PR9821: staprun supports subset of strftime.

Add strftime subset format support for output file name to systemtap.
This format will be evaluated when opening a new output file.

7 files changed, 240 insertions, 34 deletions

diff --git a/main.cxx b/main.cxx
index 6f4064a5..cdcae41a 100644
--- a/main.cxx
+++ b/main.cxx
@@ -108,7 +108,9 @@ usage (systemtap_session& s, int exitcode)
     << "              " << s.kernel_build_tree << endl
     << "   -m MODULE  set probe module name, instead of " << endl
     << "              " << s.module_name << endl
-    << "   -o FILE    send script output to file, instead of stdout" << endl
+    << "   -o FILE    send script output to file, instead of stdout. This supports" << endl
+    << "              a subset of strftime(3) (%%,%C,%Y,%y,%m,%d,%e,%F,%H,%I,%j,%k," << endl
+    << "              %l,%M,%S,%R,%T,%u,%w) for FILE." << endl
     << "   -c CMD     start the probes, run CMD, and exit when it finishes" << endl
     << "   -x PID     sets target() to PID" << endl
     << "   -F         run as on-file flight recorder with -o." << endl
diff --git a/runtime/staprun/common.c b/runtime/staprun/common.c
index 194488ef..8200ec9d 100644
--- a/runtime/staprun/common.c
+++ b/runtime/staprun/common.c
@@ -53,6 +53,113 @@ static char *get_abspath(char *path)
 	return path_buf;
 }
 
+int stap_strfloctime(char *buf, size_t max, const char *fmt, time_t t)
+{
+	char *c = buf;
+	const char *c2 = fmt, *end = buf + max;
+	int ret, num;
+	struct tm tm;
+	if (buf == NULL || fmt == NULL || max <= 1)
+		return -EINVAL;
+	localtime_r(&t, &tm);
+
+	while (*c2 != '\0'){
+		if (c + 1 >= end)
+			return -EINVAL;
+		if (*c2 != '%') {
+			*c++ = *c2++;
+			continue;
+		}
+		c2++;
+		switch (*c2++) {
+		case '%':
+			*c++ = '%';
+			break;
+		case 'Y':
+			num = tm.tm_year + 1900;
+			goto numbering;
+		case 'y':
+			num = tm.tm_year % 100;
+			goto numbering02;
+		case 'C':
+			num = ((tm.tm_year + 1900 - 1) / 100) + 1;
+			goto numbering;
+		case 'm':
+			num = tm.tm_mon + 1;
+			goto numbering02;
+		case 'd':
+			num = tm.tm_mday;
+			goto numbering02;
+		case 'e':
+			num = tm.tm_mday;
+			goto numbering;
+		case 'F':
+			ret = snprintf(c, end - c, "%d-%02d-%02d",
+				tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday);
+			if (ret < 0) return ret;
+			c += ret;
+			break;
+		case 'H':
+			num = tm.tm_hour;
+			goto numbering02;
+		case 'I':
+			num = tm.tm_hour % 12;
+			if (num == 0) num = 12;
+			goto numbering02;
+		case 'j':
+			ret = snprintf(c, end - c, "%03d", tm.tm_yday);
+			if (ret < 0) return ret;
+			c += ret;
+			break;
+		case 'k':
+			num = tm.tm_hour;
+			goto numbering;
+		case 'l':
+			num = tm.tm_hour % 12;
+			if (num == 0) num = 12;
+			goto numbering;
+		case 'M':
+			num = tm.tm_min;
+			goto numbering02;
+		case 'S':
+			num = tm.tm_sec;
+			goto numbering02;
+		case 'R':
+			ret = snprintf(c, end - c, "%02d:%02d",
+					tm.tm_hour, tm.tm_min);
+			if (ret < 0) return ret;
+			c += ret;
+			break;
+		case 'T':
+			ret = snprintf(c, end - c, "%02d:%02d:%02d",
+					tm.tm_hour, tm.tm_min, tm.tm_sec);
+			if (ret < 0) return ret;
+			c += ret;
+			break;
+		case 'u':
+			num = tm.tm_wday == 0 ? 7 : tm.tm_wday;
+			goto numbering;
+		case 'w':
+			num = tm.tm_wday;
+			goto numbering;
+		default:
+			return -EINVAL;
+		}
+		continue;
+numbering:
+		ret = snprintf(c, end - c, "%d", num);
+		if (ret < 0) return ret;
+		c += ret;
+		continue;
+numbering02:
+		ret = snprintf(c, end - c, "%02d", num);
+		if (ret < 0) return ret;
+		c += ret;
+	}
+	*c = '\0';
+	return c - buf;
+}
+
 void parse_args(int argc, char **argv)
 {
 	int c;
@@ -125,11 +232,19 @@ void parse_args(int argc, char **argv)
 		}
 	}
 	if (outfile_name) {
+		char tmp[PATH_MAX];
+		int ret;
 		outfile_name = get_abspath(outfile_name);
 		if (outfile_name == NULL) {
 			err("File name is too long.\n");
 			usage(argv[0]);
 		}
+		ret = stap_strfloctime(tmp, PATH_MAX - 18, /* = _cpuNNN.SSSSSSSSSS */
+				       outfile_name, time(NULL));
+		if (ret < 0) {
+			err("Filename format is invalid or too long.\n");
+			usage(argv[0]);
+		}
 	}
 	if (attach_mod && load_only) {
 		err("You can't specify the '-A' and '-L' options together.\n");
@@ -191,7 +306,9 @@ void usage(char *prog)
 	err("                exit when it does.  The '_stp_target' variable\n");
 	err("                will contain the pid for the command.\n");
 	err("-x pid          Sets the '_stp_target' variable to pid.\n");
-	err("-o FILE         Send output to FILE.\n");
+	err("-o FILE         Send output to FILE. This supports a subset of\n");
+	err("                strftime(3) (%%%%,%%C,%%Y,%%y,%%m,%%d,%%e,%%F,%%H,%%I\n");
+	err("                %%j,%%k,%%l,%%M,%%S,%%R,%%T,%%u,%%w) for FILE.\n");
 	err("-b buffer size  The systemtap module specifies a buffer size.\n");
 	err("                Setting one here will override that value.  The\n");
 	err("                value should be an integer between 1 and 4095 \n");
diff --git a/runtime/staprun/relay.c b/runtime/staprun/relay.c
index 891913b0..50f295b5 100644
--- a/runtime/staprun/relay.c
+++ b/runtime/staprun/relay.c
@@ -17,6 +17,9 @@ static pthread_t reader[NR_CPUS];
 static int relay_fd[NR_CPUS];
 static int bulkmode = 0;
 static volatile int stop_threads = 0;
+static time_t *time_backlog[NR_CPUS];
+static int backlog_order=0;
+#define BACKLOG_MASK ((1 << backlog_order) - 1)
 
