr)
+			dup_devnull(2);
+		else if (need_err) {
+			dup2(fderr[1], 2);
+			close_pair(fderr);
+		}
+
+		if (cmd->no_stdout)
+			dup_devnull(1);
+		else if (cmd->stdout_to_stderr)
+			dup2(2, 1);
+		else if (need_out) {
+			dup2(fdout[1], 1);
+			close_pair(fdout);
+		} else if (cmd->out > 1) {
+			dup2(cmd->out, 1);
+			close(cmd->out);
+		}
+
+		if (cmd->dir && chdir(cmd->dir))
+			die("exec %s: cd to %s failed (%s)", cmd->argv[0],
+			    cmd->dir, str_error_r(errno, sbuf, sizeof(sbuf)));
+		if (cmd->env) {
+			for (; *cmd->env; cmd->env++) {
+				if (strchr(*cmd->env, '='))
+					putenv((char*)*cmd->env);
+				else
+					unsetenv(*cmd->env);
+			}
+		}
+		if (cmd->preexec_cb)
+			cmd->preexec_cb();
+		if (cmd->no_exec_cmd)
+			exit(cmd->no_exec_cmd(cmd));
+		if (cmd->exec_cmd) {
+			execv_cmd(cmd->argv);
+		} else {
+			execvp(cmd->argv[0], (char *const*) cmd->argv);
+		}
+		exit(127);
+	}
+
+	if (cmd->pid < 0) {
+		int err = errno;
+		if (need_in)
+			close_pair(fdin);
+		else if (cmd->in)
+			close(cmd->in);
+		if (need_out)
+			close_pair(fdout);
+		else if (cmd->out)
+			close(cmd->out);
+		if (need_err)
+			close_pair(fderr);
+		return err == ENOENT ?
+			-ERR_RUN_COMMAND_EXEC :
+			-ERR_RUN_COMMAND_FORK;
+	}
+
+	if (need_in)
+		close(fdin[0]);
+	else if (cmd->in)
+		close(cmd->in);
+
+	if (need_out)
+		close(fdout[1]);
+	else if (cmd->out)
+		close(cmd->out);
+
+	if (need_err)
+		close(fderr[1]);
+
+	return 0;
+}
+
+static int wait_or_whine(struct child_process *cmd, bool block)
+{
+	bool finished;
+	int result;
+
+	if (cmd->pid <= 0) {
+		cmd->finished = 1;
+		if (cmd->pid < 0 && cmd->finish_result == 0)
+			cmd->finish_result = -ERR_RUN_COMMAND_FORK;
+		return cmd->finish_result;
+	}
+
+	finished = cmd->finished;
+	result = cmd->finish_result;
+
+	while (!finished) {
+		int status, code;
+		pid_t waiting = waitpid(cmd->pid, &status, block ? 0 : WNOHANG);
+
+		if (!block && waiting == 0)
+			break;
+
+		if (waiting < 0 && errno == EINTR)
+			continue;
+
+		finished = true;
+		if (waiting < 0) {
+			char sbuf[STRERR_BUFSIZE];
+
+			fprintf(stderr, " Error: waitpid failed (%s)",
+				str_error_r(errno, sbuf, sizeof(sbuf)));
+			result = -ERR_RUN_COMMAND_WAITPID;
+		} else if (waiting != cmd->pid) {
+			result = -ERR_RUN_COMMAND_WAITPID_WRONG_PID;
+		} else if (WIFSIGNALED(status)) {
+			result = -ERR_RUN_COMMAND_WAITPID_SIGNAL;
+		} else if (!WIFEXITED(status)) {
+			result = -ERR_RUN_COMMAND_WAITPID_NOEXIT;
+		} else {
+			code = WEXITSTATUS(status);
+			switch (code) {
+			case 127:
+				result = -ERR_RUN_COMMAND_EXEC;
+				break;
+			case 0:
+				result = 0;
+				break;
+			default:
+				result = -code;
+				break;
+			}
+		}
+	}
+	if (finished) {
+		cmd->finished = 1;
+		cmd->finish_result = result;
+	}
+	return result;
+}
+
+/*
+ * Conservative estimate of number of characaters needed to hold an a decoded
+ * integer, assume each 3 bits needs a character byte and plus a possible sign
+ * character.
