[Bluez-devel] Re: bug: killing hciattach causes kernel oops if card was removed before

[Marcel Holtmann <marcel@holtmann.org>]

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Hi Matthias,

> a while ago i have posted the following bug on the linux-kernel bugtracking 
> system:
> 
> <http://bugzilla.kernel.org/show_bug.cgi?id=5944>
> 
> unfortunately i haven't got any response on that matter since the initial 
> report so i now try to contact the bluez developers directly.

the bluez-devel mailing list is the right place for such problems and
not a bugzilla that non of is monitoring.

> all necessary details (i hope) are to be found in the above mentioned 
> bugreport. if any info is missing please contact me and i will be happy to 
> provide any further information.
> 
> i would be very glad if you could take a look at that bug.

I still think that this should be fixed in the TTY layer, but the TTY
guys won't do it. However I am not an expert in the TTY layer stuff and
especially not the new serial subsystem. However I attached a patch to
hciattach that might help. Try it and report any results.

Regards

Marcel


[-- Attachment #2: patch --]
[-- Type: text/x-patch, Size: 7839 bytes --]

Index: hciattach.c
===================================================================
RCS file: /cvsroot/bluez/utils/tools/hciattach.c,v
retrieving revision 1.35
diff -u -r1.35 hciattach.c
--- hciattach.c	21 Jan 2006 01:45:01 -0000	1.35
+++ hciattach.c	15 Feb 2006 18:29:41 -0000
@@ -38,6 +38,7 @@
 #include <termios.h>
 #include <time.h>
 #include <sys/time.h>
+#include <sys/poll.h>
 #include <sys/ioctl.h>
 #include <sys/socket.h>
 
@@ -70,6 +71,23 @@
 
 #define FLOW_CTL	0x0001
 
+static volatile sig_atomic_t __io_canceled = 0;
+
+static void sig_hup(int sig)
+{
+}
+
+static void sig_term(int sig)
+{
+	__io_canceled = 1;
+}
+
+static void sig_alarm(int sig)
+{
+	fprintf(stderr, "Initialization timed out.\n");
+	exit(1);
+}
+
 static int uart_speed(int s)
 {
 	switch (s) {
@@ -110,12 +128,6 @@
 	return tcsetattr(fd, TCSANOW, ti);
 }
 
-static void sig_alarm(int sig)
-{
-	fprintf(stderr, "Initialization timed out.\n");
-	exit(1);
-}
-
 /* 
  * Read an HCI event from the given file descriptor.
  */
@@ -158,6 +170,7 @@
 			return -1;
 		count += r;
 	}
+
 	return count;
 }
 
@@ -201,6 +214,7 @@
 		perror("Failed to write init command");
 		return -1;
 	}
+
 	nanosleep(&tm, NULL);
 	return 0;
 }
@@ -237,6 +251,7 @@
 		perror("Failed to write init command");
 		return -1;
 	}
+
 	nanosleep(&tm, NULL);
 	return 0;
 }
@@ -289,7 +304,7 @@
 
 	/* Print LMP subversion */
 	fprintf(stderr, "Texas module LMP sub-version : 0x%02x%02x\n", resp[14] & 0xFF, resp[13] & 0xFF);
-	
+
 	nanosleep(&tm, NULL);
 	return 0;
 }
@@ -297,7 +312,7 @@
 static int read_check(int fd, void *buf, int count)
 {
 	int res;
-	
+
 	do {
 		res = read(fd, buf, count);
 		if (res != -1) {
@@ -305,10 +320,10 @@
 			count -= res;
 		}
 	} while (count && (errno == 0 || errno == EINTR));
-	
+
 	if (count)
 		return -1;
-	
+
 	return 0;
 }
 