 /*
  * ppoll exists in glibc >= 2.4
@@ -44,20 +47,52 @@ static int ppoll(struct pollfd *fds, nfds_t nfds,
 }
 #endif
 
-int make_outfile_name(char *buf, int max, int fnum, int cpu)
+int init_backlog(int cpu)
 {
+	int order = 0;
+	if (!fnum_max)
+		return 0;
+	while (fnum_max >> order) order++;
+	if (fnum_max == 1<<(order-1)) order--;
+	time_backlog[cpu] = (time_t *)calloc(1<<order, sizeof(time_t));
+	if (time_backlog[cpu] == NULL) {
+		_err("Memory allocation failed\n");
+		return -1;
+	}
+	backlog_order = order;
+	return 0;
+}
+
+void write_backlog(int cpu, int fnum, time_t t)
+{
+	time_backlog[cpu][fnum & BACKLOG_MASK] = t;
+}
+
+time_t read_backlog(int cpu, int fnum)
+{
+	return time_backlog[cpu][fnum & BACKLOG_MASK];
+}
+
+int make_outfile_name(char *buf, int max, int fnum, int cpu, time_t t)
+{
+	int len;
+	len = stap_strfloctime(buf, max, outfile_name, t);
+	if (len < 0) {
+		err("Invalid FILE name format\n");
+  		return -1;
+  	}
 	if (bulkmode) {
 		/* special case: for testing we sometimes want to write to /dev/null */
 		if (strcmp(outfile_name, "/dev/null") == 0) {
 			strcpy(buf, "/dev/null");
 		} else {
-			if (snprintf_chk(buf, max, "%s_cpu%d.%d",
-					 outfile_name, cpu, fnum))
+			if (snprintf_chk(&buf[len], PATH_MAX - len,
+					 "_cpu%d.%d", cpu, fnum))
 				return -1;
 		}
 	} else {
 		/* stream mode */
-		if (snprintf_chk(buf, max, "%s.%d", outfile_name, fnum))
+		if (snprintf_chk(&buf[len], PATH_MAX - len, ".%d", fnum))
 			return -1;
 	}
 	return 0;
@@ -66,19 +101,25 @@ int make_outfile_name(char *buf, int max, int fnum, int cpu)
 static int open_outfile(int fnum, int cpu, int remove_file)
 {
 	char buf[PATH_MAX];
+	time_t t;
 	if (!outfile_name) {
 		_err("-S is set without -o. Please file a bug report.\n");
 		return -1;
 	}
 
