pidof/killall: allow find_pid_by_name to find running

processes started as scripts_with_name_longer_than_15_bytes.sh
 closes bug 4054 (and is generally neat)

include/libbb.h

@@ -1166,6 +1166,7 @@ typedef struct procps_status_t {
 	uint8_t shift_pages_to_bytes;
 	uint8_t shift_pages_to_kb;
 /* Fields are set to 0/NULL if failed to determine (or not requested) */
+	uint16_t argv_len;
 	char *argv0;
 	USE_SELINUX(char *context;)
 	/* Everything below must contain no ptrs to malloc'ed data:
@@ -1213,7 +1214,7 @@ enum {
 	PSSCAN_UTIME    = 1 << 13,
 	PSSCAN_TTY      = 1 << 14,
 	PSSCAN_SMAPS	= (1 << 15) * ENABLE_FEATURE_TOPMEM,
-	PSSCAN_ARGVN    = (1 << 16) * (ENABLE_PGREP | ENABLE_PKILL),
+	PSSCAN_ARGVN    = (1 << 16) * (ENABLE_PGREP || ENABLE_PKILL || ENABLE_PIDOF),
 	USE_SELINUX(PSSCAN_CONTEXT = 1 << 17,)
 	PSSCAN_START_TIME = 1 << 18,
 	/* These are all retrieved from proc/NN/stat in one go: */

libbb/find_pid_by_name.c

@@ -38,6 +38,35 @@ execXXX("/proc/self/exe", applet_name, params....)
 and therefore comm field contains "exe".
 */
 
+static int comm_match(procps_status_t *p, const char *procName)
+{
+	int argv1idx;
+
+	/* comm does not match */
+	if (strncmp(p->comm, procName, 15) != 0)
+		return 0;
+
+	/* in Linux, if comm is 15 chars, it may be a truncated */
+	if (p->comm[14] == '\0') /* comm is not truncated - match */
+		return 1;
+
+	/* comm is truncated, but first 15 chars match.
+	 * This can be crazily_long_script_name.sh!
+	 * The telltale sign is basename(argv[1]) == procName. */
+
+	if (!p->argv0)
+		return 0;
+
+	argv1idx = strlen(p->argv0) + 1;
+	if (argv1idx >= p->argv_len)
+		return 0;
+
+	if (strcmp(bb_basename(p->argv0 + argv1idx), procName) != 0)
+		return 0;
+
+	return 1;
+}
+
 /* find_pid_by_name()
  *
  *  Modified by Vladimir Oleynik for use with libbb/procps.c
@@ -54,18 +83,14 @@ pid_t* FAST_FUNC find_pid_by_name(const char* procName)
 	int i = 0;
 	procps_status_t* p = NULL;
 
-	pidList = xmalloc(sizeof(*pidList));
-	while ((p = procps_scan(p, PSSCAN_PID|PSSCAN_COMM|PSSCAN_ARGV0))) {
-		if (
-		/* we require comm to match and to not be truncated */
-		/* in Linux, if comm is 15 chars, it may be a truncated
-		 * name, so we don't allow that to match */
-		    (!p->comm[sizeof(p->comm)-2] && strcmp(p->comm, procName) == 0)
+	pidList = xzalloc(sizeof(*pidList));
+	while ((p = procps_scan(p, PSSCAN_PID|PSSCAN_COMM|PSSCAN_ARGVN))) {
+		if (comm_match(p, procName)
 		/* or we require argv0 to match (essential for matching reexeced /proc/self/exe)*/
 		 || (p->argv0 && strcmp(bb_basename(p->argv0), procName) == 0)
 		/* TOOD: we can also try /proc/NUM/exe link, do we want that? */
 		) {
-			pidList = xrealloc(pidList, sizeof(*pidList) * (i+2));
+			pidList = xrealloc_vector(pidList, 2, i);
 			pidList[i++] = p->pid;
 		}
 	}

libbb/procps.c

@@ -78,7 +78,7 @@ const char* FAST_FUNC get_cached_groupname(gid_t gid)
 
 #define PROCPS_BUFSIZE 1024
 
-static int FAST_FUNC read_to_buf(const char *filename, void *buf)
+static int read_to_buf(const char *filename, void *buf)
 {
 	int fd;
 	/* open_read_close() would do two reads, checking for EOF.
@@ -385,17 +385,16 @@ procps_status_t* FAST_FUNC procps_scan(procps_status_t* sp, int flags)
 			n = read_to_buf(filename, buf);
 			if (n <= 0)
 				break;
-#if ENABLE_PGREP || ENABLE_PKILL
 			if (flags & PSSCAN_ARGVN) {
-				do {
-					n--;
-					if (buf[n] == '\0')
-						buf[n] = ' ';
-				} while (n);
-			}
-#endif
+				sp->argv_len = n;
+				sp->argv0 = xmalloc(n + 1);
+				memcpy(sp->argv0, buf, n + 1);
+				/* sp->argv0[n] = '\0'; - buf has it */
+			} else {
+				sp->argv_len = 0;
 				sp->argv0 = xstrdup(buf);
 			}
+		}
 #endif
 		break;
 	}

procps/pgrep.c

@@ -111,8 +111,15 @@ int pgrep_main(int argc UNUSED_PARAM, char **argv)
 		if (proc->pid == pid)
 			continue;
 		cmd = proc->argv0;
-		if (!cmd)
+		if (!cmd) {
 			cmd = proc->comm;
+		} else {
+			int i = proc->argv_len;
+			while (i) {
+				if (!cmd[i]) cmd[i] = ' ';
+				i--;
+			}
+		}
 		/* NB: OPT_INVERT is always 0 or 1 */
 		if ((regexec(&re_buffer, cmd, 1, re_match, 0) == 0 /* match found */
 		     && (!OPT_ANCHOR || (re_match[0].rm_so == 0 && re_match[0].rm_eo == (regoff_t)strlen(cmd)))) ^ OPT_INVERT

procps/pidof.c

@@ -22,7 +22,6 @@ int pidof_main(int argc UNUSED_PARAM, char **argv)
 	unsigned first = 1;
 	unsigned opt;
 #if ENABLE_FEATURE_PIDOF_OMIT
-	char ppid_str[sizeof(int)*3 + 1];
 	llist_t *omits = NULL; /* list of pids to omit */
 	opt_complementary = "o::";
 #endif
@@ -39,8 +38,7 @@ int pidof_main(int argc UNUSED_PARAM, char **argv)
 		while (omits_p) {
 			/* are we asked to exclude the parent's process ID?  */
 			if (strcmp(omits_p->data, "%PPID") == 0) {
-				sprintf(ppid_str, "%u", (unsigned)getppid());
-				omits_p->data = ppid_str;
+				omits_p->data = utoa((unsigned)getppid());
 			}
 			omits_p = omits_p->link;
 		}