+ */
+#ifndef is_signed_type
+#define is_signed_type(type) (((type)(-1)) < (type)1)
+#endif
+#define MAX_STRLEN_TYPE(type) (sizeof(type) * 8 / 3 + (is_signed_type(type) ? 1 : 0))
+
+int check_if_command_finished(struct child_process *cmd)
+{
+#ifdef __linux__
+	char filename[6 + MAX_STRLEN_TYPE(typeof(cmd->pid)) + 7 + 1];
+	char status_line[256];
+	FILE *status_file;
+#endif
+
+	if (cmd->finished)
+		return 1;
+	if (cmd->pid <= 0) {
+		cmd->finished = 1;
+		if (cmd->pid < 0 && cmd->finish_result == 0)
+			cmd->finish_result = -ERR_RUN_COMMAND_FORK;
+		return 1;
+	}
+
+#ifdef __linux__
+	/*
+	 * Check by reading /proc/<pid>/status as calling waitpid causes
+	 * stdout/stderr to be closed and data lost.
+	 */
+	sprintf(filename, "/proc/%u/status", cmd->pid);
+	status_file = fopen(filename, "r");
+	if (status_file == NULL) {
+		int status;
+		pid_t waiting;
+
+		/*
+		 * fopen() can fail with ENOENT if the process has been reaped.
+		 * It can also fail with EMFILE/ENFILE if RLIMIT_NOFILE is reached.
+		 * In those cases, use waitpid(..., WNOHANG) to robustly check
+		 * and reap the process if it has exited.
+		 */
+		if (errno == ENOENT)
+			return 1;
+
+		waiting = waitpid(cmd->pid, &status, WNOHANG);
+		if (waiting == cmd->pid) {
+			int result;
+			int code;
+
+			cmd->finished = 1;
+			if (WIFSIGNALED(status)) {
+				result = -ERR_RUN_COMMAND_WAITPID_SIGNAL;
+			} else if (!WIFEXITED(status)) {
+				result = -ERR_RUN_COMMAND_WAITPID_NOEXIT;
+			} else {
+				code = WEXITSTATUS(status);
+				switch (code) {
+				case 127:
+					result = -ERR_RUN_COMMAND_EXEC;
+					break;
+				case 0:
+					result = 0;
+					break;
+				default:
+					result = -code;
+					break;
+				}
+			}
+			cmd->finish_result = result;
+			return 1;
+		}
+		if (waiting < 0 && (errno == ECHILD || errno == ESRCH))
+			return 1;
+		return 0;
+	}
+	while (fgets(status_line, sizeof(status_line), status_file) != NULL) {
+		char *p;
+
+		if (strncmp(status_line, "State:", 6))
+			continue;
+
+		fclose(status_file);
+		p = status_line + 6;
+		while (isspace(*p))
+			p++;
+		return *p == 'Z' ? 1 : 0;
+	}
+	/* Read failed assume finish_command was called. */
+	fclose(status_file);
+	return 1;
+#else
+	wait_or_whine(cmd, /*block=*/false);
+	return cmd->finished;
+#endif
+}
+
+int finish_command(struct child_process *cmd)
+{
+	return wait_or_whine(cmd, /*block=*/true);
+}
+
+int run_command(struct child_process *cmd)
+{
+	int code = start_command(cmd);
+	if (code)
+		return code;
+	return finish_command(cmd);
+}
+
+static void prepare_run_command_v_opt(struct child_process *cmd,
+				      const char **argv,
+				      int opt)
+{
+	memset(cmd, 0, sizeof(*cmd));
+	cmd->argv = argv;
+	cmd->no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
+	cmd->exec_cmd = opt & RUN_EXEC_CMD ? 1 : 0;
+	cmd->stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
+}
+
+int run_command_v_opt(const char **argv, int opt)
+{
+	struct child_process cmd;
+	prepare_run_command_v_opt(&cmd, argv, opt);
+	return run_command(&cmd);
+}