-	if (remove_file) {
-		 /* remove oldest file */
-		if (make_outfile_name(buf, PATH_MAX, fnum - fnum_max, cpu) < 0)
-			return -1;
-		remove(buf); /* don't care */
+	time(&t);
+	if (fnum_max) {
+		if (remove_file) {
+			 /* remove oldest file */
+			if (make_outfile_name(buf, PATH_MAX, fnum - fnum_max,
+				 cpu, read_backlog(cpu, fnum - fnum_max)) < 0)
+				return -1;
+			remove(buf); /* don't care */
+		}
+		write_backlog(cpu, fnum, t);
 	}
 
-	if (make_outfile_name(buf, PATH_MAX, fnum, cpu) < 0)
+	if (make_outfile_name(buf, PATH_MAX, fnum, cpu, t) < 0)
 		return -1;
 	out_fd[cpu] = open (buf, O_CREAT|O_TRUNC|O_WRONLY, 0666);
 	if (out_fd[cpu] < 0) {
@@ -178,7 +219,7 @@ static void *reader_thread(void *data)
  */
 int init_relayfs(void)
 {
-	int i;
+	int i, len;
 	struct statfs st;
 	char rqbuf[128];
 	char buf[PATH_MAX], relay_filebase[PATH_MAX];
@@ -227,9 +268,12 @@ int init_relayfs(void)
 
 	if (fsize_max) {
 		/* switch file mode */
-		for (i = 0; i < ncpus; i++)
-			if (open_outfile(0, i, 0) < 0)
+		for (i = 0; i < ncpus; i++) {
+			if (init_backlog(i) < 0)
 				return -1;
+  			if (open_outfile(0, i, 0) < 0)
+  				return -1;
+		}
 	} else if (bulkmode) {
 		for (i = 0; i < ncpus; i++) {
 			if (outfile_name) {
@@ -237,7 +281,14 @@ int init_relayfs(void)
 				if (strcmp(outfile_name, "/dev/null") == 0) {
 					strcpy(buf, "/dev/null");
 				} else {
-					if (sprintf_chk(buf, "%s_%d", outfile_name, i))
+					len = stap_strfloctime(buf, PATH_MAX,
+						 outfile_name, time(NULL));
+					if (len < 0) {
+						err("Invalid FILE name format\n");
+						return -1;
+					}
+					if (snprintf_chk(&buf[len],
+						PATH_MAX - len, "_%d", i))
 						return -1;
 				}
 			} else {
@@ -256,9 +307,15 @@ int init_relayfs(void)
 	} else {
 		/* stream mode */
 		if (outfile_name) {
-			out_fd[0] = open (outfile_name, O_CREAT|O_TRUNC|O_WRONLY, 0666);
+			len = stap_strfloctime(buf, PATH_MAX,
+						 outfile_name, time(NULL));
+			if (len < 0) {
+				err("Invalid FILE name format\n");
+				return -1;
+			}
+			out_fd[0] = open (buf, O_CREAT|O_TRUNC|O_WRONLY, 0666);
 			if (out_fd[0] < 0) {
-				perr("Couldn't open output file %s", outfile_name);
+				perr("Couldn't open output file %s", buf);
 				return -1;
 			}
 			if (set_clexec(out_fd[i]) < 0)
diff --git a/runtime/staprun/relay_old.c b/runtime/staprun/relay_old.c
index 25ba93bf..ef8fd0da 100644
--- a/runtime/staprun/relay_old.c
+++ b/runtime/staprun/relay_old.c
@@ -81,15 +81,20 @@ void close_oldrelayfs(int detach)
 static int open_oldoutfile(int fnum, int cpu, int remove_file)
 {
 	char buf[PATH_MAX];
+	time_t t;
 	if (outfile_name) {
-		if (remove_file) {
-			 /* remove oldest file */
-			if (make_outfile_name(buf, PATH_MAX, fnum - fnum_max,
-					      cpu) < 0)
-				return -1;
-			remove(buf); /* don't care */
+		time(&t);
+		if (fnum_max) {
+			if (remove_file) {
+				 /* remove oldest file */
+				if (make_outfile_name(buf, PATH_MAX, fnum - fnum_max,
+					 cpu, read_backlog(cpu, fnum - fnum_max)) < 0)
+					return -1;
+				remove(buf); /* don't care */
+			}
+			write_backlog(cpu, fnum, t);
 		}
-		if (make_outfile_name(buf, PATH_MAX, fnum, cpu) < 0)
+		if (make_outfile_name(buf, PATH_MAX, fnum, cpu, t) < 0)
 			return -1;
 	} else if (bulkmode) {
 		if (sprintf_chk(buf, "stpd_cpu%d.%d", cpu, fnum))
@@ -143,6 +148,8 @@ static int open_relayfs_files(int cpu, const char *relay_filebase, const char *p
 	}
 
