crtools: Parse /proc/pid/stat in a more readable way

We will later need other fields of this file, so let's parse it right
now in a way, that allows to easily get new fields.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>

cr-dump.c

@@ -434,6 +434,8 @@ err:
 #define assign_reg(dst, src, e)		dst.e = (__typeof__(dst.e))src.e
 #define assign_array(dst, src, e)	memcpy(&dst.e, &src.e, sizeof(dst.e))
 
+static struct proc_pid_stat pps_buf;
+
 static int get_task_stat(pid_t pid, int pid_dir, u8 *comm, u32 *flags,
 			 u64 *start_code, u64 *end_code,
 			 u64 *start_data, u64 *end_data,
@@ -441,101 +443,29 @@ static int get_task_stat(pid_t pid, int pid_dir, u8 *comm, u32 *flags,
 			 u64 *task_sigset)
 {
 	FILE *file = NULL;
-	char *tok1, *tok2;
-	int i, ret = -1;
-
-	/*
-	 * NOTE: Be careful, /proc/$pid/stat has a parasite
-	 * '0' symbol at argument 20 in format string.
-	 */
-
-	file = fopen_proc(pid_dir, "stat");
-	if (!file) {
-		pr_perror("Can't open %d stat\n", pid);
-		goto err;
-	}
+	int ret;
 
-	if (!fgets(loc_buf, sizeof(loc_buf), file)) {
-		perror("Can't read task stat");
+	ret = parse_pid_stat(pid, pid_dir, &pps_buf);
+	if (ret < 0)
 		goto err;
-	}
-
-	tok1 = strtok(loc_buf, "(");
-	tok2 = strtok(NULL, ")");
-	if ((long)tok1 & (long)tok2) {
-		strncpy((char *)comm, tok2, TASK_COMM_LEN);
-		ret = 0;
-	} else {
-		printf("Unable to parse task stat\n");
-		ret = -1;
-	}
 
-	if (!ret) {
-		ret = -1;
-		for (i = 0; i < 7; i++) {
-			tok1 = strtok(NULL, " \n\t");
-			if (!tok1)
-				goto err_corrupted;
-		}
-		*flags = atoi(tok1);
-		ret = 0;
-	}
-
-	if (!ret) {
-		ret = -1;
-		for (i = 0; i < 16; i++) {
-			tok1 = strtok(NULL, " \n\t");
-			if (!tok1)
-				goto err_corrupted;
-		}
-
-		tok1 = strtok(NULL, " \n\t");
-		if (!tok1)
-			goto err_corrupted;
-		*start_code = atol(tok1);
-
-		tok1 = strtok(NULL, " \n\t");
-		if (!tok1)
-			goto err_corrupted;
-		*end_code = atol(tok1);
-		ret = 0;
-
-		tok1 = strtok(NULL, " \n\t");
-		if (!tok1)
-			goto err_corrupted;
-		*start_stack = atol(tok1);
-		ret = 0;
-	}
-
-	if (!ret) {
-		ret = -1;
-		for (i = 0; i < 16; i++) {
-			tok1 = strtok(NULL, " \n\t");
-			if (!tok1)
-				goto err_corrupted;
-		}
-
-		tok1 = strtok(NULL, " \n\t");
-		if (!tok1)
-			goto err_corrupted;
-		*start_data = atol(tok1);
-
-		tok1 = strtok(NULL, " \n\t");
-		if (!tok1)
-			goto err_corrupted;
-		*end_data = atol(tok1);
-
-		tok1 = strtok(NULL, " \n\t");
-		if (!tok1)
-			goto err_corrupted;
-		*start_brk = atol(tok1);
-		ret = 0;
+	strcpy((char *)comm, pps_buf.comm);
+	*flags = pps_buf.flags;
+	*start_code = pps_buf.start_code;
+	*end_code = pps_buf.end_code;
+	*start_data = pps_buf.start_data;
+	*end_data = pps_buf.end_data;
+	*start_stack = pps_buf.start_stack;
+	*start_brk = pps_buf.start_brk;
+
+	if (*start_data == 0 || *end_data == 0 || *start_brk == 0) {
+		pr_err("%d's stat is corrupted/not complete\n", pid);
+		goto err_corrupted;
 	}
 