@@ -321,13 +336,14 @@
 {
 	static int retries=0;
 	unsigned char bcsp_sync_pkt[10] = {0xc0,0x00,0x41,0x00,0xbe,0xda,0xdc,0xed,0xed,0xc0};
-	
+
 	if (retries < 10) {
 		retries++;
 		write(serial_fd, &bcsp_sync_pkt, 10);
 		alarm(1);
 		return;
 	}
+
 	tcflush(serial_fd, TCIOFLUSH);
 	fprintf(stderr, "BCSP initialization timed out\n");
 	exit(1);
@@ -337,12 +353,14 @@
 {
 	static int retries=0;
 	unsigned char bcsp_conf_pkt[10] = {0xc0,0x00,0x41,0x00,0xbe,0xad,0xef,0xac,0xed,0xc0};
+
 	if (retries < 10){
 		retries++;
 		write(serial_fd, &bcsp_conf_pkt, 10);
 		alarm(1);
 		return;
 	}
+
 	tcflush(serial_fd, TCIOFLUSH);
 	fprintf(stderr, "BCSP initialization timed out\n");
 	exit(1);
@@ -390,20 +408,19 @@
 				return -1;
 			}
 		} while (byte != 0xC0);
-		
+
 		do {
 			if ( read_check(fd, &bcsph[0], 1) == -1){
 				perror("Failed to read");
 				return -1;
 			}
-		  
 		} while (bcsph[0] == 0xC0);
-		
+
 		if ( read_check(fd, &bcsph[1], 3) == -1){
 			perror("Failed to read");
 			return -1;
 		}
-		
+
 		if (((bcsph[0] + bcsph[1] + bcsph[2]) & 0xFF) != (unsigned char)~bcsph[3])
 			continue;
 		if (bcsph[1] != 0x41 || bcsph[2] != 0x00)
@@ -437,8 +454,8 @@
 
 		do {
 			if (read_check(fd, &bcsph[0], 1) == -1){
-			      perror("Failed to read");
-			      return -1;
+				perror("Failed to read");
+				return -1;
 			}
 		} while (bcsph[0] == 0xC0);
 
@@ -446,7 +463,7 @@
 			perror("Failed to read");
 			return -1;
 		}
-		
+
 		if (((bcsph[0] + bcsph[1] + bcsph[2]) & 0xFF) != (unsigned char)~bcsph[3])
 			continue;
 
@@ -553,7 +570,7 @@
 	/* Display that to user */
 	fprintf(stderr, "CSR build ID 0x%02X-0x%02X\n", 
 		resp[15] & 0xFF, resp[14] & 0xFF);
-	
+
 	/* Try to read the current speed of the CSR chip */
 	clen = 5 + (5 + 4)*2;
 	/* -- HCI header */
@@ -638,6 +655,7 @@
 		perror("Failed to write init command (SET_UART_SPEED)");
 		return -1;
 	}
+
 	nanosleep(&tm, NULL);
 	return 0;
 }
@@ -715,7 +733,7 @@
 		//  01	flow on
 		//  01 	Hci Transport type = Uart
 		//  xx	Baud rate set (see above)
-	} else {	
+	} else {
 		// ups, got error.
 		return -1;
 	}
@@ -735,7 +753,7 @@
 	}
 
 	nanosleep(&tm, NULL);
-			
+
 	// now the uart baud rate on the silicon wave module is set and effective.
 	// change our own baud rate as well. Then there is a reset event comming in
  	// on the *new* baud rate. This is *undocumented*! The packet looks like this:
@@ -798,11 +816,11 @@
 		perror("Failed to write init command");
 		return -1;
 	}
+
 	nanosleep(&tm, NULL);
 	return 0;
 }
 
-
 /*
  * Broadcom specific initialization
  * Extracted from Jungo openrg
@@ -819,11 +837,13 @@
 	cmd[1] = 0x03;
 	cmd[2] = 0x0c;
 	cmd[3] = 0x00;
+
 	/* Send command */
 	if (write(fd, cmd, 4) != 4) {
 		fprintf(stderr, "Failed to write reset command\n");
 		return -1;
 	}
+
 	/* Read reply */
 	if ((n = read_hci_event(fd, resp, 4)) < 0) {
 		fprintf(stderr, "Failed to reset chip\n");
@@ -837,12 +857,14 @@
 	cmd[1] = 0x01;
 	cmd[2] = 0x10;
 	cmd[3] = 0x00;
+
 	/* Send command */
 	if (write(fd, cmd, 4) != 4) {
 		fprintf(stderr, "Failed to write \"read local version\" "
 			"command\n");
 		return -1;
 	}
+
 	/* Read reply */
 	if ((n = read_hci_event(fd, resp, 4)) < 0) {
 		fprintf(stderr, "Failed to read local version\n");
@@ -856,12 +878,14 @@
 	cmd[1] = 0x02;
 	cmd[2] = 0x10;
 	cmd[3] = 0x00;
+
 	/* Send command */
 	if (write(fd, cmd, 4) != 4) {
 		fprintf(stderr, "Failed to write \"read local supported "
 			"commands\" command\n");
 		return -1;
 	}
+
 	/* Read reply */
 	if ((n = read_hci_event(fd, resp, 4)) < 0) {
 		fprintf(stderr, "Failed to read local supported commands\n");
@@ -906,10 +930,12 @@
 		fprintf(stderr, "Failed to write \"set baud rate\" command\n");
 		return -1;
 	}
+
 	if ((n = read_hci_event(fd, resp, 6)) < 0) {
 		fprintf(stderr, "Failed to set baud rate\n");
 		return -1;
 	}
+
 	return 0;
 }
 