 	if (fsize_max) {
+		if (init_backlog(cpu) < 0)
+			goto err2;
 		if (open_oldoutfile(0, cpu, 0) < 0)
 			goto err2;
 		goto opened;
@@ -153,12 +160,18 @@ static int open_relayfs_files(int cpu, const char *relay_filebase, const char *p
 		if (strcmp(outfile_name, "/dev/null") == 0) {
 			strcpy(tmp, "/dev/null");
 		} else {
-			if (sprintf_chk(tmp, "%s_%d", outfile_name, cpu))
-				goto err1;
+			int len;
+			len = stap_strfloctime(tmp, PATH_MAX, outfile_name, time(NULL));
+			if (len < 0) {
+				err("Invalid FILE name format\n");
+				goto err2;
+			}
+			if (snprintf_chk(&tmp[len], PATH_MAX - len, "_%d", cpu))
+				goto err2;
 		}
 	} else {
 		if (sprintf_chk(tmp, "stpd_cpu%d", cpu))
-			goto err1;
+			goto err2;
 	}
 
 	if((percpu_tmpfile[cpu] = fopen(tmp, "w+")) == NULL) {
@@ -334,13 +347,22 @@ int init_oldrelayfs(void)
 		bulkmode = 1;
  
 	if (!bulkmode) {
-		if (fsize_max)
+		int len;
+		char tmp[PATH_MAX];
+		if (fsize_max) {
+			if (init_backlog(0))
+				return -1;
 			return open_oldoutfile(0, 0, 0);
-
+		}
 		if (outfile_name) {
-			out_fd[0] = open (outfile_name, O_CREAT|O_TRUNC|O_WRONLY, 0666);
+			len = stap_strfloctime(tmp, PATH_MAX, outfile_name, time(NULL));
+			if (len < 0) {
+				err("Invalid FILE name format\n");
+				return -1;
+			}
+			out_fd[0] = open (tmp, O_CREAT|O_TRUNC|O_WRONLY, 0666);
 			if (out_fd[0] < 0 || set_clexec(out_fd[0]) < 0) {
-				perr("Couldn't open output file '%s'", outfile_name);
+				perr("Couldn't open output file '%s'", tmp);
 				return -1;
 			}
 		} else
diff --git a/runtime/staprun/staprun.h b/runtime/staprun/staprun.h
index 6d0f9179..acc533b2 100644
--- a/runtime/staprun/staprun.h
+++ b/runtime/staprun/staprun.h
@@ -119,7 +119,10 @@ int init_oldrelayfs(void);
 void close_oldrelayfs(int);
 int write_realtime_data(void *data, ssize_t nb);
 void setup_signals(void);
-int make_outfile_name(char *buf, int max, int fnum, int cpu);
+int make_outfile_name(char *buf, int max, int fnum, int cpu, time_t t);
+int init_backlog(int cpu);
+void write_backlog(int cpu, int fnum, time_t t);
+time_t read_backlog(int cpu, int fnum);
 /* staprun_funcs.c */
 void setup_staprun_signals(void);
 const char *moderror(int err);
@@ -131,6 +134,7 @@ void start_symbol_thread(void);
 void stop_symbol_thread(void);
 
 /* common.c functions */
+int stap_strfloctime(char *buf, size_t max, const char *fmt, time_t t);
 void parse_args(int argc, char **argv);
 void usage(char *prog);
 void parse_modpath(const char *);
diff --git a/stap.1.in b/stap.1.in
index f997b788..50c092ee 100644
--- a/stap.1.in
+++ b/stap.1.in
@@ -176,6 +176,8 @@ even if they do not have an explicit probe placed into them.
 .BI \-o " FILE"
 Send standard output to named file. In bulk mode, percpu files will
 start with FILE_ (FILE_cpu with -F) followed by the cpu number.
+This supports a subset of strftime(3) (%%, %C, %Y, %y, %m, %d, %e, %F,
+%H, %I, %j, %l, %M, %S, %R, %T, %u, %w) for FILE.
 .TP
 .BI \-c " CMD"
 Start the probes, run CMD, and exit when CMD finishes.
diff --git a/staprun.8.in b/staprun.8.in
index 68b5c947..01ef2320 100644
--- a/staprun.8.in
+++ b/staprun.8.in
@@ -53,7 +53,9 @@ The '_stp_target' variable will be set to PID.
 .B \-o FILE
 Send output to FILE. If the module uses bulk mode, the output will
 be in percpu files FILE_x(FILE_cpux in backgroud and bulk mode)
-where 'x' is the cpu number.
+where 'x' is the cpu number. This supports a subset of strftime(3)
+(%%, %C, %Y, %y, %m, %d, %e, %F, %H, %I, %j, %l, %M, %S, %R, %T, %u, %w)
+for FILE.
 .TP
 .B \-b BUFFER_SIZE
 The systemtap module will specify a buffer size.