 	/*
 	 * Now signals.
 	 */
-	fclose(file);
 	file = fopen_proc(pid_dir, "status");
 	if (!file) {
 		pr_perror("Can't open %d status\n", pid);

include/proc_parse.h

 #ifndef __PROC_PARSE_H__
 #define __PROC_PARSE_H__
 int parse_maps(pid_t pid, int pid_dir, struct list_head *vma_area_list, bool use_map_files);
+
+#define TASK_COMM_LEN 16
+
+struct proc_pid_stat {
+	int pid;
+	char comm[TASK_COMM_LEN];
+	char state;
+	int ppid;
+	int pgid;
+	int sid;
+	int tty_nr;
+	int tty_pgrp;
+	unsigned int flags;
+	unsigned long min_flt;
+	unsigned long cmin_flt;
+	unsigned long maj_flt;
+	unsigned long cmaj_flt;
+	unsigned long utime;
+	unsigned long stime;
+	long cutime;
+	long cstime;
+	long priority;
+	long nice;
+	int num_threads;
+	int zero0;
+	unsigned long long start_time;
+	unsigned long vsize;
+	long mm_rss;
+	unsigned long rsslim;
+	unsigned long start_code;
+	unsigned long end_code;
+	unsigned long start_stack;
+	unsigned long esp;
+	unsigned long eip;
+	unsigned long sig_pending;
+	unsigned long sig_blocked;
+	unsigned long sig_ignored;
+	unsigned long sig_handled;
+	unsigned long wchan;
+	unsigned long zero1;
+	unsigned long zero2;
+	int exit_signal;
+	int task_cpu;
+	unsigned int rt_priority;
+	unsigned int policy;
+	unsigned long long delayacct_blkio_ticks;
+	unsigned long gtime;
+	long cgtime;
+	unsigned long start_data;
+	unsigned long end_data;
+	unsigned long start_brk;
+};
+
+int parse_pid_stat(pid_t pid, int pid_dir, struct proc_pid_stat *s);
 #endif

proc_parse.c

@@ -172,3 +172,67 @@ err_bogus_mapping:
 	goto err;
 }
 
+int parse_pid_stat(pid_t pid, int pid_dir, struct proc_pid_stat *s)
+{
+	FILE *f;
+
+	f = fopen_proc(pid_dir, "stat");
+	if (f == NULL) {
+		pr_perror("Can't open %d's stat", pid);
+		return -1;
+	}
+
+	memset(s, 0, sizeof(*s));
+	fscanf(f, "%d (%s %c %d %d %d %d %d %u %lu %lu %lu %lu %lu %lu %ld %ld %ld %ld %d %d %llu %lu %ld %lu %lu %lu %lu %lu %lu %lu %lu %lu %lu %lu %lu %lu %d %d %u %u %llu %lu %ld %lu %lu %lu",
+		&s->pid,
+		s->comm,
+		&s->state,
+		&s->ppid,
+		&s->pgid,
+		&s->sid,
+		&s->tty_nr,
+		&s->tty_pgrp,
+		&s->flags,
+		&s->min_flt,
+		&s->cmin_flt,
+		&s->maj_flt,
+		&s->cmaj_flt,
+		&s->utime,
+		&s->stime,
+		&s->cutime,
+		&s->cstime,
+		&s->priority,
+		&s->nice,
+		&s->num_threads,
+		&s->zero0,
+		&s->start_time,
+		&s->vsize,
+		&s->mm_rss,
+		&s->rsslim,
+		&s->start_code,
+		&s->end_code,
+		&s->start_stack,
+		&s->esp,
+		&s->eip,
+		&s->sig_pending,
+		&s->sig_blocked,
+		&s->sig_ignored,
+		&s->sig_handled,
+		&s->wchan,
+		&s->zero1,
+		&s->zero2,
+		&s->exit_signal,
+		&s->task_cpu,
+		&s->rt_priority,
+		&s->policy,
+		&s->delayacct_blkio_ticks,
+		&s->gtime,
+		&s->cgtime,
+		&s->start_data,
+		&s->end_data,
+		&s->start_brk);
+
+	s->comm[strlen(s->comm) - 1] = '\0'; /* trim the ending ) */
+	fclose(f);
+	return 0;
+}