@@ -996,7 +1022,7 @@
 int init_uart(char *dev, struct uart_t *u, int send_break)
 {
 	struct termios ti;
-	int  fd, i;
+	int fd, i;
 
 	fd = open(dev, O_RDWR | O_NOCTTY);
 	if (fd < 0) {
@@ -1071,23 +1097,21 @@
 	printf("\thciattach -l\n");
 }
 
-extern int optind, opterr, optopt;
-extern char *optarg;
-
 int main(int argc, char *argv[])
 {
 	struct uart_t *u = NULL;
-	int detach, printpid, opt, i, n;
+	int detach, printpid, opt, i, n, ld;
 	int to = 5; 
 	int init_speed = 0;
 	int send_break = 0;
 	pid_t pid;
 	struct sigaction sa;
+	struct pollfd p;
 	char dev[PATH_MAX];
 
 	detach = 1;
 	printpid = 0;
-	
+
 	while ((opt=getopt(argc, argv, "bnpt:s:l")) != EOF) {
 		switch(opt) {
 		case 'b':
@@ -1131,9 +1155,9 @@
 
 	for (n = 0; optind < argc; n++, optind++) {
 		char *opt;
-	
+
 		opt = argv[optind];
-		
+
 		switch(n) {
 		case 0:
 			dev[0] = 0;
@@ -1182,13 +1206,13 @@
 		u->init_speed = init_speed;
 
 	memset(&sa, 0, sizeof(sa));
-	sa.sa_flags = SA_NOCLDSTOP;
+	sa.sa_flags   = SA_NOCLDSTOP;
 	sa.sa_handler = sig_alarm;
 	sigaction(SIGALRM, &sa, NULL);
 
 	/* 5 seconds should be enough for initialization */
 	alarm(to);
-	
+
 	n = init_uart(dev, u, send_break);
 	if (n < 0) {
 		perror("Can't initialize device"); 
@@ -1197,16 +1221,46 @@
 
 	alarm(0);
 
+	memset(&sa, 0, sizeof(sa));
+	sa.sa_flags   = SA_NOCLDSTOP;
+	sa.sa_handler = SIG_IGN;
+	sigaction(SIGCHLD, &sa, NULL);
+	sigaction(SIGPIPE, &sa, NULL);
+
+	sa.sa_handler = sig_term;
+	sigaction(SIGTERM, &sa, NULL);
+	sigaction(SIGINT,  &sa, NULL);
+
+	sa.sa_handler = sig_hup;
+	sigaction(SIGHUP, &sa, NULL);
+
 	if (detach) {
 		if ((pid = fork())) {
 			if (printpid)
 				printf("%d\n", pid);
 			return 0;
 		}
-		for (i=0; i<20; i++)
-			if (i != n) close(i);
+
+		for (i = 0; i < 20; i++)
+			if (i != n)
+				close(i);
+	}
+
+	p.fd = n;
+	p.events = POLLERR | POLLHUP;
+
+	while (!__io_canceled) {
+		p.revents = 0;
+		if (poll(&p, 1, 100))
+			break;
+	}
+
+	/* Restore TTY line discipline */
+	ld = N_TTY;
+	if (ioctl(n, TIOCSETD, &ld) < 0) {
+		perror("Can't restore line discipline");
+		exit(1);
 	}
 
-	while (1) sleep(999999999);
 	return 0;
 }